Previous stimuli and responses modulate EEG signals at distinct stages of subsequent temporal processing

Perception of a current stimulus is often biased by recent history, a phenomenon known as serial dependence. Previous stimuli and responses lead to different serial dependence effects. However, the neural mechanisms underlying their influences are still unknown. Here, we tested the hypothesis that previous stimuli and responses modulate subsequent perception at different neuronal processing stages. Twenty-four participants performed an interval reproduction task with simultaneous EEG recording. Behaviorally, current reproduced intervals were repelled away from the previous stimulus interval but attracted toward the previous reproduced interval. Notably, these two history-dependent effects modulated neural dynamics on the current trial at distinct stages: while the previous stimulus modulated early encoding and memory-related processes, the previous response influenced the later decision-related stage. Specifically, a longer stimulus interval on the previous trial led to reduced amplitude of the contingent negative variation (CNV)-like EEG signal during temporal encoding, and increased amplitude of the negative slow wave (NSW) between stimulus and response (memory period), on the current trial. By contrast, a longer reproduced interval on the previous trial led to a more sustained CNV with reduced decline during the reproduction interval (decision period) on the current trial. Multivariate pattern analysis showed that the previous stimulus interval could be decoded from the current trial’s EEG signals during the temporal encoding and memory periods, while the previous reproduced interval was decodable from the current trial’s memory and decision periods. Together, these findings suggest that previous stimuli and responses modulate earlier and later stages, respectively, of subsequent temporal processing.