[Effect of aging on priming of pop-out]

In visual search tasks using pop-out stimuli, memory of the stimuli in previous 3 to 10 trials affects search performance in the present trial. This is called priming of pop-out. We examined the adult age difference of the effect with Memory Kernel Analysis (Maljkovic & Nakayama, 1994, 1996). It was revealed that with respect to target color and position, facilitation by the stimulus repetition and inhibition by the stimulus change lasted over the succeeding approximately three to eleven trials in both age groups. While eye movements were frequently observed in older subjects and their reaction times were longer than younger subjects', the priming effect was robustly observed. These results suggest that facilitation and inhibition for pop-out features are intact in older adults. The number of trials the effect persisted was discussed in terms of age-related differences of capacities of the memory mediating the effect.