title: Cascades and cognitive state: focused attention incurs subcritical dynamics.
abstract: The analysis of neuronal avalanches supports the hypothesis that the human cortex operates with critical neural dynamics. Here, we investigate the relationship between cascades of activity in electroencephalogram data, cognitive state, and reaction time in humans using a multimodal approach. We recruited 18 healthy volunteers for the acquisition of simultaneous electroencephalogram and functional magnetic resonance imaging during both rest and during a visuomotor cognitive task. We compared distributions of electroencephalogram-derived cascades to reference power laws for task and rest conditions. We then explored the large-scale spatial correspondence of these cascades in the simultaneously acquired functional magnetic resonance imaging data. Furthermore, we investigated whether individual variability in reaction times is associated with the amount of deviation from power law form. We found that while resting state cascades are associated with approximate power law form, the task state is associated with subcritical dynamics. Furthermore, we found that electroencephalogram cascades are related to blood oxygen level-dependent activation, predominantly in sensorimotor brain regions. Finally, we found that decreased reaction times during the task condition are associated with increased proximity to power law form of cascade distributions. These findings suggest that the resting state is associated with near-critical dynamics, in which a high dynamic range and a large repertoire of brain states may be advantageous. In contrast, a focused cognitive task induces subcritical dynamics, which is associated with a lower dynamic range, which in turn may reduce elements of interference affecting task performance.
authors: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom, e.fagerholm03@imperial.ac.uk.
authors: Erik D
authors: ED
authors: Fagerholm
authors: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom.
authors: Romy
authors: R
authors: Lorenz
authors: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom.
authors: Gregory
authors: G
authors: Scott
authors: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom.
authors: Martin
authors: M
authors: Dinov
authors: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom.
authors: Peter J
authors: http://orcid.org/0000-0002-5139-3401
authors: PJ
authors: Hellyer
authors: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom.
authors: Nazanin
authors: N
authors: Mirzaei
authors: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom.
authors: Clare
authors: C
authors: Leeson
authors: Imaging and Biophysics, UCL Institute of Child Health, London WC1N 1EH, United Kingdom, and.
authors: David W
authors: http://orcid.org/0000-0001-9972-0718
authors: DW
authors: Carmichael
authors: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom.
authors: David J
authors: DJ
authors: Sharp
authors: University of Arkansas, Department of Physics, Fayetteville, Arkansas 72701.
authors: Woodrow L
authors: WL
authors: Shew
authors: The Computational, Cognitive and Clinical Neuroimaging Laboratory, The Centre for Neuroscience, The Division of Brain Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, United Kingdom.
authors: Robert
authors: http://orcid.org/0000-0002-5801-6318
authors: R
authors: Leech
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: EEG; attention; criticality; fMRI; power law