Functional Organization of the Brain during the Operation of Working Memory

Event-related potentials (ERPs) recorded from various cortical areas during matching of two consecutive pictures were analyzed. Reflecting the process of trace fixation, the ERP to the reference stimulus was characterized by an increase in components P150 and P300 in the occipital and temporo-parieto-occipital areas and components N300 and N400 in the precentral areas as compared with the ERP elicited by the warning stimulus. The ERP to the test stimulus, which reflected trace retrieval and matching with current information, was characterized by a generalized increase in the late positive complex in the interval 300–600 ms. Similarity and/or dissimilarity of the test and reference stimuli was reflected in the parameters of the ERP to the test stimulus. The results testify to the difference in functional and topographic organization of the brain cortex at the initial and late stages of operation of the working memory.