We will later address this issue in detail. This functional inhibition might be a consequence of GABAergic inhibition provided by the interneuronal network. Importantly, this inhibition is reflected by oscillatory activity in the alpha band. We here promote the idea that information is routed by functionally blocking off the task-irrelevant pathways: gating by inhibition (Figure (Figure1C). It has also been proposed that functional connectivity between task-relevant regions is established by oscillatory phase coupling between the sending and receiving region (Bressler, 1995 Varela et al., 2001 Fries, 2005) (Figure (Figure1B). This could be achieved by fast changes in synaptic strength, for instance due to changes in presynaptic vesicle release (Figure (Figure1A). This can be conceptualized as the question of how information is gated from a sending region to one of two receiving regions. Network questions are often addressed by asking how different regions become functionally coupled depending on the task at hand (Friston et al., 1997). This requires fast changes in the functional architecture of the brain network which must rely on dynamic interactions. The human brain is a complex processing device which rapidly adapts to the environment. Given that alpha activity is by far the strongest signal recorded by EEG and MEG, we propose that a major part of the electrophysiological activity detected from the working brain reflects gating by inhibition. In this review we will discuss the empirical support for this framework. Specifically the framework predicts that optimal task performance will correlate with alpha activity in task-irrelevant areas. According to this framework the brain could be studied as a network by investigating cross-frequency interactions between gamma and alpha activity. Active processing in the engaged areas is reflected by neuronal synchronization in the gamma band (30–100 Hz) accompanied by an alpha band decrease. From a physiological perspective the alpha activity provides pulsed inhibition reducing the processing capabilities of a given area. The functional inhibition is reflected in oscillatory activity in the alpha band (8–13 Hz). We here propose that information is gated by inhibiting task-irrelevant regions, thus routing information to task-relevant regions. Filter: M52.0 x 0.In order to understand the working brain as a network, it is essential to identify the mechanisms by which information is gated between regions.Video Output: 3G-SDI x1 / HDMI x1 / CVBS x1.
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