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Brain mechanisms of expectation associated with insula and amygdala response to aversive taste : implications for placebo . The experience of aversion is shaped by multiple physiological and psychological factors including one 's expectations . Recent work has shown that expectancy manipulation can alter perceptions of aversive events and concomitant brain activation . Accruing evidence indicates a primary role of altered expectancies in the placebo effect . Here , we probed the mechanism by which expectation attenuates sensory taste transmission by examining how brain areas activated by misleading information during an expectancy period modulate insula and amygdala activation to a highly aversive bitter taste . In a rapid event-related fMRI design , we showed that activations in the rostral anterior cingulate cortex ( rACC ) , orbitofrontal cortex ( OFC ) , and dorsolateral prefrontal cortex to a misleading cue that the taste would be mildly aversive predicted decreases in insula and amygdala activation to the highly aversive taste . OFC and rACC activation to the misleading cue were also associated with less aversive ratings of that taste . Additional analyses revealed consistent results demonstrating functional connectivity among the OFC , rACC , and insula . Altering expectancies of upcoming aversive events are shown here to depend on robust functional associations among brain regions implicated in prior work on the placebo effect .
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Intervention_Control
placebo
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Intervention_Control
placebo
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Intervention_Educational
misleading information
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Intervention_Educational
highly aversive bitter taste
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Intervention_Educational
misleading cue
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Outcome_Physical
insula and amygdala activation
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Outcome_Adverse-effects
aversive ratings of that taste
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Outcome_Mental
.
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Participant_Condition
insula and amygdala
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Participant_Condition
brain areas activated
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Participant_Condition
during an expectancy period