ABSTRACT
The most familiar electrophysiological correlate of time estimation is a slow negative wave, called the contingent negative variation. The combination of Electroencephalography and Positron emission tomography data further indicates that cortical activity may underlie cognitive processes associated with the preparation and organization of forthcoming responses. There is some intriguing evidence of a right hemispheric bias for processing temporal information. In experimental paradigms specifically designed to study time estimation, it has been shown that the return of the negativity to baseline started largely before the imperative stimulus and the motor response that are most often temporally close together. Average waveforms synchronized to the click for 800, 900, and 1000 msec evidenced a covariation between subjects’ temporal judgments and the latency of the negative-to-positive amplitude shift of the concomitantly recorded event-related potential's. These results suggest that the differences between the latencies reflect differences in timing of the cognitive processes associated with the formation of a temporal judgment.
