Department of Psychology, University of California San Diego, La Jolla, California 92093, USA.
J Neurosci. 2013 Aug 14;33(33):13259-69. doi: 10.1523/JNEUROSCI.5651-12.2013.
In the welter of everyday life, people can stop particular response tendencies without affecting others. A key requirement for such selective suppression is that subjects know in advance which responses need stopping. We hypothesized that proactively setting up and implementing selective suppression relies on the basal ganglia and, specifically, regions consistent with the inhibitory indirect pathway for which there is scant functional evidence in humans. Consistent with this hypothesis, we show, first, that the degree of proactive motor suppression when preparing to stop selectively (indexed by transcranial magnetic stimulation) corresponds to striatal, pallidal, and frontal activation (indexed by functional MRI). Second, we demonstrate that greater striatal activation at the time of selective stopping correlates with greater behavioral selectivity. Third, we show that people with striatal and pallidal volume reductions (those with premanifest Huntington's disease) have both absent proactive motor suppression and impaired behavioral selectivity when stopping. Thus, stopping goals are used to proactively set up specific basal ganglia channels that may then be triggered to implement selective suppression. By linking this suppression to the striatum and pallidum, these results provide compelling functional evidence in humans of the basal ganglia's inhibitory indirect pathway.
在日常生活的喧嚣中，人们可以阻止特定的反应倾向而不影响他人。这种选择性抑制的一个关键要求是，受试者事先知道需要停止哪些反应。我们假设，主动建立和实施选择性抑制依赖于基底神经节，特别是与抑制性间接通路一致的区域，而人类对此通路的功能证据很少。与这一假设一致，我们首先表明，在选择性停止（经颅磁刺激索引）时主动进行运动抑制的程度与纹状体、苍白球和额叶的激活（功能磁共振成像索引）相对应。其次，我们证明，在选择性停止时纹状体的激活程度越大，行为选择性越强。第三，我们发现，纹状体和苍白球体积减小的人（有前期亨廷顿病的人）在停止时既没有主动的运动抑制，也没有受损的行为选择性。因此，停止目标被用来主动建立可能触发选择性抑制的特定基底神经节通道。通过将这种抑制与纹状体和苍白球联系起来，这些结果为人类基底神经节的抑制性间接通路提供了令人信服的功能证据。
