首页 | 本学科首页   官方微博 | 高级检索  
   检索      

The visual cortical association field: A Gestalt concept or a psychophysiological entity?
摘    要:


The visual cortical association field: A Gestalt concept or a psychophysiological entity?
Authors:F Chavane  C Monier  V Bringuier  P Baudot  L Borg-Graham  J Lorenceau  Y Frgnac
Institution:Unité de neurosciences intégratives et computationnelles, UPR CNRS 2191, Institut fédératif de neurobiologie Alfred-Fessard, CNRS, 91 198, Gif-sur-Yvette, France.
Abstract:The receptive field of a visual neurone is classically defined as the region of space (or retina) where a visual stimulus evokes a change in its firing activity. Intracellular recordings in cat area 17 show that the visually evoked synaptic integration field extends over a much larger area than that established on the basis of spike activity. Synaptic depolarizing (dominant excitation) responses decrease in strength for stimuli that are flashed at increasing distances away from the centre of the discharge field, while their onset latency increases. A detailed spatio-temporal analysis of these electrophysiological data shows that subthreshold synaptic responses observed in the 'silent' surround of cortical receptive fields result from the intracortical spread of activation waves carried by slowly conducting horizontal axons within primary visual cortex. They also predict that a perceptual facilitation may occur when feedforward activation produced by the motion signal in the retina travels in phase in the primary visual cortex with the visually induced spread of horizontal activation. A psychophysical correlate has been obtained in humans, showing that apparent motion produced by a sequence of co-linear Gabor patches, known to preferentially activate V1 orientation selective cells, are perceived by human observers as much faster than non co-linear sequences of the same physical speed.
Keywords:intracellular recording  patch-clamp  synaptic integration field  horizontal connectivity  collinearity  psychophysics  apparent motion  binding
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号