McGill University, Montreal, Quebec, Canada.
The Hong Kong Polytechnic University.
J Cogn Neurosci. 2021 Aug 1;33(9):1784-1797. doi: 10.1162/jocn_a_01652.
The frontal lobes have long been implicated in inhibitory control, but a full understanding of the underlying mechanisms remains elusive. The stop-signal task has been widely used to probe instructed response inhibition in cognitive neuroscience. The processes involved have been modeled and related to putative brain substrates. However, there has been surprisingly little human lesion research using this task, with the few existing studies implicating different prefrontal regions. Here, we tested the effects of focal prefrontal damage on stop-signal task performance in a large sample of people with chronic focal damage affecting the frontal lobes (n = 42) and demographically matched healthy individuals (n = 60). Patients with damage to the left lateral, right lateral, dorsomedial, or ventromedial frontal lobe had slower stop-signal RT compared to healthy controls. There were systematic differences in the patterns of impairment across frontal subgroups: Those with damage to the left or right lateral and dorsomedial frontal lobes, but not those with ventromedial frontal damage, were slower than controls to "go" as well as to stop. These findings suggest that multiple prefrontal regions make necessary but distinct contributions to stop-signal task performance. As a consequence, stop-signal RT slowing is not strongly localizing within the frontal lobes.
额叶一直被认为与抑制控制有关，但对于其潜在机制仍难以捉摸。停止信号任务已被广泛用于探索认知神经科学中的指令反应抑制。所涉及的过程已经被建模并与假定的大脑底物相关联。然而，使用此任务的人类病变研究却少之又少，少数现有研究表明涉及不同的前额叶区域。在这里，我们在一个影响额叶的慢性局灶性损伤的大样本人群中（n = 42）和在人口统计学上匹配的健康个体（n = 60）中测试了局灶性前额叶损伤对停止信号任务表现的影响。与健康对照组相比，左侧、右侧、背内侧或腹内侧额叶损伤的患者停止信号 RT 更慢。在额叶亚组之间存在损伤模式的系统差异：那些左侧或右侧以及背内侧额叶损伤的患者，而不是腹内侧额叶损伤的患者，不仅停止信号反应变慢，“go”信号反应也变慢。这些发现表明多个前额叶区域对停止信号任务表现做出了必要但不同的贡献。因此，停止信号 RT 减慢并不是在额叶内部强烈定位的。
