The use of galvanic skin response (GSR), the core measurement in lie detector tests, is proposed as a method for “locked-in” patients to communicate with the outside world. “Locked-in” patients have lost all ability to move, and, in some cases, even to communicate with any kind of brain-computer interface. The GSR measures changes in the electrical conductivity of the skin.
Moore and Dua worked with one locked-in subject to see whether he could in fact control his level of GSR response, to tell the researchers “yes” or “no.” A “yes” response required the subject to raise his galvanic response; a “no” response required him to hold it steady. The data are all based on this one subject, and are unfortunately rather weakly correlated with the desired communications (a requested “yes” or “no” response), though they are somewhat better correlated for “no” responses, as one might expect.
Artifacts were a problem, and using only one subject had its limitations as well. Having said that, this is an interesting snapshot of work in progress, and the authors say that they are moving on to study more locked-in subjects, as well as some healthy controls. It will be interesting to see whether the communication accuracy rises with some subjects, and with experience with the research protocols.