Single-trial decoding of auditory novelty responses facilitates the detection of residual consciousness.
Neuroimage December 1, 2013 J R King, F Faugeras, A Gramfort et al.
A multivariate pattern classifier can decode single-trial EEG responses to auditory novelty, distinguishing local (automatic) from global (conscious) novelty detection. In 38 high-density EEG, MEG, and intracranial EEG recordings, the method overcame individual variability and multiple-comparison issues. Local responses were robust to distraction, while global responses depended on attention. Among 104 patients in vegetative state (VS), minimally conscious state (MCS), and conscious state (CS), local response decoding was significant in about 60% of recordings regardless of consciousness state. For global responses, significant decoding occurred in 14% of VS patients, 31% of MCS patients, and 52% of CS patients, indicating that global novelty decoding tracks consciousness level.