Although intellectual engagement is a significant factor associated with adult cognitive health, it is unclear what it includes, why and how it declines across the lifespan, and importantly, whether its decline has a causal role in cognitive aging. This integrative review introduces a novel theoretical life course framework that synthesizes research on early childhood experiences and cognitive aging to address the following three points. First, we specify six critical factors of intellectual engagement for long-term, broad cognitive development: (a) open-minded input-driven learning, (b) individualized scaffolding, (c) growth mindset, (d) forgiving environment, (e) serious commitment to learning, and (f) learning multiple skills simultaneously. We show that these factors increase basic cognitive abilities (e.g., working memory, inhibition) and promote far transfer. Second, we trace the decline of the six factors from infancy to aging adulthood (broad learning to specialization). Finally, we propose that these six factors can be applied to expand cognitive functioning in aging adults beyond currently known limits.

OBJECTIVES: Increasing evidence suggests that depression is a risk factor for cognitive impairment, but it is unclear if this is true among the oldest old. We determined whether elevated depressive symptoms predicted 5-year incident mild cognitive impairment (MCI) or dementia, and neuropsychological test performance among oldest-old women. DESIGN: Prospective. SETTING: Three study sites. PARTICIPANTS: 302 women ≥85 years (mean, 87 ± 2). MEASUREMENTS: Depressive symptoms were measured with the 15-item Geriatric Depression Scale (GDS); scores of 6 or more indicated elevated symptoms. Five years later, participants completed neuropsychological testing and clinical cognitive status was adjudicated. RESULTS: In analyses of MCI versus normal cognition, 70% of women with GDS score 6 or more at baseline developed MCI versus 37% with GDS score less than 6. After adjustment for age, education, alcohol, and benzodiazepine use, and study site, GDS score 6 or more remained independently associated with much greater likelihood of developing MCI (multivariable odds ratio [MOR] = 3.71, 95% confidence interval (CI): 1.30-10.59). In analyses of dementia versus normal cognition, 65% of women with GDS score 6 or more developed dementia compared with 37% of those with GDS score less than 6 (MOR = 3.15, 95% CI: 1.03-9.65). Only 19% of women with GDS score 6 or more had normal cognitive status 5 years later, compared with 46% of those with GDS score less than 6 (MOR = 0.28, 95% CI: 0.11-0.73). Women with elevated depressive symptoms had worse scores on tests of global cognition and working memory. CONCLUSION: Elevated depressive symptoms are an important risk factor for cognitive disorders and lower cognitive performance among women living to their ninth and tenth decades.

OBJECTIVES: To determine the association between objectively measured sleep and subsequent placement in a nursing home or a personal care home. DESIGN: Prospective cohort. SETTING: Participants homes and sites of the Study of Osteoporotic Fractures. PARTICIPANTS: One thousand six hundred sixty-four community-dwelling women with a mean age of 83 ± 4. MEASUREMENTS: At baseline, participants completed an average of 4 nights of wrist actigraphy; they provided data on place of residence at baseline and at follow-up, 5 years later. RESULTS: At baseline, participants had a mean total sleep time of 408 ± 72 minutes, mean wake after sleep onset of 71 ± 43 minutes, and mean sleep efficiency of 79 ± 11%. At follow-up, 71 (4%) were residing in a nursing home, and 127 (8%) were in a personal care home. Women with the most wake after sleep onset (by quartile) had more than twice the odds as those with the least of placement in a nursing home (adjusted odds ratio (AOR) = 2.94, 95% confidence interval (CI) = 1.34-6.44) or a personal care home (AOR = 2.33, 95% CI = 1.26-4.30). Similarly, women with the lowest sleep efficiency had more than three times the odds as those with the highest of nursing home placement (AOR = 3.25, 95% CI = 1.35, 7.82) and more than twice the odds of placement in a personal care home (AOR = 2.38, 95% CI = 1.33, 4.24). There was no association between sleep duration and placement. CONCLUSION: In very old community-dwelling women, greater wake after sleep onset and lower sleep efficiency are risk factors for placement in a nursing home or personal care home. Sleep duration alone does not appear to increase the risk of placement in these long-term care settings.

Objectives

To determine the association between objectively measured sleep and subsequent placement in a nursing home or a personal care home.

Design

Prospective cohort.

Setting

Participants' homes and sites of the Study of Osteoporotic Fractures.

Participants

One thousand six hundred sixty-four community-dwelling women with a mean age of 83 ± 4.

Measurements

At baseline, participants completed an average of 4 nights of wrist actigraphy; they provided data on place of residence at baseline and at follow-up, 5 years later.

Results

At baseline, participants had a mean total sleep time of 408 ± 72 minutes, mean wake after sleep onset of 71 ± 43 minutes, and mean sleep efficiency of 79 ± 11%. At follow-up, 71 (4%) were residing in a nursing home, and 127 (8%) were in a personal care home. Women with the most wake after sleep onset (by quartile) had more than twice the odds as those with the least of placement in a nursing home (adjusted odds ratio (AOR) = 2.94, 95% confidence interval (CI) = 1.34-6.44) or a personal care home (AOR = 2.33, 95% CI = 1.26-4.30). Similarly, women with the lowest sleep efficiency had more than three times the odds as those with the highest of nursing home placement (AOR = 3.25, 95% CI = 1.35, 7.82) and more than twice the odds of placement in a personal care home (AOR = 2.38, 95% CI = 1.33, 4.24). There was no association between sleep duration and placement.

Conclusion

In very old community-dwelling women, greater wake after sleep onset and lower sleep efficiency are risk factors for placement in a nursing home or personal care home. Sleep duration alone does not appear to increase the risk of placement in these long-term care settings.

OBJECTIVES: To determine whether objectively measured sleep quality predicts 5-year incident instrumental activity of daily living (IADL) impairment and decline in grip strength and gait speed in older women. DESIGN: Prospective cohort. SETTING: Participants homes, Study of Osteoporotic Fractures sites. PARTICIPANTS: Eight hundred seventeen women with a mean age of 82.4 at baseline. MEASUREMENTS: Participants completed 4.1 ± 0.7 nights of wrist actigraphy at baseline and measures of IADL impairment, grip strength, and gait speed at baseline and 5-year follow-up. RESULTS: After 5 years of follow-up, approximately 41% of participants had incident impairment in one or more IADLs. The quartile of women with the shortest total sleep time (TST) had 93% greater odds of incident IADL impairment than the longest sleepers (adjusted odds ratio (AOR) = 1.93, 95% confidence interval (CI) = 1.25-2.97). Similarly, the quartile of women with the lowest sleep efficiency (SE) had 65% greater odds of impairment than those with the highest (AOR = 1.65, 95% CI = 1.06-2.57). Women in the shortest TST quartile had twice the odds of declining grip strength as those with the longest TST (AOR = 1.97, 95% CI = 1.17-3.32). Finally, women in the quartiles with the most wake after sleep onset (WASO) and the lowest SE had approximately 90% greater odds of grip strength decline than those with the least WASO (AOR = 1.90, 95% CI = 1.11-3.24) and SE (AOR = 1.92, 95% CI = 1.12-3.29). CONCLUSION: Findings indicate that shorter sleep duration, greater WASO, and lower SE are risk factors for functional or physical decline in older women.

Objectives

Increasing evidence suggests that depression is a risk factor for cognitive impairment, but it is unclear if this is true among the oldest old. We determined whether elevated depressive symptoms predicted 5-year incident mild cognitive impairment (MCI) or dementia, and neuropsychological test performance among oldest-old women.

Design

Prospective.

Setting

Three study sites.

Participants

302 women ≥85 years (mean, 87 ± 2).

Measurements

Depressive symptoms were measured with the 15-item Geriatric Depression Scale (GDS); scores of 6 or more indicated elevated symptoms. Five years later, participants completed neuropsychological testing and clinical cognitive status was adjudicated.

Results

In analyses of MCI versus normal cognition, 70% of women with GDS score 6 or more at baseline developed MCI versus 37% with GDS score less than 6. After adjustment for age, education, alcohol, and benzodiazepine use, and study site, GDS score 6 or more remained independently associated with much greater likelihood of developing MCI (multivariable odds ratio [MOR] = 3.71, 95% confidence interval (CI): 1.30-10.59). In analyses of dementia versus normal cognition, 65% of women with GDS score 6 or more developed dementia compared with 37% of those with GDS score less than 6 (MOR = 3.15, 95% CI: 1.03-9.65). Only 19% of women with GDS score 6 or more had normal cognitive status 5 years later, compared with 46% of those with GDS score less than 6 (MOR = 0.28, 95% CI: 0.11-0.73). Women with elevated depressive symptoms had worse scores on tests of global cognition and working memory.

Conclusion

Elevated depressive symptoms are an important risk factor for cognitive disorders and lower cognitive performance among women living to their ninth and tenth decades.

OBJECTIVES: The natural learning experience from infancy to emerging adulthood, when considerable cognitive and functional growth is observed, mandates learning multiple real-world skills simultaneously. The present studies investigated whether learning multiple real-world skills simultaneously is possible in older adults and also whether it improves both their cognitive abilities (working memory, episodic memory, and cognitive control) and functional independence. METHODS: Over two studies (15 and 27 participants), older adults learned at least three new skills (e.g., Spanish, drawing, music composition) simultaneously for 3 months. Participants completed cognitive and functional assessments before, during, and after the intervention in both studies. Participants were recruited sequentially for an intervention or no-contact control group in Study 1, and Study 2 included only an intervention group, who also completed assessments 4-6 weeks prior to the start of the intervention (i.e., they served as their own control group). RESULTS: Results from both studies show that simultaneously learning multiple skills is feasible and potentially beneficial for healthy older adults. Learning multiple skills simultaneously increased cognitive abilities in older adults by midpoint of the intervention, to levels similar to performance in a separate sample of middle-aged adults. DISCUSSION: Our findings demonstrate the feasibility and potential of conducting a real-world skill-learning intervention involving learning three novel skills with older adults. Our multiskill intervention may provide broad cognitive gains, akin to the benefits experienced earlier in the life span.

Objectives To determine the association between sleep-disordered breathing (SDB) and decline in instrumental activities of daily living (IADLs) and mobility in older women. Design Prospective cohort. Setting Minneapolis and Pittsburgh sites of the Study of Osteoporotic Fractures, participants' homes. Participants Women with a mean age ± standard deviation of 82.3 ± 3.2 (N = 302). Measurements Participants completed a single night of unattended polysomnography and provided data regarding difficulty with IADLs and mobility. They repeated IADL and mobility measures 5.0 ± 0.7 years later. Results After adjustment for age, obesity, Mini-Mental State Examination score, depressive symptoms, history of hypertension and chronic obstructive pulmonary disease, and number of IADL impairments at baseline, women with an apnea-hypopnea index (AHI) of 15 or greater at baseline had more than twice the odds of an increase in number of IADL difficulties (adjusted odds ratio (aOR) = 2.22, 95% confidence interval (CI) = 1.09-4.53) and of incident IADL difficulty (aOR = 2.43, 95% CI = 1.00-5.92), of women with an AHI less than 5. There was no association between AHI and mobility difficulty. Women in the middle and highest tertiles of oxygen desaturation index had more than double the odds as those in the lowest tertile of an increase in number of IADL difficulties (middle tertile aOR = 2.64, 95% CI = 1.38-5.04, highest tertile aOR = 2.17, 95% CI = 1.13-4.17) and approximately three times the odds of incident IADL difficulty (middle tertile aOR = 2.84, 95% CI = 1.27-6.36, highest tertile aOR = 3.07, 95% CI = 1.31-7.18). Neither sleep fragmentation nor sleep duration was associated with IADL outcomes. Conclusion SDB and associated hypoxemia are risk factors for functional decline in older women. Research is needed to determine whether treatment of SDB prevents functional decline.

The present prospective observational study aimed to identify the existence of successful cognitive agers among a group of well-defined cognitively healthy older adults (n = 354, mean age = 75 years), and to examine baseline individual-level predictors and associated health outcomes over time. Episodic memory (EM) and executive function (EF) composite scores and multiple health outcomes were obtained annually over 5 years. Potential individual-level predictors that were related to Alzheimer's disease pathology or genetic risk, neurodegeneration, and vascular risks were collected at baseline. Three latent classes with matched age and education were identified using growth mixture modeling: a group of participants who exhibited high, stable EM and EF (40.7% of the sample, "successful agers"); a group who had initial high cognitive performance that declined over time (21.2%, "declining agers"); and a group who had normal (EM) or poor (EF) but stable cognitive performance over time (38.1%, "low stable agers"). The group classification predicted significant differences in the incidence of global cognitive impairment, the development of at least one depressive symptom, and everyday functional impairment. Sex, apolipoprotein E allele 4, amyloid-β1-42, and t-tau significantly contributed to the difference in cognitive trajectories between the successful agers and the other two groups. Characterizing successful cognitive agers who are relatively resistant to both tau and amyloid pathology provides potential pathways for promoting successful cognitive aging and preventing cognitive decline.

Growth mindset (belief in the malleability of intelligence) is a unique predictor of young learners' increased motivation and learning, and may have broader implications for cognitive functioning. Its role in learning in older adulthood is unclear. As part of a larger longitudinal study, we examined growth mindset and cognitive functioning in older adults engaged in a 3-month multi-skill learning intervention that included growth mindset discussions. Before, during, and after the intervention, participants reported on their growth mindset beliefs and completed a cognitive battery. Study 1 indicated that intervention participants, but not control participants, increased their growth mindset during the intervention. Study 2 replicated these results and found that older adults with higher preexisting growth mindsets showed larger cognitive gains at posttest compared to those with lower preexisting growth mindsets. Our findings highlight the potential role of growth mindset in supporting positive learning cycles for cognitive gains in older adulthood.