Objective: To test a training procedure designed to enable severely paralyzed patients to communicate by means of self-regulation of slow cortical potentials.
Design: Application of the Thought Translation Device to evaluate the procedure in patients with late-stage amyotrophic lateral sclerosis (ALS).
Setting: Training sessions in the patients' homes.
Participants: Two male patients with late-stage ALS.
Interventions: Patients learned voluntary control of their slow cortical potentials by means of an interface between the brain and a computer. Training was based on visual feedback of slow cortical potentials shifts and operant learning principles. The learning process was divided into small steps of increasing difficulty.
Main outcome measures: Accuracy of self-control of slow cortical potentials (percentage of correct responses). Learning progress calculated as a function of training session.
Results: Within 3 to 8 weeks, both patients learned to self-regulate their slow cortical potentials and to use this skill to select letters or words in the Language Support Program.
Conclusions: This training schedule is the first to enable severely paralyzed patients to communicate without any voluntary muscle control by using self-regulation of an electroencephalogram potential only. The protocol could be a model for training patients in other brain-computer interface techniques.
Copyright 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation