Writing words with your mind’s eye

Writing with your eyes. Or to be more precise: formulating words through measuring changes in the size of the eye’s pupil. This new technology has been jointly developed by researchers from Utrecht University and Aix-Marseille University /CNRS (France). Stefan van der Stigchel, Utrecht-based experimental psychologist working on the research: “No movement at all is required, including eye movement. This technology offers a new perspective for communication by and with completely paralysed people.” The results of the research can be read in the online magazine PLoSONE.

In their article, the researchers acknowledge that communication with paralysed people has already been possible for some time. However, the existing methods use elaborate technology and expensive equipment that record and convert brain signals. The new technology described by the French and Dutch researchers in their article The Mind-Writing Pupil is considerably easier and cheaper.

Pupil size

Participants in the research were shown a range of letters on a computer screen. The background of the letters continuously changed from bright to dark and back again. The participants only had to covertly attend to the letters in question, i.e. they did not have to directly look at each letter. The pupil dilated slightly when the background of the chosen letter was dark and constricted when the background was brighter. The researchers were able to measure these changes in pupil size and this enabled them to determine which letter the participant intended to select. Researcher Sebastiaan Mathôt explains the process in a film.

Promising

The researchers have some reservations about the use of the new technology by fully disabled (locked-in) people, as the participants in their study were all able-bodied. Further research is needed to see if this technology does work for locked-in patients. “But the results of this research are very promising,” says Van der Stigchel.