Selective attention affects conceptual object priming and recognition: a study with young and older adults

Abstract

In the present study, we investigated the effects of selective attention at encoding on conceptual object priming (Experiment 1) and old-new recognition memory (Experiment 2) tasks in young and older adults. The procedures of both experiments included encoding and memory test phases separated by a short delay. At encoding, the picture outlines of two familiar objects, one in blue and the other in green, were presented to the left and to the right of fixation. In Experiment 1, participants were instructed to attend to the picture outline of a certain color and to classify the object as natural or artificial. After a short delay, participants performed a natural/artificial speeded conceptual classification task with repeated attended, repeated unattended, and new pictures. In Experiment 2, participants at encoding memorized the attended pictures and classify them as natural or artificial. After the encoding phase, they performed an old-new recognition memory task. Consistent with previous findings with perceptual priming tasks, we found that conceptual object priming, like explicit memory, required attention at encoding. Significant priming was obtained in both age groups, but only for those pictures that were attended at encoding. Although older adults were slower than young adults, both groups showed facilitation for attended pictures. In line with previous studies, young adults had better recognition memory than older adults.

Keywords: aging; conceptual repetition priming; explicit memory; implicit memory; recognition; selective attention.

FIGURE 1

An example of the two picture outlines, one green and the other blue, presented during the encoding phase of Experiments 1 and 2.

FIGURE 2

Experimental procedure during the encoding phase (Experiments 1 and 2); ISI refers to the inter-stimulus interval.

FIGURE 3

Experimental procedure during the test phase (Experiments 1 and 2); ISI refers to the inter-stimulus interval.

FIGURE 4

Mean reaction time (in ms) obtained in the conceptual implicit memory task as a function of group (young and older adults), corresponding to attended, unattended and non-studied picture outlines (Experimrnt 1). Bars indicate ±1 SD from the mean.

FIGURE 5

Mean total number of hits-false alarms for recognized picture names as a function of study condition: studied attended, studied unattended pictures (Experiment 2). Bars indicate ±1 SD from the mean.