Auditory cortical contrast enhancing by global winner-take-all inhibitory interactions.
Brains decompose the world into discrete objects of perception, thereby facing the problem of how to segregate and selectively address similar objects that are concurrently present in a scene. Theoretical models propose that this could be achieved by neuronal implementations of so-called winner-take-all algorithms where neuronal representations of objects or object features interact in a competitive manner. Here we present evidence for the existence of such a mechanism in an animal species. We present electrophysiological, neuropharmacological and neuroanatomical data which suggest a novel view of the role of GABA(A)-mediated inhibition in primary auditory cortex (AI), where intracortical GABA(A)-mediated inhibition operates on a global scale within a circular map of sound periodicity representation in AI, with functionally inhibitory projections of similar effect from any location throughout the whole map. These interactions could underlie the proposed competitive "winner-take-all" algorithm to support object segregation, e.g., segregation of different speakers in cocktail-party situations.
Kurt
Simone
S
Leibniz Institute for Neurobiology, Magdeburg, Germany.
Deutscher
Anke
A
Crook
John M
JM
Ohl
Frank W
FW
Budinger
Eike
E
Moeller
Christoph K
CK
Scheich
Henning
H
Schulze
Holger
H
D000161:Acoustic Stimulation; D000465:Algorithms; D000818:Animals; D001303:Auditory Cortex / Q000166:cytology / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D004594:Electrophysiology; D005849:Gerbillinae; D016571:Neural Networks, Computer; D011963:Receptors, GABA-A / Q000502:physiology*
D011963:Receptors, GABA-A