BRAIN POTENTIALS AND TIME-ESTIMATION IN HUMANS

Several parameters of the event-related potential (ERP) were assessed while 12 healthy volunteers performed a time production task. Each tri al consisted of a series of 20 flashes presented at regular intervals on a videomonitor (interval 768 ms). After these flashes the subjects had to estimate the time it would take for an additional five flashes and to press a button upon the 5th interval. ERPs were recorded from 1 9 electrodes with three effects being of interest: (1) possible emitte d potentials at the times at which flashes had occurred, if the series had continued, (2) the ERP to probe flashes presented during the prod uction period, and (3) the slow potential shift during the estimation period. In addition reaction times were recorded. While ERP effects (I ) and (2) were not informative with respect to time estimation process es, the slow potential shift with a frontopolar distribution appears t o index time-keeping functions in humans. (C) 1997 Elsevier Science Ir eland Ltd.