Early interference of context congruence on object processing in rapid visual categorization of natural scenes.

Joubert, O., Fize, D., Rousselet, G.A. and Fabre-Thorpe, M. (2008) Early interference of context congruence on object processing in rapid visual categorization of natural scenes. Journal of Vision, 8(40495), pp. 1-18.

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Abstract

Whereas most scientists agree that scene context can influence object recognition, the time-course of such object/context interactions is still unknown. To determine the earliest interactions between object and context processing, we used a rapid go/no-go categorization task in which natural scenes were briefly flashed and subjects required to respond as fast as possible to animal-targets. Targets were pasted on congruent (natural) or incongruent (urban) contexts. Experiment 1 showed that pasting a target on another congruent background induced performance impairments, whereas segregation of targets on a blank background had very little effect on behavior. Experiment 2 used animals pasted on congruent or incongruent contexts. Context incongruence induced a 10% drop of correct hits and a 16ms increase in median reaction times, affecting even the earliest behavioral responses. Experiment 3 replicated the congruency effect with other subjects and other stimuli, thus demonstrating its robustness. Object and context must be processed in parallel with continuous interactions possibly through feed-forward co-activation of populations of visual neurons selective to diagnostic features. Facilitation would be induced by the customary co-activation of "congruent" populations of neurons whereas interference would take place when conflictual populations of neurons fire simultaneously.\r\n \r\nArticle available here: http://journalofvision.org/8/13/11

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Rousselet, Dr Guillaume
Authors: Joubert, O., Fize, D., Rousselet, G.A., and Fabre-Thorpe, M.
College/School:College of Science and Engineering > School of Psychology
College of Medical Veterinary and Life Sciences > Institute of Neuroscience and Psychology
Journal Name:Journal of Vision

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