Stimulus‐specific adaptation to visual but not auditory motion direction in the barn owl's optic tectum

摘要

Abstract Whether the auditory and visual systems use a similar coding strategy to represent motion direction is an open question. We investigated this question in the barn owl's optic tectum (OT ) testing stimulusspecific adaptation (SSA ) to the direction of motion.SSA , the reduction of the response to a repetitive stimulus that does not generalize to other stimuli, has been well established inOT neurons.SSA suggests a separate representation of the adapted stimulus in upstream pathways. So far, onlySSA to static stimuli has been studied in theOT . Here, we examined adaptation to moving auditory and visual stimuli.SSA to motion direction was examined using repeated presentations of moving stimuli, occasionally switching motion to the opposite direction. Acoustic motion was either mimicked by varying binaural spatial cues or implemented in free field using a speaker array. WhileOT neurons displayedSSA to motion direction in visual space, neither stimulation paradigms elicited significantSSA to auditory motion direction. These findings show a qualitative difference in how auditory and visual motion is processed in theOT and support the existence of dedicated circuitry for representing motion direction in the early stages of visual but not the auditory system.