Cerebral cortex (New York, N.Y. : 1991)
June 30, 2020
Andrés Canales-Johnson, Alexander J Billig, Francisco Olivares et al.
51 citations
During auditory bistable perception, a sequence of tones can be heard either as a single stream (integrated percept) or as two parallel streams (differentiated percept). Neural recordings showed that when perceptual alternations arose spontaneously, the integrated percept corresponded to increased neural information integration and decreased neural information differentiation across frontoparietal regions, while the differentiated percept showed the opposite pattern. When perception was driven by an external change in the sound stream, neural oscillatory power distinguished between percepts but information measures did not. The findings demonstrate that integration and differentiation of conscious perception map onto theoretically motivated neural information signatures, suggesting a direct link between phenomenology and neurophysiology.
Cerebral cortex (New York, N.Y. : 1991)
August 1, 2024
Evan Lewis-Healey, Enzo Tagliazucchi, Andrés Canales-Johnson et al.
27 citations
Intentional breathing techniques (breathwork) can induce altered states of consciousness similar to those produced by psychedelics. By tracking subjective experiences moment-by-moment alongside portable EEG recordings across 301 sessions from 14 novice participants, researchers found that psychedelic-like experiences—especially intense bliss—corresponded with increased neural complexity (Lempel-Ziv complexity) and changes in the aperiodic exponent of brain activity, but not with alpha brainwave power. These non-linear neural features map onto both broad positive experiences and specific psychedelic-like states, suggesting breathwork alters consciousness through mechanisms distinct from simple relaxation or meditation.
The European journal of neuroscience
March 1, 2022
Claudia Pascovich, Santiago Castro-Zaballa, Pedro A M Mediano et al.
16 citations
Neural complexity, measured by the Lempel-Ziv (LZ) compression algorithm, is lowest during NREM sleep and similar during REM sleep and wakefulness in cats with intracranial electrodes. Under subanaesthetic doses of ketamine (5, 10, and 15 mg/kg), complexity follows an inverted U-shaped curve in some electrodes, primarily in prefrontal cortex, rising at low doses and falling as doses approach anaesthetic levels. The variability in the ketamine dose-response curve across cats and cortices was larger than across sleep stages, highlighting differential local dynamics. These results replicate findings in humans and other species, showing neural complexity is sensitive to changes in conscious state.