The Journal of Neurophysiology Vol. 79 No. 4 April 1998, pp. 2040-2062
Copyright ©1998 The American Physiological Society

Auditory Motion Induces Directionally Dependent Receptive Field Shifts in Inferior Colliculus Neurons

Willard W. Wilson¹ and William E. O'Neill^{1, 2}

¹ Program in Neuroscience and ² Department of Physiology, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642

Wilson, Willard W. and William E. O'Neill. Auditory motion induces directionally dependent receptive field shifts in inferior colliculus neurons. J. Neurophysiol. 79: 2040-2062, 1998. This research focused on the response of neurons in the inferior colliculus of the unanesthetized mustached bat, Pteronotus parnelli, to apparent auditory motion. We produced the apparent motion stimulus by broadcasting pure-tone bursts sequentially from an array of loudspeakers along horizontal, vertical, or oblique trajectories in the frontal hemifield. Motion direction had an effect on the response of 65% of the units sampled. In these cells, motion in opposite directions produced shifts in receptive field locations, differences in response magnitude, or a combination of the two effects. Receptive fields typically were shifted opposite the direction of motion (i.e., units showed a greater response to moving sounds entering the receptive field than exiting) and shifts were obtained to horizontal, vertical, and oblique motion orientations. Response latency also shifted as a function of motion direction, and stimulus locations eliciting greater spike counts also exhibited the shortest neural latency. Motion crossing the receptive field boundaries appeared to be both necessary and sufficient to produce receptive field shifts. Decreasing the silent interval between successive stimuli in the apparent motion sequence increased both the probability of obtaining a directional effect and the magnitude of receptive field shifts. We suggest that the observed directional effects might be explained by "spatial masking," where the response of auditory neurons after stimulation from particularly effective locations in space would be diminished. The shift in auditory receptive fields would be expected to shift the perceived location of a moving sound and may explain shifts in localization of moving sources observed in psychophysical studies. Shifts in perceived target location caused by auditory motion might be exploited by auditory predators such as Pteronotus in a predictive tracking strategy to capture moving insect prey.

This article has been cited by other articles:

				A. Borisyuk, M. N. Semple, and J. Rinzel Adaptation and Inhibition Underlie Responses to Time-Varying Interaural Phase Cues in a Model of Inferior Colliculus Neurons J Neurophysiol, October 1, 2002; 88(4): 2134 - 2146. [Abstract] [Full Text] [PDF]

				B. J. Malone, B. H. Scott, and M. N. Semple Context-Dependent Adaptive Coding of Interaural Phase Disparity in the Auditory Cortex of Awake Macaques J. Neurosci., June 1, 2002; 22(11): 4625 - 4638. [Abstract] [Full Text] [PDF]

				R. M. Burger and G. D. Pollak Reversible Inactivation of the Dorsal Nucleus of the Lateral Lemniscus Reveals Its Role in the Processing of Multiple Sound Sources in the Inferior Colliculus of Bats J. Neurosci., July 1, 2001; 21(13): 4830 - 4843. [Abstract] [Full Text] [PDF]

				N. J. Ingham, H. C. Hart, and D. McAlpine Spatial Receptive Fields of Inferior Colliculus Neurons to Auditory Apparent Motion in Free Field J Neurophysiol, January 1, 2001; 85(1): 23 - 33. [Abstract] [Full Text] [PDF]