Selective attention modulates information processing and implicit memory
Keywords:Alzheimer´s disease, Implicit memory, Integral-separable dimensions, Selective attention, Stroop effect
Selective attention allows to process relevant stimuli while suppressing irrelevant ones that appear simultaneously in the visual field. However, many times the perceiver cannot ignore irrelevant information. In this review, I discussed results from the Stroop task with fragmented colour word stimuli as well as other findings showing that the variation of an irrelevant dimension on same-different visual judgments as two examples that irrelevant stimulus dimensions produced interference. Finally, I describe the results of several studies designed to investigate the effect of selective attention at encoding on implicit memory across lifespan. Priming for attended stimuli at encoding was found for children, young adults and healthy older adults. Priming was not found for unattended stimuli suggesting that implicit memory requires attention at encoding. Alzheimer´s patients and cognitively impaired older adults did not show priming for attended or for unattended stimuli. The findings suggest that: (1) implicit memory is not automatic and requires attention at encoding; and (2) an early deficit of selective attention might be a marker of pathological aging.