Pattern motion is present in V1 of awake but not anaesthetized monkeys

Guo, Kun and Benson, Philip J. and Blakemore, Colin (2004) Pattern motion is present in V1 of awake but not anaesthetized monkeys. European Journal of Neuroscience, 19 (4). pp. 1055-1066. ISSN 0953-816X

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Official URL: http://dx.doi.org/10.1111/j.1460-9568.2004.03212.x

Abstract

We compared responses of neurons, recorded in striate cortex (area V1) of awake, fixating monkeys, to a single drifting grating with those to a ‘plaid’ pattern comprised of two superimposed drifting gratings separated in orientation by 90°. Five out of 54 (9%) of V1 direction selective neurons responded to the direction of motion of the whole pattern [pattern motion (PM) selectivity]. Tuning curves for plaid stimuli were similar in both optimum direction and width of tuning to those for single gratings. Twenty nine out of 54 (54%) responded simply to the motion of individual orientated gratings within the pattern [component motion (CM) selectivity]. The remaining 37% (20/54) neurons were unclassified. In control experiments, 39 direction selective neurons were recorded in area V1 of anaesthetized monkey and cats. Unlike area V1 in behaving monkeys, none of these neurons exhibited PM selectivity to the drifting plaids. Twenty eight out of 39 (72%) of them responded to the direction of the component gratings and were classified as CM selectivity. Our results indicate that although most V1 neurons are CM selective, as described in anaesthetized animals, a subpopulation is clearly PM selective in behaving monkeys, reflecting integration of locally derived motion signals. Neurons in V1 therefore carry signals that may contribute to pattern motion processing and perception. This perceptual interpretation in V1 might depend much more critically on information integration mechanisms that only function properly in awake, perceiving animals.

Item Type:Article
Additional Information:We compared responses of neurons, recorded in striate cortex (area V1) of awake, fixating monkeys, to a single drifting grating with those to a ‘plaid’ pattern comprised of two superimposed drifting gratings separated in orientation by 90°. Five out of 54 (9%) of V1 direction selective neurons responded to the direction of motion of the whole pattern [pattern motion (PM) selectivity]. Tuning curves for plaid stimuli were similar in both optimum direction and width of tuning to those for single gratings. Twenty nine out of 54 (54%) responded simply to the motion of individual orientated gratings within the pattern [component motion (CM) selectivity]. The remaining 37% (20/54) neurons were unclassified. In control experiments, 39 direction selective neurons were recorded in area V1 of anaesthetized monkey and cats. Unlike area V1 in behaving monkeys, none of these neurons exhibited PM selectivity to the drifting plaids. Twenty eight out of 39 (72%) of them responded to the direction of the component gratings and were classified as CM selectivity. Our results indicate that although most V1 neurons are CM selective, as described in anaesthetized animals, a subpopulation is clearly PM selective in behaving monkeys, reflecting integration of locally derived motion signals. Neurons in V1 therefore carry signals that may contribute to pattern motion processing and perception. This perceptual interpretation in V1 might depend much more critically on information integration mechanisms that only function properly in awake, perceiving animals.
Keywords:Monkey, Striate cortex, Pattern motion
Subjects:C Biological Sciences > C800 Psychology
C Biological Sciences > C830 Experimental Psychology
Divisions:College of Social Science > School of Psychology
ID Code:720
Deposited By: Jill Partridge
Deposited On:25 Jun 2007
Last Modified:13 Mar 2013 08:23

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