The brain’s default state interacts with working memory processes in a complex and load-dependent manner

Bänninger, Anja; Schläpfer, Anthony; Brandeis, Daniel; König, Thomas (24 January 2014). The brain’s default state interacts with working memory processes in a complex and load-dependent manner (Unpublished). In: Joint Annual Meeting Clinical Neuroscience Bern and SSN. University of Bern. 24.-25.01.2014.

Recently, many studies about a network active during rest and deactivated during tasks emerged in the literature: the default mode network (DMN). Spatial and temporal DMN features are important markers for psychiatric diseases. Another prominent indicator of cognitive functioning, yielding information about the mental condition in health and disease, is working memory (WM) processing. In EEG studies, frontal-midline theta power has been shown to increase with load during WM retention in healthy subjects. From these findings, the conclusion can be drawn that an increase in resting state DMN activity may go along with an increase in theta power in high-load WM conditions.
We followed this hypothesis in a study on 17 healthy subjects performing a visual Sternberg WM task. The DMN was obtained by a BOLD-ICA approach and its dynamics represented by the percent-strength during pre-stimulus periods. DMN dynamics were temporally correlated with EEG theta spectral power from retention intervals. This so-called covariance mapping yielded the spatial distribution of the theta EEG fluctuations associated with the dynamics of the DMN.
In line with previous findings, theta power was increased at frontal-midline electrodes in high- versus low-load conditions during early WM retention. However, load-dependent correlations of DMN with theta power resulted in primarily positive correlations in low-load conditions, while during high-load conditions negative correlations of DMN activity and theta power were observed at frontal-midline electrodes. This DMN-dependent load effect reached significance during later retention.
Our results show a complex and load-dependent interaction of pre-stimulus DMN activity and theta power during retention, varying over the course of the retention period. Since both, WM performance and DMN activity, are markers of mental health, our results could be important for further investigations of psychiatric populations.

Item Type:

Conference or Workshop Item (Poster)

Division/Institute:

04 Faculty of Medicine > University Psychiatric Services > University Hospital of Psychiatry and Psychotherapy > Psychiatric Neurophysiology [discontinued]
04 Faculty of Medicine > University Psychiatric Services > University Hospital of Psychiatry and Psychotherapy

UniBE Contributor:

Bänninger, Anja Katharina, König, Thomas

Subjects:

100 Philosophy > 150 Psychology
600 Technology > 610 Medicine & health

Language:

English

Submitter:

Mara Kottlow

Date Deposited:

29 Jan 2015 11:13

Last Modified:

02 Mar 2023 23:25

URI:

https://boris.unibe.ch/id/eprint/62213

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