Date of Award
Master of Science (MS)
The purpose of this investigation was to examine experimentally the phenomenon of perceptual defense as it is related to cigarette smoking behavior. In making this examination a population of undergraduate college students was divided into three groups according to their smoking habits. The three groups were identified as smokers, non-smokers, and quitters. A list of smoking related words was equated with a list of neutral words according to their frequency of appearance in print. These lists of words were then combined to form one list with a random distribution of smoking and neutral words, and this list was presented as stimuli to the subjects. The stimulus presentations were made by tachistoscopic projection, and the response thresholds were recorded in units of illumination of the stimulus required for correct identification. The hypothesis that persons who had recently stopped smoking would exhibit the greatest degree of perceptual defense, followed in order by smokers and non-smokers was not supported by the results. Neither was there any significant evidence to support the prediction that perceptual defense would be positively correlated with anxiety as measured by selected scales of the MMPI. A post hoc investigation of the data did reveal that the smoking group contained a significantly greater proportion of persons exhibiting perceptual defense than was found in either of the other groups. It was recommended that additional research of this nature be conducted using a larger sample of older subjects, and incorporating more highly refined tachistoscopic equipment.
Johnson, David A., "The Effects of Anxiety Producing Stimuli on Visual Perceptual Thresholds: A Study in Perceptual Defense" (1964). Electronic Thesis Collection. 9.