Interval of time uncertainty in visual detection

The effects of increasing the length of an interval of continuous temporal uncertainty (ITU) on the detectability of visualsignals were investigated in a ‘Yes/No’ detection situation. Ss were uncerlain about when a signal might occur within a given observalion interval, the duration of which was varied. Longer intervals of uncertainty resulted in a decrement in detectability, which was shown to be directly attributable to increased false alarm rates. It was suggested that observers have more opportunities for confusing signals with noise. The time course of detectability within a givenITU was also investigated, but there were no significant variations.