Brain Networks and α-Oscillations: Structural and Functional Foundations of Cognitive Control. Issue 11 (November 2016)

• Record Type: Journal Article
• Authors: Sadaghiani, Sepideh; Kleinschmidt, Andreas
• Is Part Of: Trends in cognitive sciences. Volume 20:Issue 11(2016)
• Page Start: 805
• Page End: 817
• Publication Date: 2016-11
• Subjects: Cognitive science -- Periodicals; Cognitive neuroscience -- Periodicals; 153.05
• DOI: 10.1016/j.tics.2016.09.004
• Languages: English
• ISSNs: 1364-6613

Abstract

Abstract : The most salient electrical signal measured from the human brain is the α-rhythm, neural activity oscillating at ∼100 ms intervals. Recent findings challenge the longstanding dogma of α-band oscillations as the signature of a passively idling brain state but diverge in terms of interpretation. Despite firm correlations with behavior, the mechanistic role of the α-rhythm in brain function remains debated. We suggest that three large-scale brain networks involved in different facets of top-down cognitive control differentially modulate α-oscillations, ranging from power within and synchrony between brain regions. Thereby, these networks selectively influence local signal processing, widespread information exchange, and ultimately perception and behavior. Trends: The α-rhythm causes cyclic inhibition and thereby modulates neural excitability. Cross-frequency coupling is observed between α phase and the power of high-frequency (γ) population activity. The functional impact of α power, phase, and long-range phase synchrony are dissociable. The α-rhythm is actively deployed to serve cognitive processes, and α-oscillations can be modulated by top-down functions. The functional role of the α-rhythm is comparable across different sensory modalities (visual, auditory, somatosensory) and the motor system. Spontaneous variations in α-band power and phase synchrony are related to activity fluctuations in large-scale functional networks (multimodal imaging). Large-scale cognitive control networks may top-down modulate α-oscillations to influence neural excitability and information flow.