title: A possible neuronal basis for representation of acoustic scenes in auditory cortex of the big brown bat.
abstract: Behavioural studies and field observations demonstrate that echolocating bats simultaneously perceive range, direction and shape of multiple objects in the environment as acoustic images derived from echoes. Cortical echo delay-tuned neurons contribute to the perception of object range, because focal inactivation of these neurons disrupts behavioural discrimination of range. We report here that response properties of delay-tuned neurons in the cortical tonotopic area of the bat, Eptesicus, transform the sequential arrival times of echoes with different delays into a concurrent, accumulating neural representation of multiple objects at different ranges. The sharpness of delay tuning systematically increases at each best delay in a subpopulation of these neurons while responses to echoes at different delays are accumulated. The resulting concurrent, multiresolution representation of echo delay corresponds to neural implementation of a common representation of images used in computational vision and may provide the basis for representing acoustic images of multiple objects as acoustic 'scenes'.
authors.affiliation: Department of Neuroscience, Brown University, Providence, Rhode Island 02912.
authors.forename: S P
authors.initials: SP
authors.lastname: Dear
authors.forename: J A
authors.initials: JA
authors.lastname: Simmons
authors.forename: J
authors.initials: J
authors.lastname: Fritz
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001303:Auditory Cortex / Q000166:cytology / Q000502:physiology*; D001931:Brain Mapping; D002685:Chiroptera / Q000033:anatomy & histology / Q000502:physiology*; D004455:Echolocation / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology