The Journal of Neuroscience, June 15, 2001, 21(12):4408-4415
Auditory Space-Time Receptive Field Dynamics Revealed by
Spherical White-Noise Analysis
Rick L.
Jenison1, 2, 3,
Jan W. H.
Schnupp4,
Richard
A.
Reale2, 3, and
John F.
Brugge2, 3
Departments of 1 Psychology and
2 Physiology, and 3 Waisman Center, University
of Wisconsin, Madison, Wisconsin 53706, and 4 Physiology
Laboratory, University of Oxford, Oxford, OX1 3PT, United
Kingdom
Numerous studies have investigated the spatial sensitivity of cat
auditory cortical neurons, but possible dynamic properties of the
spatial receptive fields have been largely ignored. Given the
considerable amount of evidence that implicates the primary auditory
field in the neural pathways responsible for the perception of
sound source location, a logical extension to earlier observations of
spectrotemporal receptive fields, which characterize the dynamics of
frequency tuning, is a description that uses sound source direction, rather than sound frequency, to examine the evolution of spatial tuning
over time. The object of this study was to describe auditory space-time
receptive field dynamics using a new method based on cross-correlational techniques and white-noise analysis in spherical auditory space. This resulted in a characterization of auditory receptive fields in two spherical dimensions of space (azimuth and
elevation) plus a third dimension of time. Further analysis has
revealed that spatial receptive fields of neurons in auditory cortex,
like those in the visual system, are not static but can exhibit marked
temporal dynamics. This might result, for example, in a neuron becoming
selective for the direction and speed of moving auditory sound sources.
Our results show that ~14% of AI neurons evidence significant
space-time interaction (inseparability).
Key words:
auditory cortex; receptive field; white-noise analysis; reverse-correlation; sound localization; motion sensitivity
Copyright © 2001 Society for Neuroscience 0270-6474/01/21124408-08$05.00/0