Signals from the brain can provide nonmuscular communication and control channels, or brain-computer interfaces (BCIs), to people with amyotrophic lateral sclerosis (ALS), brainstem stroke, cerebral palsy, or spinal cord injury. BCIs can allow people who are severely paralyzed, or even "locked in," to use brain signals to write, communicate with others, control their environments, access the Internet, or operate neuroprostheses. BCI research at the Wadsworth Center has focused on the realization of clinically useful BCI systems by emphasizing work in three areas: (1) acquisition of brain signals; (2) signal processing; and (3) clinical implementation. To facilitate this work we have developed and disseminated to more than 200 research groups a general-purpose BCI software platform, called BCI2000. Using the BCI2000, we have evaluated: alternative brain signals, including elecroencephalographic (EEG) and electrocortographic (ECoG) signals; specific features of brain signals including sensorimotor rhythms (SMR) and the P300 evoked potential; and signal processing techniques, emphasizing time-space feature extraction methods, optimization schemes, and adaptation. Finally, we have developed the first BCI system designed for independent home use, and successfully tested this prototype in long-term home use by a small group of people severely disabled by ALS.