Visualising time in the human brain
- Laboratoire de Neurosciences Cognitives, Marseille
Abstract: We all have a sense of time. Yet it is a particularly intangible sensation. So how is time represented in the brain? Functional neuroimaging studies of time perception frequently employ duration judgement tasks (“is this stimulus shorter/longer than another?”), Such timing studies typically identify structures traditionally implicated in motor function (SMA, basal ganglia) despite non-motor task goals. 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. Interestingly, fMRI studies have shown that the RT benefits of temporal predictability engage left inferior parietal cortex, an area that has been linked to motor intention. The neuroanatomical overlap between timing and motor function might have functional significance for the way in which we build up a “sense” of time.
Invited by D. Robbe