ABSTRACT
Effects of differential stimulus familiarity on simple cognitive tasks were investigated. Reaction time tasks of varying cognitive complexity were administered on three subsequent days to samples of Iranian and Dutch subjects. For three tasks a set of geometric patterns was used for stimulus materials. To investigate the effects of experience one of these tasks was trained. An isomorphic task with Arabic letters as stimuli was also administered. With the geometric figures very similar patterns of results were found for the two samples across tasks and across days. The Dutch subjects responded faster on all the tasks. With the Arabic letters also similar patterns were found over the three days, but the Iranian subjects were consistently faster. It is argued that the systematic manipulation of stimulus familiarity in an experimental design obviates the need for diffuse and subjective explanatory concepts.
