Researchers from the United Kingdom and Ireland have presented results from trials of a lightweight wireless EEG headset that can detect signs of hidden consciousness in patients who, outwardly, do not respond to the world around them.
The experiment involved 42 patients with various disorders of consciousness and two healthy volunteers. The system, which used 16 sensors, recorded electrical brain activity while participants imagined moving an arm or a leg. In the first stage alone, signals above the level of chance were detected in 73.8% of patients, suggesting that the brain may be able to respond to instructions even when there are no external reactions.
In the second part of the study, patients were asked to answer “yes” or “no” questions by imagining different movements. The questions were recorded by relatives or caregivers. It was among patients considered fully unresponsive that the quality of the brain signals increased noticeably. The authors emphasize that this is not yet direct proof of hidden consciousness, but it is consistent with earlier findings that familiar voices can activate the brain even in severe disorders of consciousness.
In recent years, scientists have already shown that functional MRI and high-resolution EEG can detect signs of hidden consciousness in some such people. The main advantage of the new technology is that this compact wireless system can be used directly in hospitals, care facilities and even at home, without the complex equipment required for functional MRI.
