A new fMRI-based spelling device allows people to answer questions with their thoughts alone. Assigning unique patterns of brain activity to each letter of the alphabet lets people answer questions with their thoughts, which might help patients with locked-in syndrome communicate.In a new study reported by the Scientific American, six healthy adults learned to answer questions by selecting letters on a computer screen with their minds.
The new system requires very little effort to setup, becoming “immediately operational.” It also has a high application potential “both in terms of diagnostics and establishing short-term communication with nonresponsive and severely motor-impaired patients.”
How does it work?
Most volunteers learned to communicate in this way after a single one-hour training session. While lying inside a functional magnetic resonance imaging (fMRI) scanner, volunteers stared at a computer screen displaying a table of three rows, nine columns and 27 squares. The squares contained the 26 letters of the alphabet and a blank space for separating words. Each row of letters was paired with one of three mental tasks:
- a motor imagery task, such as tracing stars or flowers in one’s mind;
- a mental calculation task, in which patients rehearsed multiplication tables;
- and an inner speech task, during which patients silently recited a poem or prayer.
Different blocks of letters were highlighted on the screen at different times. To choose a particular letter, participants waited for the computer screen to highlight that letter and performed the mental task associated with that letter’s row for as long as the letter was highlighted.
The computer program could not read the volunteers’ thoughts, but it could distinguish between the different kinds of brain activity associated with the three different mental tasks, as well as measure how long the volunteers performed a particular task.
Read more about this research on the Scientific American