Timing in the visual cortex and its investigation.

While many high-level cortical areas have been implicated in timing, timing activity has also been observed even in the earliest cortical stages of the visual system over the past decade. This activity has been formally modeled as one arising from a reinforcement signal, leading to testable hypotheses with recent experimental support, demonstrating the necessity and sufficiency of that reinforcement signal. As observed in other cortical areas implicated in timing, interval timing activity within the visual cortex abides by the temporal scalar property. Finally, perturbations of the visual cortex during interval timing results in lawful shifts in timing. These and related observations advance the notion that visual cortex is a substrate for learning and expressing visually-associated temporal expectations governing behaviorally-relevant actions.