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1. Are latent working memory items retrieved from long-term memory?

   https://doi.org/10.1177/17470218231217723  

   Chao, Chang-Mao; Xu, Chenlingxi; Loaiza, Vanessa; Rose, Nathan S (August 2024, Quarterly Journal of Experimental Psychology)

   Switching one’s focus of attention between to-be-remembered items in working memory (WM) is critical for cognition, but the mechanisms by which this is accomplished are unclear. A long-term memory (LTM) account suggests that switching attention away from an item, and passively retaining and reactivating such “latent” items back into the focus of attention involves episodic LTM retrieval processes, even for delays of only a few seconds. We tested this hypothesis using a two-item, double-retrocue WM task that requires participants to switch attention away from and reactivate items followed by subsequent LTM tests for reactivated items from the initial WM task (vs. continuously retained or untested control items). We compared performance on these tests between older adults (a population with LTM deficits) and young adults with either full (Experiment 1) or divided (Experiment 2) attention during the WM delay periods. The effects of reactivating latent items, as well as ageing and divided attention, had significant effects on WM performance, but did not interact with or systematically affect subsequent LTM for reactivated versus control items on item-, location-, or associative-recognition memory judgements made with either high or low confidence. Experiment 3 confirmed that these effects did not depend on whether or not young participants were warned about the subsequent LTM tests before performing the WM task. These dissociations between WM and LTM are inconsistent with the LTM account of latent WM; they are more consistent with the dynamic processing model of WM (Current Directions in Psychological Science). 

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2. Complex span measures of working memory do not mediate the effects of age on the P3 and N400 ERPs

   https://doi.org/10.1016/j.nbas.2025.100140  

   Joshi, Jasmin; Denaro, Chandlyr M; Hartley, Alan A; Reed, Catherine L (January 2025, Aging Brain)

   Working memory (WM), the temporary maintenance of a limited amount of information in an accessible state, is required for the performance of many tasks. Studies have shown that WM demands are related to the neural processing of tasks requiring attention: Age affects the ERP components associated with WM context updating processes in the visual oddball task (P3) and semantic processing in the word-pair judgment task (N400). This study investigated whether WM capacity measured by complex span tasks mediates the effects of age on these ERPs. Younger adults (YA, n = 44, ages 18–23 yr) and older adults (OA, n = 41, ages 69–89 yr) completed operation, reading, and symmetry complex span tasks and two ERP tasks (P3/visual oddball; N400/word-pair judgment). Results showed age-related differences for all complex span tests. Principal components analysis of these tests showed a single factor for both groups, so a combined WM capacity factor score was created. Regressions of age group and WM factor score on P3 and N400 amplitudes and latencies showed that OAs had relatively lower amplitudes and longer latencies. However complex span was not related to P3 or N400 amplitudes or latencies and that result was the same for younger and older adults; that is, complex span did not mediate the age effects. WM processes indexed by the P3 and N400 components appear to be different from those elicited by complex span tasks. Attentional control processes of WM influence oddball and semantic judgement tasks more than storage components. 

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3. Differences in the functional brain architecture of sustained attention and working memory in youth and adults

   https://doi.org/10.1371/journal.pbio.3001938  

   Kardan, Omid; Stier, Andrew J.; Cardenas-Iniguez, Carlos; Schertz, Kathryn E.; Pruin, Julia C.; Deng, Yuting; Chamberlain, Taylor; Meredith, Wesley J.; Zhang, Xihan; Bowman, Jillian E.; et al (December 2022, PLOS Biology)

   Cohen Kadosh, Roi (Ed.)

   Sustained attention (SA) and working memory (WM) are critical processes, but the brain networks supporting these abilities in development are unknown. We characterized the functional brain architecture of SA and WM in 9- to 11-year-old children and adults. First, we found that adult network predictors of SA generalized to predict individual differences and fluctuations in SA in youth. A WM model predicted WM performance both across and within children—and captured individual differences in later recognition memory—but underperformed in youth relative to adults. We next characterized functional connections differentially related to SA and WM in youth compared to adults. Results revealed 2 network configurations: a dominant architecture predicting performance in both age groups and a secondary architecture, more prominent for WM than SA, predicting performance in each age group differently. Thus, functional connectivity (FC) predicts SA and WM in youth, with networks predicting WM performance differing more between youths and adults than those predicting SA. 

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4. Differences in the functional brain architecture of sustained attention and working memory in youth and adults

   https://doi.org/10.15154/1528288  

   Kardan, O. (January 2023, PLoS Biology)

   Sustained attention (SA) and working memory (WM) are critical processes, but the brain networks supporting these abilities in development are unknown. We characterized the functional brain architecture of SA and WM in 9–11-year-old children and adults. First, we found that adult network predictors of SA generalized to predict individual differences and fluctuations in SA in youth. A WM model predicted WM performance both across and within children—and captured individual differences in later recognition memory—but underperformed in youth relative to adults. We next characterized functional connections differentially related to SA and WM in youth compared to adults. Results revealed two network configurations: a dominant architecture predicting performance in both age groups and a secondary architecture, more prominent for WM than SA, predicting performance in each age group differently. Thus, functional connectivity predicts SA and WM in youth, with networks predicting WM performance differing more between youths and adults than those predicting SA. 

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5. Age Differences In Retrieval-Related Reinstatement Reflect Age-Related Dedifferentiation At Encoding

   https://doi.org/10.1093/cercor/bhaa210  

   Hill, Paul F; King, Danielle R; Rugg, Michael D (August 2020, Cerebral Cortex)

   Abstract Age-related reductions in neural selectivity have been linked to cognitive decline. We examined whether age differences in the strength of retrieval-related cortical reinstatement could be explained by analogous differences in neural selectivity at encoding, and whether reinstatement was associated with memory performance in an age-dependent or an age-independent manner. Young and older adults underwent fMRI as they encoded words paired with images of faces or scenes. During a subsequent scanned memory test participants judged whether test words were studied or unstudied and, for words judged studied, also made a source memory judgment about the associated image category. Using multi-voxel pattern similarity analyses, we identified robust evidence for reduced scene reinstatement in older relative to younger adults. This decline was however largely explained by age differences in neural differentiation at encoding; moreover, a similar relationship between neural selectivity at encoding and retrieval was evident in young participants. The results suggest that, regardless of age, the selectivity with which events are neurally processed at the time of encoding can determine the strength of retrieval-related cortical reinstatement. 

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