Résumé : Functional neuroimaging studies of time perception frequently employ duration judgement tasks (“is this stimulus shorter/longer than another ?”), which typically identify a frontostriatal network for timing (SMA, inferior frontal cortex, basal ganglia). Yet duration judgements are not the only way of measuring how accurately time is perceived. Being able to predict when relevant events are likely to occur allows us to orient attentional resources to the predicted moment in time, thereby enhancing how quickly and accurately events are processed. Speeded response times (RT) to temporally predictable events are therefore another, more indirect, measure of the internal representation of time. Indeed, they may even be a more suitable method for studying timing in cognitively fragile populations. In contrast to duration judgement tasks, the performance benefits of temporal predictability implicate left parietal cortex in a context-independent manner. Neuroanatomical differences in duration judgement versus temporal prediction paradigms reflect distinct functional mechanisms for processing the same underlying representation of time, which itself may be represented more fundamentally in context-specific sensorimotor processing regions of the brain.
Lieu : BSHM A6