Consciously and subliminally processed information can both lead to conflicts that hinder goal-directed behaviour. Conflict monitoring processes are required to cope with situations where one or multiple conflicts occur. It has been suggested, that medial-frontal theta oscillations are associated with the implementation of cognitive control and that conflicts increase theta band activity. Still, a causal mechanistic understanding of theta oscillations during the resolution of combined subliminal and conscious conflicts is missing. To investigate this, we combined EEG signal decomposition methods with EEG beamforming approaches and used the obtained information to modulate theta oscillations with tACS in a second experiment. This showed that theta oscillations in the superior frontal cortex (BA6) and the left paracentral lobule encoded stimulus-related processes during the resolution of conflicts arising from both conscious and subliminal information processing. Response selection and motor-related processes encoded by theta oscillations were not similarly modulated. Thus, the joint modulation of conflicts by conscious and subliminal information affects very specific aspects of the information coded in theta oscillations. Results indicate, that entraining theta-oscillations using tACS modulates conflict resolution depending on the already existing theta activity level. In summary, the study provides further evidence that frontal theta oscillations play a crucial role in conflict monitoring and control.

意识地和潜移默化地处理信息都可能导致冲突，从而阻碍目标导向的行为。需要使用冲突监视过程来应对发生一个或多个冲突的情况。已经提出，内侧-额叶θ振荡与认知控制的实施有关，并且冲突增加θ带活动。仍然，在解决潜意识和意识冲突相结合的过程中，对θ振荡的因果机理缺乏了解。为了对此进行研究，我们在第二个实验中将EEG信号分解方法与EEG波束形成方法结合起来，并使用获得的信息通过tACS来调制theta振荡。这表明在解决由意识和潜意识信息处理引起的冲突时，上额叶皮层（BA6）和左中叶旁小叶的θ振荡编码了与刺激相关的过程。响应选择和由theta振荡编码的与电机相关的过程未得到类似的调制。因此，有意识和潜意识信息对冲突的联合调制会影响以θ振荡编码的信息的非常具体的方面。结果表明，使用tACS引诱theta振荡会根据已经存在的theta活动水平来调节冲突解决方案。总而言之，该研究提供了进一步的证据，表明额叶theta振荡在冲突监控中起着至关重要的作用。