Swick Diane, Ashley Victoria, Turken And U
Research Service, Veterans Affairs Northern California Health Care System, Martinez, CA 94553, USA.
BMC Neurosci. 2008 Oct 21;9:102. doi: 10.1186/1471-2202-9-102.
Lesion studies in human and non-human primates have linked several different regions of prefrontal cortex (PFC) with the ability to inhibit inappropriate motor responses. However, recent functional neuroimaging studies have specifically implicated right inferior PFC in response inhibition. Right frontal dominance for inhibitory motor control has become a commonly accepted view, although support for this position has not been consistent. Particularly conspicuous is the lack of data on the importance of the homologous region in the left hemisphere. To investigate whether the left inferior frontal gyrus (IFG) is critical for response inhibition, we used neuropsychological methodology with carefully characterized brain lesions in neurological patients.
Twelve individuals with damage in the left IFG and the insula were tested in a Go/NoGo response inhibition task. In alternating blocks, the difficulty of response inhibition was easy (50% NoGo trials) or hard (10% NoGo trials). Controls showed the predicted pattern of faster reaction times and more false alarm errors in the hard condition. Left IFG patients had higher error rates than controls in both conditions, but were more impaired in the hard condition, when a greater degree of inhibitory control was required. In contrast, a patient control group with orbitofrontal cortex lesions showed intact performance.
Recent neuroimaging studies have focused on a highly specific association between right IFG and inhibitory control. The present results indicate that the integrity of left IFG is also critical for successful implementation of inhibitory control over motor responses. Our findings demonstrate the importance of obtaining converging evidence from multiple methodologies in cognitive neuroscience.
对人类和非人类灵长类动物的损伤研究已将前额叶皮层（PFC）的几个不同区域与抑制不适当运动反应的能力联系起来。然而，最近的功能神经影像学研究特别指出右下前额叶皮层与反应抑制有关。尽管对这一观点的支持并不一致，但右额叶在抑制性运动控制方面占主导地位已成为一种普遍接受的观点。特别明显的是，缺乏关于左半球同源区域重要性的数据。为了研究左下额回（IFG）对反应抑制是否至关重要，我们采用神经心理学方法，对神经病患者具有精确特征的脑损伤进行了研究。
对12名左下额回和脑岛受损的个体进行了Go/NoGo反应抑制任务测试。在交替的组块中，反应抑制的难度分为容易（50%不执行试验）或困难（10%不执行试验）。对照组在困难条件下表现出预期的模式，即反应时间更快且虚报错误更多。左下额回患者在两种条件下的错误率均高于对照组，但在需要更高程度抑制控制的困难条件下受损更严重。相比之下，一组眶额叶皮层受损的患者对照组表现正常。
最近的神经影像学研究集中在右下额回与抑制控制之间高度特定的关联上。目前的结果表明，左下额回的完整性对于成功实施对运动反应的抑制控制也至关重要。我们的研究结果证明了在认知神经科学中从多种方法获得汇聚证据的重要性。
