Brain fitness grew out of the study of neuropsychology and is the science of maintaining and training cognitive abilities. Its training principles are based on concepts derived from phenomena contributing to neuroplasticity and neurogenesis. Cognitive abilities like attention, memory, visual/spatial processing, auditory processes and language, motor coordination, and executive functions like planning and problem solving diminish over time unless they are used regularly. A major hypothesis is that improvement in cognitive abilities through brain exercise represents brain fitness, in an analogy with how physical exercise produces physical fitness. A major limitation on this hypothesis is how the effects of improvements on a mental task through practice can be separated from the improvements based on brain fitness. Brain fitness typically seeks to improve attention, memory, thinking, and stress management.
Brain fitness is the capacity of a person to meet the various cognitive demands of life. It is evident in an ability to assimilate information, comprehend relationships, and develop reasonable conclusions and plans. Brain fitness can be developed by formal education, being actively mentally engaged in life, continuing to learn, and exercises designed to challenge cognitive skills. Healthy lifestyle habits including mental stimulation, physical exercise
, good nutrition
, stress management
, and sleep
can improve brain fitness. On the other hand, chronic stress
, decreasing estrogen
, excess oxytocin
, and prolonged cortisol
can decrease brain fitness as well as general health.
Brain fitness can be measured physically at the cellular level by neurogenesis, the creation of new neurons, and increased functional connections of synapses and dendrites between neurons. It can also be evaluated by behavioral performance as seen in cognitive reserve, improved memory, attention, concentration, executive functions, decision-making, mental flexibility, and other core capabilities.
Like physical fitness, brain fitness can be improved by disciplined exercise that presents a variety of challenges in a constructive environment. Recent research shows that regular brain “workouts” not only help prevent age-related cognitive decline, dementia, Alzheimer’s, and other cognitively degenerative diseases, but can also improve normally functioning minds. Although puzzles and games like chess provide mental stimulation, the most neuroprotective exercises are scientifically based to utilize multiple cognitive processes and are able to generalize to overall mental faculties and performance.
Neurogenesis is the creation of new neurons. The more active a particular brain cell is, the more connections it develops with its neighboring neurons through a process called dendritic sprouting
. A single neuron can have up to thirty thousand such connections, creating a dense web of interconnected activity throughout the brain. Each neuron can then be stimulated directly through experience (real or imagined) or indirectly through these connections from its neighbors, which saves the cell from cell death.
Physical exercise boosts the brain’s rate of neurogenesis throughout life, while mental exercise increases the rate at which those new brain cells survive and make functional connections into existing neural networks. Both physical exercise and the challenge from mental exercise increase the secretion of nerve growth factor, which helps neurons grow and stay healthy.
Consistent mental challenge by novel stimuli increases production and interconnectivity of neurons and nerve growth factor, as well as prevents loss of connections and cell death. The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) nationwide clinical trial is so far the nation's largest study of cognitive training. Researchers found that improvements in cognitive ability roughly counteract the degree of long-term cognitive decline typical among older people without dementia. The results, published in the Journal of the American Medical Association
in 2002, showed significant percentages of the 2,802 participants age 65 and older who trained for five weeks for about 2 1/2 hours per week improved their memory, reasoning and information-processing speed.
Joe Verghese, M.D. found that people could reduce their risk of Alzheimer’s by 64% simply by raising their activity score by 1 point, and a 1-point increase corresponded to a reduction of dementia risk by 7%. That means that people could lower their dementia risk by 7% simply by adding one activity per week (such as doing a crossword puzzle or playing a board game) to their schedule. According to the findings of that same study, subjects who did crossword puzzles four days a week had a 47% lower risk of dementia than subjects who did a crossword puzzle just once a week.
Effective mental stimulation should provide:
Practice effects or brain fitness?
A significant issue in brain fitness work has been establishing that brain training exercises have impacts on brain function that
exist outside the context of the training task. . For
example, in the ACTIVE studies, subjects were trained only in one of these three modalities: speed of processing, reasoning, or memory. Subjects did not significantly improve in non-trained modalities.
Other studies, however, have looked at changes in tests of everyday function that occur after brain-based
training. In a review of these studies, the following significant effects were noted. Improvements on speed of processing training tests were related to improvements in the Timed Instrumental Activities of Daily Living test (TIADL). Evidence of ceiling effects were also noted, indicating that subjects who were further below normal at the beginning of training had the largest expected gains. Further, the effect sizes may be related to customizing the training difficulty to the performance level of the trainee. Subjects trained with one training strategy, the Useful Field of View test (UFOV), showed significant improvements in an on-the-road driving test designed to evaluate driver response during potential dangerous situations. Specifically, subjects trained with UFOV made fewer dangerous maneuvers after training.
Important research papers
- Ambrogini P, et al. Learning may induce neurogenesis in adult rat dentate gyrus. Neuroscience Letters. 2004;359:13-16.
- Ando J, Ono Y, Wright MJ. Genetic structure of spatial and verbal working memory. Behavioral Genetics. 2001;31(6):615-24.
- Bennett, DA, et al. Education modifies the relation of AD pathology to level of cognitive function in older persons. Neurology. 2003;60/12:1909-15.
- Bigio EH, Hynan LS, Sontag E, Satumtira S, White CL. Synapse loss is greater in presenile than senile onset Alzheimer disease: implications for the cognitive reserve hypothesis. Neuropathology and Applied Neurobiology. 2002;28(3):218-27.
- Bruel-Jungerman ES, Laroche, Rampon C. New neurons in the dentate gyrus are involved in the expression of enhanced long-term memory following environmental enrichment. European Journal of Neuroscience. 2005;21/2:513-21.
- Cameron, M.I., Robinson, V.M. “Effects of Cognitive Training on Academic and On-Task Behavior of Hyperactive Children.” Journal of Abnormal Child Psychology. 1980 Sep; 8(3): 405-19.
- Döbrössy MDE, et al. Differential effects of learning on neurogenesis: learning increases or decreases the number of newly born cells depending on their birth date. Molecular Psychiatry. 2003;8:974-82.
- Gopher D, Weil M, Baraket T. Transfer of skill from a computer game trainer to flight. Human Factors. 1994;36,1-19.
- Gould E, et al. Learning enhances adult neurogenesis in the hippocampal formation. Nature Neuroscience. 1999;2/3:260-5.
- Katzman R. Education and the prevalence of dementia and Alzheimer's disease. Neurology. 1993;43(1):13-20.
- Kempermann G, Gast D, Gage FH. Neuroplasticity in old age: sustained fivefold induction of hippocampal neurogenesis by long-term environmental enrichment. Annals of Neurology. 2002;52:135-43.
- Kempermann G, Kuhn HG, Gage FH. More hippocampal neurons in adult mice living in an enriched environment. Nature. 1997;386(6624):493-5.
- Klingberg T, Fernell E, Olesen PJ, Johnson M, Gustafsson P, Dahlstrom K, Gillberg CG, Forssberg H, Westerberg H. Computerized training of working memory in children with ADHD--a randomized, controlled trial. J Am Acad Child Adolesc Psychiatry. 2005;44(2):177-86.
- Kotwal, D.B., Burns, W.J., & Montgomery, D.D. "Computer-assisted cognitive training for ADHD." Behavior Modification. 1996; 20. 85-96.
- Leuner B, et al. Learning enhances the survival of new neurons beyond the time when the hippocampus is required for memory. Journal of Neuroscience. 2004;4:7477-81.
- Maguire EA, Gadian DG, Johnsrude IS, Good CD, Ashburner J, Frackowiak RS, Frith CD. Navigation-related structural change in the hippocampi of taxi drivers. Proceedings of the National Academy of Science USA. 2000;97(8):4398-403.
- Mahncke, HW, et al. "Memory enhancement in healthy older adults using a brain plasticity-based training program: a randomized, controlled study." Proc Nat Acad. Sci. USA 2006 Aug 15;103(33):12523-8
- Scarmeas N, Stern Y. Cognitive reserve and lifestyle. J Clin Exp Neuropsychol. 2003;25(5):625-33.
- Stern Y, Gurland B, Tatemichi TK, Tang MX, Wilder D, Mayeux R. Influence of education and occupation on the incidence of Alzheimer's disease. JAMA. 1994;271(13):1004-10.
- Verghese J, et al. Leisure activities and the risk of dementia in the elderly. The New England Journal of Medicine. 2003;348/25:2508-16.
- Willis SL, Tennstedt SL, Marsiske M, et al. Long-term effects of cognitive training on everyday functional outcomes in older adults. JAMA. 2006;296:2805-14.
- Wilson RS, et al. Participation in cognitively stimulating activities and risk of incident Alzheimer disease. JAMA. 2002;287/6:742-8.
- Jaeggi, S.M., Buschkuehl, M., Jonides, J., Perrig, W.J. Improving fluid intelligence with training on working memory. Proceedings of the National Academy of Sciences. 2008;105(19):6829-6833.