Consciousness depends on integration between parietal cortex, striatum and thalamus
M. Afrasiabi, Michelle J. Redinbaugh, Jessica M. Phillips, Niranjan A. Kambi, S. Mohanta, A. Raz, A. Haun, Y. Saalmann
Cell Systems March 12, 2021 DOI: 10.1016/j.cels.2021.02.003 (opens in new tab) via Semantic Scholar
Summary
AI-generated from the abstractThe neural basis of consciousness remains unclear, with competing theories disagreeing on the roles of frontal versus posterior cortex and neglecting subcortical influences. To investigate, researchers recorded neural activity from frontal cortex, parietal cortex, striatum, and thalamus in macaques that were awake, sleeping, or anesthetized, and also used thalamic stimulation to rouse them from anesthesia. A measure capturing neural integration (Φ*) robustly correlated with changes in consciousness, unlike measures targeting complexity alone. Machine learning revealed that parietal cortex, striatum, and thalamus contributed more than frontal cortex to decoding consciousness states. These findings emphasize integration between parietal and subcortical structures and challenge a key role for frontal cortex in consciousness.
Study at a glance
| Characteristics | Observational and experimental study in non-human primates Peer reviewed |
|---|---|
| Population | Macaques |
| Intervention | thalamic stimulation |
| Keywords | Medicine Biology |
| Key finding | A measure of neural integration (Φ*) robustly correlated with changes in consciousness, and parietal cortex, striatum, and thalamus contributed more than frontal cortex to decoding differences in consciousness. |
Abstract
SUMMARY: The neural substrates of consciousness remain elusive. Competing theories that attempt to explain consciousness disagree on the contribution of frontal versus posterior cortex and omit subcortical influences. This lack of understanding impedes the ability to monitor consciousness, which can lead to adverse clinical consequences. To test substrates and measures of consciousness, we recorded simultaneously from frontal cortex, parietal cortex and subcortical structures, the striatum and thalamus, in awake, sleeping and anesthetized macaques. We manipulated consciousness on a finer scale using thalamic stimulation, rousing macaques from continuously administered anesthesia. Our results show that, unlike measures targeting complexity, a measure additionally capturing neural integration (Φ*) robustly correlated with changes in consciousness. Machine learning approaches show parietal cortex, striatum and thalamus contributed more than frontal cortex to decoding differences in consciousness. These findings highlight the importance of integration between parietal and subcortical structures and challenge a key role for frontal cortex in consciousness.