Memory for the order of sequential visual events

Subjects' ability to discriminate the relative temporal location of pairs of events in a rapid sequential illumination of four lights positioned equidistant about a central fixation point was examined. There was no significant effect of cue delays up to one second indicating good retention of order information. The data were successfully analysed in terms of a random walk model which provides separate estimates of discrimination and response bias indices. Evidence was provided for a unidimensional representation of psychological time for durations less than 100 msec.