Psychosomatic Medicine 27:274-285 (1965)
© 1965 American Psychosomatic Society

Discrimination and Recognition of Weak Stimuli

III. Further Experiments on Interaction of Cognitive and Autonomic-Feedback Mechanisms

¹ Department of Psychiatry, Albert Einstein College of Medicine of Yeshiva University, New York, N. Y.

Psychologic and physiologic (GSR) discrimination thresholds were compared in 139 subjects exposed to prior pairing of one of two visual stimuli with electric shocks. Seventy-seven subjects conditioned and 62 did not in response to this procedure. Forty-four control subjects received no shock, but were otherwise exposed to identical experimental schedules. The schedules permitted comparison of the effects of immediate vs. delayed communication of identification and confidence reports by the subjects. All subjects were healthy volunteer male college students.

In conditioned subjects, stimuli presented at illumination intensities just below verbal correctness threshold still evoke autonomic responses appropriate to their true nature and/or to the nature of mistaken identification--depending upon the timing of the reports. Under appropriate circumstances, subjects exposed to the conditioning procedure show evidence of additional veridical information in their verbal resports. This effect is attributed to autonomic feedback, the possible modes and mechanisms of action of which are discussed.

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