Anatomy and time course of discrimination and categorization processes in vision:: an fMRI study
Anatomy and time course of discrimination and categorization processes in vision:: an fMRI study
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DOI：
10.1016/j.neuroimage.2004.03.044
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发表时间：
2004-08-01
期刊：
影响因子：
5.7
通讯作者：
Celsis, P
中科院分区：
文献类型：
--
作者：
Pernet, C;Franceries, X;Celsis, P
研究涉及视觉过程的大脑区域的研究通常反对不同的任务或不同的刺激类型。这项工作的地址，通过功能磁共振成像，任务类型（歧视与分类）和刺激类型（拉丁字母，众所周知的几何图形，韩国字母）之间的相互作用。行为数据显示，这两个任务没有不同的错误或正确的反应的百分比，但延迟185毫秒的分类任务相比，歧视任务。所有条件激活了一个共同的神经网络，包括纹状体和纹外区，特别是梭状回，楔前叶，岛，和背外侧额叶皮层。此外，交互作用分析显示，右额叶对任务和刺激都很敏感，并且刺激类型在右额叶皮层、右枕中回、右楔叶和左、右梭状回中引起分类任务的几个显著信号变化，而在辨别任务中，仅在右枕顶交界处观察到显著信号变化。最后，分析BOLD信号的潜伏期也揭示了根据任务而不是刺激类型的差异神经动力学。这些时间上的差异表明，一个平行的半球处理的歧视任务与合作的半球间处理的分类任务，可能反映了观察到的反应时间的差异。(C)2004年爱思唯尔公司All rights reserved.
Studies investigating the cerebral areas involved in visual processes generally oppose either different tasks or different stimulus types. This work addresses, by fMRI, the interaction between the type of task (discrimination vs. categorization) and the type of stimulus (Latin letters, well-known geometrical figures, and Korean letters). Behavioral data revealed that the two tasks did not differ in term of percentage of errors or correct responses, but a delay of 185 ms was observed for the categorization task in comparison with the discrimination task. All conditions activated a common neural network that includes both striate and extrastriate areas, especially the fusiform gyri, the precunei, the insulae, and the dorsolateral frontal cortex. In addition, interaction analysis revealed that the right insula was sensitive to both tasks and stimuli, and that stimulus type induced several significant signal variations for the categorization task in right frontal cortex, the right middle occipital gyrus, the right cuneus, and the left and right fusiform gyri, whereas for the discrimination task, significant signal variations were observed in the right occipito-parietal junction only. Finally, analyzing the latency of the BOLD signal also revealed a differential neural dynamics according to tasks but not to stimulus type. These temporal differences suggest a parallel hemisphere processing in the discrimination task vs. a cooperative interhemisphere processing in the categorization task that may reflect the observed differences in reaction time. (C) 2004 Elsevier Inc. All rights reserved.