Leveraging adaptation to study perceptual weighting of interaural time differences

摘要

An important question in auditory cognition is how we perceive the location of an object in space. Converging evidence from animal models and humans suggests that when judging sound direction, the central nervous system weighs the anticipated reliability of binaural cues. Here, we used short-term adaptation to bias normal-hearing listeners towards source direction favoring either the left or the right frontal quadrant. Listeners rated perceived laterality of tokens of band-pass filtered noise (300 Hz - 1200 Hz) with interaural time differences that were randomly selected from a uniform distribution spanning either -375 to 0 μs or 0 to 375 μs. Using non-linear mixed effects modeling of behavioral laterality reports, we tested how exposure to source quadrant affects how listeners weigh the reliability of interaural time differences. The cue reliability hypothesis predicts that perceived direction should be skewed, such that unreliable frontal source angles are more affected by short-term adaptation than the more reliable lateral source angles. Alternatively, short-term adaptation may affect all source angles equally, predicting an overall shift in perceived direction. Results show that frontal angles are more strongly affected by short-term adaptation than lateral angles, supporting the cue reliability hypothesis.