Cingulate oscillatory activity reflects the quality of memory representations in visuospatial working memory

The human brain has the high likelihood for committing errors when confronted by a day-to-day situation that demands to process more than four integrated items in working memory, for example driving a car to a new destination in high traffic. However, neural mechanisms underlying the response outcome in working memory is still unclear. High temporal resolution and improved spatial resolution of dense array electroencephalogram (EEG) make it an ideal tool to investigate the dynamics of brain networks. In the present study, the brain activity of twenty healthy male volunteers was investigated during correct and error trials of visuospatial working memory task using dense array EEG. Independent brain components were identified using independent component analysis (ICA). Event-related spectral perturbations (ERSP) were computed for each independent component using Morlet wavelet transform for the frequency range of 3-70 Hz. ERSP of independent component clusters identified using K-means algorithm were statistically compared between correct and error trials. Delta and theta power increased in the component cluster located at cingulate gyrus before the error response of visuospatial working memory task. The current study findings suggest that cingulate oscillatory activity might reflect the quality of memory representation and intensity of target uncertainty during the visuospatial search.