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

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.

To bind or not to bind, that's the wrong question: Features and objects coexist in visual short-term memory.

In three experiments, we investigated whether features and whole-objects can be represented simultaneously in visual short-term memory (VSTM). Participants were presented with a memory set of colored shapes; we probed either for the constituent features or for the whole object, and analyzed retrieval dynamics (cumulative response time distributions). In our first experiment, we used whole-object probes that recombined features from the memory display; we found that subjects' data conformed to a kitchen-line model, showing that they used whole-object representations for the matching process. In the second experiment, we encouraged independent-feature representations by using probes that used features not present in the memory display; subjects' data conformed to the race-model inequality, showing that they used independent-feature representations for the matching process. In a final experiment, we used both types of probes; subjects now used both types of representations, depending on the nature of the probe. Combined, our three experiments suggest that both feature and whole-object representations can coexist in VSTM.