Auditory spatial alternation transforms auditory time.

Abstract

Recent research has shown that a sequence of auditory events that is alternated between the ears is stretched out in auditory memory, as compared with nonalternating sequences. Although the stimulus-onset asynchronies (SOAs) of the interaural and monaural sequences were the same, the perceptual-onset asynchronies (POAs) differed by 24 msec. Because this result was only established for a restricted range of SOAs (125-250 msec), the present study tested a much larger range (40-2,130 msec). It turned out that the POA difference of 25 msec remained invariant over this whole range. Furthermore it was investigated how the angle of alternation affected the POA difference. It was found that (a) this difference increased linearly with increasing angular separation, and (b) the effects of SOA and angular separation on the POA difference were additive. The merits of six different attention-switching models were inspected to explain these results, but none of the models could describe the effects satisfactorily. We offer a new model, the space-time network, that copes not only with the present results but also explains several other studies reported in the literature.