Apparent Changes in the Visual Threshold as a Function of Subliminal Stimulation: A Preliminary Report

Abstract

A methodological difficulty in the traditional perceptual defence experiment is that of trying to use verbal reports as a measure of threshold changes. The following experiment handles this difficulty by using the method of closed loop control. The design involves obtaining from the subject a continuous record of his awareness threshold for light entering the left eye while verbal material, dichotomized regarding emotional value, is presented, below threshold to the right eye. The data from this first stage of the research provide some support for the hypothesis that the threshold of awareness will vary as a function of sub-threshold presentations.