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Deconstructing the most sensationalistic recent findings in Human Brain Imaging, Cognitive Neuroscience, and Psychopharmacology
The Neurocritic
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by The Neurocritic in The Neurocritic
And I'll be easyLike living and forgettingAnd if I pick you upI'll be sure to let you down-Living and Forgetting, Glasstown (mp3)Forgetting Emotional Information Is HardOur memory for emotional events is generally better than our memory of neutral events. This is a key issue in developing treatments for post-traumatic stress disorder. How do we rid ourselves of unpleasant memories? In structured laboratory environments, the best way to forget is intentional inhibition during the encoding phase, when exposed to the material for the first time. In other words, engage in a deliberate strategy to forget while the event is actually occurring, as shown in a recent study by Nowicka and colleagues. This process is effortful, and it engages a larger proportion of the brain when the material is emotionally laden (i.e., negative pictures from the International Affective Picture System, or IAPS), relative to when it is neutral (Nowicka et al., 2010).In the study phase, intention to forget and successful forgetting of emotionally negative images were associated with widespread activations extending from the anterior to posterior regions mainly in the right hemisphere, whereas in the case of neutral images, they were associated with just one cluster of activation in the right lingual gyrus [occipital cortex]. Therefore, forgetting of emotional information seems to be a demanding process that strongly activates a distributed neural network in the right hemisphere. In the test phase, in turn, successfully forgotten images—either neutral or emotionally negative—were associated with virtually no activation... These results suggest that intentional inhibition during encoding may be an efficient strategy to cope with emotionally negative memories.However, "directed forgetting" is usually not a practical strategy when real life events are unfolding. Whether it can effectively occur at all during horrible tragedies is highly controversial (e.g., Terr vs. Loftus). The phenomenon is more often studied when applied to the retrieval of traumatic or unwanted memories (Anderson & Levy, 2009; Geraerts & McNally, 2008; Levy & Anderson, 2008), not during the encoding phase.How to ForgetObviously, it's unethical to expose people to traumatic events for experimental purposes. Instead, the present study used an item-method directed forgetting task in the lab and measured brain activity with fMRI (Nowicka et al., 2010). Twenty-three participants1 viewed a set of images from the IAPS that were either negative or neutral in content. During the initial encoding phase, participants were instructed to either REMEMBER or FORGET each picture by means of a cue that was presented after the item appeared on the screen. Then in the memory test phase, these previously presented pictures were intermixed with new ones, and the subjects were told to indicate whether they recognized them or not, regardless of the task instruction.Trials were sorted according to task instruction (Remember or Forget) and memory outcome (Remembered or Forgotten). Behavioral data showed that the directed forgetting manipulation was successful. Participants remembered fewer pictures in the To-Be-Forgotten (TBF) condition than in the To-Be-Remembered (TBR) condition. The valence manipulation appeared to be successful as well: recognition was better for emotional pictures, especially in the TBF condition. However, the rate of "false alarms" (incorrect responses to new items) was higher for emotional pictures as well (see figure below). This suggests a bit of a response bias: participants were more likely to say "yes I saw it before" for emotional images than for neutral.Figure 1B (modified from Nowicka et al., 2010). Percentage of correctly recognized TBR and TBF images (TBR_R and TBF_R, respectively) and percentage of false alarms for the group of 16 subjects included in the fMRI analyses. Bars represent SD; E, emotionally negative images; N, neutral images.When corrected for false alarm rate, it appears that recognition accuracy was actually lower for the To-Be-Forgotten emotional pictures, meaning they were easier to forget [unless I'm missing something here]. Hmm.On to the fMRI data. The major analysis was done in relation to the FORGET vs. REMEMBER cue. Was there differential activity when trying to forget an emotional picture compared to a neutral picture? Figure 2A shows the answer: yes, there was greater activity in the bilateral occipital cortex and elsewhere in the right hemisphere for emotional pictures, with only a small occipital focus of activation for the neutral ones.Figure 2 (modified from Nowicka et al., 2010). The study phase. (A) Effect of memory instruction: intention to forget contrasted with intention to remember (F instruction R instruction for all trials). Significant group activations are superimposed on a normalized single subject's T1 image.This indeed suggests that the intention to forget an emotional image (such as a car crash or mutilated body) is more effortful for the brain than trying to forget a neutral landscape scene. During the memory test, however, it didn't matter if you forgot the picture on purpose or by accident -- the neural response to forgotten items was identical to the response produced by entirely new images. Nary a trace [at least as a change in BOLD signal]. Have other investigators found this as well? What does it all mean?In conclusion, the findings of this item-method directed forgetting fMRI study reveal that forgetting of emotional information is supported by a widely distributed neural network, indicating more effort than forgetting of neutral information. These differences were observed in the study phase but not the test phase, which suggests that the directed forgetting effect is mainly based on inhibition at the encoding level rather than at retrieval (but see: Ullsperger et al. 2000; ... Read more »
Nowicka, A., Marchewka, A., Jednorog, K., Tacikowski, P., & Brechmann, A. (2010) Forgetting of Emotional Information Is Hard: An fMRI Study of Directed Forgetting. Cerebral Cortex. DOI: 10.1093/cercor/bhq117
by The Neurocritic in The Neurocritic
It's not just for headaches anymore! The active ingredient in TYLENOL® (acetaminophen, also known as paracetamol) has been shown to ease the pain of social rejection. Wouldn't it be great if you could pop an over-the-counter medication to lessen the hurt of being excluded from that grad student party? Of being ostracized by all your old friends? Even disowned by your family? The journal article, which was promoted by press release six months ago, has finally appeared online (Dewall et al., 2010). An excerpt from the December 2009 press release is below.A Pill for Psychological Pain?. . ."The idea—that a drug designed to alleviate physical pain should reduce the pain of social rejection—seemed simple and straightforward based on what we know about neural overlap between social and physical pain systems. To my surprise, I couldn't find anyone who had ever tested this idea," [psychologist C. Nathan] DeWall said.Perhaps because there's no clear mechanistic basis for such an idea? The authors themselves never proposed one either. One might expect that a psychopharmacological experiment with a drug that can cause serious liver damage would be conducted with a specific hypothesis in mind and some basic knowledge about how the drug is thought to work, but we didn't see that here. Granted, that would not be typical fare for Psych Sci. So instead the rationale given by Dewall et al. (2010) is partially linguistic, partially based on a neuroimaging study (Eisenberger et al., 2003):Studies suggest that the similar linguistic descriptions of social and physical pain extend beyond metaphor, and demonstrate overlap in the neurobiological systems underlying physical pain and social pain (DeWall & Baumeister, 2006; Eisenberger, Lieberman, & Williams, 2003; Way, Taylor, & Eisenberger, 2009). In the present experiments, we examined one functional consequence of the hypothesis that social and physical pain rely on shared neurobiological systems—whether acetaminophen, a common physical pain reliever, also reduces social pain. The "shared neurobiological systems" are thought to be located in the dorsal anterior cingulate cortex (ACC), a brain structure that contains discrete regions responsive to physical pain (Kwan et al., 2000). Interestingly, externally applied vs. self-administered thermal pain activate anatomically distinct areas of the ACC (Mohr et al., 2005). Furthermore, it is not at all clear whether the same regions of ACC represent social pain and the affective components of physical pain. In a study designed to dissociate expectancy violations from social rejection, the dorsal ACC was activated when expectations were violated, while ventral ACC (quite distant from the physical pain regions) was activated by social rejection (Somerville et al., 2006).Figure 2 (Somerville et al., 2006). Differential ACC response to expectancy violation and social feedback. (a) A three-dimensional rendering of the medial surface of the brain illustrates a functional dissociation between dorsal (dACC) and ventral (vACC) anterior cingulate. A whole-brain voxel-by-voxel ANOVA was used to identify voxels that showed a significant main effect (P less than 0.001, uncorrected) of expectancy violation (blue) and a main effect of feedback type (yellow). At any rate, participants in the Eisenberger et al. (2003) study took part in a computerized ball-tossing game while being scanned. Initially, two fictitious players included the scanned subject in the game, but then started to exclude him/her. This was the "social exclusion" condition, which was compared to the inclusion condition. But it happens to be the case that this paper was singled out as one of the worst of the "voodoo correlation" violators by Vul and his colleagues [PDF], since it reported a statistically unlikely value based on a non-independent analysis:Eisenberger, Lieberman, and Williams (2003), writing in Science, described a game they created to expose individuals to social rejection in the laboratory. The authors measured the brain activity in 13 individuals at the same time as the actual rejection took place, and later obtained a self-report measure of how much distress the subject had experienced. Distress was correlated at r=.88 with activity in the anterior cingulate cortex (ACC).A correlation of r=.88 between dACC activity and self-reported distress is implausibly high... But I'll stop here, and point to Lieberman, Berkman, and Wager's (2009) reply to Vul et al.That brings us to the present study by Dewall et al. (2010). In Experiment 1, 30 participants (24 women, 6 men) took one 500 mg acetaminophen pill immediately after waking up and another 500 mg an hour before going to sleep (1,000 mg per day for 3 weeks). The other 32 participants (24 women, 8 men) took the same dosing of placebo for 3 weeks. Each evening, subjects filled out the the Hurt Feelings Scale (the "today" version) to report how much social pain they had experienced that day. Despite the fact that the half life of acetaminophen is 4 hours, it took about 10 days for the drug group to report significantly lower hurt feelings than the placebo group. The difference on day 21 was greatest (p The explanation of the time course for these effects was unclear:Acetaminophen has a relatively short half-life, lasting approximately 4 hr, which means that it is unlikely that acetaminophen had a cumulative effect in our experiments. Our finding that acetaminophen reduced hurt feelings over time could be due to a combination of not feeling hurt and having a greater ability to reappraise the rejection experience.In Experiment 2, the dose was upped to 2,000 mg acetaminophen per day for 3 weeks. Instructions were given to refrain from drinking entirely, since alcohol can potentiate liver damage when taken with acetaminophen. In 2009, an FDA panel made a recommendation to lower the maximum daily dose from 4,000 mg (to an unspecified value). The panel also endorsed limiting the maximum single dose of the drug to 650 mg, down from the current 1,000 mg dose (which was given in E... Read more »
Dewall CN, Macdonald G, Webster GD, Masten CL, Baumeister RF, Powell C, Combs D, Schurtz DR, Stillman TF, Tice DM.... (2010) Acetaminophen Reduces Social Pain: Behavioral and Neural Evidence. Psychological science : a journal of the American Psychological Society / APS. PMID: 20548058
Edward Vul, Christine Harris, Piotr Winkielman, . (2009) Voodoo Correlations in Social Neuroscience. Perspectives on Psychological Science.
by The Neurocritic in The Neurocritic
Scene from 50 First Dates with Drew Barrymore and Adam Sandler.50 First Dates maintains a venerable movie tradition of portraying an amnesiac syndrome that bears no relation to any known neurological or psychiatric condition (Baxendale, 2004).That isn't true anymore...Smith et al. (2010) have recently reported an unusual case of functional, or psychogenic amnesia in which FL, a 51 year old woman with 15 years of education and average intelligence, cannot remember what happened to her from one day to the next. Her case history is summarized below.In May 2005, FL was involved in a motor vehicle accident in which her car was struck from behind. She hit the left side of her head and briefly lost consciousness. She was treated and released from the emergency room, but upon awakening the next morning, she had no memory for the previous day and believed that the accident had just occurred. Every morning since has been similar. She awakens with anxiety, believes it to be the day of the accident, and states that she has no memory for anything that has occurred since the accident. Each morning her husband orients her to time and place and provides her with her journal where she has recorded salient events from previous days and weeks. During the course of the day, she describes her memory as normal, but states that memory for each day is lost at night during sleep. The plot summary for 50 First Dates, taken from Wikipedia, is as follows:One morning, Henry (Sandler) meets Lucy Whitmore (Barrymore), a local art teacher, in a café. They hit it off and agree to meet the next day, but when Henry returns, Lucy has no memory of him or their previous meeting. Pulling him aside to where Lucy can't hear them, the café owner explains to Henry that, as a result of a car accident a year earlier, Lucy suffers from Goldfield Syndrome, a fictional form of anterograde amnesia in which each day's events disappear from her memory overnight. FL reported she did not see the movie before her accident, but noted that Drew Barrymore was her favorite actress. Smith et al. (2010) speculated that FL could have known the plot of the film, which could have influenced her unusual manifestation of memory loss after the auto accident. Her husband mentioned that she had seen the movie several times since her accident.FL underwent a series of imaging and neuropsychological tests in Dr. Larry Squire's Memory Research Laboratory. Her MRI was read as normal by the neuroradiologist, and quantatitive analysis revealed the volumes of her medial temporal lobe structures [critical for forming new memories] to be quite well matched with a small group of control participants.Fig. 1 (Smith et al., 2010). (A) A T1-weighted coronal MRI image from FL. The left side of the brain is on the left side of the image. (B) The volume of bilateral hippocampus (HIP) and parahippocampal gyrus (PHG) were similar for FL and controls (n = 4). The volumes are expressed as a percentage of the whole-brain volume for each participant. FL's neurological exam was normal. She had no previous history of psychiatric disorder. On the basis of these negative neurological and MRI findings, combined with her neuropsychological profile, the psychiatrist diagnosed psychogenic [i.e. functional] amnesia, with one unusual difference: she did not have retrograde amnesia [memory loss for remote events].Although functional amnesia is not associated with structural brain damage, there is evidence of hypometabolism, especially in the frontal lobe as measured by neuroimaging. Similar findings have also been observed in other psychiatric and neurological conditions (i.e., transient global amnesia, bipolar and major depressive disorder, schizophrenia).The pattern of impairment in functional amnesia is variable, though it typically presents as severe retrograde amnesia (sometimes including loss of personal identity) in the absence of anterograde amnesia [problems encoding new memories].However, FL was impaired on some standardized neuropsychological measures of memory when tested the same day, which belied her claim of intact memory for events occurring within a day. But as expected, she was at chance performance for material tested 24 hrs later, after she had slept.The authors constructed a tricky memory test of their own to see whether FL could retain some memory for items she had learned 24 hrs ago but believed to be presented on the same day. This did work to some extent, as shown in the black bars for FL on the left (Next-day Covert).Fig. 2 (Smith et al., 2010). Recognition memory for color photographs of scenes. One presentation: FL, Controls (n = 3), and Simulators (n = 2) [asked to fake an amnesia like FL's] saw 160 scenes once each and then took recognition memory tests later on the same day (Same day) as well as on the morning of the next day (Next day). After the Next-day test, participants studied 160 new scenes and then took recognition memory tests later on the same day. In this case, unbeknownst to the participants, the retention tests included scenes that had been studied and tested on the previous day (Next-day Covert). Multiple Presentations: the same scenes that had been studied and tested during the first 2 days were studied an additional time. As above, testing was done in three ways (Same day, Next day, and Next-day Covert). FL exhibited evidence of day-to-day memory in the Next-day covert tests (black bars) and in her improved performance when the same scenes had been viewed across multiple days (compare the two white bars and the two black bars in the left panel).In an interesting twist to the story, an intensive training program at Johns Hopkins University taught FL to sleep for 3.5 hrs at a time, at which point she could still retain the day's memories.Initially, she was placed on a sleep deprivation protocol and remained awake for 36 h. There was no loss of memory during this period. The following day the treatment team initiated a regimen in which she was awakened after longer and longer periods of sleep each night. After 1, 2, 3, or 4 h of sleep... Read more »
Smith, C., Frascino, J., Kripke, D., McHugh, P., Treisman, G., & Squire, L. (2010) Losing memories overnight: A unique form of human amnesia. Neuropsychologia. DOI: 10.1016/j.neuropsychologia.2010.05.025
by The Neurocritic in The Neurocritic
In Short Cuts, the "vegetarians and vegans are more empathetic" neuroimaging article was mentioned in passing, but I didn't actually blog about it. However, there has been one thing [OK, more than one thing] bothering me about this paper... But first, a quick summary of the Methods which were rather straightforward.Filippi and colleagues (2010) recruited 20 omnivores, 19 vegetarians, and 20 vegans to participate in a study that examined their brain responses to images of human and animal suffering. They were naïve as to the goals of the experiment. Before entering the scanner, all participants completed the Empathy Quotient, a 40 item questionnaire [plus 20 filler questions] that rates one's level of empathy (Baron-Cohen & Wheelwright, 2004). And the omnivores did indeed have lower EQ scores (38.8) than the vegetarians (49.5) and the vegans (44.6), who did not differ from each other.The fMRI experiment used an......event-related design during observation of negative affective pictures of human beings and animals (showing mutilations, murdered people, human/animal threat, tortures, wounds, etc.). Participants saw negative-valence scenes related to humans and animals, alternating with natural landscapes. So what were the neuroimaging findings? To no one's surprise, results indicated differences between the groups, as shown below.Figure 3. Results of the between-group comparisons of emotional (human and animal) negative valence picture views. Results are superimposed on a high resolution T1-weighted image in the standard MNI space, at a threshold of p less than 0.05 corrected for multiple comparisons. Areas activated during human picture view in vegetarians and vegans vs. omnivores are shown in yellow. Activations specific for vegetarians are shown in blue. Activations specific for vegans are shown in red. A: human picture view; B: animal picture view. [NOTE: I've labeled the corpus callosum.]Also to no one's surprise, differences between the groups were more pronounced for animal pictures (Fig. 3B) than for human pictures (Fig. 3A).Some of the results were interpreted in Rorschach inkblot fashion: the authors saw want they wanted to see in them. Since when are the specific regions of the anterior cingulate cortex (ACC) and the inferior frontal gyrus (IFG) shown above primarily known as "empathy-related regions"? They're not.2...vegetarians and vegans have constantly an higher engagement of empathy related areas while observing negative scenes, independently of the species of the individuals involved, which is characterized by an increased recruitment of the ACC and the IFG. Increased activation in the ACC and left IFG in vegetarians and vegans during human and animal suffering view is likely to reflect a stronger empathic response in the first two groups.Curiously enough, the amygdala (a limbic structure important for emotion) was not activated by animal suffering in either the vegetarians or the vegans. Although the amygdala (LeDoux, 2007) is predominantly known for its role in fear conditioning, it is also activated by other emotional responses including disgust (e.g., Kober et al., 2008).Remarkably, the within-group analysis during animal picture view, showed the absence of signal changes (in terms of activations and deactivations) within the amygdala in vegetarians and vegans, suggesting a down-regulation of amygdala response from areas located in the frontal lobes, in an attempt to regulate emotion through cortical processes in these subjects.Why would the vegetarians and vegans attempt to downregulate their emotional responses to animal suffering? And why would the vegans show greater amygdala responses to human suffering than did the omnivores and vegetarians??Figure 4. Interactions between stimuli (animal/human) and groups (omnivore/vegetarian/vegan). (A) An interaction was found in the right amygdala, indicating greater increase to animal negative valence picture view in omnivores and to human negative valence picture view in vegans. An interaction between "human pictures" and "vegan group" was also found in the left amygdala.Previously, NeuroKüz mentioned some objections to the study design in a post on The empathetic vegetarian brain.1 I won't detail his critique here other than to summarize:The control condition consisted of "neutral" scenes that did not include living beings, faces, or suffering of any kind.Participants passively viewed the photos, they did not have to respond by indicating their emotional reactions.Participants could be desensitized to human suffering by watching the news. One of the greatest issues, in my view, is with the mode of stimulus presentation. The event-related design (which is usually preferable) may not have allowed adequate time between pictures to "recover" from the shock of seeing a mutilated human or animal. If this were especially true for vegetarians and vegans viewing images of animal suffering, it could explain the curious silence of the amygdala. In such scenario, a blocked design (presenting all stimuli of one category in blocks, rather than intermixed) might have been a better idea.The vegetarians and vegans in this study all made their dietary choices for ethical reasons. It is quite conceivable that they differed from the omnivores on any number of other dimensions. For example, evolutionary psychology extremist Satoshi Kanazawa recently blogged about Why Vegetarians Are More Intelligent than Meat Eaters, but this only held for a UK sample born in 1958, but not for a US sample born b... Read more »
Filippi, M., Riccitelli, G., Falini, A., Di Salle, F., Vuilleumier, P., Comi, G., & Rocca, M. (2010) The Brain Functional Networks Associated to Human and Animal Suffering Differ among Omnivores, Vegetarians and Vegans. PLoS ONE, 5(5). DOI: 10.1371/journal.pone.0010847
by The Neurocritic in The Neurocritic
There is way too much to blog about these days. I can't decide among these 3 new papers:Sometimes, Categorical Statements about Prefrontal Neurons Are Just Wrong(1) Earl K. Miller (2007) in The Prefrontal Cortex: Categories, Concepts, and Cognitive Control (PDF):There was virtually no category effect across the ITC [inferior temporal cortex] population and no examples of neurons whose activity showed the sharp across-distinction/within-category generalization that is the behavioral signature of categorization. Rather, ITC neurons were sensitive to the physical appearance of the individual stimuli; its neurons did not "throw away" information about individuals in favor of the category groupings, like PFC [prefrontal cortex] neurons did. This finding suggests that learned visual categories are abstracted at the level of the PFC, not in visual cortex.No, not really. Monkeys were able to easily learn visual categories when their lateral prefrontal cortices were ablated bilaterally, IF they were tested using an incentive value task (Minamimoto et al., 2010). Earlier single-unit recording studies (reviewed in the Miller 2007 chapter) required maintenance of a set of two stimulus-response mappings. Thus PFC might be necessary for rule-based response selection, but not for visual categorization.Minamimoto T, Saunders RC, Richmond BJ (2010). Monkeys Quickly Learn and Generalize Visual Categories without Lateral Prefrontal Cortex. Neuron 66:501-507.Categorization is a basic mental process that helps individuals distinguish among groups of negative and positive objects, e.g., poisons and nutrients, or predators and prey. Monkey experiments have suggested that lateral prefrontal cortex (LPFC) participates in learning and processing visual categories. However, in humans category specific visual agnosia follows inferior temporal cortex but not LPFC damage. Here, we use a new behavioral approach to show that both normal monkeys and those with bilateral removal of LPFC learn and generalize perceptual categories of related visual stimuli rapidly without explicit instruction. These results strongly indicate that visual categorization occurs at some earlier stage of feed-forward processing, presumably in temporal cortex, without top-down information from LPFC.Minamimoto et al.'s incentive value task is shown below.Figure 1 (A) Sequence of events during a trial of the reward-delay task. A visual cue (Cue) indicates size and delay interval for the reward after successful behavioral reaction (bar release within 200–3000 ms after green target appears).You Are What You Eat, or Don't Eat(2) Empathy and Diet? Are vegetarians too sensitive, or more empathetic? And those vegans, they're out of control!Filippi M, Riccitelli G, Falini A, Di Salle F, Vuilleumier P, Comi G, Rocca MA (2010). The Brain Functional Networks Associated to Human and Animal Suffering Differ among Omnivores, Vegetarians and Vegans. PLoS ONE 5(5): e10847.Empathy and affective appraisals for conspecifics are among the hallmarks of social interaction. Using functional MRI, we hypothesized that vegetarians and vegans, who made their feeding choice for ethical reasons, might show brain responses to conditions of suffering involving humans or animals different from omnivores. We recruited 20 omnivore subjects, 19 vegetarians, and 21 vegans. The groups were matched for sex and age. Brain activation was investigated using fMRI and an event-related design during observation of negative affective pictures of human beings and animals (showing mutilations, murdered people, human/animal threat, tortures, wounds, etc.). Participants saw negative-valence scenes related to humans and animals, alternating with natural landscapes. During human negative valence scenes, compared with omnivores, vegetarians and vegans had an increased recruitment of the anterior cingulate cortex (ACC) and inferior frontal gyrus (IFG). More critically, during animal negative valence scenes, they had decreased amygdala activation and increased activation of the lingual gyri, the left cuneus, the posterior cingulate cortex and several areas mainly located in the frontal lobes, including the ACC, the IFG and the middle frontal gyrus. Nonetheless, also substantial differences between vegetarians and vegans have been found responding to negative scenes. Vegetarians showed a selective recruitment of the right inferior parietal lobule during human negative scenes, and a prevailing activation of the ACC during animal negative scenes. Conversely, during animal negative scenes an increased activation of the inferior prefrontal cortex was observed in vegans. These results suggest that empathy toward non conspecifics has different neural representation among individuals with different feeding habits, perhaps reflecting different motivational factors and beliefs.How did the authors get the idea for this experiment??How Dare You! I Feel So Guilty! This Is an Outrage!(3) Oh no! The neural correlates of "moral sentiments"? Smells like phrenology to me...Green S, Ralph MA, Moll J, Stamatakis EA, Grafman J, Zahn R. Selective functional integration between anterior temporal and distinct fronto-mesolimbic regions during guilt and indignation. Neuroimage 2010 May 19. [Epub ahead of print].It has been hypothesized that the experience of different moral sentiments such as guilt and indignation is underpinned by activation in temporal and fronto-mesolimbic regions and that functional integration between these regions is necessary for the differentiated experience of these moral sentiments. A recent fMRI study revealed that the right superior anterior temporal lobe (ATL) was activated irrespective of the context of moral feelings (guilt or indignation). This region has been associated with context-independent conceptual social knowledge which allows us to make fine-grained differentiations between qualities of social behaviours (e.g. "critical" and "faultfinding"). This knowledge is required to make emotional evaluations of social behaviour. In contrast to the context-independent activation of the ATL, there were context-dependent activations within different fronto-mesolimbic regions for guilt and indignation. However, it is unknown whether functional integration occurs between these regions and whether regional patterns of integration are distinctive for the experience of different moral sentiments. Here, we used fMRI and psychophysiological interaction analysis, an established measure of functional integration to investigate this issue. We found selective functional integration between the right superior ATL and a subgenual cingulate region during the experience of guilt and between the right superior ATL and the lateral orbitofrontal cortex for indignation. Our data provide the first evidence for functional integration of conceptual social knowledge representations in the right superior ATL with representations of different feeling contexts in fronto-mesolimbic regions. We speculate that this functional architecture allows for the conceptually differentiated experience of moral sentiments in healthy individuals. ... Read more »
Minamimoto T, Saunders RC, Richmond BJ. (2010) Monkeys Quickly Learn and Generalize Visual Categories without Lateral Prefrontal Cortex. Neuron, 66(4), 501-507. info:/10.1016/j.neuron.2010.04.010
by The Neurocritic in The Neurocritic
Global or Local? Gay or Eurotrash? Navon figure flanked by two game pieces from Gay or EUROtrash? the ultimate gaydar game!Believe it or not, there's an article in the new journal Frontiers in Cognition1 entitled "Sexual orientation biases attentional control: a possible gaydar mechanism" (Colzato et al., 2010). What is "gaydar"? And why on earth would one think of studying the allocation of attention to global and local visual perceptual features in relation to gaydar? Here's why:Individuals with a homosexual orientation are often believed to have a "telepathic sixth sense" (Reuter, 2002) for recognizing each other, an ability that is often referred to as gaydar (Shelp, 2002) – a portmanteau of gay and radar. Even though perceivable differences between homosexuals and heterosexuals may not be salient to everyone, some studies revealed subtle but distinctive features that homosexuals tend to share, such as coiffure (Rule et al., 2008), body-movement and gesturing style (Ambady et al., 1999), speech patterns (Linville, 1998), and penile size (Bogaert and Hershberger, 1999).2 Hence, there is a rich perceptual basis for people to develop a reliable gaydar, and homosexuals are apparently better trained in making use of it.To test the possible perceptual basis of gaydar, the authors made use of Navon figures (1977), which are comprised of small letters that form a larger letter. The characters can be the same or different, as shown below.Navon (1977) demonstrated that global visual features take precedence over the local ones ("forest before trees"). When in conflict, the large letter (global) interferes with the ability to identify the smaller letters (local), but local features do not hinder the ability to identify global features. Colzato et al. (2010) reasoned that gay individuals might need to focus on specific and local perceptual cues in order to correctly identify others with the same (or different) sexual orientation. Hence, the global precedence effect was predicted to be smaller in gay people than in straight people.To test this hypothesis, 42 Dutch participants (25 male and 17 female) were recruited for the study. On a multidimensional Kinsey-like scale (with seven variables each scored from 1-7), half were self-identified as straight (1.0) and the other half as gay (6.5). The stimuli were composed of large and small rectangles and/or triangles. Participants made button press responses to stimulus shape, based on the stimulus dimension (global or local) that was cued on each trial. The results demonstrated that the gay group did indeed show a smaller global precedence effect than the straight folk (see below).Figure 1 (Colzato et al., 2010). Mean global precedence effect for homosexuals and heterosexuals. Vertical capped lines atop bars indicate standard error of the mean.Heterosexuals were 68 msec faster to respond to global than to local features, but homosexuals were only 40 msec faster. The groups differed for this main effect of global/local dimension... but we don't know about the interaction with congruity. Nor do we know anything about potential male/female differences, because those weren't reported either. Nonetheless, results are consistent with the interpretation that gay men and women might have a relative bias towards detail-oriented processing when compared to heterosexuals.Now sexual orientation can join the other studies of group identity and attention to global vs. local features. These same authors previously showed that Dutch Calvinists (who have an independent view of the self) show a smaller global precedence effect than Dutch atheists (Colzato et al., 2008). Other research has demonstrated that participants raised in collectivist Asian cultures tend to be more globally-oriented than individualistic North American participants (Masuda & Nisbett, 2001). What might all this mean?From a more general perspective, our findings add to previous observations that being a member of a particular social group seems to shape cognitive-control operations in specific ways – whether this group is defined by shared culture, religious practice or, as the present study suggests, shared sexual orientation. Footnotes1 The bar for article titles in this journal has been set pretty high, since the other two papers are DOOM'd to switch: superior cognitive flexibility in players of first person shooter games and Games with(out) Frontiers: toward an integrated science of human cognition.2 Yes, the mean size is larger in gay men. On all five measures of penile length and circumference from Kinsey's original protocol (Bogaert & Hershberger, 1999).ReferencesColzato LS, van den Wildenberg WP, Hommel B. (2008). Losing the big picture: how religion may control visual attention. PLoS One 3:e3679.Colzato, L., van Hooidonk, L., van den Wildenberg, W., Harinck, F., & Hommel, B. (2010). Sexual orientation biases attentional control: a possible gaydar mechanism. Frontiers in Psychology DOI: 10.3389/fpsyg.2010.00013Masuda T, Nisbett RE. (2001). ... Read more »
Colzato, L., van Hooidonk, L., van den Wildenberg, W., Harinck, F., & Hommel, B. (2010) Sexual orientation biases attentional control: a possible gaydar mechanism. Frontiers in Psychology. DOI: 10.3389/fpsyg.2010.00013
by The Neurocritic in The Neurocritic
Moving right along with our timely, fast-paced, cutting edge blog coverage from the CNS 2010 Annual Meeting [held last month], the first symposium urged the field to advance beyond the current piecemeal single-study approach to neuroimaging by moving Towards a cumulative science of human brain function.1 Building comprehensive, structured, and searchable databases (Van Essen, 2009) and using meta-analytic tools (Wager et al., 2009) were proposed to be key methods aimed at achieving this goal.In his talk, prolific neuroanatomist Dr. David Van Essen (of primate visual cortex wiring diagram fame)2 discussed SumsDB (Surface Management System Database), "a repository of brain-mapping data (surfaces & volumes; structural & functional data) from many laboratories."---------------Talk 2: Lost in Localization – But Found with Foci!David Van Essen; Washington University in St. LouisMore than 50,000 studies related to functional imaging of the human brain have been published in recent decades. Of these, more than 10,000 report key experimental data (centers of fMRI activation foci, etc.) in tables of stereotaxic coordinates ('foci') in one or another standardized atlas space. To aid in mining this extensive literature, we developed the SumsDB database, which supports storage, visualization, and searching of many types of neuroimaging data. SumsDB includes a Foci Library that currently contains 40,000 foci from ~1,400 published studies. This includes comprehensive coverage of five major journals and almost 15% of the relevant literature. Foci searches can be based on many criteria (e.g., cortical area or region, spatial coordinates, functional criteria, or disease condition). Search results can be viewed online (WebCaret) or downloaded for offline visualization and analysis using Caret sofware. As the Foci Library continues to expand, through contributions from curators and volunteers alike, it will become increasingly valuable as a way to efficiently access the burgeoning neuroimaging literature.---------------Van Essen emphasized the importance of maintaining a central repository of neuroimaging foci, the 3D localization of peak activations in x, y, z coordinates (Fox et al., 1985). He and his lab have established SumsDB, which currently contains 50,000 foci from 1,700 studies, a relatively small fraction of the literature (see figure below).Fig. 1 (Derrfuss & Mar, 2009). Total number of published fMRI studies reporting coordinates by year and number of studies included in current coordinate databases. One impediment to having more complete coverage of the literature is how labor intensive it is to add new articles to the database (30-60 min per paper after 5-10 hr training), as lamented by Derrfuss and Mar (2009) in their Comments and Controversies article in NeuroImage. Because of the effort involved, many in the neuroimaging community haven't been particularly motivated to participate in the project. In in his reply (2009) to Derrfuss and Mar, Van Essen listed the benefits of voluntary data entry duties:submitting foci from publications of your own lab will increase their visibility, through data mining initiated in SumsDB or NIF [Neuroscience Information Framework];submitting relevant studies from your research subfield will facilitate cross-study comparisons and promote broader awareness of research in that area;individual contributors are recognized by 'provenance' assignments for each study (or version) entered into SumsDB.SumsDB libraries can also be used to store foci and study collections for ongoing projects that are not yet published. (Data in these libraries are not made public until requested by the submitter and then vetted by a curator in the Van Essen lab to insure conformance to basic metadata description standards.)And what a great classroom project for graduate students and highly motivated undergraduates! (suggested Van Essen, 2009). Greater participation is essential, however. But who wants to do all that work for free?An attractive and feasible model is for one or two individuals (students, postdocs, or knowledgeable technicians) from each of many laboratories to enter data published by their own laboratory plus selected topics related to that lab's research interests. For example, if 50 volunteers each added ~20 studies per year (15–30 h per volunteer, including training), the current rate of submission would approximately double, and about half of the relevant literature would be covered in ~5 years.But even more appealing, a semi-automated data entry system for SumsDB is under development...What does one do with all that data? In the next talk, Dr. Tor Wager discussed meta-analysis, a statistical technique for summarizing quantitative research. Why is it important to combine results across multiple studies (Wager et al. 2007)?Meta-analysis is an increasingly popular and valuable tool for summarizing results across many neuroimaging studies. It can be used to establish consensus on the locations of functional regions, test hypotheses developed from patient and animal studies and develop new hypotheses on structure–function correspondence. It is particularly valuable in neuroimaging because most studies do not adequately correct for multiple comparisons; based on statistical thresholds used, we estimate that roughly 10–20% of reported activations in published studies are false positives. The 'Quick-Search' function in SumsDB can be used to retrieve foci of interest from all papers in the database. For example, one can search by anatomical area (Fig. 1B) or by research topic (Fig. 1C). Searches can also be performed by task, function, disorder, etc.Adapted from Fig. 1 (Van Essen, 2009). ... Read more »
Van Essen, D. (2009) Lost in localization — But found with foci?!. NeuroImage, 48(1), 14-17. DOI: 10.1016/j.neuroimage.2009.05.050
Wager, T., Lindquist, M., Nichols, T., Kober, H., & Van Snellenberg, J. (2009) Evaluating the consistency and specificity of neuroimaging data using meta-analysis. NeuroImage, 45(1). DOI: 10.1016/j.neuroimage.2008.10.061
by The Neurocritic in The Neurocritic
"Head-wound Hank", from Geek Orthodox.The 19th century archive of The Lancet1 is filled with simply delightful case reports. Who can resist the allure of early plastic surgery failures, such as RHINOPLASTIC OPERATION, PERFORMED BY M. LISFRANC, FOLLOWED BY DEATH? Or how about a Case of Local Tubercular Deposit on the Surface of the Brain, presented by Robert Dunn, Esq.? Finally, the tragic History of a Case of Hydrophobia, treated at the Hotel Dieu at Paris, by an injection of water into the veins did not end well (through no fault of R. Magendie, of course):2 It results from the history of this case, that a disease, which exhibited all the characters of hydrophobia, ceased by the introduction of a pint* of warm water into the veins; that the patient survived this introduction eight days: that no accident appeared to follow from it; and that the death of the patient appears to have been caused by a local disease, which was wholly unconnected with the hydrophobia, and the new mode of treatment.* The pint of Paris contains 48 cubic inches. -ED.In 1828, Dr. Sewall (Professor of Anatomy in the Colombian College, D.C.) reported on two of his cases. They are not for the faint of heart. A warning for political incorrectness is also warranted here.CASE 1. In February 1827, W. Brown, a coloured man, aged fifty years, in encountering with another individual, received a severe blow on the right side of the head with a sharp spade. When Dr. Sewall arrived, which was only a few minutes after the accident, he found him bleeding profusely, and much exhausted from the loss of blood. Though not insensible, he had lost his reason, and did not know how he came by the injury. There was a deep wound dividing the integuments, the whole of the temporal muscle, penetrating the cavity of the cranium, and extending horizontally, from an inch above the external angular process of the frontal bone, through the parietal bone just above the squamous suture, forming a fissure of three inches in length. The lower portion of bone was considerably depressed, and the two edges separated about half an inch. Two branches of the temporal artery were taken up; when, on a more critical examination, it was ascertained that the dura mater was divided for an inch in extent...OK, so the patient really did have a 3 inch crack in his skull with brain matter oozing out. Mr. Brown was treated by Dr. Sewall ("dressings were applied"). When pus was coming from the gaping wound, there was swelling followed by sloughing (apparently). Then bits of brain were scooped away with a spatula. Lovely.Although he suffered from severe headaches, Mr. Brown was declared none the worse for the wear:For about ten days after the accident, the patient complained of constant, and sometimes of severe, pain in the head; and on one occasion was affected with a slight spasm of the muscles of the face, neck, and extremities. The wound healed, and in six weeks the patient was quite well. He subsequently followed his occupation, that of scavenger, and did not manifest any deviation in the functions either of body or mind from their ordinary healthy condition.The bar was probably set pretty low for what was considered an "ordinary healthy condition" for a "coloured" man who worked as a scavenger in 1827...The second case was of a five year old boy who was kicked in the head by a horse. No race was specified, so we'll assume he was white. More oozing and scooping of brain:CASE 2. September 18th, 1827, Lewis Poole, aged five years, while playing in the street, was kicked by a horse, and taken up in a state of insensibility. Dr. Sewall arrived a quarter of an hour after the accident, and found a semicircular wound in the integuments of the head, and, corresponding with this, a large fissure in the frontal and parietal bones, about three inches above the external angle of the right eye. Through this fissure a portion of brain protruded, somewhat larger than a walnut, and was composed both of cortical [gray] and medullary [white] matter, which were easily distinguished. This was so far separated from the parts beneath, as to be removed without any violence.Once again we're informed of the patient's full recovery, but only after much unpleasantness. He was bled to the point of unconsciousness initially and then given a powerful and toxic emetic for two weeks straight:Particular circumstances prevented the subsequent use of the lancet; but he was purged actively and daily for two weeks, and the pulse kept down by nauseating doses of the tartate of antimony. Extensive suppuration came on, with a copious discharge of pus; the wound gradually healed, and in about five weeks the child was quite well. He has since remained in perfect health.I wonder for how long that lasted, since Antimony Potassium Tartate is considered a dangerous good (.doc). Inhalation can cause irritation, sore throat, coughing, and shortness of breath. Eye or skin contact causes irritation, redness, and pain. Ironically, the recommended treatment after swallowing this compound is to induce vomiting immediately. The long-term consequences of antimony poisoning are not likely to be conducive to perfect health. Neurosurgical care has certainly come a long way since 1827.Footnotes1 Now on Facebook and Twitter! Keeping up with the 21st century.2 It probably wasn't his fault if the patient was really infected with the rabies virus (aka hydrophobia).ReferenceDr. Sewall (1828). CASES OF INJURY OF THE HEAD, ACCOMPANIED BY LOSS OF BRAIN. The Lancet, 10 (265) DOI: 10.1016/S0140-6736(02)98130-4
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Dr. Sewall. (1828) CASES OF INJURY OF THE HEAD, ACCOMPANIED BY LOSS OF BRAIN. The Lancet, 10(265), 817. DOI: 10.1016/S0140-6736(02)98130-4
by The Neurocritic in The Neurocritic
Why are large-scale structured databases and meta-analyses important to advance the field of human brain mapping? One reason is that individual functional magnetic resonance imaging (fMRI) studies can be notoriously unreliable and underpowered (Bennett & Miller, 2010; Fliessbach et al., 2010; Kriegeskorte et al., 2009; Vul et al., 2009). At the recent CNS 2010 Annual Meeting, symposium organizer Dr. Tal Yarkoni gave the first talk in a session on the value of a cumulative cognitive neuroscience.---------------Symposium Session 1Sunday, April 18, 10:00 am - 12:00 pm, Westmount et al BallroomTowards a cumulative science of human brain function. . .Talk 1: Motivating a cumulative cognitive neuroscienceTal Yarkoni; Columbia University and University of Colorado at BoulderThousands of functional neuroimaging studies are published every year. Only a small fraction of these studies explicitly attempt a formal synthesis of previous findings. In this talk, I argue for an increased emphasis on cumulative approaches to the study of brain function that aim to synthesize and distill the results of previous studies. Three different motives for such an approach are discussed, including (a) the need to distinguish real findings from false alarms; (b) the desire to organize both cognitive tasks and brain activations into coherent ontologies; and (c) the high likelihood that many fMRI studies are underpowered and consequently produce distorted results. I focus primarily on the last of these points, using simulations and empirical analyses to demonstrate that the results of many individual fMRI studies are likely to appear considerably stronger and more selective than they actually are. I conclude by arguing that these limitations are difficult or impossible to overcome in individual studies, necessitating a stronger focus on consensus building at the disciplinary level.---------------What are the motivations for consensus building? Here are four major reasons:The value of a cumulative scienceMake the literature manageableDistinguish true positives from false positivesDevelop overarching frameworksMinimize the effects of low powerYarkoni's talk focused on the last point. The problem with most individual fMRI studies is a lack of statistical power. Yarkoni (2009) argued that:the primary cause of grossly inflated correlations in whole-brain fMRI analyses is not nonindependence, but the pernicious combination of small sample sizes and stringent alpha-correction levels. Far from defusing Vul et al.'s conclusions [from their notorious 2009 paper], the simulations presented suggest that the level of inflation may be even worse than Vul et al.'s empirical analysis would suggest. Fig. 2 (Yarkoni, 2009). Inflation of significant r values as a function of sample size (x axis) and population effect size (lines). Each point represents the result of 10,000 simulated correlation tests, each conducted at a threshold of p Simply put, small n's result in massively inflated brain-behavior correlations. What can be done about this problem? Include more participants in your studies! And make use of the tools that were described by the subsequent speakers (Van Essen, Wager, Poldrack) for synthesis of mega-databases.For more information, the slides from Tal's talk are available online (PDF).ReferencesBennett CM, Miller MB. (2010). How reliable are the results from functional magnetic resonance imaging? Ann NY Acad Sci. 1191:133-55.Fliessbach K, Rohe T, Linder NS, Trautner P, Elger CE, Weber B. (2010). Retest reliability of reward-related BOLD signals. Neuroimage 50:1168-76.Kriegeskorte N, Simmons WK, Bellgowan PS, Baker CI. (2009). Circular analysis in systems neuroscience: the dangers of double dipping. Nat Neurosci. 12:535-40.Vul E, Harris C, Winkielman P, Pashler H (2009). Puzzlingly High Correlations in fMRI Studies of Emotion, Personality, and Social Cognition. Perspectives on Psychological Science 4:274-290.Yarkoni, T. (2009). Big Correlations in Little Studies: Inflated fMRI Correlations Reflect Low Statistical Power-Commentary on Vul et al. (2009). Perspectives on Psychological Science, 4 (3), 294-298. DOI: 10.1111/j.1745-6924.2009.01127.x
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Yarkoni, T. (2009) Big Correlations in Little Studies: Inflated fMRI Correlations Reflect Low Statistical Power-Commentary on Vul et al. (2009). Perspectives on Psychological Science, 4(3), 294-298. DOI: 10.1111/j.1745-6924.2009.01127.x
by The Neurocritic in The Neurocritic
Conflict of interest: ABN, NJS and DRS are scientific co-founders of Mindscape Diagnostics, Inc.Special review article!AbstractWhat are mind, consciousness and happiness, in the fundamental context of life? We propose a convergent perspective (coupling evolutionary biology, genomics, neurobiology and clinical medicine) that could help us better understand what life, mind, consciousness and happiness are, as well as provides empirically testable practical implications.Well. So a speculative, flaky, and pretentious journal article1 (Niculesc et al., 2010) proposed a grandiose theoretical framework for understanding "life" et cetera, et cetera. I was amused.We propose that the mind can be viewed as a composite of mechanisms that have evolved to achieve GuU [genes (G), proximal umbrella (u), general umbrella (U)] objectives. The latest genetic, neurobiological and clinical evidence suggest that normal mental functioning and psychiatric disorders can be classified in three broad and overlapping domains: the anxiety domain, the mood domain and the cognitive domain (Niculescu, 2006), somewhat paralleling the archaic Freudian constructs of id, ego and super-ego.Each section of the paper (n=8) is introduced by a scientific quote or aphorism, such as..."It is always advisable to perceive clearly our ignorance".-Charles Darwinand..."For a scientist, it is a unique experience to live through a period in which his field of endeavour comes to bloom — to be witness to those rare moments when the dawn of understanding finally descends upon what appeared to be confusion only a while ago — to listen to the sound of darkness crumbling."- George E. PaladeHere are the main bullet points, followed by a Venn diagram lacking in explanatory value:Anxiety is about reactivity in the face of uncertainty and potential dangerMood is about trophicityCognition is about connectivity and congruence—within the organism, and with the environment Consciousness is about monitoring the environment through the mind (anxiety, mood and cognition)Happiness is about achieving GuU objectivesFig. 1 (Niculesc et al., 2010). Overlap and interdependence: Venn diagram.In my view this general framework is comparable to horoscopes and fortune telling: so vague that almost anything could fit. However, the authors do get more specific when they speculate on the testable therapeutic implications of "whole organism effects" (see Table 1 below, in the Appendix). Some are radical (anti-cancer medications to treat mood disorders; mood meds to treat cancer); others are mundane (anti-hypertensive medication to treat anxiety [yeah, beta blockers, how novel]; anti-anxiety meds to treat hypertension).But it gets better!The above ideas and paradigms can be modeled using a three-dimensional spatial representation of the life landscape–Lifescape, and of the mental landscape–Mindscape. The three dimensions for the Lifescape are G, u, U. The three dimensions for the Mindscape are mood, cognition and anxiety. The axes are not orthogonal, to reflect the interdependence of the three domains. Thus, changes in one dimension translate into changes in the other two dimensions.Fig. 2 (Niculesc et al., 2010). Mindscape 3D modelling of anxiety, mood and cognition. At each moment in time, an individual is represented by a point with (x, y, and z) coordinates in this tri-dimensional space. The sum of points over time is distributed as a cloud, unique to each individual.What a coincidence that the name of the authors' company is Mindscape Diagnostics! Hence we have Mindscape psychiatry, Mindscape therapeutics, Mindscape addictions, et cetera, et cetera. Looks like they're really on cloud 9...Footnote1 No, the article was not in Medical Hypotheses. Presumably the Journal of Affective Disorders requires some sort of peer review for special review articles.ReferencesNiculescu AB 3rd (2006). Polypharmacy in oligopopulations: what psychiatric genetics can teach biological psychiatry. Psychiatr Genet. 16:241-4.Niculescu AB 3rd, Schork N, Salomon D. (2010). Mindscape: A convergent perspective on life, mind, consciousness and happiness. Journal of Affective Disorders, 123 (1-3), 1-8 DOI: 10.1016/j.jad.2009.06.022Appendix (click on image fo... Read more »
Niculescu III, A., Schork, N., & Salomon, D. (2010) Mindscape: A convergent perspective on life, mind, consciousness and happiness. Journal of Affective Disorders, 123(1-3), 1-8. DOI: 10.1016/j.jad.2009.06.022
by The Neurocritic in The Neurocritic
The Cognitive Neuroscience Society 2010 Annual Meeting was held last week in Montreal, Québec. Unfortunately, many European registrants were unable to attend because of the Eyjafjallajokull volcano. The meeting website has links to the PDFs for 67 of these "Volcano Posters".One of those unable to attend was Dr. Jonas Persson of Stockholm University. He was scheduled to speak in the final symposium of the conference, which was on control of executive control, or who controls the "controller" in the brain (without resorting to a homunculus or an infinite regress of Mini-Me's). His co-author, Dr. Patricia Reuter-Lorenz of the University of Michigan, gave an interesting presentation about their work on the ups and downs of cognitive training: gains that transfer to other tasks across sessions and fatigue that transfers to other tasks within a session. The abstract is reprinted below.---------------Symposium Session 5Tuesday, April 20, 1:00 - 3:00 pm, Westmount et al BallroomWhat Controls Executive Control? The Influence of 'Control Context'Chair: Amishi Jha, University of Pennsylvania. . .Talk 3: Training and Depletion of Executive Functions: The Case of Interference ControlJonas Persson1, Patricia Reuter-Lorenz2; 1Stockholm University, 2University of MichiganBrain imaging reveals overlapping sites of prefrontal activation for different cognitive tasks suggesting they may share core executive processes. We tested this hypothesis by measuring behavioral interactions between memory tasks presumed to require interference control - a putative executive process that mediates selection from competing representations. Behavioral data show that different training regimens produce either negative or positive transfer from working memory to semantic and episodic memory task performance. We show that eight days of training on high interference versions of three different working memory tasks increased the efficiency of interference control on the training tasks and on untrained tasks in new memory domains. In contrast we have also demonstrated negative transfer and process-specific "fatigue" effects indicating that control efficiency in a second task is diminished by high control demands in a prior task immediately preceding it in time. This suggests that interference control is a finite resource that can be temporarily depleted. Functional magnetic resonance imaging (fMRI) was used to elucidate the mechanisms associated with decreasing efficiency or resource depletion of the interference control process. Along with reduced performance, fMRI indicates negative transfer is associated with reduced process-specific activation, and increased homologous activation that may be compensatory. In sum, this suggests that interference control is an executive function that is both resource limited and plastic making it possible for training to alter its efficiency.---------------These findings became extremely relevant (albeit ignored) in light of the ultra-high impact paper by Adrian Owen et al. (2010) published in BBC/Nature on April 20, informing us there was "No gain from brain training" in a massive group of 11,430 volunteers. The research volunteers participated in online training exercises that tapped (1) reasoning, planning, problem solving; (2) short-term memory, attention, visuospatial processing, mathematics; or (3) ability to answer obscure questions using the internet.Numerous other outlets have already summarized these results, so I won't attempt to do so here. The main issue was whether the gains obtained through simple practice effects transferred to tasks that weren't in the training set. The short answer is no.Brain training doesn't boost brain power, work suggests (BBC)Brain-training games don't work (Guardian)Brain training games don't work (BPS Research Digest)Brain-training games get a D at brain-training tests (Not Exactly Rocket Science)Brain Test Britain - Results in-depth (BBC - Lab UK)I am not a proponent of brain training games that make unsound claims lacking credible scientific evidence to back them up. But in light of the spectacularly negative findings of Owen et al., the question arises of whether their training regimen (10 min 3 times a week for 6 weeks) was adequate to produce significant effects. Predictably, those with a stake in the matter said no, the training was neither sufficient in duration nor applicable to other commercially available products.BBC "Brain Training" Experiment: the Good, the Bad, the UglyPosit Science Disputes Results of the BBC Brain Training StudyA final issue concerns the population under study, a presumably "normal" group of 18-60 year olds without cognitive impairments or cognitive decline. Would the same training exercises help an older population at risk for dementia? On the other hand, seniors might be especially vulnerable to persuasive false claims from unscrupulous brain training vendors. Thus it's important to have scientifically valid and accessible research on whether cognitive training might help an aging population (Lustig et al., 2009). Coincidentally, the NIH is currently trying to reach a consensus on:NIH State-of-the-Science ConferencePreventing Alzheimer's Disease and Cognitive DeclineApril 26–28, 2010Bethesda, MarylandLive webcast, also information on archived video and publicly available consensus statement.Let us now return to the studies of Persson and Reuter Lorenz (2008). This work examined wheth... Read more »
Persson, J., & Reuter-Lorenz, P. (2008) Gaining Control: Training Executive Function and Far Transfer of the Ability to Resolve Interference. Psychological Science, 19(9), 881-888. DOI: 10.1111/j.1467-9280.2008.02172.x
PERSSON, J., WELSH, K., JONIDES, J., & REUTER-LORENZ, P. (2007) Cognitive fatigue of executive processes: Interaction between interference resolution tasks. Neuropsychologia, 45(7), 1571-1579. DOI: 10.1016/j.neuropsychologia.2006.12.007
by The Neurocritic in The Neurocritic
Move over, Marilyn Monroe neurons and Halle Berry neurons... The cellular media darlings of action observation and action execution would like to join you in the human hippocampus and surrounding medial temporal lobe (MTL) areas critical for memory."What?" you say. "Direct evidence for the existence of mirror neurons has been obtained from single cell recordings in monkeys in specific brain regions. These include the ventral premotor cortex (area F5) and the inferior parietal lobule (Rizzolatti & Sinigaglia, 2010), not the hippocampus!"Figure 1 (Rizzolatti & Sinigaglia, 2010): The parieto-frontal mirror network. Lateral view of the macaque brain. The coloured areas represent the areas of the parieto-frontal circuit containing mirror neurons: the ventral premotor cortex (area F5), area PFG (located between parietal areas PF and PG) and the anterior intraparietal area (AIP)... The parieto-frontal circuit receives high-order visual information from areas located inside the superior temporal sulcus (STS) and the inferior temporal lobe (IT). Neither of these temporal regions has motor properties. The parieto-frontal circuit is under control of the frontal lobe (area F6 or pre-supplementary motor area and the ventral prefrontal cortex (VPF)). The inset provides an enlarged view of area F5. IAS, inferior limb of the arcuate sulcus; LIP, lateral intraparietal area; VIP, ventral intraparietal area.Yet we've been led to believe that a new study published in Current Biology (Mukamel et al., 2010) has recorded from mirror neurons in the human brain for the first time. Last Friday, BPS Research Digest asked:Is this the first ever direct evidence for human mirror neurons?...Although recordings from single cells in the brains of monkeys have identified 'mirror' neurons that respond both to the execution of a movement and the observation of another agent performing that same movement, the existence of such cells in humans has, up until now, been inferred only from indirect evidence, particularly brain imaging. Now Roy Mukamel and colleagues have provided what appears to be the first ever direct evidence, using implanted electrode recordings of single cells, for the existence of mirror neurons in humans.The short answer to this question is "no" (unless you want to dilute the meaning of "mirror neurons" beyond recognition). To briefly summarize, the participants in the study were 21 patients with pharmacologically intractable epilepsy. Depth electrodes were implanted into their brains to monitor for seizures, in advance of a possible surgical intervention to remove the epileptic focus. The electrode locations were constrained by clinical considerations and included regions in the medial frontal cortex (supplementary motor area, anterior cingulate cortex) and the medial temporal lobe (amygdala, hippocampus, parahippocampal gyrus, entorhinal cortex). The ventral premotor cortex and inferior parietal lobe were not targeted.The experimental protocol consisted of 3 tasks: Grasp, Facial expressions and Control.During Grasp, subjects were presented with video clips of a hand grasping a mug and with the words 'Finger' or 'Hand'. They were instructed to grasp a mug with precision grip or whole hand prehension when the words 'Finger' or 'Hand', respectively, were presented and to simply observe when the video clips were played. During Facial expressions, subjects were presented with a picture of a smiling or a frowning face and with the word 'Smile' or 'Frown'. They were instructed to perform the corresponding action when the words were presented and to simply observe when the pictures were presented... In the Control task, subjects were presented with the words used as cues in the Grasp and Facial expression parts of the experiment and were instructed to covertly read the words and refrain from making hand movements or facial gestures.Results are depicted in Table 1 below (click on image for a larger view).In each brain region, only a minority of cells responded with an increased (or decreased) firing rate during both observation and execution of the same action. Percentages of these Observation/Execution neurons ranged from a low of 2% in dorsal anterior cingulate cortex to 11% in hippocampus, 12% in parahippocampal gyrus, and 14% in supplementary motor area. The MTL regions also contain neurons that respond during the spontaneous recall of episodic memories (Gelbard-Sagiv et al., 2008). So how can you tell if a neuronal response in the current experiment is related to memory recall or to action observation/execution? You can't, but that doesn't matter!The action observation/execution matching neurons in the medial temporal lobe may match the sight of actions of others with the memory of those same actions performed by the observer. Thus during action-execution, a memory of the executed action is formed, and during action-observation this memory trace is reactivated. This interpretation is in line with the hypothesis of multiple mirroring mechanisms in the primate brain, a hypothesis that can easily account for the presence of mirroring cells in many cortical areas."Now wait a minute," said Professor Patricia Churchland [as paraphrased by Prof. Greg Hickok in Talking Brains]. "If mirror neurons are all over the brain then don't they lose their explanatory power?"Good point.Another issue is whether a given single- or multi-unit recording responded by increasing or decreasing its firing rate relative to the passive condition. It could be either, or both:Among the 68 action observation/execution matching cells [out of 1170 total cells recorded], 33 increased their firing rate during both observation and execution of a particular action. In ... Read more »
Mukamel, R., Ekstrom, A., Kaplan, J., Iacoboni, M., & Fried, I. (2010) Single-Neuron Responses in Humans during Execution and Observation of Actions. Current Biology. DOI: 10.1016/j.cub.2010.02.045
Quian Quiroga, R., Kraskov, A., Koch, C., & Fried, I. (2009) Explicit Encoding of Multimodal Percepts by Single Neurons in the Human Brain. Current Biology, 19(15), 1308-1313. DOI: 10.1016/j.cub.2009.06.060
Quiroga, R., Reddy, L., Kreiman, G., Koch, C., & Fried, I. (2005) Invariant visual representation by single neurons in the human brain. Nature, 435(7045), 1102-1107. DOI: 10.1038/nature03687
by The Neurocritic in The Neurocritic
Brain injuries caused by strokes, tumors or head trauma can, on occasion, result in Unusual Changes in Sexuality, as discussed in an earlier blog post. A new case report by Bianchi-Demicheli et al. (2010) describes a unique paraphilia1 in a married 34 year old man. The authors called it Sleeping Beauty paraphilia:This [man] felt sexually aroused from seeing sleeping women as well as from taking care of their hands and nails while they were asleep.The patient came to the attention of the authors when he was brought to the emergency psychiatric unit after assaulting his wife with pepper spray while wearing a latex mask.2 More details of the case are as follows:His marriage had been in crisis for several years because over the time the patient developed a particular and progressive sexual deviant behaviour. He felt sexually aroused from seeing sleeping women as well as from taking care of their hands and nails while they were asleep, beginning mostly with the right hand. In the first time of his marriage he could control these fantasies, but over the years he lost the control of his sexual urges and he must irresistibly act his deviant behaviour. In order to realize his uncontrollable impulse, he was used to provide his wife sleeping pills to satisfy his paraphilia. In the first time his wife used to agree to take sleeping pills, but later she refused to bend to man's freakish will. The man began secretly to administer benzodiazepines since the dosage of 23 mg of Bromazepam.In September 2006, his wife discovered this practice and refused to take sleeping pills and the couple entered in a very strong conflict.The assault occurred because the woman refused to comply with her husband's "freakish will":Because of the extremely powerful obsession with sleeping women and painting their nails, the patient disguised himself with a latex mask an attacked his wife, as she returned from work, with an Olerosin Capsicum (OC) spray, to anaesthetize her. During this episode, his wife succeeded in taking off his mask, escaped and called the police who brought him to the psychiatric emergencies.The psychiatric exam and laboratory tests all came out as normal. The patient reported no family history of mental illness. However, he sustained a head injury at the age of 10 which resulted in a four day coma.3 He was given a neurological exam, including an MRI, which showed "moderate atrophy in the fronto-parietal region with a diffuse and severe white matter injury compatible with his previous head trauma (Figure 1)." I don't know that I would characterize the white matter damage as severe, but then again I'm not a neuroradiologist.Figure 1 (Bianchi-Demicheli et al., 2010). On the T2 images (A–C) one notes atrophy in the parietal and frontal lobes as well as subcortical lesions in the frontal white matter (arrows B,C); FLAIR also shows multiple subcortical white matter lesions (arrows: D); DTI [dffusion tensor imaging] demonstrates a decrease of the fractional anisotropy in the areas seen on the right (E: arrow) and on the left (F: arrow).Bianchi-Demicheli et al. (2010) linked the fronto-parietal damage to behavioral disinhibition and a specific disturbance in body image, which was revealed by neuropsychological testing:The patient was diagnosed with a moderate dysexecutive syndrome and a very specific body image disorder characterized by an incomplete mental image of his hands, mostly the right (i.e., personal representational hemineglect), as ascertained by his graphical representation of his body parts.The clinical hypothesis was that the paraphilia might be related to his post-traumatic disturbed body image and more specifically to the incomplete hands representation.One puzzling aspect of this case is why the "Sleeping beauty paraphilia" became uncontrollable only in adulthood, showing a progressive escalation during his marriage. This might be suggestive of a neurodegenerative disorder, but that was not part of his diagnosis. And I'm not sure why an old traumatic brain injury would have lead to "moderate" atrophy in the fronto-parietal region. I might have expected more involvement of the orbitofrontal cortex (e.g. Burns & Swerdlow, 2003), given the nature of the patient's behavioral changes. However, many other examples of impulsive sexual offenses (Langevin, 2006) are even less obviously related to neurological status (e.g. after head injuries when the damage might not be visible on an MRI scan, and of course the population of offenders who have never sustained a TBI). Since the lesions were distributed and not focal, a final mystery is why the body image disturbance was confined to the right hand (implying a left hemisphere origin). This type of personal representational hemineglect (neglect for a mental representation of one side of the body) is most often associated with lesions in the right hemisphere (Ortigue et al., 2006).A final comment concerns the sort of urges or behaviors that are categorized as paraphilias. What is considered acceptable can vary widely across cultures and subcultures (Bhugra et al., 2010) and across individuals. If the patient of Bianchi-Demicheli et al. found a partner willing to have her fingernails done while sedated with sleeping pills, perhaps the classification would change from paraphilic disorder (see Footnote 1 below) to something that might be considered strange and paraphilic to most people, but causing no distress to the two willing participants.Footnotes1 According to DSM-IV, paraphilias are defined as recurrent, and intense sexual urges, fantasies, or behaviors that involve unusual objects, activities, or situations and cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. Changes in this set of diagnoses are being discussed for the new DSM-5 (currently under development):The Paraphilias Subworkgroup is proposing two broad changes that affect all or several of the paraphilia diagnoses, in addition to various amendments to specific diagnoses. The first broad change follows from our consensus that paraphilias are not ipso facto psychiatric disorders. We are proposing that the DSM-V make a distinction between paraphilias and paraphilic disorders. A paraphilia by itself would not automatically justify or require psychiatric intervention. A paraphilic disorder is a paraphilia that causes distress or impairment to the individual or harm to others. One would ascertain a paraphilia (according to the nature of the urges, fantasies, or behaviors) but diagnose a paraphilic disorder (on the basis of distress and impairment). In this conception, having a paraphilia would be a necessary but not a sufficient condition for having a paraphilic disorder. 2 No mention of whether or not it was a Prince Charming mask.3 The authors did not speculate too much on the Freudian im... Read more »
Bianchi-Demicheli F, Rollini C, Lovblad K, & Ortigue S. (2010) "Sleeping Beauty paraphilia": deviant desire in the context of bodily self-image disturbance in a patient with a fronto-parietal traumatic brain injury. Medical science monitor : international medical journal of experimental and clinical research, 16(2). PMID: 20110923
by The Neurocritic in The Neurocritic
Haskins Laboratories - brain areas activated during reading.An unfocused and rambling article in the New York Times the other day was excited about the potential use of neuroimaging to revive the gloomy state of university literature departments. It also tried to convey the importance of evolutionary psychology in explaining fiction. The piece opened with Professor Lisa Zunshine discussing Phoebe's complex theory of mind in the sitcom Friends:(Follow closely now; this is about the science of English.) Phoebe and Rachel plot to play a joke on Monica and Chandler after they learn the two are secretly dating. The couple discover the prank and try to turn the tables, but Phoebe realizes this turnabout and once again tries to outwit them.As Phoebe tells Rachel, "They don't know that we know they know we know." 1The juxtaposition of ideas makes perfect sense, now doesn't it?Theory of mind is "the ability to attribute mental states—beliefs, intents, desires, pretending, knowledge, etc.—to oneself and others and to understand that others have beliefs, desires and intentions that are different from one's own." ToM has been studied by cognitive and developmental psychologists for a long time (quite nicely) without input from English professors.But the Next Big Thing in English: Knowing They Know That You Know continues, trying to convince us of the coming revolution.. . .At a time when university literature departments are confronting painful budget cuts, a moribund job market and pointed scrutiny about the purpose and value of an education in the humanities, the cross-pollination of English and psychology is a providing a revitalizing lift.Jonathan Gottschall, who has written extensively about using evolutionary theory to explain fiction, said "it's a new moment of hope" in an era when everyone is talking about "the death of the humanities." To Mr. Gottschall a scientific approach can rescue literature departments from the malaise that has embraced them over the last decade and a half. Zealous enthusiasm for the politically charged and frequently arcane theories that energized departments in the 1970s, '80s and early '90s — Marxism, structuralism,2 psychoanalysis — has faded. Since then a new generation of scholars have been casting about for The Next Big Thing.So literature is abandoning Marxism and psychoanalysis in favor of neuroimaging!! Meanwhile, key neuroimagers have taken up psychoanalysis (Carhart-Harris & Friston, 2010) and socialism (Tricomi et al., 2010).These recent efforts seem to fit into the recently maligned microfield of neuro-lit-crit. An article by Raymond Tallis appeared in The Times Literary Supplement with the provocative title, "The Neuroscience Delusion." Its central theme?Neuroaesthetics is wrong about our experience of literature – and it is wrong about humanity....The literary critic as neuroscience groupie is part of a growing trend.We have become accustomed over the past half-century to critics sending out to other disciplines for "theoretical frameworks" in which to place their engagement with works of literature. The results have often been dire, the work or author in question disappearing in a sea of half-comprehended or uncritically incorporated linguistics, mathematics, psychiatry, political theory, history, or whatever.Tallis was writing in response to an article by acclaimed novelist A.S. Byatt on how the scientific zeitgeist influences contemporary writers. In an obvious example, the centrality of sex in Darwinian and Freudian thought had a clear impact on the novels of Saul Bellow and Philip Roth. Byatt also looks ahead to the possible role of neuroscience in illuminating artistic understanding:Novel thoughtsNeuroscience is helping us to understand how art works – and it may offer us a way out of narcissism. . ....Neuroscience, and the study of the activity of the brain, is beginning to bring its own illumination to our understanding of how art works, and what it is. I have come to see the delight in making connections – of which metaphor-making is one of the most intense – as perhaps the fundamental reason for art and its pleasures. Philip Davis, at Liverpool University, has been working with scientists on responses to Shakespeare's syntax, and has found that the connecting links between neurones stay "live" – lit up for longer – after responding to Shakespeare's words, especially his novel formations of verbs from nouns, than they do in the case of "ordinary" sentences.I critiqued an early version of the Shakespeare study, before it was published in a peer-reviewed journal (by Thierry et al., 2008). At the time, press coverage was rather simplistic (and incorrect) about the observed findings, using phrases like "the brain is positively excited" to describe an EEG component of positive polarity. However, the published paper was written by an expert on EEG studies of language and is quite respectable. That is part of the point here: it's best to not leave the neuroimaging media sound bytes entirely up to the English professors.3In brief, Thierry, Davis and colleagues wanted to observe what happens to the brain when people read passages containing the Shakespearean functional shift, a linguistic device that involves using a noun to serve as a verb (for example).To explain a little, the researchers recorded EEG while participants read selections from Shakespeare. They were looking for EEG signatures of semantic violations (indexed by a negative voltage brain wave at ~400 msec, called the N400) and syntactic violations (indexed by a positive-voltage brain wave at ~600 msec, called the P600).Above figure from a different study, published in Biological Psychology by Isel et al. (2006)The brain waves were obtained by averaging a bunch of EEG trials together, and these event-related potential (ERP) components reflect summed electrical activity (post-synaptic potentials) from a huge number of pyramidal cells, recorded remotely from the scalp (to put it simply). The polarity of these components (i.e., positive or negative) does not indicate whether they are excitatory or inhibitory.The stimulus materials were well-controlled for a number of factors. Some example sentences are given below.Alternatives to the critical word are given between brackets. The functional shift is in bold, followed by... Read more »
Thierry, G., Martin, C., Gonzalez-Diaz, V., Rezaie, R., Roberts, N., & Davis, P. (2008) Event-related potential characterisation of the Shakespearean functional shift in narrative sentence structure. NeuroImage, 40(2), 923-931. DOI: 10.1016/j.neuroimage.2007.12.006
by The Neurocritic in The Neurocritic
Scene from Paranormal ActivityAfter a young, middle class couple moves into what seems like a typical suburban "starter" tract house, they become increasingly disturbed by a presence that may or may not be demonic but is certainly most active in the middle of the night.Especially when they sleep. Or try to.A new case study in Cortex by neurologist Dr. Fabienne Picard (2010) reports on a patient who experienced unusual phenomena during epileptic seizures. She had the convincing sense that several familiar people (family members) were standing before her. This experience of a "sensed presence" is a classic trope in movies with supernatural themes (e.g., Carnival of Souls [available at Internet Archive], The Haunting [trailer for the 1963 version], Poltergeist, Dark Water), but it's generally attributed to ghosts and not to seizure activity.Here's the case report:A 62-year-old right-handed woman of normal psychiatric history presented a simple focal epileptic seizure including a complex sensation characterized by feeling the presence of several members of her family in the immediate environment, associated with paresthesia of the right hemibody (excluding the face). The feeling of presences and the paresthesia (numbness) appeared concomitantly and lasted in total several minutes. The episode occurred while she was sitting alone on the sofa of her living room and immediately felt the presence of four persons in her frontal space. She did not see or hear these persons (no visual or auditory hallucinations), but felt vividly their presence in her peripersonal [within reach] and near extrapersonal space [just outside of reach]. She "recognized" them as close family members. Closest was her grand-daughter who was sitting on the floor immediately in front of her, without any left or right lateralization in relation to her body, whereas the three other persons, her daughter and two other grand-children, were experienced to be localized at a distance of several meters. ... This highly vivid and convincing feeling of presences was described by the patient as deeply pleasant, although she guessed that it was not possible that they were really there, as she was alone just before. ... She was treated with pregabalin (300 mg/day) and there was no recurrence of simple or complex partial seizures and no further feeling of presences.MRIs revealed abnormal findings due to a right hemisphere subcortical stroke 10 months before the episode (Fig. 1A). The patient's stroke affected a portion of the basal ganglia (the putamen and the globus pallidus) and a large white matter tract within (the internal capsule). Left hemisphere findings in the insular cortex were also apparent, and this was the likely seizure focus. Strokes are known to increase the incidence of seizures: in one study 8.6% of those with ischemic stroke [occlusion of blood supply] and 10.6% of those with hemorrhagic stroke [bleed] had one or more seizures within a year (Bladin et al., 2000).Fig. 1 (adapted from Picard, 2010). FLAIR coronal MR images of the patient. (A) two days after a right capsulo-lenticular haemorragic stroke. (B) ten months later, at the time of the episode of feeling of presence. In addition to the right capsulo-lenticular sequela extending to the insula, a hypersignal is visible in the white matter/grey matter border of the left insular region [already visible in (A)], as well as a diffuse corticosubcortical atrophy, predominating in the right hemisphere, and a leukoencephalopathy [white matter disease]. Picard (2010) thinks this particular case is unique and not a more typical disorder of body perception:Most authors consider the feeling of a presence (FP) as a disorder of own body perception, an illusory reduplicative phenomena involving the self. Thus FP would be akin to the three main forms of autoscopic phenomena (seeing a double of oneself) which include a) out-of-body experience. The subjects appear to see themselves and the world from a location above their physical body. The self is localized outside one's physical body (disembodiment); b) autoscopic hallucination, which consists of seeing one's body in extracorporeal space (as a double) without disembodiment; and c) heautoscopy, an intermediate form between out-of-body experience and autoscopic hallucination.Instead, the felt presence was more akin to a "hallucination" for known people going about normal daily activities. Nonetheless, involvement of the insula, important for interoceptive awareness of bodily states (Craig, 2009), is still suggestive of a disruption in the sense of self and its interaction with the external world.To end our story, the patient's experience of a sensed presence did not recur once her seizures were controlled with medication. A short neurological horror film resolved by prescription of an anticonvulsant drug might not be a strong sell in Hollywood.ReferencesBladin CF, Alexandrov AV, Bellavance A, Bornstein N, Chambers B, Coté R, Lebrun L, Pirisi A, Norris JW. (2000). Seizures after stroke: a prospective multicenter study. Arch Neurol. 57:1617-22.Craig AD. How do you feel--now? The anterior insula and human awareness. (2009). Nat Rev Neurosci. 10:59-70.... Read more »
Picard, F. (2010) Epileptic feeling of multiple presences in the frontal space. Cortex. DOI: 10.1016/j.cortex.2010.02.002
by The Neurocritic in The Neurocritic
"Voodoo correlations in social neuroscience" was the original title of a paper that first caused a stir in late December 2008, when a manuscript accepted by Perspectives on Psychological Science was made available on the authors' websites. Vul, Harris, Winkielman, and Pashler produced a "bombshell of a paper" that questioned the implausibly high correlations observed in some fMRI studies in the field of Social Neuroscience. Ed Vul et al. surveyed the authors of 54 papers to determine the analytic methods used. All but three of the authors responded to the survey, and 54% admitted to using faulty methods to obtain their results:More than half acknowledged using a strategy that computes separate correlations for individual voxels, and reports means of just the subset of voxels exceeding chosen thresholds. We show how this non-independent analysis grossly inflates correlations, while yielding reassuring-looking scattergrams. This analysis technique was used to obtain the vast majority of the implausibly high correlations in our survey sample. In addition, we argue that other analysis problems likely created entirely spurious correlations in some cases.For background reading I suggest starting with Voodoo Correlations in Social Neuroscience. Given the paper's inflammatory title and its naming of names, the accused researchers did not take the criticism lying down (see Voodoo Schadenfreude).Here we have a public debate between Dr. Piotr Winkielman, one of the authors of the Voodoo paper (Vul et al. 2009, PDF), and Dr. Matthew Lieberman, one of the accused (rebuttal: Lieberman et al. 2009, PDF) at the 2009 meeting of the Society of Experimental Social Psychologists. Dr. Lieberman has made these videos and papers available on his website, and I thank him for drawing my attention to them.The Voodoo Debate Continues...Piotr Winkielman, opening remarks (21:12)Matt Lieberman, opening remarks (19:03) [better view of slides]Piotr Winkielman, rebuttal (10:22)... Read more »
Lieberman, M., Berkman, E., & Wager, T. (2009) Correlations in Social Neuroscience Aren't Voodoo: Commentary on Vul et al. (2009). Perspectives on Psychological Science, 4(3), 299-307. DOI: 10.1111/j.1745-6924.2009.01128.x
by The Neurocritic in The Neurocritic
Anna O.'s Default Mode. Anna O. is the famous patient whose case was included in Studies on Hysteria by Josef Breuer and Sigmund Freud. Midsagittal brain image (PALS cortical surface atlas, Van Essen 2005) shows resting state functional connectivity in three cortical networks: (i) dorsal attention system (DAS, blue); (ii) the salience system (light green); and (iii) the default mode network (orange). [Taken from Fig. 2 of Carhart-Harris & Friston 2010. Justin Vincent and Randy Buckner are not to blame.]"Given the nature of this synthesis, different readers will find merit in different aspects of it."-R. L. Carhart-Harris and K. J. Friston, The default-mode, ego-functions and free-energy: a neurobiological account of Freudian ideasOur previous post (Friston is Freudian) presented an overview of the new megawork [metawork?] of Carthart-Harris & Friston (2010), an ambitious project to map selected Freudian ideas (id and ego but not super-ego)1 onto the brain's large-scale intrinsic networks as revealed by modern neuroscientific methods (fMRI, resting state functional connectivity, intracranial EEG recordings, and computational models). As mentioned before, they marshalled the neuroscientific concepts of Bayesian Brain, Default Mode Network, Free Energy, Gamma Oscillations, Prediction, Prediction Error, Theta Oscillations, and Top-Down Control in support of their neuropsychoanalytic scheme. After reading the article, I was amazed at the boldness and creativity it took to develop this framework. The 70 pages of Supplementary Data included 493 quotes from Freud.Freud's Model of the Mind: "The ego is not sharply separated from the id; its lower portion merges into it.... But the repressed merges into the id as well, and is merely a part of it. The repressed is only cut off sharply from the ego by the resistances of repression; it can communicate with the ego through the id." (From Freud's 1923 paper "The Ego and the Id")However, not all 493 quotes were used in support of selected characteristics of the ego (Secondary Process - 'normal waking consciousness of adult humans') and the id (Primary Process - 'altered' or 'non-ordinary' states of consciousness). For instance, I don't see Q439 (on early childhood sexuality) anywhere in Table 1 or the text:The sexual life of human beings exhibits an efflorescence which comes to an end at about the fifth year and it followed by what is known as the period of latency (till puberty)… [Q439, Freud, 1939, p. 75]Likewise, the super-ego is neglected (see also Footnote 1):If we consider once more the origin of the super-ego as we have described it, we shall recognise that it is the outcome of two highly important factors, once biological and the other of a historical nature: namely, the lengthy duration in man of his childhood helplessness and dependence, and the fact of his Oedipus complex, the repression of which we have shown to be connected with the interruption of libidinal development by the latency period and so with the diphasic onset of man's sexual life... [Q344, Freud, 1923, p. 35]But let's return to what they did include in their synthesis. C-H and F want to establish the construct validity of Freudian concepts (id and ego) to operationalize them and subject them to empirical scrutiny. In brief, the ego (normal adult human consciousness) is more or less equated with activity in the brain's "default mode" network (Raichle et al., 2001), measured as spontaneous fluctuations in the BOLD signal during unconstrained cognition. Activity in the default mode network (DMN)2 is anti-correlated with activity in "active task" networks, which are engaged by typical neuroimaging experiments. In contrast to the ego, the limbic id is equated with unusual and altered states of consciousness, as seen in psychosis, the aura of temporal lobe epilepsy, hallucinogenic states, and REM sleep.3Added to this is a key concept in recent Fristonian thought. The "free-energy principle" is the idea that the brain is an inference engine (Helmhotz, 1860) that makes probabilistic predictions about the world (i.e., its external and internal input) based on past experience, then updates these predictions based on current events (Friston, 2010). The goal is to minimize "free-energy"4 or prediction error.In The Prophetic Brain, Friston attempts to explain this for a lay audience:5The emerging picture is that the brain makes its inferences by minimizing the free-energy of messages passing between hierarchical brain regions. ... Information fro... Read more »
Carhart-Harris, R., & Friston, K. (2010) The default-mode, ego-functions and free-energy: a neurobiological account of Freudian ideas. Brain. DOI: 10.1093/brain/awq010
by The Neurocritic in The Neurocritic
Professor Karl Friston is one of the most prominent (and prolific) researchers in the field of neuroimaging. His contributions to methodological development in functional magnetic resonance imaging (fMRI) are immense:He invented statistical parametric mapping; SPM is an international standard for analysing imaging data and rests on the general linear model and random field theory (developed with Keith Worsley). In 1994, his group developed voxel-based morphometry. VBM detects differences in neuroanatomy and is used clinically and as a surrogate in genetic studies... In 2003, he invented dynamic causal modelling (DCM), which is used to infer the architecture of distributed systems like the brain. Mathematical contributions include variational filtering and dynamic expectation maximization (DEM) for Bayesian model inversion and time-series analysis. Dr Robin Carhart-Harris and Professor Friston have a new article in the Occasional Papers section of the journal Brain that might raise a few eyebrows. Its title? The default-mode, ego-functions and free-energy: a neurobiological account of Freudian ideas. What might cause the raising of eyebrows? Well, Freudian ideas have been largely rejected by mainstream neuroscience, although there have been some notable exceptions (Turnbull & Solms, 2007):Psychoanalysis has had a turbulent and complex relationship with neuropsychology for the century in which the two fields have existed – largely side by side. Some within the neuroscientific community have found much of value in Freudian ideas – Paul Schilder springs to mind as an early example, with Eric Kandel as the most prominent recent advocate (Kandel, 1999). However, for most neuropsychologists, indeed for most scientists, the obvious response to the mention of psychoanalysis has been one of blanket rejection.The renowned sleep and dreaming expert J. Allan Hobson (2007) has been a particularly harsh critic:With respect to dreams, Sigmund Freud was not only not right. He was dead wrong. And so are Turnbull and Solms (2007) in their desperate effort to save Freudian psychoanalysis from the junk heap of speculative philosophy. Neuroscientists, psychologists, and psychiatrists beware: you are being led down the garden path by this pair of misguided neo-Freudians.It is with this stormy background in mind that one should embark on reading the Brain paper. Mercifully, for those lacking the mathematical background to understand even the most rudimentary quantitative formulation of Friston's free-energy principle (2009, 2006), the paper is free of equations. No matter what you think of the final result, it's an intellectual tour de force with 493 quotes from Freud in 70 pages of Supplementary Data. Essentially, the approach is to take a collection of cutting-edge and trendy ideas in neuroscience and map them onto Freud's id and ego. For your convenience, here is a list of the main neuroscientific concepts:Baysian brainDefault Mode NetworkFree EnergyGamma OscillationsPredictionPrediction ErrorTheta OscillationsTop-Down ControlYou might be saddened by the lack of mirror neurons, social cognition, and empathy in the current conceptualization. But it should be all about sex, right? Well, actually, Carhart-Harris and Friston are much more chaste in their mapping of Freudian ideas onto neurobiology and default mode function. The words sex, sexual, sexuality (and any variants) appear zero times in the Brain article, but 18 times in the collection of Freud quotes. The word libido was mentioned 112 times in the Freud quotes but only 4 times by the present authors [excluding reproduction of Freud quotes in the main text].For "accessibility" cathexis was interpreted in a generic (not specifically sexual) sense to mean activation or energy . But according to Freud, mental energy is the id, the psychic energy that powers the mind:Freud defined Libido as the instinct energy or force. Freud later added the Death drive (also contained in the id) as a second source of mental energy.Next time we'll take a closer look at this ambitious synthesis of psychoanalysis and neuroimaging.Arrangement for psychotherapy fMRI studies using the couch of Sigmund Freud. See Psychodynamic Psychotherapy in the Scanner?ReferencesCarhart-Harris, R., & Friston, K. (2010). The default-mode, ego-functions and free-energy: a neurobiological account of Freudian ideas Brain DOI: 10.1093/brain/awq010Friston K. (2009) The free-energy principle: a rough guide to the brain? Trends Cog Sci. 13:293-301. [PDF]Friston K, Kilner J, Harrison L. (2006). A free energy principle for the brain. J Physiol Paris 100:70-87. [PDF]Kandel ER. (1999). Biology and the future of psychoanalysis: A new intellectual framework for psychiatry revisited. Am J Psychiatry 156: 505-524.Hobson JA. (2007). Wake up or dream on? Six questions for Turnbull and Solms. Cortex 43:1113-5; discussion 1116-21.Turnbull OH, Solms M. (2007). Awareness, desire, and fa... Read more »
Carhart-Harris, R., & Friston, K. (2010) The default-mode, ego-functions and free-energy: a neurobiological account of Freudian ideas. Brain. DOI: 10.1093/brain/awq010
by The Neurocritic in The Neurocritic
Author and blogger Jonah Lehrer has a lengthy (and controversial) essay in the Feb. 28 New York Times Magazine on Depression's Upside. The main idea, that depression has cognitive and evolutionary advantages, was largely based on a review paper by Andrews and Thomson (2009). In it, they put forth the analytical rumination hypothesis: depression is an evolved response to complex problems, and focusing on them to the exclusion of everything else is beneficial. Lehrer's piece generated an outpouring of comments (both pro and con), questions, and critiques. One notably critical rejoinder (The Myth of Depression's Upside) was written by Dr. Ronald Pies, the Editor in Chief of Psychiatric Times:Now, with all due respect to Dr. Thomson, I am inclined to ask, "[Insights gained during depression are] worth it to whom?" Perhaps the patients Dr. Thomson has treated emerge from their three-month bouts of depression saying, "Ya know what, Doc? It's been a bad three months—lost my job, almost killed myself, and couldn't get a damn thing done—but overall, it was worth it!" The depressed patients I evaluated over the past nearly 30 years almost never reported that their major depressive episodes had a "net mental benefit," to quote Lehrer's article. Most felt that their lives and souls had been stolen from them for the duration of their depressive episode.In other words, Dr. Pies's patients don't feel like they've solved all their problems. Most of the studies cited in favor of improved problem-solving abilities involved a sad "mood induction" procedure such as watching a 10 min film showing a death from cancer or being given false negative feedback on cognitive test performance (Forgas, 2007). It should be obvious that a transient, slightly sad state is drastically different from a prolonged major depressive episode. Jonah does acknowledge this in his article, but the distinction appears to undermine Andrews and Thomson's entire basis for asserting analytical advantages for the depressed ruminator. It's another in a long line of evo psych just-so stories.The literature is filled with papers describing the cognitive impairments associated with major depression. Jonah recognizes this as well, but then overstates how easy it is to dispense with the deficits:The end result is poor performance on tests for memory and executive function, especially when the task involves lots of information. (These deficits disappear when test subjects are first distracted from their depression and thus better able to focus on the exercise.)On the contrary, numerous papers have shown that impairments in cognitive processes such as executive control, attention, and memory persist after a depressed person has recovered (Andersson et al., 2010; Baune et al., 2010; Hammar et al., 2009). In actively depressed patients, Baune and colleagues (2010) found impairments in all domains tested: immediate memory, visuospatial construction, language, attention, and delayed memory. These deficits can contribute to lower social and occupational functioning and a diminished quality of life. In addition, depression can be associated with declines in problem solving abilities on neuropsychological tests such as the Wisconsin Card Sorting Test and the Tower of London test.A recent review of the literature provided additional support for the existence of pervasive cognitive deficits (Hammar et al., 2009):Research during the past decade has mainly focused on cognitive functioning in the severe phase of depression, and today it is widely accepted that the disease is characterized by cognitive impairment in the acute state. There are reports of findings in different cognitive domains, such as executive functions, attention, memory and psychomotor speed.Well (you say), what about Social Dilemmas? Aren't these different from the Stroop task? The Psych Review manifesto on the Bright Side of Being Blue states that "Complex social problems may be the primary evolutionarily relevant trigger of depression in human beings." But support for the view that depression improves the ability to solve such issues is meager, apparently consisting of two old papers (Hokanson et al., 1980; Pietromonaco & Rook, 1987). The Hokanson paper turns out to be not-so-great for the analytical rumination hypothesis: (1) The "depressed" group had scores on the Beck Depression Inventory of 10 or greater, which includes those with only very mild depression. (2) Ironically, Hokanson et al. view their own results as evidence of social skills deficits, not enhanced social problem solving:If, indeed, depressed individuals display different social responses, depending on situational or social role variables, one might expect that real-world relations are characterized by contradictory behaviors, mixed messages, emotional ambivalence, and so forth. Such stimulus arrays may indeed evoke several competing response tendencies in others, a situation that a simple reinforcement-punishment view would be hard pressed to handle.The conclusion of the Pietromonaco and Rook (1987) paper is even more problematic:This work suggests that depressives' cognitive analysis of common life situations leads them to make decisions that promote their social isolation and, thereby, perpetuate their depression. The analytical rumination hypothesis even has the potential to be harmful. Belief in the glorious "upside" of their ailment could prevent some severely depressed individuals from getting proper treatment, placing them at greater risk of suicide and other adverse events. Needless to say, such an outcome would be of no evolutionary advantage.ReferencesAndersson S, Lövdahl H, Malt UF. (2010). Neuropsychological function in unmedicated recurrent brief depression. J Affect Disord. Jan 18. [Epub ahead of print]Andrews PW, Thomson JA Jr. (2009). The bright side of being blue: depression as an adaptation for analyzing complex problems. Psychol Rev. 116:620-54.... Read more »
Baune, B., Miller, R., McAfoose, J., Johnson, M., Quirk, F., & Mitchell, D. (2010) The role of cognitive impairment in general functioning in major depression. Psychiatry Research. DOI: 10.1016/j.psychres.2008.12.001
Åsa Hammar, Guro Årdal. (2009) Cognitive functioning in major depression – a summary. Frontiers in Human Neuroscience. info:/
by The Neurocritic in The Neurocritic
Headache, by Robert Magginetti (Tranquility Base)In the last post we learned about Alice in Wonderland syndrome, a rare phenomenon involving distortions of visual perception and body image, most often caused by migraines. Although a specialty practice in headache might seem dull [so to speak] at first glance to those interested in behavioral neurology, unusual and colorfully-named types of headaches can make things more interesting. In Case Studies of Uncommon Headaches (2006), Dr. Randolph Evans reviews a number of these unfortunate ailments, which include exploding head syndrome, neck-tongue syndrome, red ear syndrome, and burning mouth syndrome. So let's begin with a hot ear.Case 6. My ear is red, hot, and burningA 54-year-old white woman was seen who had a 10-year history of episodes of a burning sensation of the left ear. The episodes are preceded by nausea and a hot feeling for approximately 15 seconds and then the left ear becomes visibly red for an average of approximately 1 hour, with a range of approximately 30 minutes to 2 hours. Approximately once every 2 years, she had a flurry of episodes occurring over approximately a 1-month period during which she averaged approximately five episodes, with a range of 1 to 6. There also was an 18-year history of migraine without aura occurring approximately once a year. ... A cerebral arteriogram revealed a proximal left internal carotid artery occlusion of uncertain cause after extensive testing. MRI scan at age 45 was normal. Neurologic examination was normal. A carotid ultrasound study demonstrated complete occlusion of the left internal carotid artery and a normal right.The diagnosis? Red Ear Syndrome, first described by Lance (1994) in the aptly-titled article, The mystery of one red ear. Following a plea to colleagues to "lend me your ear," Lance (1996) subsequently reported on 12 cases. He concluded that RES:may be associated with irritation of the third cervical root [nerve in the neck], temporomandibular joint [jaw] dysfunction, or thalamic [pain] syndrome. It may also occur without obvious structural cause in response to touch or heat. The condition may be an example of the ABC (Angry Back-firing C-nociceptor) syndrome with the increase in ear temperature being caused by the antidromic ["backwards"] release of vasodilator peptides [calcitonin gene-related peptide and substance P].It can also occur in association with migraines, glossopharyngeal and trigeminal neuralgia, upper cervical spine pathology, and herpes zoster [shingles]. The GABA analogue and anti-seizure medication gabapentin can be helpful in preventing RES.By the way, the girl in the picture above [who is not Case 6] says her red ear doesn't hurt, and that she doesn't get headaches.Case 7. My mouth is burningA 49-year-old woman was referred by her primary care physician with a 1.5-year history of daily constant burning or numbness of the entirety of her tongue and the back of her throat. She also complains that the inside of her mouth is sensitive. She has had a dry mouth for the past year. ... Artificial saliva has not been helpful. She has tried a variety of pain pills without any help....Burning Mouth Syndrome1 most often afflicts middle-aged and older women. Causes include dry mouth (e.g., from medications or diabetes), nutritional deficiency, food allergies, fungal infection (candidiasis aka thrush), trigeminal small fiber neuropathy (nerve damage), and hormonal changes. Treatments range from estrogen-progesterone replacement therapy to nutritional supplements to switching prescription medications to addressing an underlying medical condition. I don't know if this syndrome can be considered a "headache" in the standard usage of the word, but then again I'm not a neurologist.Case 1. Noises in the nightA 43-year-old woman was seen with a 5-month history of a noise in her head. On an almost nightly basis, as she was falling asleep, she would hear a loud noise like "electrical current running" lasting a second. Sometimes her whole body would shake for a second afterwards. Very occasionally, she would have an associated flash of light. Frequently, a second episode of the loud noise occurred shortly after the first. She then could fall asleep without any problem.Exploding Head Syndrome (Pearce, 1988) is a bang-up way to be aroused from your nightly slumber. A small percentage (~10%) of sufferers see a flash of light, even fewer feel as if they've stopped breathing for a short time. It's more frightening than it is painful. Interestingly, Evans (2006) suggests that EHS might be caused by delay in the reduction of activity in the brainstem reticular formation as the patient transitions from wakefulness to sleep. In 1949, Moruzzi and Magoun were the first to recognize that stimulation of the brainstem reticular formation produces low-voltage fast activity in the EEG, characteristic of an alert and attentive behavioral state. So something might be neurologically amiss with the EHS patient's sleep-wake cycle, although Evans gave no direct evidence of this. And the explosion phenomenology is largely unexplained, as noted by Pearce (1988):The cause of the bomb-like noise remains a mystery: no known vascular or hydrodynamic changes in the brain, labyrinths, or cerebrospinal fluid would cause such a symptom, although a momentary (almost ictal) disinhibition of the cochlea or its central connections in the temporal lobes, or a sudden involuntary movement of the tympanum or tensor tympani, might be the explanation...Evans' other case studies recounted complaints of numb tongue (neck-tongue syndrome), painful scalp (nummular headache... Read more »
EVANS, R. (2006) Case Studies of Uncommon Headaches. Neurologic Clinics, 24(2), 347-362. DOI: 10.1016/j.ncl.2006.01.006
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