Effects of stimulus duration and ISI on accuracy and transference errors in pictorial recognition

The influence of stimulus duration and ISI on accuracy of recognition for two-part configurations was investigated in two experiments. A six-alternative forced-hoice recognition procedure is described that tested (1) subjects’ ability to recognize correct or partially correct stimuli, and (2) their tendencies to make transference errors. Subjects were significantly more accurate in recognition of pictorial components when given a longer (2-sec) rather than a shorter (.5-sec) exposure to stimuli, with ISI held constant (.5 sec). There was no beneficial effect on recognition of pictorial components when ISI was lengthened from .5 to 2 sec Iwith a .5-sec stimulus duration) or from .5 to 1.5 to 7 sec Iwith a 2-sec stimulus duration). The total time hypothesis received no support, since when two groups were given the same total time (2.5 sec for stimulus duration plus ISI), the group given the longer 12-sec) stimulus duration was significantly more accurate in partial recognition than a group given a longer 12-sec) ISI. There was a high incidence of transference errors in all experimental groups, although subjects’ ability to distinguish old stimuli from distractors made by recombining parts from different targets was not affected by any of the temporal manipulations. It appeared that, although length of stimulus duration determines the number of components encoded from a picture, the encoding of information that integrates these components into a whole does not require additional processing time.