Lauren L. Richmond

Working memory training and transfer in older adults.

There has been a great deal of interest, both privately and commercially, in using working memory training exercises to improve general cognitive function. However, many of the laboratory findings for older adults, a group in which this training is of utmost interest, are discouraging due to the lack of transfer to other tasks and skills. Importantly, improvements in everyday functioning remain largely unexamined in relation to WM training. We trained working memory in older adults using a task that encourages transfer in young adults (Chein & Morrison, 2010). We tested transfer to measures of working memory (e.g., Reading Span), everyday cognitive functioning [the Test of Everyday Attention (TEA) and the California Verbal Learning Test (CVLT)], and other tasks of interest. Relative to controls, trained participants showed transfer improvements in Reading Span and the number of repetitions on the CVLT. Training group participants were also significantly more likely to self-report improvements in everyday attention. Our findings support the use of ecological tasks as a measure of transfer in an older adult population.

Transcranial direct current stimulation enhances verbal working memory training performance over time and near transfer outcomes

Studies attempting to increase working memory (WM) capacity show promise in enhancing related cognitive functions but have also raised criticism in the broader scientific community given the inconsistent findings produced by these studies. Transcranial direct current stimulation (tDCS) has been shown to enhance WM performance in a single session [Fregni, F., Boggio, P., Nitsche, M., Bermpohl, F., Anatal, A., Feredoes, E., et al. Anodal transcranial direct current stimulation of prefrontal cortex enhances working memory. Experimental Brain Research, 166, 23–30, 2005]; however, the extent to which tDCS might enhance learning on a WM training regime and the extent to which learning gains might transfer outside the training task remains largely unknown. To this end, participants engaged in an adaptive WM training task [previously utilized in Richmond, L., Morrison, A., Chein, J., & Olson, I. Working memory training and transfer in older adults. Psychology & Aging, 26, 813–822, 2011; Chein, J., & Morrison, A. Expanding the minds workspace: Training and transfer effects with a complex working memory span task. Psychonomic Bulletin & Review, 17, 193–199, 2010] for 10 sessions over 2 weeks, concurrent with either active or sham stimulation of dorsolateral pFC. Before and after training, a battery of tests tapping domains known to relate to WM abilities was administered. Results show that tDCS enhanced learning on the verbal portion of the training task by 3.65 items. Furthermore, tDCS was shown to enhance near transfer to other untrained WM tasks in comparison with a no-contact control group. These results lend support to the idea that tDCS might bolster training and transfer gains in populations with compromised WM abilities.

Reflecting on past failures leads to increased perseverance and sustained attention

Psychology has struggled for years to define the traits and tendencies that make an individual successful. Past research has focused on intelligence. Recently, there has been a focus on perseverance or “grit”. We set out to examine the extent to which grit exhibits state-like facets and the relation between manipulations of grit and performance. Results from the first experiment provide evidence that reflecting on failures results in higher grit scores than reflecting on success. The second experiment extends the failure–grit relationship to explore how this relation might modify performance: Encouraging individuals to reflect on failures resulted in a significant reduction in error rates on a cognitive task requiring perseverance. Together, these results provide support for the idea that grit exhibits state-like tendencies, and that encouraging individuals to reflect on failures may result in improved behavioural outcomes.

Individual differences in autistic trait load in the general population predict visual working memory performance

Prior studies have reported instances of both intact and impaired working memory (WM) performance in people with autism spectrum disorder (ASD). In order to investigate the relation between autistic traits that extend into the normal population and WM, 104 normal college-aged students who varied in their levels of autistic traits were tested. The loading of ASD-associated traits in the normal population leads to differing predictions about WM performance. ASD traits related to a local processing style (or “attention to detail”) might enhance WM while ASD-associated traits related to difficulty switching attention and reorienting focus (or “social interaction”) might impair WM performance. To assess these predictions, participants filled out the Autism Spectrum Quotient (AQ) and performed a working memory task with both visual and verbal variants. AQ scores were then broken into “attention to detail” and “social interaction” factors, as proposed by Hoekstra and colleagues. The results showed that AQ scores did not predict verbal WM performance but they did predict visual WM performance. The social interaction and attention to detail factors of the AQ had opposing relationships with visual WM performance: A higher level of social difficulty was associated with significantly poorer visual WM performance while a higher level of attention to detail was associated with enhanced visual WM performance. Further investigation of the relation between AQ and WM using the original five-factor model proposed by Baron-Cohen and colleagues (2001) revealed an association between impoverished imagination and visual WM overall.

Constructing Experience: Event Models from Perception to Action

Mental representations of everyday experience are rich, structured, and multimodal. In this article we consider the adaptive pressures that led to human construction of such representations, arguing that structured event representations enable cognitive systems to more effectively predict the trajectory of naturalistic everyday activity. We propose an account of how cortical systems and the hippocampus (HPC) interact to construct, maintain, and update event representations. This analysis throws light on recent research on story comprehension, event segmentation, episodic memory, and action planning. It also suggests how the growing science base can be deployed to diagnose impairments in event perception and memory, and to improve memory for everyday events.

Age differences in spatial memory for mediated environments.

Compared with younger adults, older adults have more difficulty with navigation and spatial memory in both familiar and unfamiliar domains. However, the cognitive mechanisms underlying these effects have been little explored. We examined three potential factors: (a) use of and coordination across spatial reference frames, (b) nonspatial cognitive abilities, and (c) the ability to segment a route into effective chunks. In two experiments, healthy young and older adults watched videos of navigation in a novel environment and had to remember the placement of landmarks along the route. Participants completed three spatial memory tasks—a virtual pointing task, a distance estimation task, and sketch map drawing—for each route. The pointing task depends on updating and accessing the updated egocentric reference frame relative to other frames. Map drawing may rely more on environment-centered processing. The distance estimation task could be solved using either frame of reference. Last, participants segmented each route. In a separate session, working memory, processing speed, and verbal memory were assessed. Older adults performed less well on all spatial tasks compared with younger adults; aging had a stronger negative effect on pointing performance. This may point to impairments in older adults’ ability to update and coordinate information across reference frames. Performance on all spatial tasks was predicted by nonspatial task performance. Segmentation did not predict spatial memory. These results underline the importance of situating age differences in navigation in the context of basic transformations of spatial reference frames, and also in the context of nonspatial cognitive abilities.

Adult Age Differences in Production and Monitoring in Dual-List Free Recall

The present experiment examined adult age differences in the production and monitoring of responses in dual-list free recall. Younger and older adults studied 2 lists of unrelated words and were instructed to recall from List 1, List 2, or List 1 and List 2. An externalized free recall procedure required participants to: (a) report all responses that came to mind while recalling from specific lists, (b) classify responses as correct or incorrect, and (c) provide confidence judgments for their accuracy classifications. Relative to younger adults, older adults showed a monitoring deficit by misclassifying proportionally more responses and discriminating more poorly between correct and incorrect responses in their confidence judgments. This deficit was especially pronounced under conditions of retroactive interference that occurred when participants recalled from List 1 only. A comparison of retrieval dynamics for all responses produced and for those that participants were reasonably confident were correct provided information about age differences in preretrieval context reinstatement and postretrieval monitoring of retrieved context. One noteworthy finding was that total production when recalling from List 1 showed that List 2 responses remained more accessible across the first several retrieval attempts for older than younger adults, which indicated a substantial age difference in the ability to reinstate List 1 context. Overall, the present findings provide a nuanced characterization of age differences in the operation of production and monitoring mechanisms under conditions of proactive and retroactive interference that can inform models of free recall.