Exercising the Brain to Avoid Cognitive Decline

Examining the Evidence

William E Reichman; Alexandra J Fiocco; Nathan S Rose

Disclosures

Aging Health. 2010;6(5):565-584. 

In This Article

Nontraditional Cognitive Methods & Alternative Approaches

A variety of studies have now been published exploring the cognitive benefits of recreational activities, social networks, physical fitness and other related and integrated activities. The goal of these investigations is to determine whether activities that are part of everyday life may result in better transfer effects to function than stand-alone cognitive exercises (training workshops or computer based). Many of these investigations explore the benefit of activities that are multidimensional and that require creativity as well as new skill acquisition. Although these studies do not match the scientific rigor of clinical trials that isolate and train a specific cognitive ability, they fulfill an important role by potentially revealing potent factors to be targeted by more controlled intervention studies in the future.

Nontraditional Training

In a study using nontraditional cognitive approaches, de Medeiros and coworkers studied whether participation in an autobiographical writing workshop had positive effects on cognition.[57] A total of 18 physically and cognitively healthy seniors were enrolled in 90-min writing sessions over an 8-week period, and were taught a variety of different writing techniques. The investigators reported that participants in the structured workshop demonstrated improvements in processing speed, verbal learning and attention. Noice and colleagues studied the effects of theatre training on cognitive, emotional and physiological functions in a cohort of 124 community-dwelling seniors.[58] Participants were assigned to one of two intervention groups (theatre training and visual arts education), consisting of nine sessions over 4 weeks. There was a third, no-intervention control group. The authors reported that theatre training participants showed significant improvements over controls in memory recall, problem-solving and emotional well-being. These effects were not seen in the visual arts education group, who did not perform as well as the theatre group in problem solving and emotional well-being. After 4 months, the problem solving effects were stable and memory performance continued to improve. These same investigators conducted a related study in a sample of seniors who were less educated and of a lower socioeconomic status, residing in publicly subsidized retirement homes. These participants also demonstrated the positive impact of theatre training on cognitive performance.[59]

In an ongoing pilot program called Experience Corps®,[60] researchers are starting to report on the benefits of volunteering on brain health. The program provides a model that enhances physical, social and cognitive activity, which is expected to produce enhanced mental flexibility, improved working memory skills, cooperative problem solving and other cognitive and functional benefits. The initiative consists of older volunteers working within a school for grades K-3 for a minimum of 15 h per week. The work involves special areas of need within the school; literacy tutoring, behavior management and library use. In an 8-month follow-up study, Carlson and coworkers found that when compared with controls, older adults who volunteered in Experience Corps displayed a nonstatistically significant trend towards improvements in executive functions and memory.[61] However, active volunteer participants with impaired baseline executive functions showed the greatest degree of improvement in executive and memory functioning at follow-up while the similarly impaired controls declined in executive functions ability (p < 0.05). Carlson and colleagues assessed the benefits of Experience Corps in 'at risk' volunteers (i.e., African–American women with low level education, low income and low Mini-mental status exam [MMSE] score at baseline).[62] Not only were cognitive improvements found in executive inhibitory processes, but intervention-specific increases in brain activity were observed in the prefrontal and anterior cingulate cortex at 6-month follow-up using functional MRI. This study suggests that engaging in stimulating activities (via volunteering) may enhance brain plasticity, and presents the possibility of mapping brain changes to behavioral outcomes.

Overall, nontraditional cognitive approaches provide some promising results; however, more vigorous randomized control studies are required in order to elucidate beneficial components of each activity and to isolate the specific cognitive domains that are being altered as a result.

Alternative Approaches

Epidemiological studies show that physical activity,[63,64] nutrition[65] and social engagement[66,67] may play a protective role against brain aging. Furthermore, these findings coincide with the animal literature. For example, monkey[68,69] and rodent[19,70] studies have demonstrated that caloric intake restriction may prevent age-related decrements in brain structure and function. In addition, it has been shown that the exercise component of the rodent enriched environment (i.e., the running wheel) produces additional neurogenesis effects by enabling the maturation of neuroblasts into functional hippocampal neurons.[71] These studies suggest that cognitive function may be enhanced by alternative strategies that indirectly affect brain function.

Given the important role of exercise on brain function,[72,73] researchers have started to assess the combined effects of physical and cognitive activity on brain health. In a 6-month, randomized control trial, Klusmann and colleagues assessed the effects of mental and physical activity on cognitive performance in older women 70–93 years of age.[74] Women were randomly assigned to an exercise group, a computer course group or a control group. At follow-up, women in the computer group and the exercise group demonstrated improvements in episodic memory and maintenance in working memory, compared with controls who showed a decline in cognitive performance. However, this study did not assess the interaction effect between exercise and mental activity on cognitive outcomes. In a sample of 19 middle-aged and older adults with subjective mild memory complaints, Small and colleagues reported on the combined effects of cognitive and physical exercise, stress reduction and a healthy diet on cognitive performance and cerebral metabolic activity as measured by positron emission tomography data.[75] They reported improvement in verbal fluency with correlated changes in prefrontal cortical metabolism, perhaps indicating enhanced cognitive reserve. Finally, the investigators concluded that such a lifestyle program may result in enhanced cognitive efficiency of a brain region involved in working memory.

In summary, more research is needed to understand what constitutes the most effective type of cognitive training, the long-term retention of training effects and whether training can demonstrate transfer of cognitive gains to daily function or global cognition. Initially, promising associations were found between a reduced level of cognitive decline in late-adulthood and a life-long pursuit of cognitive engagement, which supports the idea of a brain/cognitive reserve. However, the limited number of well-designed trials that fully test the nature of benefits attainable from cognitive training interventions prevent one from definitively concluding that it is possible to maintain or improve cognitive function, or prevent cognitive decline associated with healthy or pathological aging. Furthermore, additional research is required to assess other life-style domains (e.g., exercise and nutrition) and how they may interact with cognitive training strategies on brain function. Nonetheless, it is important to note that there is also 'little evidence to suggest that interventions designed to improve cognitive function either worsen it or produce unwanted side effects'.[76] Additional research is also needed to determine the intervention-based neurological changes that may occur: whether these changes are short or long-lived and whether they may be observed in both healthy and patient groups.

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