Dissociation of frontal and cerebellar activity in a cognitive task: Evidence for a distinction between selection and search
Dissociation of frontal and cerebellar activity in a cognitive task: Evidence for a distinction between selection and search
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DOI：
10.1006/nimg.1998.0340
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发表时间：
1998-05-01
期刊：
影响因子：
5.7
通讯作者：
Glover, GH
中科院分区：
文献类型：
--
作者：
Desmond, JE;Gabrieli, JDE;Glover, GH
人类大脑成像研究发现，在认知任务期间，左额叶皮质功能激活的增加往往伴随着右侧小脑区域类似的增加。本研究使用功能磁共振成像(FMRI)60通过词干补全任务来研究这些区域的独特贡献。有许多可能完成(许多条件)的词干被交替呈现给几乎没有可能完成(几个条件)的词干，受试者被要求用一个词秘密地完成每个词干，并为每次成功完成按下一个反应开关。相对于少数情况，在左侧额中回(Brodmann区9/10)和左侧尾状核，多数情况下的激活显著增加。相反，右侧小脑半球的部分(后四角形小叶和上半月小叶)和小脑蛔虫在少数情况下表现出相对于多数情况下的增加。这种双重分离表明，额叶和小脑区域对认知表现做出了不同的贡献，左侧额叶(和纹状体)的激活反映了反应选择，当有许多适当的反应时，这一点会增加难度；右侧小脑的激活反映了对反应的搜索，当甚至连一个适当的反应都很难提取时，这就增加了难度。(C)1998年学术出版社。
Human brain imaging studies have found that increases in functional activation in left-frontal cortex during cognitive tasks are often accompanied by similar increases in right-cerebellar regions. The present study used functional magnetic resonance imaging (fMRI) 60 investigate the distinctive contributions of these regions using a word stem completion task. Stems with many possible completions (MANY condition) were alternately presented with stems that had few possible completions (FEW condition), and subjects were asked to covertly complete each stem with a word and press a response switch for each successful completion. Prominent increases in activation in the MANY, relative to the FEW, condition were observed in the left middle frontal gyrus (Brodmann areas 9/10) and left caudate nucleus. In contrast, portions of the right-cerebellar hemisphere (posterior quadrangular lobule and superior semilunar lobule) and cerebellar vermis exhibited increases in the FEW, relative to the MANY, condition. This double dissociation suggests that the frontal and cerebellar regions make distinctive contributions to cognitive performance, with left-frontal (and striatal) activations reflecting response selection, which increases in difficulty when there are many appropriate responses, and right-cerebellar activation reflecting the search for responses, which increases in difficulty when even a single appropriate response is hard to retrieve. (C) 1998 Academic Press.