Anesthetized Brains Can Process and Predict Words, New Study Finds

A study published May 6 in Nature reveals that the hippocampus remains responsive under general anesthesia, processing sounds and even predicting words. Researchers at Baylor College of Medicine used Neuropixels probes to record neuronal activity in seven epilepsy patients given propofol. Three participants heard repetitive beeps with oddball tones; their neurons learned to discriminate over time. Four heard podcast segments; hippocampal neurons responded to nouns and verbs, and firing patterns predicted upcoming words. The results parallel those in awake patients, suggesting complex cognitive functions can occur without consciousness. Study co-author Sameer Sheth says this challenges understanding of consciousness, though findings may not apply to all unconscious states.