Brain injury such as following traffic or sports accidents can lead to severe disorders, including disorders of consciousness. This disorder is currently diagnosed through behavioural assessments, but this method fails when patients are not able to respond overtly. We investigated whether neural responses to speech as measured from the clinically-applicable EEG can aid to diagnose disorders of consciousness. We focussed on the neural tracking of the speech envelope that can index attention to speech as well as speech comprehension. We find that the latency of the neural envelope tracking related to the severity of the disorder of consciousness: patients in a vegetative state without signs of consciuosness showed neural responses to the speech envelope that were significantly delayed compared to patients that exhibited consciusness.
C. Braiman, E. A. Fridman, M. M. Conte, C. S. Reichenbach, T. Reichenbach, N. D. Schiff
Cortical Response to the Natural Speech Envelope Correlates with Neuroimaging Evidence of Cognition in Severe Brain Injury,
Curr. Biol. 28:1-7 (2018). [pdf]