By Ericka Berman

One way to decrease the likelihood of Alzheimer’s disease is by increasing cognitive reserves (CR). Research supports the idea that education, intelligence, and cognitively stimulating activities modify the risk for dementia. CR is a theoretical construct, so it is measured indirectly.

Dr. Megan Lenehan and her team of researchers used data from 459 participants ages 50-79 from the Tasmanian Healthy Brain Project (THBP). Participants volunteered to participate either in the control (N = 100) or intervention (N = 359) conditions. The intervention group studied at a university for 12 months with a minimum study load of two units. The control group did not engage in any study load. Researchers hypothesized that individuals in the intervention group would display an increase in CR.

To measure baseline CR, the Wechsler Test of Adult Reading and five sub-scores from the Life Experience Questionnaire were used to measure experiences in education, occupation, and leisure activities. Additionally, the Medical Health Status Questionnaire was used to report on total education. Researchers used the Wechsler Adult Intelligence Scale, Third Edition, Short Form 1 and Wide Range Achievement Test, Fourth Edition, Progress Monitoring Version (WRAT-4-PMV) to measure current CR. Form 1 of the WRAT-4-PMV was used at baseline and Form 2 at Year 1 follow-up to avoid familiarity effects from using the same test more than once. Tests were re-administered at one-year intervals for 4 years.

At baseline, the control group had lower CR (p < .01). When analyzing the control group, 44.3% were “maintainers,” meaning that the change in CR did not significantly differ from 0. The rest (55.7%) were “improvers,” including a significant linear slope, suggesting an increase in CR over the 4-year span. In the intervention group, 7.5% were maintainers and 92.5% were improvers.

Results of this study support the hypothesis that participants in the intervention group would have an increased CR. Those from the intervention group who displayed no change in CR already had a higher CR on average, suggesting they may have lacked the capacity for improvement. The results from this study are not as generalizable as possible due to the use of participants from the THBP, because they were already more likely to have a higher level of education.

References:

1. M. Lenehan, et al., Sending your grandparents to university increases cognitive reserve: The tasmanian healthy brain project. Neuropsychology 30, 525-531 (2016). doi: 10.1037/neu0000249

2. Image retrieved from: https://www.flickr.com/photos/jetheriot/6186786217