Martin S. Mumenthaler

Context Processing in Older Adults: Evidence for a Theory Relating Cognitive Control to Neurobiology in Healthy Aging

A theory of cognitive aging is presented in which healthy older adults are hypothesized to suffer from disturbances in the processing of context that impair cognitive control function across multiple domains, including attention, inhibition, and working memory. These cognitive disturbances are postulated to be directly related to age-related decline in the function of the dopamine (DA) system in the prefrontal cortex (PFC). A connectionist computational model is described that implements specific mechanisms for the role of DA and PFC in context processing. The behavioral predictions of the model were tested in a large sample of older (N = 81) and young (N = 175) adults performing variants of a simple cognitive control task that placed differential demands on context processing. Older adults exhibited both performance decrements and, counterintuitively, performance improvements that are in close agreement with model predictions.

Donepezil and flight simulator performance: Effects on retention of complex skills

Abstract—We report a randomized, double-blind, parallel group, placebo-controlled study to test the effects of the acetylcholinesterase inhibitor, donepezil (5 mg/d for 30 days), on aircraft pilot performance in 18 licensed pilots with mean age of 52 years. After 30 days of treatment, the donepezil group showed greater ability to retain the capacity to perform a set of complex simulator tasks than the placebo group, p < 0.05. Donepezil appears to have beneficial effects on retention of training on complex aviation tasks in nondemented older adults.

Psychoactive Drugs and Pilot Performance: A Comparison of Nicotine, Donepezil, and Alcohol Effects

The cholinergic system plays a major role in cognitive abilities that are essential to piloting an aircraft: attention, learning, and memory. In previous studies, drugs that enhance the cholinergic system through different pharmacologic mechanisms have shown beneficial effects on cognition; but dissimilar cognitive measures were used and samples were not comparable. A comparison within the same cognitive tasks, within comparable samples appears desirable. Toward this aim, we compared effect sizes (ES) of performance-enhancing doses of nicotine (a nicotinic receptor agonist) and donepezil (an acetylcholinesterase inhibitor) as found in our prior work on pilot performance. We also compared cholinergic ES to those of performance-impairing doses of alcohol. In three randomized, placebo-controlled trials, we assessed the flight performance of aircraft pilots in a Frasca 141 simulator, testing I: the acute effects of nicotine gum 2 mg; II: the effects of administration of 5 mg donepezil/day for 30 days; and III: the acute and 8 h-carryover effects of alcohol after a target peak BAC of 0.10%. We calculated the ES of nicotine, donepezil, and alcohol on a flight summary score and on four flight component scores. Compared to placebo, nicotine and donepezil significantly improved, while alcohol significantly impaired overall flight performance: ES (nicotine)=0.80; ES (donepezil)=1.02; ES (alcohol acute)=−3.66; ES (alcohol 8 h)=−0.82. Both cholinergic drugs showed the largest effects on flight tasks requiring sustained visual attention. Although the two tested cholinergic drugs have different pharmacologic mechanisms, their effects on flight performance were similar in kind and size. The beneficial effects of the cholinergic drugs on overall flight performance were large and the absolute (ie nondirectional) sizes were about one-fourth of the absolute ES of acute alcohol intoxication and roughly the same as the absolute 8 h-carryover ES of alcohol.

Influence of nicotine on simulator flight performance in non-smokers.

Abstract In a placebo-controlled study, we investigated the influence of nicotine on late-day aviation performance in 15 non-smoking subjects. In a within-subjects design, subjects were tested on 2 days, each lasting 8 h and consisting of three 75-min simulator flights (late-afternoon practice, evening test, night test). Prior to each test, subjects received either nicotine polacrilex 2 mg or placebo gum. As expected, overall performance was significantly better after nicotine, compared to placebo (P < 0.01). Post-hoc analysis of individual flight tasks showed that nicotine improved scores on approach to landing, a task which appears to require sustained attention. We conclude that nicotine may improve late-day flight performance in non-smoking aviators.

Relationship of age and simulated flight performance.

OBJECTIVE: To determine the relationship between age and aviator performance on a flight simulator.

Hormone replacement therapy and longitudinal cognitive performance in postmenopausal women

OBJECTIVE The authors examined the impact of hormone replacement therapy (HRT) on longitudinal cognitive performance (controlling for mood state) in 69 community-dwelling, postmenopausal women. METHODS The authors conducted a 5-year follow-up of cognitive performance in 37 postmenopausal HRT users and 32 non-users. The groups did not differ with respect to age, years of education, or inter-test interval. RESULTS No main effect of HRT was observed on any of the cognitive measures, and depressive symptomatology did not affect the relationship between HRT and cognition. CONCLUSION Overall, our findings do not suggest that HRT affects longitudinal cognitive performance in postmenopausal, community-dwelling older women.

Should One Use Medications in Combination With Cognitive Training? If So, Which Ones?

In this article, we review current research regarding diagnosis of cognitive impairment in nondemented adults and discuss why medications and cognitive training together may be more beneficial than either alone. We also review potential cognitive enhancers and future research challenges. There are major reasons for such research: (a) Large numbers of older adults without dementia but with cognitive problems are not treatable with current cognitive training techniques; (b) some medications offer a rationale (i.e., cognitive enhancement) and some evidence that they might be a useful adjunct; and (c) there are unanswered questions about which population to target, which medications to use, how to administer them, and issues regarding tolerance and use of appropriate (active) placebo controls. As the number of cognitively impaired older adults grows, it is likely that there will be pressure to treat more broadly with both medications and cognitive training.

Behavioral Problems in Older Adults in Acute Care Settings: Challenges for Staff

Abstract The combination of mental and physical changes with age will impact agencies focusing on both acute and chronic problems. One of the biggest challenges for staff new to such patients is contending with agitated and aggressive behaviors. Conducting a needs assessment with staff is one method of mapping the nature and extent of problem behaviors for a specific setting. In the current study, a total of 71 staff members from different disciplines, across three acute care units and two VA health care facilities, completed a survey assessing the type and frequency of reported behavior problems, the extent to which staff members could identify and document relevant patient risk factors and to identify gaps in their training. Staff reported a large range of problem behaviors. They felt highly confident in their ability to respond effectively to the most frequently observed behaviors, such as patients appearing anxious or having difficulty concentrating and trouble sleeping. However, they felt less prepared for less frequent behaviors, such as physical aggression. This information will be used to design follow-up training for the staff in targeted areas, including the management of various behaviors and the recognition of risk factors for problematic behaviors.