September 1, 2007 |
by Warren Grill, senior technical editor
September 1, 2007
The rapid growth of the aged population and age-associated cognitive decline have led to an explosion of interest and activity in potential therapies to avert adverse changes in cognitive function. The idea is not entirely new. For example the late Lawrence Katz of Duke University and Manning Rubin published an exercise manual for the brain back in 1998, Keeping Your Brain Alive: 83 Neurobic Exercises. This approach was primarily concerned with novelty to enhance or modify sensory experiences, for example showering with your eyes closed.
Further, memory training, cognitive training, and physical activity have all been recommended as protection against cognitive decline, but the evidence to support these interventions is limited. Two recent studies, however, provide evidence supporting the notion that cognitive behavioral training produces gains in cognitive function and that these gains outlast the period of training.
Sherry Willis from Penn State University and a multi-institutional consortium reported late last year in the Journal of the American Medical Association on the ACTIVE trial of the long-term effects of cognitive training in healthy older adults. In the trial, 2,832 subjects with an average age of 74 received 10 sessions of training in specific domains: memory, reasoning, or processing speed, and some subjects received “booster” session 11 and 35 months after the initial period.
The initial period of training produced improvements in performance within the trained domain, as compared to an untreated control group. These domain-specific improvements in function were preserved at five years after training, but there was no transference to other cognitive domains. Further, the improvements in these cognitive domains did not translate into improvements in instrumental activities of daily living (IADL), except for self-reported IADL by the group receiving reasoning training.
Also late last year, a group from Posit Science published in the Proceedings of the National Academy of Sciences on memory enhancement in healthy older adults. The study of 182 subjects with an average age of 71 demonstrated training-related improvements in the trained and other memory functions, and these gains were preserved at 3 months after training. The training tasks were related to identification and processing of auditory stimuli and were quite intensive—1 hour per day, 5 days per week for 8 to 10 weeks.
Between 77 and 93 percent of the subjects receiving training improved on the trained tasks during the training period, and the level of improvement was between 10 and 41 percent. Further, the trained group exhibited improvement in global auditory memory, and these effects were preserved at three months post training.
As stated by Shumaker et al. in a commentary on the ACTIVE trial, “The prevalence of age-related cognitive impairment is predicted to reach 84 million by 2040, [and] the growing threat of an aging population with limited options for maintaining cognitive function is a major challenge.”
These results demonstrate that comparatively short bouts of cognitive training can produce domain-specific gains in function, and that these gains are preserved. However, the studies were limited to healthy subjects, and it is not clear whether the results translate to persons with nascent cognitive decline where there may be organic changes in the brain that limit the impact of cognitive behavioral training.
The commercial opportunity of brain maintenance has led to a number of offerings besides that from Posit Science including Nintendo’s Brain Age2, a web-based system called BrainBuilder.com, and the [m]Power cognitive fitness system from Dakim, Inc.
