Same-different discrimination: Simultaneous versus successive presentation of stimuli

It was found that in the same-different task when a participant has to answer whether several presented stimuli are identical or different, participants can apply two stimuli comparison strategies - holistic or analytic. In the present investigation, it was attempted to assess if the manifestation of such individual differences can depend on the stimuli presentation procedure successive or simultaneous. Psychophysical experiments of same-different task were carried out in which figures, irregular polygons of various degree of similarity, were presented in pairs simultaneously or successively. In the case of successive presentation of figures, participants were divided into two groups: for the majority of participants, same-different discrimination had an inverse relationship on the degree of similarity - the more two figures were similar, the lower was the accuracy and the longer response time; for the other participants, same-different discrimination did not depend on the similarity of figures. In the case of simultaneous presentation, participants clearly did not differ by the pattern of task performances.