Spatial and temporal working memory identified by distinct oscillatory activity

Working Memory (WM) represents our ability to process information and guide future behavior (Baddeley, 1992). Several studies have investigated brain activity associated with spatial WM in humans and primates, while few have focused on the neural mechanisms of WM for temporal order information, and on the possible distinct neural resources employed in the processing of temporal and spatial information. Available evidence indicates that similar fronto-parietal regions are recruited during temporal and spatial WM, although there are data suggesting that they are distinct processes. The mechanisms that allow for differential maintenance of these two types of information are unclear.
One possibility is that neural oscillations may differentially contribute to temporal and spatial WM (Gmeindl et al., 2011; Delogu et al., 2012). In a pioneer study on this topic, Roberts and colleagues (Roberts and al., 2013) used scalp electroencephalography (EEG) to compare patterns of oscillatory activity during maintenance of spatial and temporal information in WM using the very same items for different WM modalities. This study represents the first step in distinct mechanisms for the maintenance of temporal and spatial information in WM. We plan to implement the same stimulus material in MEG settings, which facilitates the visibility of gamma band components, and provides a better source reconstruction in order to allow seed-based connectivity analysis. The characterization of the circuitry orchestrating the working memory processing of spatial and temporal information opens the venue to stimulation studies targeting specific nodes of the network and modulating the single individual performance.

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Project Leader - Tommaso Fedele.