Temporal learning modulates post-interval ERPs in a categorization task with hidden reference durations.

The investigation of time-related activity in human electrophysiological activity has recently expanded from signals during the estimated interval to post-interval activity. Previous findings show timing-associated event-related potentials (ERPs) in both early ([~]150ms) and late positive components (LPC; [~]300ms) post-interval signals. However, it is still unclear whether and what aspects of temporal information these different patterns of EEG activity are capturing, especially, if these signals are associated with interval duration or other task parameters. In the present work, we designed a modified temporal categorization task to investigate if participants adaptation to a changing decisional context led to changes in post-interval ERPs. Participants had to learn a hidden reference duration on each block to categorize the presented target intervals correctly. We found an early posterior N200 potential correlated to target durations and decisional context. A central LPC, which interacted with duration and learning of the hidden reference, predicted behavioral responses. Our findings add to the current evidence that interval duration modulates post-interval activity in timing categorization tasks and shows that late signals are associated with interval duration and decisional context.