Age-related decline of sleep-dependent consolidation

Sleep-dependent memory consolidation is observed following motor skill learning: Performance improvements are greater over a 12-h period containing sleep relative to an equivalent interval without sleep. Here we examined whether older adults exhibit sleep-dependent consolidation on a sequence learning task. Participants were trained on one of two sequence learning tasks. Performance was assessed after a 12-h break that included sleep and after a 12-h break that did not include sleep. Older and younger adults showed similar degrees of initial learning. However, performance of the older adults did not improve following sleep, providing evidence that sleep-dependent consolidation is diminished with age.     

Space Fortress game training and executive control in older adults: a pilot intervention

We investigated the feasibility of using the Space Fortress (SF) game, a complex video game originally developed to study complex skill acquisition in young adults, to improve executive control processes in cognitively healthy older adults. The study protocol consisted of 36 one-hour game play sessions over 3 months with cognitive evaluations before and after, and a follow-up evaluation at 6 months. Sixty participants were randomized to one of three conditions: Emphasis Change (EC)--elders were instructed to concentrate on playing the entire game but place particular emphasis on a specific aspect of game play in each particular game; Active Control (AC)--game play with standard instructions; Passive Control (PC)--evaluation sessions without game play. Primary outcome measures were obtained from five tasks, presumably tapping executive control processes. A total of 54 older adults completed the study protocol. One measure of executive control, WAIS-III letter-number sequencing, showed improvement in performance from pre- to post-evaluations in the EC condition, but not in the other two conditions. These initial findings are modest but encouraging. Future SF interventions need to carefully consider increasing the duration and or the intensity of the intervention by providing at-home game training, reducing the motor demands of the game, and selecting appropriate outcome measures.     

Space Fortress game training and executive control in older adults: A pilot intervention

ABSTRACT

We investigated the feasibility of using the Space Fortress (SF) game, a complex video game originally developed to study complex skill acquisition in young adults, to improve executive control processes in cognitively healthy older adults. The study protocol consisted of 36 one-hour game play sessions over 3 months with cognitive evaluations before and after, and a follow-up evaluation at 6 months. Sixty participants were randomized to one of three conditions: Emphasis Change (EC) – elders were instructed to concentrate on playing the entire game but place particular emphasis on a specific aspect of game play in each particular game; Active Control (AC) – game play with standard instructions; Passive Control (PC) – evaluation sessions without game play. Primary outcome measures were obtained from five tasks, presumably tapping executive control processes. A total of 54 older adults completed the study protocol. One measure of executive control, WAIS-III letter–number sequencing, showed improvement in performance from pre- to post-evaluations in the EC condition, but not in the other two conditions. These initial findings are modest but encouraging. Future SF interventions need to carefully consider increasing the duration and or the intensity of the intervention by providing at-home game training, reducing the motor demands of the game, and selecting appropriate outcome measures.     

Differential brain shrinkage over 6 months shows limited association with cognitive practice

The brain shrinks with age, but the timing of this process and the extent of its malleability are unclear. We measured changes in regional brain volumes in younger (age 20–31) and older (age 65–80) adults twice over a 6 months period, and examined the association between changes in volume, history of hypertension, and cognitive training. Between two MRI scans, 49 participants underwent intensive practice in three cognitive domains for 100 consecutive days, whereas 23 control group members performed no laboratory cognitive tasks. Regional volumes of seven brain structures were measured manually and adjusted for intracranial volume. We observed significant mean shrinkage in the lateral prefrontal cortex, the hippocampus, the caudate nucleus, and the cerebellum, but no reliable mean change of the prefrontal white matter, orbital-frontal cortex, and the primary visual cortex. Individual differences in change were reliable in all regions. History of hypertension was associated with greater cerebellar shrinkage. The cerebellum was the only region in which significantly reduced shrinkage was apparent in the experimental group after completion of cognitive training. Thus, in healthy adults, differential brain shrinkage can be observed in a narrow time window, vascular risk may aggravate it, and intensive cognitive activity may have a limited effect on it.     

Training effects on dual-task performance: are there age-related differences in plasticity of attentional control?

A number of studies have suggested that attentional control skills required to perform 2 tasks concurrently become impaired with age (A. A. Hartley, 1992; J. M. McDowd & R. J. Shaw, 2000). A. A. Hartley (2001) recently observed that the age-related differences in dual-task performance were larger when the 2 tasks required similar motor responses. The present study examined the extent to which age-related deficits in dual-task performance or time sharing--in particular, dual-task performance of 2 discrimination tasks with similar motor requirements--can be moderated by training. The results indicate that, even when the 2 tasks required similar motor responses, both older and younger adults could learn to perform the tasks faster and more accurately. Moreover, the improvement in performance generalized to new task combinations involving new stimuli. Therefore, it appears that training can substantially improve dual-task processing skills in older adults.     

Testing the limits of cognitive plasticity in older adults: application to attentional control

Laboratory based training studies suggest that older adults can benefit from training in tasks that tap control aspects of attention. This was further explored in the present study in which older and younger adults completed an adaptive and individualized dual-task training program. The testing-the-limits approach was used [Lindenberger, U., & Baltes, P. B. (1995). Testing-the-limits and experimental simulation: Two methods to explicate the role of learning in development. Human Development, 38, 349-360.] in order to gain insight into how attentional control can be improved in older adults. Results indicated substantial improvement in overlapping task performance in both younger and older participants suggesting the availability of cognitive plasticity in both age groups. Improvement was equivalent among age groups in response speed and performance variability but larger in response accuracy for older adults. The results suggest that time-sharing skills can be substantially improved in older adults.     

Memory training interventions require a tailor-made approach: Commentary on McDaniel and Bugg

Memory training for older adults often produces gains that are limited to the particular memory tasks encountered during training. We suggest that memory training programs may be misguided by an implicit "generalist" assumption-memory training on a couple of memory tasks will have a positive benefit on memory ability in general. One approach to increase memory-training benefits is to target training for the everyday memory tasks for which older adults struggle. Examples include training retrieval strategies, prospective memory strategies, and strategies for learning and remembering names. Another approach is to design training to foster transfer. Possible elements to improve transfer are increasing the variation that is experienced during the course of training at the level of stimuli and tasks, incorporating "homework" that guides the older adult to become attuned to situations in which the strategies can be applied, and providing older adults with a better understanding of how memory works. Finally, incorporating aerobic exercise into memory training programs may potentiate the acquisition and maintenance of the trained cognitive strategies.     

Adult age differences in subjective and objective measures of strategy use on a sequentially cued prediction task

Differences in strategy use are thought to underlie age-related performance deficits on many learning and decision-making tasks. Recently, age-related differences in learning to make predictions were reported on the Triplets Prediction Task (TPT). Notably, deficits appeared early in training and continued with experience. To assess if age differences were due to early strategy use, neural networks were used to objectively assess the strategies implemented by participants during Session 1. Then, the relationship between these strategies and performance was examined. Results revealed that older adults were more likely to implement a disadvantageous strategy early in learning, and this led to poorer task performance. Importantly, the relationship between age and task performance was partially mediated by early strategy use, suggesting that early strategy selection played a role in the lower quality of predictions in older adults.     

Performance gains from directed training do not transfer to untrained tasks

Given the increasing complexity of the tasks and skills needed in modern society, developing effective training strategies is of tremendous practical importance. Furthermore, training that improves performance of both trained and untrained tasks would be highly efficient. In the present study, we examined how directed training contributes to skill acquisition, and more importantly, to engendering transfer of training to untrained tasks. Participants learned a complex video game for 30 h (Space Fortress, Donchin, Fabiani, & Sanders, 1989) using one of two training regimens: Hybrid Variable-Priority Training (HVT), with a focus on improving specific skills and managing task priority, or Full Emphasis Training (FET) in which participants simply practiced the game to obtain the highest overall score. We compared game performance, retention of training gains, and transfer of training to untrained tasks as a function of the training regimen. Compared to FET, HVT learners reached higher levels of mastery on the game and HVT was particularly beneficial for initially poor performing participants. This benefit persisted seven months after training. However, contrary to expectation, both HVT and FET were unsuccessful in producing transfer to untrained tasks compared to a group that received limited game experience, suggesting that directed training and practice can produce task-specific improvements, but improvements do not necessarily transfer from trained to untrained tasks.     

Growth curve models in retrospective memory and prospective memory: the relationship between prediction and performance with task experience

Older adults commonly experience declines in episodic memory that affect their daily lives. The aim was to examine whether the acquired metacognitive awareness that comes with task experience, indexed by meta-retrospective memory (meta-RM)/meta-prospective memory (meta-PM), influences how older adults predict performance on later trials. Participants were 178 community-dwelling older adults. RM performance and predictions were measured using a multi-trial word-list learning task. Predictions and performance for PM were measured using a PM paradigm. Change in RM/PM performance and predictions over the trials/blocks were modelled using latent growth curve analyses. For RM, both predictions and performance increased with task experience. However, for PM, neither performance nor predictions changed with task experience. Hierarchical multiple regressions revealed that metacognitive awareness acquired during the RM and PM tasks influenced how older adults’ modified their predictions of subsequent task performance. Findings are consistent with [Toglia and Kirk’s (2000). Understanding awareness deficits following brain injury. NeuroRehabilitation, 15(1), 57–70] hypothesis that individuals compare ongoing performance to expectations based on metacognitive knowledge, such that a discrepancy between actual and expected performance may influence emergent awareness.     

Aging and automaticity: Evaluation of instance-based and strength-based mechanisms

Abstract

Experiments evaluated instance-based learning as a possible sole mechanism underlying development of automaticity. Age differences in extended practice lexical decision and factors that could effect age-related performance on lexical decision tasks were also examined. the first experiment was conducted to evaluate the role of stimulus-specific and strategic, task-specific learning underlying performance improvement in a trained lexical decision task. the first experiment consisted of a training and a transfer phase. the training phase assessed age-related differences on a lexical decision task where an attention response could, in principle, be developed (Search condition) and where an attention response could not develop (Nonsearch condition). the transfer phase was conducted to evaluate the role of strategic, task-specific factors on performance improvement observed in the training phase. Age-related differences in word-nonword response time differences were eliminated with practice in the nonsearch, but not the search, version of the task. Transfer tests also implicate strategic differences as a partial source of age differences in lexical decision performance. Experiment 2 was a 10-session (two-week) extended practice study which was conducted to provide a strong test of instance-based learning as a sole mechanism for automaticity. Contrary to predictions of instance theory, the Search and Nonsearch conditions converged for the young adults. Consistent with a strength-based theory of automaticity applied to cognitive aging, the conditions did not converge for older adults. the results provide further support for age differences in automaticity-as-attention training. Based on these and other results, the importance of considering varieties of automaticity in theories of cognitive aging is discussed.     

Effects of age simulation and age on motor sequence learning: Interaction of age-related cognitive and motor decline

Aging is known to lead to decrements in sensory and cognitive functioning and motor performance. The purpose of the present experiment was twofold: a) We assessed the influence of wearing an age simulation suit on motor sequence learning, cognitive speed tasks and far visual acuity in healthy, younger adults. b) We evaluated the interaction of cognitive aging and declining motor sequence learning in older adults. In a between-subjects design we tested 11 younger adults (M_age = 23.6 years) without the age suit, 12 younger adults wearing the age suit (M_age = 23.2 years), and 23 older adults (M_age = 72.6 years). All participants learned a simple, spatial-temporal movement sequence on two consecutive days, and we assessed perceptual processing speed (Digit Symbol Substitution test and Figural Speed test) and far visual acuity. Wearing an age simulation suit neither affected the learning of the simple motor sequence nor the performance at the cognitive speed tasks in younger adults. However, far visual acuity suffered from wearing the suit. Younger adults with and without the suit showed better motor sequence learning compared to older adults. The significant correlations between the cognitive speed tests and the motor learning performance in older adults indicated that cognitive aging partially explains some of the variance in age-related motor learning deficits.     

New Developments in Understanding Skilled Performance

ABSTRACT— Skilled performance, whether it involves rapid and accurate motor movements (such as playing a video game or using a scalpel in the operating room) or a high degree of domain knowledge (such as finding a small tumor in an X-ray or writing a journal article) typically involves learning and practice over an extended period of time. In light of recent theory and empirical research, I consider two enduring issues associated with skill acquisition: whether individuals become more alike in performance or more different over the course of skill acquisition, and what the determinants of individual differences in skilled performance are. Two broad classes of tasks are considered: tasks that involve speed and accuracy of motor movements and tasks that primarily involve domain knowledge. Issues of practice, ability, and other determinants of skilled performance such as gender and aging are discussed.     

Role of age in relation between two kinds of abilities and performance in acquisition of new motor skill

Better understanding of age-related differences in skilled performance was the focus of analyses of cognitive-performance scores-relationships in acquisition of a new motor skill. 31 younger adults and 33 older adults were tested on both a cognitive and a psychomotor test. Then, they were asked to learn a juggling task over 12 sessions of 20 min. Analysis indicated age-related differences in the rate of learning. Acquisition by the younger adult group was significantly faster than that by the older adult group. This difference was also reflected in the relationship of cognition and performance for the two age groups. Motor execution for the older adults seemed to require more psychomotor ability, especially at the end of the learning sessions, and was dependent on cognitive control. This trend is consistent with the perspective that cognitive predictors of performance are related to age.     

Aging, Training, and the Brain: A Review and Future Directions

As the population ages, the need for effective methods to maintain or even improve older adults’ cognitive performance becomes increasingly pressing. Here we provide a brief review of the major intervention approaches that have been the focus of past research with healthy older adults (strategy training, multi-modal interventions, cardiovascular exercise, and process-based training), and new approaches that incorporate neuroimaging. As outcome measures, neuroimaging data on intervention-related changes in volume, structural integrity; and functional activation can provide important insights into the nature and duration of an intervention’s effects. Perhaps even more intriguingly, several recent studies have used neuroimaging data as a guide to identify core cognitive processes that can be trained in one task with effective transfer to other tasks that share the same underlying processes. Although many open questions remain, this research has greatly increased our understanding of how to promote successful aging of cognition and the brain.     

Visual search for real world targets under conditions of high target-background similarity: Exploring training and transfer in younger and older adults

Real world visual search tasks often require observers to locate a target that blends in with its surrounding environment. However, studies of the effect of target-background similarity on search processes have been relatively rare and have ignored potential age-related differences. We trained younger and older adults to search displays comprised of real world objects on either homogenous backgrounds or backgrounds that camouflaged the target. Training was followed by a transfer session in which participants searched for novel camouflaged objects. Although older adults were slower to locate the target compared to younger adults, all participants improved substantially with training. Surprisingly, camouflage-trained younger and older adults showed no performance decrements when transferred to novel camouflage displays, suggesting that observers learned age-invariant, generalizable skills relevant for searching under conditions of high target-background similarity. Camouflage training benefits at transfer for older adults appeared to be related to improvements in attentional guidance and target recognition rather than a more efficient search strategy.     

Transfer of skill engendered by complex task training under conditions of variable priority

We explored the theoretical underpinnings of a commonly used training strategy by examining issues of training and transfer of skill in the context of a complex video game (Space Fortress, Donchin, 1989). Participants trained using one of two training regimens: Full Emphasis Training (FET) or Variable Priority Training (VPT). Transfer of training was assessed with a large battery of cognitive and psychomotor tasks ranging from basic laboratory paradigms measuring reasoning, memory, and attention to complex real-world simulations. Consistent with previous studies, VPT accelerated learning and maximized task mastery. However, the hypothesis that VPT would result in broader transfer of training received limited support. Rather, transfer was most evident in tasks that were most similar to the Space Fortress game itself. Results are discussed in terms of potential limitations of the VPT approach.     

Executive process training in young and old adults

There is a growing body of research on the modifiability of executive functions in different stages of life. Previous studies demonstrate robust training effects but limited transfer in younger and particularly in older adults. The aim of the present study was to investigate whether a theoretically derived intervention for executive functioning, addressing several basic processes (updating, shifting, and inhibition), can induce transfer effects in early and late adulthood. Fifty-nine healthy adults, 29 young and 30 older adults, were randomly assigned to either training or no-contact control groups. The training groups received 15 sessions of executive process training for about 45 min/session during 5 weeks. A test battery including a criterion task and near, intermediate, and far transfer tasks was administered before and after training. Results showed pronounced age-equivalent gains on the criterion task. Near transfer was seen to non-trained updating and inhibition tasks for the young and older trained participants. However, only the young adults showed intermediate transfer to two complex working memory tasks. No far transfer effects were seen for either age group. These findings provide additional evidence for age-related constraints in the ability to generalize acquired executive skills, and specifically show that training of multiple executive processes is not sufficient to foster transfer beyond the very near in older adults.     

Instance-based automaticity and aging: acquisition, reacquisition, and long-term retention

This research examined age differences in the acquisition and reacquisition of instance-based automaticity. In 2 experiments, young and older adults were trained to enumerate targets presented in otherwise empty displays or in displays that contained distractors. Experiment 1 revealed that older adults required more practice to reach asymptote than young adults. For both age groups, modifications of the identities and locations of targets produced substantial disruptions in performance, whereas modifications of the identities or locations of distractors produced little interference. However, no age differences in the representations of instances in memory were obtained in participants who reached asymptote. Experiment 2 revealed age deficits in the long-term retention and rate of reacquisition of instance-based automaticity 18 months after initial training.     

Memory training and strategy use in older adults: results from the ACTIVE study

Little is known about the long-term effects of memory training in later life on strategy use. Data from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study (n = 1,401) were used to describe strategy use in a community-dwelling sample of older adults. Strategy clustering scores on verbal list learning tasks of episodic memory were used to test the impact of memory training on strategy use and study longitudinal associations between strategy clustering, memory performance, and everyday functioning. Results suggested that younger, female, white, healthier, and more educated participants show higher strategy clustering scores initially but no characteristics were consistently associated with different trajectories in strategy clustering across all strategy clustering measures together. Memory training had significant immediate effects on all measures of strategy use that were maintained through five years of follow-up. With respect to longitudinal mediation, pre-post training changes in most strategy clustering scores mediate changes in objective memory performance and everyday functioning, implying that strategies can be modified and are closely related to both memory ability and the ability to function independently. This study provides evidence that older adults can be trained to use cognitive strategies, the effects are durable, and strategies are associated with memory and everyday functioning.