Defining the functional properties of chronotopic maps in the human brain:the role of temporal context and stimulus features

How is millisecond unit of time represented in the human brain? Recent empirical evidences have shown that tuning and topography lay at the foundation of duration representation in the human brain. Duration-selective neuronal populations have been found in wide network of brain areas from occipital to frontal regions. These duration-selective neuronal populations are also topographically organized along the cortical surface as to form “chronomaps”. Through a series of high-spatial resolution magnetic resonance imaging (7T fMRI) experiments in which I have manipulated the sensory modality (visual and auditory), the task, the temporal context and spatial position of the stimuli, I have tried to disclose a few functional properties of chronomaps. Specifically, I explored chronomaps’ modality and task specificity, perceived versus physical time representation, as well as the interaction with the representation of other quantities (i.e., numerosity maps) and with the representation of the visual field (i.e., retinotopic maps). Overall, the results suggest that the temporal representation stored in the chronomaps, although amodal and task independent, is highly flexible and contextual in nature. It changes with perception and stimulus features and gradually, along the cortical hierarchy, becomes independent from low level stimulus’s feature (e.g., spatial position). Overall, this work should be seen as a first step to deepen our understanding of the modality in which the human brain processes, transforms and represents time.