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

人类的行为是基于根据内部目标和外部环境需求做出的决定，后者主要是通过感觉加工来感知的。当目标无关的自动信息或优势信息在行为选择中干扰目标相关信息时，即当与任务无关的刺激特征与不同于当前任务教学所需的反应相关联时，就需要认知控制。刺激-反应映射的这种不匹配导致了不相容的反应倾向之间的冲突，这阻碍了正常的、目标导向的行为。认知控制系统克服这种干扰以实现冲突解决的机制仍然不完全清楚。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调节能力。因此，认知控制功能将在外部诱导冲突(见上文)和与反应错误相关的内部冲突情况下被检验。为此，在同时进行NIRS/EEG测量期间，将应用引起冲突的面部Stroop任务以及通常用于研究错误处理的改进的Eriksen侧翼任务。此外，在促进和抑制方案方面，将通过经颅磁刺激(TMS)对区域皮质区域进行有针对性的调制。使用这种方法的组合，我们计划1)通过实验确认背外侧前额叶皮质(DLPFC)是神经网络中的关键结构，不仅在感觉干扰之后，而且在反应错误造成的干扰之后，冲突适应也是潜在的；2)澄清认知控制系统适应信息处理以解决冲突的确切(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可能表现出认知控制缺陷的健康风险人群的神经靶结构(3)。为此，将使用一种促进TMS的方案来调节高度冲动受试者的前额叶功能，目的是通过这样加强的认知控制系统来改善冲突解决。对于直接假设检验，抑制性TMS将被用来暂时扰乱健康对照组的正常额叶功能，并将确定冲突适应对神经和行为的影响。使用这种包括抑制性和促进性挑战干预的双向方法，结合神经成像方法，我们将在人类认知控制的神经基础和功能机制以及表现出前额叶控制缺陷的神经精神风险人群中它们的调节能力方面提供重要的新数据。

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.