The time-course of distractor processing in auditory spatial negative priming.

The spatial negative priming effect denotes slowed-down and sometimes more error-prone responding to a location that previously contained a distractor as compared with a previously unoccupied location. In vision, this effect has been attributed to the inhibition of irrelevant locations, and recently, of their task-assigned responses. Interestingly, auditory versions of the task did not yield evidence for inhibitory processing of task-irrelevant events which might suggest modality-specific distractor processing in vision and audition. Alternatively, the inhibitory processes may differ in how they develop over time. If this were the case, the absence of inhibitory after-effects might be due to an inappropriate timing of successive presentations in previous auditory spatial negative priming tasks. Specifically, the distractor may not yet have been inhibited or inhibition may already have dissipated at the time performance is assessed. The present study was conducted to test these alternatives. Participants indicated the location of a target sound in the presence of a concurrent distractor sound. Performance was assessed between two successive prime-probe presentations. The time between the prime response and the probe sounds (response-stimulus interval, RSI) was systematically varied between three groups (600, 1250, 1900 ms). For all RSI groups, the results showed no evidence for inhibitory distractor processing but conformed to the predictions of the feature mismatching hypothesis. The results support the assumption that auditory distractor processing does not recruit an inhibitory mechanism but involves the integration of spatial and sound identity features into common representations.