Preserved implicit form perception and orientation adaptation in visual   form agnosia

doi:10.1016/j.neuropsychologia.2006.03.009

CORC > 北京大学 > 心理与认知科学学院

	Preserved implicit form perception and orientation adaptation in visual form agnosia
	Yang, Jiongjiong ; Wu, Ming ; Shen, Zheng
刊名	neuropsychologia
	2006
关键词	object recognition visual awareness lateral occipital area visual cortex OBJECT RECOGNITION APPERCEPTIVE AGNOSIA AWARENESS CORTEX COLOR DISCRIMINATION MECHANISMS CORRELATE LESIONS MEMORY
DOI	10.1016/j.neuropsychologia.2006.03.009
英文摘要	Visual form agnosia is mainly characterized by profound deficits in visual form and shape discrimination. Previous studies have shown that patients retain the capacity for coordinated motor behaviors, color naming and implicit letter perception. However, it is unknown to what extent other visual functions, such as implicit form and orientation perception, are preserved. To address these questions, we investigated a single visual form agnosic patient, X.F., in two distinct experiments. X.F.'s visual lesions were mainly localized in the bilateral occipitotemporal cortex, with the dorsal visual stream and early visual cortex largely spared. In Experiment 1, X.F. named the color of different forms across 12 blocks of trials. After the first six blocks, the combinations of a form with its color were changed and the new combination was presented for the remaining six blocks. X.F.'s reaction time increased during the switch block and was significantly greater than the overall RT changes between adjacent, non-switch blocks. This indicates that X.F. retained the ability to perceive changes in form despite her inability to discriminate the forms. In Experiment 2, X.F. showed selective orientation adaptation effects to different spatial frequencies; that is, her contrast threshold was significantly higher when the adapting and test orientations were the same than when they were orthogonal, although her orientation discrimination performance was severely impaired. These data provide evidence of a functional dissociation between explicit and implicit visual abilities, and suggest that the residual early visual cortex mediates form and orientation processing in the absence of awareness. (c) 2006 Elsevier Ltd. All rights reserved.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000239403200020&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; Behavioral Sciences; Neurosciences; Psychology, Experimental; SCI(E); PubMed; SSCI; 2; ARTICLE; 10; 1833-1842; 44
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/198925]
专题	心理与认知科学学院
推荐引用方式 GB/T 7714	Yang, Jiongjiong,Wu, Ming,Shen, Zheng. Preserved implicit form perception and orientation adaptation in visual form agnosia[J]. neuropsychologia,2006.
APA	Yang, Jiongjiong,Wu, Ming,&Shen, Zheng.(2006).Preserved implicit form perception and orientation adaptation in visual form agnosia.neuropsychologia.
MLA	Yang, Jiongjiong,et al."Preserved implicit form perception and orientation adaptation in visual form agnosia".neuropsychologia (2006).