While declarative learning is dependent on the hippocampus, procedural learning and repetition priming can operate independently from the hippocampus, making them potential targets for behavioral interventions that utilize non-declarative memory systems to compensate for the declarative learning deficits associated with hippocampal insult. Few studies have assessed procedural learning and repetition priming in individuals with amnestic mild cognitive impairment (aMCI).

This study offers an overview across declarative, conceptual repetition priming, and procedural learning tasks by providing between-group effect sizes and Bayes Factors (BFs) comparing individuals with aMCI and controls. Seventy-six individuals with aMCI and 83 cognitively unimpaired controls were assessed. We hypothesized to see the largest differences between individuals with aMCI and controls on declarative learning, followed by conceptual repetition priming, with the smallest differences on procedural learning.

Consistent with our hypotheses, we found large differences between groups with supporting BFs on declarative learning. For conceptual repetition priming, we found a small-to-moderate between-group effect size and a non-conclusive BF somewhat in favor of a difference between groups. We found more variable but overall trivial differences on procedural learning tasks, with inconclusive BFs, in line with expectations.

The current results suggest that conceptual repetition priming does not remain intact in individuals with aMCI while procedural learning may remain intact. While additional studies are needed, our results contribute to the evidence-base that suggests that procedural learning may remain spared in aMCI and helps inform behavioral interventions that aim to utilize procedural learning in this population.

Lifestyle modifications for those with mild cognitive impairment (MCI) may promote functional stability, lesson disease severity, and improve well-being outcomes such as quality of life. The current analysis of our larger comparative effectiveness study evaluated which specific combinations of lifestyle modifications offered as part of the Mayo Clinic Healthy Action to Benefit Independence in Thinking (HABIT) program contributed to the least functional decline in people with MCI (pwMCI) over 18 months.

We undertook to compare evidence-based interventions with one another rather than to a no-treatment control group. The interventions were five behavioral treatments: computerized cognitive training (CCT), yoga, Memory Support System (MSS) training, peer support group (SG), and wellness education (WE), each delivered to both pwMCI and care partners, in a group-based program. To compare interventions, we randomly withheld one of the five HABIT® interventions in each of the group sessions. We conducted 24 group sessions with between 8 and 20 pwMCI–partner dyads in a session.

Withholding yoga led to the greatest declines in functional ability as measured by the Functional Activities Questionnaire and Clinical Dementia Rating. In addition, memory compensation (calendar) training and cognitive exercise appeared to have associations (moderate effect sizes) with better functional outcomes. Withholding SG or WE appeared to have little effect on functioning at 18 months.

Overall, these results add to the growing literature that physical exercise can play a significant and lasting role in modifying outcomes in a host of medical conditions, including neurodegenerative diseases.