PT  - JOURNAL ARTICLE
AU  - Francesca Siclari
AU  - Joshua J. LaRocque
AU  - Giulio Bernardi
AU  - Bradley R. Postle
AU  - Giulio Tononi
TI  - The neural correlates of consciousness in sleep: A no-task, within-state paradigm
AID  - 10.1101/012443
DP  - 2014 Jan 01
TA  - bioRxiv
PG  - 012443
4099  - http://biorxiv.org/content/early/2014/12/30/012443.short
4100  - http://biorxiv.org/content/early/2014/12/30/012443.full
AB  - What are the neural correlates of consciousness? Studies that have addressed this question in the past either compared neural activity during tasks in which subjects report perceiving a stimulus or not, or have contrasted conscious wakefulness with unconscious sleep or anesthesia. However, such contrasts may include correlates of stimulus processing, response preparation or of changes in behavioral state, rather than of consciousness per se. To overcome these limitations, we developed a no-task, within-state paradigm in which sleeping subjects recorded with high density-EEG reported retrospectively whether they had been conscious or not. We identified specific frontal and parieto-occipital regions showing EEG changes several seconds preceding awakenings that distinguished between reports of consciousness and unconsciousness. While decreased parieto-occipital low-frequency activity was associated with highly perceptual experiences, increased frontal high-frequency activity was associated with highly thought-like experiences. Finally, we identified localized, content-specific activations for faces, spatial setting, movement and speech experienced in dreams.