The technology expands on an earlier use of fMRI to assess conciousness in people described as being in an unconcious or vegetative state by introducing the capability of answering simple yes or no questions. Going beyond the earlier version, the new scanning technique uses the entire alphabet as well as blank spaces.
While volunteers performed 27 different mental task with each linked to an alphabetical letter or the space key, blood flow in very precise parts of the brain corresponding to these tasks was measured by fMRI and a deterrmination was made of which character they had chosen.
"The work of Adrian Owen and colleagues led me to wonder whether it might even become possible to use fMRI, mental tasks, and appropriate experimental designs to freely encode thoughts, letter-by-letter, and therewith enable back-and-forth communication in the absence of motor behavior," said Bettina Sorger of Maastricht University in The Netherlands, one of the researchers working on the study.
