Cognitive Reserve: Developing a Model of the Social Processes that Influence Age-Related Cognitive Decline

Background: Cognitive reserve (CR) is a hypothetical construct proposed by [1] to explain individual differences in risk for, and patterns of cognitive impairment associated with ageing and dementia. There is considerable evidence that reserve is influenced by lifestyle variables including education, IQ, occupation, social engagement and mental stimulation; and the hypothetical construct of CR is typically measured using proxy indicators that reflect these experiences. However, the inconsistent use of several indicators has attracted criticism as it limits comparability across studies. While there is evidence that these life experience variables contribute to the protective effects of CR, there is currently little understanding as to how these protective effects occur. Robertson (2013) proposes that the protective effect of CR functions via the neurotransmitter noradrenaline. We aim to elucidate CR by (a) developing a model of the lifestyle variables that influence it and (b) using this model to test the hypothesis that CR is mediated by noradrenergic function. Methods: Participants were normally ageing adults aged 50+ (N = 221) with a mean age of 64.3 years (SD 8.4). Participants completed a comprehensive assessment battery including neuropsychological, cognitive and psychological measurement tools, along with self-report questionnaires and scales to measure proxy indicators of CR. Protocol for a study to test the hypothesis that CR is mediated by noradrenergic function will also be presented. Results: A multiple-indicator model of CR indicators will be used to explore the relationship between CR and age-related cognitive performance, both cross-sectionally and longitudinally. Conclusions: Potential implications of the findings in terms of further research, interventions aimed at preventing cognitive decline and clinical practice will be discussed