Citation

Henry CE. J. Exp. Psychol. 1941; 29(3): 236-247.

Copyright

(Copyright © 1941, American Psychological Association)

DOI

10.1037/h0057822

PMID

unavailable

Abstract

Samples of electroencephalic records 50 cm. in length were taken from the left motor and left occipital area of 4 subjects who were selected as typifying the 4 groups which are often distinguished in terms of the percentage of time alpha waves are exhibited on the record. Samples were secured under experimental conditions involving a variety of psychological activities (resting, reading aloud and silent, talking, rotation, etc.), and statistical methods of analysis of variance and covariance were employed to determine whether individual differences in the alpha index of the electroencephalograms suffer changes and tend to disappear during various types of mental activity. In some instances in combination with visual stimulation, interindividual differences were found to be reduced to a magnitude not significantly in excess of intraindividual differences. Even where heterogeneity was exhibited, it was found to be an expression of a significantly different distribution of alpha indices from that evinced in the resting condition. (PsycINFO Database Record (c) 2012 APA, all rights reserved)