Enhancement, extension, and reversal of the frequency selectivity effect.

The influence of a frequency cue on judgments of whether or not a subsequent target incorporated a brief silent gap was examined. In Experiment 1, there was no predictive frequency relation and evidence of auditory inhibition of return was obtained with frequency repetitions, producing a facilitative effect at 175-msec stimulus onset asynchrony (SOA) and an inhibitory effect at 775-msec SOA. Relative to this baseline performance pattern, increasing the probability of a frequency match to .75 (Experiment 2) served to generate a beneficial effect of frequency repetitions at lengthy SOAs and to enlarge its magnitude at 175-msec SOA. In contrast, a reduction in the probability of a frequency match to .25 (Experiment 3) resulted in the elimination of any facilitative effect of repetition at 175-msec SOA and the development of an inhibitory effect at 475- and 1,075-msec SOA. These results establish that a frequency cue may engage both exogenous and endogenous attentional processes within 175 msec following its presentation.