School of Psychology, Georgia Institute of Technology, 654 Cherry Street, Atlanta, GA 30332, USA.
Psychol Res. 2011 Nov;75(6):499-512. doi: 10.1007/s00426-011-0369-9. Epub 2011 Aug 28.
The neurocognitive architecture for response selection is uncertain. Some theorists suggest that it is mediated by an amodal central mechanism, whereas others propose a set of independent control mechanisms. In a functional neuroimaging experiment, we investigated the nature of response selection by examining how its underlying brain mechanisms are affected by stimulus modality. To do this, we used a modified flanker task, in which the target and flanker (distractor) stimuli differed in time rather than space, making it accessible for both visual and auditory stimuli. As in the traditional flanker task, larger reaction times were observed for incongruent than congruent trials (i.e., a congruency effect) for both modalities. Congruency affected brain activation for both modalities in prefrontal cortex, parietal cortex, and the putamen. Modality-dependent activation was found in additional prefrontal and parietal regions for the visual modality and in left inferior prefrontal cortex for the auditory modality. Modality-dependent activity specifically related to response congruency was also found in sensory cortical regions. These data suggest that modality affects the brain regions throughout the cortex mediating response selection even for conceptually identical stimuli and tasks. They are consistent with the hypothesis that (at least partially) independent brain networks mediate response selection and that input modality may be a powerful factor for organizing neural activity to support task performance.
反应选择的神经认知架构尚不确定。一些理论家认为它是由一个非模态的中央机制介导的，而另一些人则提出了一组独立的控制机制。在一项功能神经影像学实验中，我们通过检查其潜在的大脑机制如何受到刺激模式的影响来研究反应选择的性质。为此，我们使用了一种改良的侧翼任务，其中目标和侧翼（干扰）刺激在时间上而不是空间上有所不同，这使得视觉和听觉刺激都可以使用。与传统的侧翼任务一样，对于两种模态，不一致的试验比一致的试验观察到更长的反应时间（即，一致性效应）。一致性对两种模态的前额叶皮层、顶叶皮层和纹状体的大脑激活都有影响。对于视觉模态，在前额叶和顶叶的额外区域发现了与模态相关的激活，对于听觉模态，在左侧下前额叶皮层也发现了与模态相关的激活。在感觉皮层区域还发现了与反应一致性具体相关的模态依赖性活动。这些数据表明，即使对于概念上相同的刺激和任务，模态也会影响介导反应选择的整个皮层中的大脑区域。它们与假设一致，即（至少部分）独立的大脑网络介导反应选择，并且输入模态可能是组织神经活动以支持任务表现的有力因素。
