Researchers at Baylor College of Medicine have found that the brain continues advanced language processing even during general anesthesia. Patients under unconsciousness distinguished parts of speech and anticipated upcoming words in stories. The results, published in Nature, challenge prior views on consciousness and cognition.
The team recorded neuron activity in the hippocampus of patients undergoing epilepsy surgery. They used Neuropixels probes while playing tones and short stories to patients with no conscious awareness.
Neurons detected unexpected sounds and improved at the task over time. Neural patterns also distinguished nouns, verbs, and adjectives, with signals predicting words before they were spoken.
"Our findings show that the brain is far more active and capable during unconsciousness than previously thought," said Dr. Sameer Sheth. Dr. Benjamin Hayden noted that this predictive coding occurs without wakefulness.
The study suggests consciousness may depend on communication across brain regions rather than isolated activity. Researchers cautioned the work covers only one anesthesia type and one brain area.
