The effect of pre-exposure on overall similarity categorization

Abstract

This paper examines the effect that prior exposure to perceptual stimuli has on the prevalence of overall similarity (family resemblance) categorization. Experiment 1 demonstrated that participants who had previously encountered stimuli produced more overall similarity sorting when asked to free classify them than participants who were pre-exposed to different stimuli to those they later classified. Experiments 2a and 2b showed that this effect is modulated by the perceptual difficulty of the stimuli - pre-exposure statistically increased overall similarity sorting for perceptually easy stimuli but not for perceptually difficult stimuli. Overall similarity sorting was also significantly higher for perceptually easy stimuli than for perceptually difficult stimuli. Experiment 2b additionally showed that pre-exposure increased the discriminability of the perceptually easy stimuli but this effect was not statistically detectable for perceptually difficult stimuli. Experiment 3 established that the pre-exposure effect is also influenced by the spatial separateness of the stimulus dimensions - pre-exposure significantly elevated overall similarity sorting when the dimensions were integrated into a coherent object but not when they were spatially separated. Similarly, there was a statistically significant increase in the perceptual discriminability of the spatially integrated stimuli after pre-exposure but not for the spatially separate stimuli. Taken together, these results demonstrate that pre-exposure can elevate overall similarity sorting and provide insight into the conditions under which the effect will occur.