Brain Mechanisms of Storing Visual Images in the Working Memory

Abstract

The EEG-experiment consisted of four series in which 18 subjects were given identical sets of stimuli (patterns of coloured squares) under different instructions: either to look at the stimuli, to memorise them, to find the stimulus's element that was previously displayed to them, or to count the stimuli. The evoked potentials of the brain were recorded; for each series the co-ordinates of the dynamic equivalent dipoles were calculated; they were superposed with the subjects' MRI-tomogramms. In the series, in which the subject had to memorise and retain the image of the stimulus, the prefrontal areas 9 and 10 were activated, which did not occur in other series. There is a high correlation between the activity of the prefrontal area 10 and the visual area V3 (R=0.81), and between the activity of the area 9 and the area V4 (R=0.99). On the basis of these results, the author suggests a psychophysiological model of storing visual information in the working memory.