The psychological moment: Complexity of percept as a factor in the temporal processing of input

Two studies were performed comparing a subject's ability to identify tachistoscopically presented letters to his ability to identify consonant-vowel-consonant (C.V.C.) trigrams presented in an identical manner. These two types of stimuli are regarded as causing percepts of differing levels of complexity, the C.V.C.s being more complex than the letters. It was expected that the different levels of complexity would result in a difference in the length of the psychological moment. As described by Stroud (1956), this moment is a discreet segment of psychological time, within which all sensory input is treated as being simultaneous. A method of stimulus presentation developed by Ericksen and Collins (1968) was employed to eliminate a criticism of earlier studies, that the criteria of perceptual simultaneity was subjective. Analysis of the results by non-parametric statistics showed that complexity of percept, as defined in this paper, had no effect on the length of the interval or moment of simultaneity. It is suggested, however, that the method presented might be advantageously employed in further investigation of individual differences in moment length.