Adaptation Reveals Multiple Levels of Representation in Auditory Stream Segregation

Abstract

When presented with alternating low and high tones, listeners are more likely to perceive 2 separate streams of tones ("streaming") than a single coherent stream when the frequency separation (Δf{hook}) between tones is greater and the number of tone presentations is greater ("buildup"). However, the same large-Δf{hook} sequence reduces streaming for subsequent patterns presented after a gap of up to several seconds. Buildup occurs at a level of neural representation with sharp frequency tuning. The authors used adaptation to demonstrate that the contextual effect of prior Δf{hook} arose from a representation with broad frequency tuning, unlike buildup. Separate adaptation did not occur in a..