Spatial generalization in short-term perceptual adaptation to novel auditory spaces

Abstract

Previous work shows that humans can rapidly adapt to novel mappings between auditory spatial cues and exocentric location and localize accurately with the novel mapping. Here, experiments using (1) a rotation and (2) a linear magnification of auditory space examined generalization of spatial adaptation to untrained or neglected regions of space. Individual head-related transfer functions (HRTFs) were used to simulate different source locations using headphones. Each experimental session was broken into three blocks: initial normal cues (measuring baseline performance), altered cues (showing adaptation), and final normal cues (measuring an adaptation aftereffect). In the altered cues trials, a source at X degrees was simulated using HRTFs that normally correspond to a source at (1) X+30 deg (rotation) or (2) 2X deg (linear magnification). After obtaining subjects’ localization responses to the sound stimulus, feedback was given using a light-emitting diode located at the correct position (X deg). Results of these experiments show the extent to which training subjects to adjust their localization responses in one region of space affects how they localize sources in adjacent regions, and provide a measure of the spatial kernel that drives spatial auditory adaptation.