Auditory tracking magnitude, temporal alignment, and anatomical distribution during wakefulness and propofol-based anesthesia in human sEEG

In 13 patients with drug-resistant epilepsy, propofol-based anesthesia at ~1.61 Hz reduces stimulus-rate power and makes phase alignment with auditory rhythms less consistent, though some channels still show detectable responses.

• Why it matters: General anesthesia attenuates auditory responses, but it is unclear how residual activity tracks sound over time and how these tracking properties vary across brain locations.
• What they did: Using stereoelectroencephalography during wakefulness and clinically defined unresponsiveness under propofol, the study presented rhythmic humming sequences at approximately 1.61 Hz and quantified stimulus-rate power, phase alignment, and anatomical distance effects; it also used CEBRA embeddings to assess acoustic-envelope decoding.
• The result: During anesthesia, stimulus-rate power shows widespread reductions and CEBRA embeddings yield lower held-out acoustic-envelope decoding accuracy and lower consistency across model fits, while wakefulness shows distance-dependent response strength from posteromedial Heschl’s gyrus that is weaker under anesthesia.