A new mode of communication between man and his surroundings

The material presented in this paper is the result of a research project that was designed to study the feasibility of establishing an alternative mode of communication between man and his surroundings. The new form of communication proposed uses only the subject's brain waves with no overt physical action required. Subjects' electroencephalograms (EEG) were recorded while they performed various mental tasks designed to elicit hemispheric responses. Features formed from the EEG recording were then used as inputs into a Bayes quadratic classifier to test classification accuracy between the various tasks. The results obtained indicate that it is possible to accurately distinguish between any pair of the five tasks investigated. A comparison between three different methods for creating the feature sets is also presented.     

Man-machine communications through brain-wave processing

The possibility of monitoring voluntarily produced changes in the electroencephalogram (EEG) of a subject and translating these changes into a set of commands to be issued to an external device was investigated. Subjects performed five distinct tasks under both eyes-open and eyes-closed conditions. A feature set consisting of the asymmetry ratios and the power values for each lead at four frequency bands-delta (0-3 Hz) theta (4-7 Hz), alpha (8-13 Hz), and beta (14-20 Hz)-was used to characterize the EEG. The feature sets created from an estimate of the spectral density of the EEG for each task were used to test classification accuracy among the various tasks using a Bayes quadratic classifier. The results show that it is possible to distinguish, to a high degree of accuracy, among the various mental tasks studied, using only the EEG.