Age-Related Differences in the Statistical Learning of Target Selection and Distractor Suppression

In recent years, the use of implicit mechanisms based on statistical learning (SL) has emerged as a strong factor in biasing visuospatial attention, so that target selection is improved at frequently attended locations and distractor filtering is facilitated at frequently suppressed locations. Although these mechanisms have been consistently described in younger adults, similar evidence in healthy aging is scarce. Therefore, we studied the learning and persistence of SL of target selection and distractor suppression in younger and older adults in visual search tasks where the frequency of target (Experiment 1) or distractor (Experiment 2) was biased across spatial locations. The results show that SL of target selection was preserved in the older adults so, similar to their younger counterparts, they showed a strong and persistent advantage in target selection at locations more frequently attended. However, unlike young adults, they did not benefit from implicit SL of distractor suppression, so that distractor interference was maintained throughout the experiment independently of the contingencies associated with distractor locations. Taken together, these results provide novel evidence of distinct developmental patterns for SL of task-relevant and task-irrelevant visual information, likely reflecting differences in the implementation of proactive suppression attentional mechanisms between younger and older adults.