Some effects of 'mental set' on the electrophysiological processes of the human cerebral cortex.

Abstract

With the introduction of the electroencephalographic technique in 1929 by Dr. Hans Berger (5), and with the subsequent verification of his original observations by Adrian and Matthews (1), Gibbs, Davis and Lennox (9), and Jasper and Carmichael (11), it became increasingly apparent that psychology had available a new tool which might be of value in uncovering some physiological correlates of 'mental' events.All of these pioneer investigators reported changes in the electrocortical record when a subject engaged in 'mental* activity. Later and more delimiting studies by Bagchi (3), Knott (13), Loomis, Harvey and Hobart (15), Travis (16), Travis, Knott and Griffith (18), and Travis and Knott (19,20) added to the body of experimental proof that there is a relationship between the electroencephalogram, as a physiological index, and 'mental' activity.Cruikshank (6), Jasper (11), Jasper and Cruikshank (12) and Travis and Hall ( 17) have made significant contributions to the correlation of sensation, .and after-sensation, and electrocortical phenomena, thus demonstrating the availability of electroencephalography in psychophysiological studies.Although the use of this new electrophysiological technique has been somewhat restricted, psychologically, to the study of sensation and centrally aroused processes, a few observa-* These investigators have not calculated the statistical significance of their observed differences, nor have they published sufficient data for such calculations to be made.• A preliminary survey of the approach has been published elsewhere in brief form (14).

Effects of foreperiod, induced muscular tension, and stimulus regularity on simple reaction time.

“…Other information concerning the relations among foreperiod, tension, and reaction time comes from studies of induced muscular tension. These studies (1,5,6,7,8) also report an inverse relationship between tension level and RT. However, in studies done by Freeman (6) and Freeman and Kendall (7) with irregularly presented foreperiods and induced tension levels, it was found that the foreperiod which was most effective in producing a short RT was longer with the greater than it was with the J The major results of this study were presented at the 1956 meeting of the Eastern Psychological Association.…”

Experimental studies in affective processes: I. Some effects of cognitive structure and active participation on certain autonomic reactions during and following experimentally induced stress.

“…Familiar examples include studies of simple reactions (e.g., 60,65), perception (30, 53, 69> 74, 75, 80), learning and memory (8,26,60), and problem solving (55,56). With regard to conditioning studies in particular, a difference in this factor has been shown to modify to a significant degree the salivary (71)(72)(73) and eyelid (10,27,57,58) reflexes, the GSR (2,11,21,63,87) and EEG (3,13,50), reactions to electric shock (31,42,66,76,85,86), conditioned discrimination (35)(36)(37)(38)(39) and other sensory processes (5,17,18,63,65).…”

Electroencephalography and physiological psychology: evaluation and statement of problem.

“…Knott (37) investigated the latent time of blocking to light when light was a signal for manual response. It was found that in such contexts the mean latent time of blocking was shorter than when light had no response value and that the S. D. of the distribution was also smaller.…”

“…The previously cited work on the alteration of the latent time of blocking of the alpha rhythm (2,37), in which a "set" to respond to a stimulus, visual or auditory, decreased the latent time of blocking to that stimulus, and in which artificial loading of muscle groups was observed in the case of visual stimuli to reduce the latent time, bears significantly on this general issue. In this instance there is reasonable evidence in support of the hypothesis that peripheral (sensory) factors can operate to alter a central con-dition, apparently "sensitizing" and thus assisting in more rapid cortical responses.…”

“…! Functional structuring is a concept introduced(37) to assist in the interpretation of the electrical activity of the cortex. "Its meaning is essentially…”