Resolving Age-Related Differences in Working Memory: Equating Perception and Attention Makes Older Adults Remember as Well as Younger Adults

ABSTRACT

Objectives: Older adults show clear deficits in working memory functioning. Here, we investigate the often-reported decline in focus switching, that is, the ability to shift items from the focus of attention into working memory, and back. Specifically, we examined whether equating subjects on early processing (perception and attention) might ameliorate the deficit.

Method: We examined 1-Back and 2-Back performance in younger and older adults, with line segments of different orientation as the stimuli. Stimuli were calibrated depending on each individual’s 75% threshold for 1-Back performance. Subjects made match/mismatch judgments.

Results: After the calibration on 1-Back performance, no age-related differences were found on either accuracy or sensitivity in the 2-Back task. Additionally, when investigating focus-switch trials versus non-focus-switch trials in a random-order 2-Back task, older adults were more efficient at switching the focus of attention than younger adults.

Discussion: These results provide evidence for the view that age-related limitations in focus switching in working memory are caused (at least in part) by changes in early processing (perception and attention), suggesting that (at least some of the) age-related differences in working memory functioning may be due to shifts in trade-off between early processing and memory-related processing.

Notes

¹ This task is often considered an updating task (e.g., Schmiedek, Hildebrandt, Lövdén, Wilhelm, & Lindenberger, 2009). We make a distinction between the processes of focus switching and of updating per se – the former concerns access, the latter requires replacing the content of the outer store with new content. These two processes are dissociable, as shown in training studies (Jain, 2018; Price et al., 2014).

² The cited studies all explicitly examine age-related differences in focus switching using the N-Back paradigm, or closely related paradigms. Other mechanisms proposed for age-related changes in more global aspects of working memory include associative deficits (e.g., Chen & Naveh-Benjamin, 2012) and potential deficits in memory refreshing (e.g., Loaiza, Rhodes, & Anglin, 2013). At present, it remains an open question whether the age-related issues with memory refreshing found in some studies (e.g., Fanuel, Plancher, Monsaingeon, Tillmann, & Portrat, 2018; Loaiza et al., 2013) are related to, or even reducible to, age-related differences in focus switching.

Additional information

Funding

This work was supported by the National Institutes of Health under grant AG-16201.