In visual working memory, cross-frequency synchrony is a novel mechanism for connecting fast and slow brain rhythm networks

9.11.2016
Docent Satu Palva’s research group from the Neuroscience Center have studied neuronal mechanisms that may underlie the integration and coordination of neuronal processing across slow and fast brain rhythm i.e. oscillatory networks in relation to the visual working memory in human brain networks. Palva’s group found a novel mechanism that can connect fast and slow oscillatory networks. The study was published on Elife journal in September 2016.

Human cognitive functions, including visual working memory, are subjectively coherent, such that we memorize coherent images not their components, of prior events.  However neuronal processing underlying working memory takes place concurrently in many brain areas in which brain rhythms - oscillations- in many frequencies are ubiquitous and characterize processing. Fast oscillatory synchronization is thought to integrate the processing of visual information in the visual system of the brain whereas slower oscillatory synchronization is thought to coordinate executive functions in the frontal and parietal brain areas.

– A key challenge has been to understand which mechanisms integrate neuronal processing across fast and slow oscillatory networks and thereby the sensory and executive functions, explains Palva.

Using concurrent magneto- and electroencephalography (MEG and EEG), Palva’s group found a novel mechanism that can connect fast and slow oscillatory networks. During visual working memory, fast and slow oscillatory networks in sensory and frontoparietal brain areas became connected via cross-frequency phase synchronization. 

– Our finding may explain how processing between distinct brain rhythms carrying out distinct computational functions may be integrated, summarizes Satu Palva.

Original article

Siebenhühner F, Wang SH, Palva JM, Palva S. Cross-frequency synchronization connects networks of fast and slow oscillations during visual working memory maintenance. Elife. 2016 Sep 26;5. pii: e13451. DOI: http://dx.doi.org/10.7554/eLife.13451

Contact info
 

Docent Satu Palva, satu.palva@helsinki.fi, tel. +258 50 4484742
Neuroscience Center

 

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