Evidence for rhythmic attention.

Three studies compared effects of different rhythmic contexts on order judgments of targets embedded in auditory patterns designed to manifest auditory stream segregation. Of interest was the effect of rhythmic structure upon the frequency-based captor effect, wherein tones in one stream "capture" those of similar frequencies from another. Three rhythmic structures were studied. Experiment 1 compared a rhythm conducive to pairwise-target stream formation with one conducive to a four-tone stream, and one based on an isochronous rhythm in a within-subjects design. Patterns embedding the target tone pair contained a preliminary string of captor tones at frequencies either close or far from frequencies of distracting tones that flanked the target pair. No effect of captor distance was found. Experiments 2 and 3 varied rhythm between subjects using 9- and 11-tone patterns, respectively. In general, the magnitude of the captor effect was found to vary with temporal predictability of flanking and/or target tones. The pairwise rhythm was most likely to improve order judgments by facilitating frequency-based capture. Results are discussed in terms of a rhythmic attentional hypothesis.