Facilitative and inhibitory effects of location and frequency cues: evidence of a modulation in perceptual sensitivity.

The possibility that facilitative and inhibitory effects of auditory cues result because of a modulation in perceptual sensitivity was examined. Listeners were presented with a cue followed by a target, with the time period between the two varied at stimulus onset asynchronies (SOAs) of 150, 450, or 750 msec. In two conditions, the cue and target were either the same or different in location or frequency. In both conditions, listeners were required to identify the rise time of the target. Whereas the cue was presented in isolation, the target was presented in a wide-band noise background such that the required discrimination was made relatively difficult. In both conditions, a facilitative effect was apparent at the 150-msec SOA and an inhibitory effect was apparent at the 750-msec SOA for both accuracy and response time measures of performance. That these results were apparent for a judgment unrelated to the manipulated cue-target relation suggests strongly that both location-based and frequency-based auditory inhibition of return result primarily because of changes in perceptual sensitivity.