Sleep Neuroimaging and Models of Consciousness
Open Access
- 1 January 2013
- journal article
- review article
- Published by Frontiers Media SA in Frontiers in Psychology
- Vol. 4, 256
- https://doi.org/10.3389/fpsyg.2013.00256
Abstract
Human deep sleep is characterized by reduced sensory activity, responsiveness to stimuli, and conscious awareness. Given its ubiquity and reversible nature, it represents an attractive paradigm to study the neural changes which accompany the loss of consciousness in humans. In particular, the deepest stages of sleep can serve as an empirical test for the predictions of theoretical models relating the phenomenology of consciousness with underlying neural activity. A relatively recent shift of attention from the analysis of evoked responses toward spontaneous (or “resting state”) activity has taken place in the neuroimaging community, together with the development of tools suitable to study distributed functional interactions. In this review we focus on recent functional Magnetic Resonance Imaging (fMRI) studies of spontaneous activity during sleep and their relationship with theoretical models for human consciousness generation, considering the global workspace theory, the information integration theory, and the dynamical core hypothesis. We discuss the venues of research opened by these results, emphasizing the need to extend the analytic methodology in order to obtain a dynamical picture of how functional interactions change over time and how their evolution is modulated during different conscious states. Finally, we discuss the need to experimentally establish absent or reduced conscious content, even when studying the deepest sleep stages.This publication has 69 references indexed in Scilit:
- Hierarchical clustering of brain activity during human nonrapid eye movement sleepProceedings of the National Academy of Sciences of the United States of America, 2012
- Functional MRI of sleep spindles and K-complexesClinical Neurophysiology, 2012
- Dynamic reconfiguration of human brain networks during learningProceedings of the National Academy of Sciences of the United States of America, 2011
- Spontaneous BOLD event triggered averages for estimating functional connectivity at resting stateNeuroscience Letters, 2011
- Time–frequency dynamics of resting-state brain connectivity measured with fMRINeuroImage, 2010
- Thalamic deactivation at sleep onset precedes that of the cerebral cortex in humansProceedings of the National Academy of Sciences of the United States of America, 2010
- Decoupling of the brain's default mode network during deep sleepProceedings of the National Academy of Sciences of the United States of America, 2009
- Cortical network functional connectivity in the descent to sleepProceedings of the National Academy of Sciences of the United States of America, 2009
- Network structure of cerebral cortex shapes functional connectivity on multiple time scalesProceedings of the National Academy of Sciences of the United States of America, 2007
- Theories and measures of consciousness: An extended frameworkProceedings of the National Academy of Sciences of the United States of America, 2006