Brain Networks of Maintenance, Inhibition and Disinhibition during Working Memory

Working memory (WM) - one of the brain ability that maintains information - can evaluate the function of brain. Activities related to memory sustention, inhibition and disinhibition have gathered significant attention for the basic neurocognitive architecture. Although researchers have proposed some brain models that attempt to explain the entire procedure of WM, little evidence can proof and describe it, and more particularly, regions and structures of maintenance, inhibition and disinhibition require more investigation. We used phase lock coherence and general partial directed coherence to construct connections among four adaptively fitted EEG sources, and we also applied previous published models to describe the brain circuits of maintenance, inhibition and disinhibition. Referring to a classical visual n-back paradigm, we recruited forty five mental health undergraduates in this experiment. We found that the bilateral prefrontal cortex (PFC) mainly focused on some cognitive components, for example, rehearsal before recognition to classify objects, inhibition to maintain positive memory and activities, and disinhibition to arouse or activate subsequent interactions in brain. Meanwhile, the right PFC sometimes could assist left PFC to implement high capacity WM tasks. By contrast, the posterior regions, PPC, tends to be engaged in attention arousing and maintaining. These two findings suggest that a) the recurrent maintenance circuit may keep the brain executing positive cognitive components, b) then the instantly monitoring inhibition would pause the deadlocked sustention function to save energy, and c) the arriving of disinhibition arouses the next step in brain to select new subject or focus on novel subjects.