β functional connectivity modulation during the maintenance of motion information in working memory: importance of the familiarity of the visual context.

The purpose of this study was to examine whether mechanisms, involved during the maintenance of familiar movement information in memory, were influenced by the degree of familiarity of the display in which the movements were embedded. Twelve gymnasts who possessed high visual and motor familiarity with the movements employed in this study, were recruited. They were invited to retain for a short period of time familiar movements viewed previously and presented under different displays with the aim of recognizing them at a later stage. The first display was a realistic, familiar display which presented videos of movements. The second display was an unfamiliar impoverished display never experienced in every day life which showed point-light movements. Activity during the maintenance period was considered in five frequency bands (4-8 Hz, 8-10 Hz, 10-13 Hz, 13-20 Hz, 20-30 Hz) using a non-linear measure of functional connectivity. The results in the 13-20 Hz frequency band showed that functional connectivity was greater within the frontal and right temporal areas during the unfamiliar display (i.e., point-light maintenance condition) compared to the familiar display (i.e., video maintenance condition). Differences in functional connectivity between the two maintenance conditions in the beta frequency band are mainly discussed in the light of the process of anticipation. Subjects' perception of the expected difficulty of the upcoming recognition task is discussed.