Greater priming for previously distracting information in young than older adults when suppression is ruled out

Abstract

The use of previously distracting information on memory tests with indirect instructions is usually age-equivalent, while young adults typically show greater explicit memory for such information. This could reflect qualitatively distinct initial processing (encoding) of distracting information by younger and older adults, but could also be caused by greater suppression of such information by younger adults on tasks with indirect instructions. In Experiment 1, young and older adults read stories containing distracting words, which they ignored, before studying a list of words containing previously distracting items for a free recall task. Half the participants were informed of the presence of previously distracting items in the study list prior to recall (direct instruction), and half were not (indirect instruction). Recall of previously distracting words was age-equivalent in the indirect condition, but young adults recalled more distracting words in the direct condition. In Experiment 2, participants performed the continuous identification with recognition task, which captures a measure of perceptual priming and recognition on each trial, and is immune to suppression. Priming and recognition of previously distracting words was greater in younger than older adults, suggesting that the young engage in more successful suppression of previously distracting information on tasks in which its relevance is not overtly signaled.

Keywords:

• aging
• distraction
• priming
• implicit memory
• suppression

Notes

1. The terms “direct” and “explicit” and “indirect” and “implicit” are frequently used interchangeably. Here, the terms “direct” and “indirect” are used to describe task instructions (whether or not they refer to the relevance of specific previously studied information), and the terms “explicit” and “implicit” are used to describe types of test. For example, recall and recognition are explicit memory tests that call upon participants to retrieve previously studied information, and perceptual identification is an implicit test that does not call upon participants to retrieve previously studied information. The implicit test therefore involves indirect instructions, and the explicit tests involve direct instructions. (In some conditions, however, the explicit tests involve indirect instructions where the use of previously distracting information is concerned).

2. The idea that implicit memory is age-invariant has come to be widely accepted, yet many studies have demonstrated significantly reduced priming in older compared to younger adults (e.g., Abbenhuis, Raaijmakers, Raaijmakers, & Van Woerden, 1990; Chiarello & Hoyer, 1988; Davis et al., 1990; Hultsch, Masson, & Small, 1991; Ward et al., 2013a). Moreover, in published studies that claim to have revealed preserved priming in older individuals, performance has most often been numerically reduced (see Fleischman & Gabrieli, 1998), and it has been argued that there is a genuine decline in priming with age that may sometimes go undetected due to inadequate statistical power to detect small but real age effects in priming (a detailed discussion is provided in Mitchell & Bruss, 2003; Ward et al., 2013a, 2013b).