University of California, Berkeley, USA.
J Cogn Neurosci. 2011 Jan;23(1):1-10. doi: 10.1162/jocn.2010.21516.
Different categories of visual objects evoke distinct stimulus-evoked sensory responses in extrastriate visual cortex. Although numerous lines of evidence support a distinct representational neural architecture, the mechanisms underlying the modulation of the category selectivity by top-down influences remains uncertain. In this study, we investigate the causal role of the PFC in the modulation of evoked activity to face and scene stimuli in the extrastriate cortex. We used two experimental approaches to disrupt prefrontal cortical function-repetitive TMS to PFC in healthy participants (Experiment 1) and focal PFC lesions in stroke patients (Experiment 2). After these perturbations to normal PFC function (pre- vs. post-TMS and lesion vs. intact hemisphere), stimulus-evoked activity in extrastriate cortex exhibited less distinct category selectivity to faces and scenes. These two experiments provide convergent evidence highlighting a direct role of PFC in the top-down modulation of bottom-up visual signals.
不同类别的视觉对象在外侧纹状视觉皮层中引发不同的刺激诱发感觉反应。尽管有大量证据支持独特的代表性神经结构，但由自上而下的影响调节类别选择性的机制仍不确定。在这项研究中，我们研究了 PFC 在调节外侧纹状皮层对面部和场景刺激的诱发活动中的因果作用。我们使用了两种实验方法来破坏前额叶皮层的功能——健康参与者的 PFC 重复 TMS（实验 1）和中风患者的 PFC 局灶性损伤（实验 2）。在对正常 PFC 功能进行这些干扰（TMS 前后和损伤半球与完整半球）之后，外侧纹状皮层的刺激诱发活动对面部和场景的类别选择性降低。这两项实验提供了一致的证据，突出了 PFC 在自上而下调节下的视觉信号中的直接作用。
