title: Episodic but not semantic order memory difficulties in autism spectrum disorder: Evidence from the Historical Figures Task Prospective memory in adults with high-functioning autism spectrum disorders: exploring effects of implementation intentions and retrospective memory load. Diminished Time-Based, but Undiminished Event-Based, Prospective Memory Among Intellectually High-Functioning Adults With Autism Spectrum Disorder: Relation to Working Memory Ability More is not necessarily better: Examining the nature of the temporal reference memory component in timing Discrimination of temporal synchrony in intermodal events by children with autism and children with developmental disabilities without autism. A Virtual Week study of prospective memory function in autism spectrum disorders. Double standards: Memory loading in temporal reference memory Temporal generalization in 3- to 8-year-old children. Time-Based and Event-Based Prospective Memory in Autism Spectrum Disorder: The Roles of Executive Function and Theory of Mind, and Time-Estimation The discrimination of and orienting to speech and non-speech sounds in children with autism Temporal processing in the basal ganglia. Do Adults with Autism Spectrum Disorders Compensate in Naturalistic Prospective Memory Tasks?
abstract: Considerable evidence suggests that the episodic memory system operates abnormally in autism spectrum disorder ( ASD ) whereas the functions of the semantic memory system are relatively preserved . Here we show that the same dissociation also applies to the domain of order memory . We asked adult participants to order the names of famous historical figures either according to their chronological order in history ( probing semantic memory ) or according to a r and om sequence shown once on a screen ( probing episodic memory ) . As predicted , adults with ASD  performed less well than age- and IQ-matched comparison individuals only on the  episodic task .  This observation is of considerable importance in the context of developmental theory because semantic and episodic order memory abilities can be dissociated in typically developing infants before they reach the age at which the behavioural markers associated with ASD are first apparent . This raises the possibility that early emerging memory abnormalities play a role in shaping the developmental trajectory of the disorder . We discuss the broader implication s of this possibility and highlight the urgent need for greater scrutiny of memory competences in ASD early in development This study examined , for the first time , the impact of implementation intentions on prospect i ve memory ( PM ) performance in adults with autism spectrum disorders ( ASD ) and further explored the role of retrospective memory for PM in ASD . PM was assessed with Virtual Week , a computerized game simulating upcoming everyday-life tasks .  Twenty-seven adults with ASD and 27 age- and ability-matched controls were included . Half of the participants were instructed to form implementation intentions ( i.e. , encoding PM tasks in form of if-then statements ) , while the rest received simple PM instructions . Results provide first tentative evidence for beneficial effects of implementation intentions and PM tasks with low dem and s on retrospective memory for adults with ASD 's PM . Overall , results point to the importance of planning and retrospective memory for successful prospect i ve remembering in ASD Objective : Prospect i ve memory ( PM ) is the ability to remember to carry out an intended action . Working memory is the ability to store information in mind while processing potentially distracting information . The few previous studies of PM in autism spectrum disorder ( ASD ) have yielded inconsistent findings . Studies of working memory ability in ASD have suggested a selective impairment of “ visual working memory . ” However , it remains unclear whether any such impairment is the result of diminished ( domain-specific ; visual/verbal ) storage capacity or diminished ( domain-general ) processing capacity . We aim to clarify these issues and explore the relation between PM and working memory in ASD . Method : Seventeen adults with ASD and 17 age- and IQ-matched comparison participants completed experimental measures of both event-based ( perform action x when event y occurs ) and time-based ( perform action a at time b ) PM , plus a self-report measure of PM skills  . Participants also completed a working memory test battery . Results : Participants with ASD self-reported diminished PM skill , and showed diminished performance on the time-based , but not event-based , PM task . On the working memory test battery , visual but not verbal storage capacity was diminished among participants with ASD , as was processing ability . Whereas visual storage was associated with event-based PM task performance among comparison participants , verbal storage was associated among ASD participants . Conclusions : ASD appears to involve a selective deficit in time-based PM and a selective difficulty with aspects of working memory that depend on the storage of visual information . However , event-based PM may be achieved through compensatory strategies in ASD Three experiments compared the timing performance of humans on a modified temporal generalization task with 1 , 3 , or 5 presentations of the st and ard duration .  In all three experiments subjects received presentations of a st and ard duration at the beginning of a trial block and then had to judge whether each of a number of comparison stimuli was or was not the st and ard . The duration of the st and ard changed between blocks . The three experiments varied the experimental design ( between or within subjects ) , task difficulty ( how closely the comparison stimuli were spaced around the st and ards ) , and  presence or absence of feedback on performance accuracy . Number of presentations of the st and ard never affected the proportion of identification s of the st and ard when it was presented , nor other features of the temporal generalization gradients observed . The implication s for the operation of reference memories within the scalar timing system were explored via models that made different assumptions about how the individual presentations of the st and ard were stored and used BACKGROUND This project examined the intermodal perception of temporal synchrony in 16 young children ( ages 4 to 6 years ) with autism compared to a group of children without impairments matched on adaptive age , and a group of children with other developmental disabilities matched on chronological and adaptive age . METHOD A preferential looking paradigm was used , where participants viewed non-linguistic , simple linguistic or complex linguistic events on two screens displaying identical video tracks , but one offset from the other by 3 seconds , and with the single audio track matched to only one of the displays . RESULTS As predicted , both comparison groups demonstrated significant non-r and om preferential looking to violations of temporal synchrony with linguistic and non-linguistic stimuli . However , the group with autism showed an impaired , chance level of responding , except when presented with non-linguistic stimuli . CONCLUSIONS Several explanations are offered for this apparently autism-specific , language -specific pattern of responding to temporal synchrony , and potential developmental sequelae are discussed Prospect i ve memory ( PM ) refers to the implementation of delayed intentions , a cognitive ability that plays a critical role in daily life because of its involvement in goal -directed behavior and consequently the development and maintenance of independence . Emerging evidence indicates that PM may be disrupted in autism spectrum disorders ( ASDs ) , potentially contributing to the functional difficulties that characterize this group . However , the degree , nature , and specificity of ASD-related impairment remains poorly understood . In the current study , children between 8 and 12 years of age who were diagnosed with ASDs ( n=30 ) were compared with typically developing children ( n=30 ) on a child-appropriate version of the Virtual Week board game . This measure provides an opportunity to investigate the different sorts of PM failures that occur . The ASD group showed significant PM impairment on measures of time-based ( but not event-based ) prospect i ve remembering . However , only a subtle difference emerged between regular and irregular PM tasks , and group differences were consistent across these tasks . Because regular and irregular tasks differentially load retrospective memory , these data imply that the PM difficulties seen in ASDs may primarily reflect a monitoring deficit and not an encoding and memory storage deficit . PM performance was poorer under conditions of high ongoing task absorption , but the magnitude of this effect did not vary as a function of group . In both groups , time-based ( but not event-based ) PM difficulties were associated with functional outcomes in daily life , but only an inconsistent association with executive control emerged Three experiments compared human performance on temporal generalization  tasks with either one or two different , and distinct , st and ard duration s encoded . In the first two experiments participants received presentations of two different st and ards at the beginning of each trial block and were instructed to encode either one or both of them . When instructed to encode one st and ard they then had to judge whether each of a number of comparison stimuli was or was not that st and ard . When instructed to encode both they were then tested using just one of the st and ards but the participants were unaware , at the time of encoding , which st and ard would later be used as a reference . No marked effect of the number of temporal st and ards encoded was found . In Experiment 3 participants received either one or two temporal st and ards and had to use both when two were presented . This manipulation produced flatter generalization gradients when two st and ards were encoded than when just one was , and modelling attributed this difference mainly to an increase in reference memory variability in the double-st and ard case . This suggests that the variability of representation of duration s in temporal reference memory can be systematic ally increased by increasing temporal reference memory load Children aged 3 , 5 , and 8 years were tested on temporal generalization with visual stimuli . Different groups received 4- and 8-s st and ards . Gradients at all ages superimposed when plotted on the same relative scale , indicating underlying scalar timing . The principal developmental changes were ( i ) increasing sharpness of the generalization gradient with increasing age and ( ii ) a change from symmetrical ( 3 and 5 years ) to adultlike asymmetrical generalization gradients in the oldest children . Theoretical modeling attributed these changes to increasing precision of the reference memory of the st and ard  with increasing age , as well as a decreased tendency to " misremember " the st and ard  as being shorter than it actually was , as the children developed Prospect i ve memory ( remembering to carry out an action in the future ) has been studied relatively little in ASD . We explored time-based ( carry out an action at a pre-specified time ) and event-based ( carry out an action upon the occurrence of a pre-specified event )  prospect i ve memory , as well as possible cognitive correlates , among 21 intellectually high-functioning children with ASD , and 21 age- and IQ-matched neurotypical comparison children . We found impaired time-based , but undiminished event-based , prospect i ve memory among children with ASD . In the ASD group , time-based prospect i ve memory performance was associated significantly with diminished theory of mind , but not with diminished cognitive flexibility . There was no evidence that time-estimation ability contributed to time-based prospect i ve memory impairment in ASD The present study aim ed to find out how different stages of cortical auditory processing ( sound encoding , discrimination , and orienting ) are affected in children with autism . To this end ,  auditory event-related potentials ( ERP ) were studied in 15 children with autism and their controls . Their responses were recorded for pitch , duration , and vowel changes in speech stimuli , and for corresponding changes in the non-speech counterparts of the stimuli , while the children watched silent videos and ignored the stimuli . The responses to sound repetition were diminished in amplitude in the children with autism , reflecting impaired sound encoding . The mismatch negativity ( MMN ) , an ERP indexing sound discrimination , was enhanced in the children with autism as far as pitch changes were concerned . This is consistent with earlier studies reporting auditory hypersensitivity and good pitch-processing abilities , as well as with theories proposing enhanced perception of local stimulus features in individuals with autism . The discrimination of duration changes was impaired in these children , however . Finally , involuntary orienting to sound changes , as reflected by the P3a ERP , was more impaired for speech than non-speech sounds in the children with autism , suggesting deficits particularly in social orienting . This has been proposed to be one of the earliest symptoms to emerge , with pervasive effects on later development This study investigated the role of the basal ganglia in timing operations . Nondemented , medicated Parkinson 's disease ( PD ) patients and controls were tested on 2 motor-timing tasks ( paced finger tapping at a 300- or 600-ms target interval ) , 2 time perception tasks ( duration perception wherein the interval between the st and ard tone pair was 300 or 600 ms ) , and 2 tasks that controlled for the auditory processing ( frequency perception ) dem and s of the time perception task and the movement rate ( rapid tapping ) in the motor-timing task . Using A.M. Wing and A.B. Kristofferson 's ( 1973 ) model , the total variability in motor timing was partitioned into a clock component , which reflects central timekeeping operations , and a motor delay component , which estimates r and om variability due to response implementation processes . The PD group was impaired at both target intervals of the time perception and motor-timing tasks . Impaired motor timing was due to elevated clock but not motor delay variability . The findings implicate the basal ganglia and its thalamocortical connections in timing operations The present study is the first to directly compare event- and time-based prospect i ve memory in Autism Spectrum Disorders ( ASD ) using a context ual task mirroring real life dem and s of prospect i ve memory . Twenty-five individuals with ASD and 25 age- and ability-matched controls completed the Dresden Breakfast task which required participants to prepare breakfast following a set of rules and time restrictions . Overall , adults with ASD had less correct time- and event-based prospect i ve memory responses in comparison to controls , which is consistent with previous research in children with ASD . Moreover , ASD participants completed fewer tasks , followed rules less closely , and monitored the elapsing time less closely than controls . Individuals with ASD seem not to be compensating in naturalistic prospect i ve memory tasks
target: The results show different consistency across studies between the three types of timing ability .
  The highest consistency of results showing atypical time perception abilities is found in high-level time perception studies .
  It remains unclear if autism is characterized by a fundamental time perception impairment .
  Overall , there are a number of studies that show differences between autistic and non-autistic individuals , but some studies do not find such differences .
  Group differences are more consistent across studies using complex tasks rather than simpler more fundamental timing tasks .
background: Problems with timing and time perception have been suggested as key characteristics of autism spectrum condition ( ASC ) .
  Studies and personal accounts from clinicians , parents , caregivers , and self-reports from autistic people themselves often refer to problems with time .
  Although a number of empirical studies have examined aspects relating to time in autistic individuals , there remains no clear consensus on whether or how timing mechanisms may be affected in autism .