Abstract
Quantifying the timing (duration and frequency) of brief visual events is vital to human perception, multisensory integration and action planning. For example, this allows us to follow and interact with the precise timing of speech and sports. Tuned neural responses to visual event timing have been found in areas of human association cortices implicated in visual perception, multisensory integration and action planning. We hypothesized that such event timing representations may be derived from sensory processing areas’ neural response dynamics to events, rather than from specialized central pacemakers or processes, as predominant models predict. Therefore, we asked whether and how timing-tuned responses are related to early visual responses, which monotonically increase with event duration and frequency. Participants were presented with repetitive visual events which gradually varied in event duration and/ or period during 7T fMRI. We characterized both monotonic and tuned responses to visual event timing using neural model-based analyses. We found increasingly clear monotonic responses to visual event duration and frequency from primary visual cortex to lateral occipital cortex. From here, we found a gradual transition from monotonic to tuned responses beginning in area MT/V5. Therefore, across successive stages of visual processing, timing-tuned response components gradually become dominant over the inherent modulation of sensory responses by event timing. This additional timing-tuned response component was independent of retinotopic location. We propose that this hierarchical emergence of timing-tuned responses from sensory processing areas quantifies sensory event timing while abstracting temporal representations from the spatial properties of their inputs.