MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
Perception in Action Research Centre, Department of Cognitive Science, Macquarie University, Sydney, NSW, Australia.
Commun Biol. 2021 May 17;4(1):588. doi: 10.1038/s42003-021-02109-x.
Dorsolateral prefrontal cortex (dlPFC) is proposed to drive brain-wide focus by biasing processing in favour of task-relevant information. A longstanding debate concerns whether this is achieved through enhancing processing of relevant information and/or by inhibiting irrelevant information. To address this, we applied transcranial magnetic stimulation (TMS) during fMRI, and tested for causal changes in information coding. Participants attended to one feature, whilst ignoring another feature, of a visual object. If dlPFC is necessary for facilitation, disruptive TMS should decrease coding of attended features. Conversely, if dlPFC is crucial for inhibition, TMS should increase coding of ignored features. Here, we show that TMS decreases coding of relevant information across frontoparietal cortex, and the impact is significantly stronger than any effect on irrelevant information, which is not statistically detectable. This provides causal evidence for a specific role of dlPFC in enhancing task-relevant representations and demonstrates the cognitive-neural insights possible with concurrent TMS-fMRI-MVPA.
背外侧前额叶皮层（dlPFC）被认为通过偏向于任务相关信息的处理来驱动全脑聚焦。一个长期存在的争论是，这是通过增强相关信息的处理还是通过抑制无关信息来实现的。为了解决这个问题，我们在 fMRI 期间应用了经颅磁刺激（TMS），并测试了信息编码的因果变化。参与者关注视觉对象的一个特征，同时忽略另一个特征。如果 dlPFC 对于促进是必要的，那么破坏性 TMS 应该会降低对关注特征的编码。相反，如果 dlPFC 对抑制至关重要，那么 TMS 应该会增加对忽略特征的编码。在这里，我们表明 TMS 降低了整个额顶叶皮层中相关信息的编码，并且这种影响明显强于对无关信息的任何影响，后者在统计上不可检测。这为 dlPFC 在增强任务相关表示方面的特定作用提供了因果证据，并展示了具有并发 TMS-fMRI-MVPA 的认知神经学见解。
