Event-related potentials as indices of time processing: A review

This review examines ERP data that document the mechanisms and neural bases of time processing in the millisecond-to-minute range. Several types of ERP attest to the existence of timing capacities. Among them, one component of the Contingent Negative Variation (CNV) provides an on-line index of timing. CNV data strengthen the temporal accumulator concept, designed to subtend duration encoding. This conclusion is based on four main results: The positive relationship between temporal estimates and CNV amplitude is an index of the accumulation mechanism; the CNV peak is an index of time-based decision making; the CNV relates to temporal encoding, whereas temporal long-term memory may be linked to shifts of positive polarity; learning effects on CNV amplitude depend on topographic features, thus revealing functional differences among brain regions with respect to timing.