Adaptation reveals multi-stage coding of visual duration

In confict with historically dominant models of time perception, recent evidence suggests that the encoding of our environment’s temporal properties may not require a separate class of neurons whose raison d'être is the dedicated processing of temporal information. If true, it follows that temporal processing should be imbued with the known selectivity found within non-temporal neurons. In the current study, we tested this hypothesis for the processing of a poorly understood stimulus parameter: visual event duration. We used sensory adaptation techniques to generate duration afterefects: bidirectional distortions of perceived duration. Presenting adapting and test durations to the same vs diferent eyes utilises the visual system’s anatomical progression from monocular, pre-cortical neurons to their binocular, cortical counterparts. Duration afterefects exhibited robust inter-ocular transfer alongside a small but signifcant contribution from monocular mechanisms. We then used novel stimuli which provided duration information that was invisible to monocular neurons. These stimuli generated robust duration afterefects which showed partial selectivity for adapt-test changes in retinal disparity. Our fndings reveal distinct duration encoding mechanisms at monocular, depth-selective and depthinvariant stages of the visual hierarchy