Abstract
Teaching Matching to Sample to Totally Paralyzed Patients by Translating Their Brainwaves into Cursor Movement on a Monitor.
IVER H. IVERSEN (University of North Florida), and Niels Birbaumer, N. Ghanayim, T. Hinterberger, J. Kaiser, B. Kotchoubey, A. Kuebler, and N. Neumann (University of Tuebingen, Germany)

The purpose of the research is to enable totally paralyzed patients with amyotrophic lateral sclerosis (ALS) to communicate by means other than muscular activity. We used a computerized on-line task that translates signals from the encephalogram (EEG) into visual feedback. The patient faces a monitor that shows a ball-shaped cursor and two targets located at the top and bottom of the monitor. The vertical movement of the ball gives visual feedback of the EEG to the patient. The patient has to learn to self-regulate the EEG to make the cursor hit the correct target, which varies in location from trial to trial. We used operant conditioning methods to train two adult patients to generate the voluntary EEG response. In one task, the monitor presents two targets, and the patient is instructed verbally at session start to move the ball to one particular target; for example, the screen may present a noun and a verb, and the instruction is to move the cursor to the noun on all trials. In another task, the instruction varies from trial to trial and consists of a model (sample) presented on the screen. The subject has to move the cursor to the correct target (comparison), as in regular matching-to-sample. We used symbols, letters, and words as stimuli and established both identity and symbolic matching. In one patient, we also established three 3-member equivalence classes. The presentation will illustrate how brainwaves can be translated into cursor movement, how the patients were trained, and how results from such experiments can be used to assess "cognitive" skills in totally paralyzed patients.