Experimental Neuropsychology Research Unit, School of Psychology and Psychiatry, Monash University, Clayton 3800, Victoria, Australia.
Brain Cogn. 2012 Aug;79(3):200-8. doi: 10.1016/j.bandc.2012.02.011. Epub 2012 Apr 28.
The present study applied the Simon effect task to examine the pattern of functional brain reorganization in individuals with Friedreich ataxia (FRDA), using functional magnetic resonance imaging (fMRI). Thirteen individuals with FRDA and 14 age and sex matched controls participated, and were required to respond to either congruent or incongruent arrow stimuli, presented either to the left or right of a screen, via laterally-located button press responses. Although the Simon effect (incongruent minus congruent stimuli) showed common regions of activation in both groups, including the superior and middle prefrontal cortices, insulae, superior and inferior parietal lobules (LPs, LPi), occipital cortex and cerebellum, there was reduced functional activation across a range of brain regions (cortical, subcortical and cerebellar) in individuals with FRDA. The greater Simon effect behaviourally in individuals with FRDA, compared with controls, together with concomitant reductions in functional brain activation and reduced functional connectivity between cortical and sub-cortical regions, implies a likely disruption of cortico-cerebellar loops and ineffective engagement of cognitive/attention regions required for response suppression.
本研究应用 Simon 效应任务，使用功能磁共振成像（fMRI）来检测弗里德赖希共济失调（FRDA）个体的功能脑重组模式。13 名 FRDA 患者和 14 名年龄和性别匹配的对照组参与了研究，要求他们通过位于屏幕两侧的按钮来响应左侧或右侧呈现的一致或不一致的箭头刺激。尽管 Simon 效应（不一致刺激减去一致刺激）在两组中均显示出共同的激活区域，包括额上和额中前皮质、脑岛、顶上和顶下小叶（LP、LPi）、枕叶皮质和小脑，但 FRDA 患者的一系列脑区（皮质、皮质下和小脑）的功能激活减少。与对照组相比，FRDA 患者的 Simon 效应行为更大，同时伴随着功能脑激活的减少和皮质与皮质下区域之间功能连接的减少，这表明可能存在皮质-小脑回路的破坏以及对反应抑制所需的认知/注意区域的无效参与。
