Temporal integration following intensification of long-lasting visual displays.

Duration of visible persistence is known to be inversely related to the duration of the inducing stimulus, within a critical interval estimated at between 100 and 150 msec. Stimuli longer than the critical interval yield little or no persistence. Six experiments investigated whether a brief period of intensification at the end of a stimulus longer than the critical interval could restore visible persistence. In the first experiment, a punctate stimulus ceased to give rise to visible persistence at exposure durations longer than the critical interval. The second experiment showed that persistence could be restored to a long display by briefly intensifying the component dots just before the end of the display. The remaining four experiments explored the limits and the distinguishing characteristics of this effect. Two alternative explanations of the results are described and evaluated.