Thought recognition is the ability of a computer to recognize neural patterns in the brain as a form of input and control of computer processes. Computer programming and the necessary sensing devices already exist to detect other forms of biophysical activity, such as muscular activity and eye movement. Using these forms of input, paralyzed and other handicapped people have been made able to communicate with a computer. Brain waves suggest the possibility of an even more direct form of computer input - the thought command. However, thus far it has been difficult to interpret the brain waves with sufficient delineation to afford any kind of discriminatory input - for example, to sense a letter or word that a person might be thinking of.
Brain waves can be discerned in these patterns:
- Alpha waves, with large modulations and moderate frequencies, indicate unfocused brain activity
- Beta waves, with higher frequencies and small modulations, indicate focused brain activity
- Theta waves, with moderately low frequencies, indicate emotional stress
- Delta waves, with extremely low frequencies, indicate a condition of sleep
- Mu waves, have a croquet-shaped pattern of frequencies and modulation, are associated with physical activity
Scientists feel that a number of more refined distinctions about brain patterns must be made before they can be used as computer input.