Cognitive control and the prefrontal cortex: Functional measurements and effects of neuromodulation in healthy controls and a highly-impulsive risk population

人类行为是基于根据内部目标和外部环境需求做出的决定，后者主要是通过感官处理来感知的。当与目标无关的自动或优势信息干扰行为选择中的目标相关信息时，需要认知控制，即，当与任务无关的刺激特征与不同于当前任务指令所必需的响应的响应相关联时。这种刺激-反应映射的不匹配导致了不相容的反应倾向之间的冲突，阻碍了正常的目标导向行为。认知控制系统克服这种干扰以实现冲突解决的机制仍然没有完全理解。因此，该项目旨在进一步阐明人类认知控制的神经过程及其在健康受试者和神经认知风险人群中的可调节性。因此，认知控制功能将被检查后，外部引起的冲突（见上文）和内部冲突的情况下，有关的反应错误。为此，在同时进行NIRS/EEG测量期间，将应用冲突诱导面部Stroop任务以及通常用于研究错误处理的修改后的Eriksen Flanker任务。此外，通过经颅磁刺激（TMS）的区域皮质区的有针对性的调制将在促进和抑制协议。使用这种方法的组合，我们计划：1）实验证实背外侧前额叶皮层（DLPFC）作为神经网络内的关键结构，不仅在感觉干扰之后，而且在反应错误产生的干扰之后，也是冲突适应的基础; 2）澄清认知控制系统以冲突解决为目的调整信息处理的确切（神经）机制。在最后一步中，我们计划利用所获得的发现来选择性地影响表现出认知控制缺陷的健康风险人群中的神经靶结构（3）。为此，一个促进TMS协议将被用来调节前额叶功能在高度冲动的科目，通过由此加强认知控制系统的目的是改善冲突解决。对于直接假设检验，抑制性TMS将相反地用于暂时破坏健康对照组中的正常额叶功能，并且将确定对冲突适应的神经和行为相关性的影响。使用这种双向的方法，包括抑制和促进挑战干预结合神经影像学方法，我们将贡献重要的新数据的神经基板和功能机制的基础上的认知控制在人类以及他们的调制性神经精神风险人群表现出前额叶控制缺陷。

Human behaviour is based on decisions made in accordance with both internal goals and external environmental demands, the latter of which are largely perceived via sensory processing. Cognitive control is needed when goal-irrelevant automatic or prepotent information interferes with goal-relevant information in the selection of behaviour, i.e., when task-irrelevant stimulus features are associated with a response different from the one necessary for the current task instruction. This mismatch in stimulus-response mappings causes a conflict between incompatible response tendencies that hampers normal, goal-oriented behaviour. The mechanisms via which the cognitive control system overcomes this interference to achieve conflict resolution are still not completely understood. This project, therefore, aims at further elucidating the neural processes underlying cognitive control in humans and their modulability in both healthy subjects and neurocognitive risk populations. Thereby, cognitive control function will be examined after both externally induced conflict (see above) and internal conflict situations related to response errors. To this end, a conflict-inducing facial Stroop task as well as a modified Eriksen Flanker task commonly used to study error processing will be applied during simultaneous NIRS/EEG measurements. Moreover, a targeted modulation of regional cortical areas via transcranial magnetic stimulation (TMS) will be employed in terms of both facilitating and inhibitory protocols. Using this combination of methods, we plan to 1) experimentally confirm the dorsolateral prefrontal cortex (DLPFC) as a key structure within the neural network underlying conflict-adaptation not only following sensory interference, but also interference created by response errors; and 2) clarify the exact (neural) mechanisms via which the cognitive control system adapts information processing with the aim of conflict resolution. In a last step, we then plan to utilize the gained findings to selectively impact neural target structures in a healthy risk population putatively exhibiting cognitive control deficits (3). To this end, a facilitating TMS protocol will be used to modulate prefrontal functioning in highly-impulsive subjects, with the aim of improved conflict resolution via a thusly strengthened cognitive control system. For direct hypothesis testing, inhibitory TMS will conversely be used to temporarily disrupt normal frontal lobe function in a healthy control group, and effects on neural as well as behavioural correlates of conflict-adaptation will be determined. Using this bi-directional approach involving both inhibitory and facilitating challenge interventions in combination with neuroimaging methods, we will contribute important new data on the neural substrates and functional mechanisms underlying cognitive control in humans as well as their modulability in neuropsychiatric risk populations exhibiting prefrontal control deficits.