The effects of verbal meaning and response categorisation on the fragmentation of steadily fixated patterns

Studies of steady visual stimulation have suggested that the subjective meaning of a stimulus may determine the form and degree of its perceptual fragmentation. This was tested for steady fixation by presenting a letter of the alphabet ("L") in a sequence of other letters which were either normally oriented or inverted. No evidence was found for greater stability in the former case. An investigation of the categorisation of subjective disappearances showed that, although the stability of pattern components was not determined by reporting these singly or in conjunction, the disappearances of the whole pattern were significantly increased by reporting only these as opposed to reporting disappearances of each component. Response to stimulated subjective disappearances also showed that the effect was due to the nature rather than the number of response categories. In the final experiment all subjects fixated a rotated letter, after half had received pretraining in the recognition of rotated letters. No effects of the pretraining were apparent, for either level of response categorisation, and it was concluded that the processes underlying subjective disappearances in steady fixation are not modified by the meaningfulness of a stimulus. The involvement of central processes was, however, indicated by the effects of response categorisation and the influence of simulated disappearances on pattern stability in a trial subsequent to their presentation.