Accession Number : ADA138694

Title :   New Techniques for Measuring Single Event Related Brain Potentials.

Descriptive Note : Final rept.,

Corporate Author : PURDUE UNIV LAFAYETTE IN SCHOOL OF ELECTRICAL ENGINEERING

Personal Author(s) : McGillem,C D ; Aunon,J I

PDF Url : ADA138694

Report Date : 15 Oct 1983

Pagination or Media Count : 86

Abstract : Methods for selecting features of evoked patented (EP) waveforms to improve classification accuracy are described. It is found that use of an exhaustive search procedure gives moderate improvement over forward sequential feature selection and stepwise linear discriminant analysis procedures. A new procedure for classification using a combination of temporal and spectral representations of the data is described. Experimental results are presented illustrating the effectiveness of time-varying filters for processing EP waveforms. It is shown by means of computer simulations that much greater noise reduction is obtained with time-varying filters than is possible by any of the more conventional procedures that utilize time-invariant filters. At the same time the underlying waveforms are preserved by the filtering process. Modifications of a computer controlled display system to give precise timing measurements are described. Data showing the reduction in latency variance of EP components are presented. Reductions in the standard deviations of about 20% were obtained. Experimental measurements of EP waveforms using a Sternberg paradigm are described. Preliminary analysis of the results shows an apparent substructure in the P300 and a significant correlation of certain of the P300 components and reaction time. (Author)

Descriptors :   *Algorithms, *Electroencephalography, *Waveforms, *Measurement, *Brain, Pattern recognition, Parameters, Classification, Selection, Noise reduction, Linearity, Charts, Tables(Data), Methodology, Discriminate analysis

Subject Categories : Anatomy and Physiology
      Statistics and Probability

Distribution Statement : APPROVED FOR PUBLIC RELEASE