The stimulus events in a visual RT task consisted either of a visual (V), visual-auditory (VA), or auditory (A) signal, the latter serving as a catch signal not to be responded to. On VA trials, V and A were separated by interstimulus intervals (ISIs) ranging from 0-90 msec. in 10-msec units. RT to VA events was generally faster than RT to a V event alone and was directly related to ISI. The obtained intersensory facilitation supported previous findings by M. Hershenson and L. K. Morrell (see 41:8 and 42:9). Also, an index of facilitation previously employed by Hershenson was obtained and, as with Hershenson's study, was an inverted U-shaped function of ISI. However, an artifact was noted in Hershenson's measure. (PsycINFO Database Record (c) 2006 APA, all rights reserved)