The impact of behavioral interventions on cognitive function in healthy older adults: A systematic review

Abstract

Behavioral interventions to improve cognitive function in older adults are widespread and can vary from theater classes to cognitive training programs. However, the effectiveness in maintaining different cognitive domains varies greatly both across and within intervention types. To date, no systematic reviews have synthesized findings across more than a few types of interventions (e.g., cognitive vs. exercise). This systematic review examined 11 types of behavioral interventions and the respective transfer to 19 cognitive domains, as well as transfer to everyday function. Study inclusion criteria were: peer-reviewed articles in English, samples of healthy adults aged 65 and older, and randomized controlled trials of behavioral interventions with reported cognitive outcomes. The 2017 search yielded 75 eligible articles comprising cognitive training, exercise training, combination interventions, cognitively-stimulating activities, and action video games. In general, process- (n = 26) and strategy-based (n = 16) cognitive training improved the trained domains but had weak transfer to non-trained domains. Aerobic training (n = 13) most consistently improved executive function, and strength/resistance (n = 8) and aerobic/resistance combination training (n = 6) most consistently improved cognitive inhibition and visual working memory. Combination interventions (n = 15 nonfactorial, n = 3 factorial) showed promise in improving verbal delayed recall and executive function. Few studies examined cognitively-stimulating activities or action video games, leaving inconclusive results about their effect on cognitive function. Few studies examined everyday function (n = 9), however, process- and strategy-based training demonstrated notable long-term transfer. Recommendations for future research and practice are highlighted.

Keywords: Cognition; Cognitive training; Exercise training; Healthy older adults; Randomized controlled trial; Systematic review.

Fig. 1.

Selection process of the systematic review.

Fig. 2.

Summary results for cognitively-stimulating activities, n = 7. Note. Cognitively-stimulating activities included education (n = 3), theatre (n = 2), and stress-reduction (n = 2) interventions. Red and blue colors provided to aid in readability of chart. Red = cognitive speed, verbal immediate recall, visual delayed recall, or executive function. Blue = visual attention, cognitive inhibition, visual immediate recall, verbal working memory, verbal delayed recall, or subjective cognition. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 3.

Summary results for cognitive training, n = 42. Note. Cognitive training consisted of process-based (n = 26) and strategy-based (n = 16) cognitive training interventions. Red and blue colors provided to aid in readability of chart. Red = cognitive speed, verbal attention, multimodal attention, verbal immediate recall, multimodal immediate recall, visual working memory, visual delayed recall, executive function, dementia status, or visual perception. Blue = visual attention, cognitive inhibition, visual immediate recall, verbal working memory, verbal delayed recall, multimodal delayed recall, or subjective cognition. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 4.

Summary results for action video game interventions, n = 3. Note. Red and blue colors provided to aid in readability of chart. Red = cognitive speed or dementia status. Blue = visual attention or cognitive inhibition. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 5.

Summary results for exercise training, n = 27. Note. Exercise interventions consisted of aerobic (n = 13), strength/resistance (n = 8), and aerobic/resistance combination training (n = 6). Red and blue colors provided to aid in readability of chart. Red = cognitive speed, verbal immediate recall, visual working memory, visual delayed recall, executive function, or dementia status. Blue = (psycho) motor function, visual attention, cognitive inhibition, visual immediate recall, verbal working memory, verbal delayed recall, subjective cognition, or verbal perception. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 6.

Summary results for combination (nonfactorial) interventions, n = 15. Note. Red and blue colors provided to aid in readability of chart. Red = cognitive speed, multimodal attention, verbal immediate recall, visual working memory, executive function, or dementia status. Blue = (psycho)motor function, visual attention, cognitive inhibition, visual immediate recall, verbal working memory, verbal delayed recall, subjective cognition, or verbal perception. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 7.

Summary results for combination (factorial) interventions, n = 3. Note. Red and blue colors provided to aid in readability of chart. Red = cognitive speed, verbal immediate recall, visual working memory, visual delayed recall, or executive function. Blue = visual attention, cognitive inhibition, verbal working memory, or verbal delayed recall. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Fig. 8.

Transfer of behavioral interventions to everyday function, n = 9. Note. Imm = Immediate Outcome, LT = Long-Term Outcome, PB = Performance-Based Outcome, SR = Self-Report Outcome.