Structural and Functional Imaging Correlates of Cognitive and Brain Reserve Hypotheses in Healthy and Pathological Aging

Abstract

In the field of ageing and dementia, brain- or cognitive reserve refers to the capacity of the brain to manage pathology or age-related changes thereby minimizing clinical manifestations. The brain reserve capacity (BRC) hypothesis argues that this capacity derives from an individual's unique neural profile (e.g., cell count, synaptic connections, brain volume, etc.). Complimentarily, the cognitive reserve (CR) hypothesis emphasizes inter-individual differences in the effective recruitment of neural networks and cognitive processes to compensate for age-related effects or pathology. Despite an abundance of research, there is scarce literature attempting to synthesize the BRC the CR models. In this paper, we will review important aging and dementia studies using structural and functional neuroimaging techniques to investigate and attempt to assimilate both reserve hypotheses. The possibility to conceptualize reserve as reflecting indexes of brain plasticity will be proposed and novel data suggesting an intimate and complex correspondence between active and passive components of reserve will be presented.

The Association of Leisure Activities in Middle Adulthood with Cognitive Performance in Old Age: The Moderating Role of Educational Level

“…Conceptually, active and passive types of reserve are discussed [4,6,7,8,9]. In the concept of passive reserve, interindividual differences in brain measures as anatomical substrates (such as neuron counts, synaptic connections, brain volume, etc.)…”

The Impact of L2 Learning on Cognitive Aging

“…Neural reserve and neural compensation are accepted as two main mechanisms by which CR functions. The former posits that some individuals with neuropathology maintain cognitive functioning by making more efficient use of the same networks engaged by healthy individuals [43]. In this case, individuals with greater neural reserve require less neural activation within the optimal task-specific network in response to a given increase in task demand compared with those with less neural reserve, as a result of which those with greater neural reserve can withstand more neuropathology before the optimal task-specific network is disrupted [44].…”

Reserve Mechanisms in Neurodegenerative Diseases: From Bench to Bedside and Back Again

“…As such, a relevant body of evidence using either functional (mainly PET and fMRI) or structural (mainly anatomical MRI) imaging is available in the ageing literature, generally addressing how Brain and Cognitive Reserve or proxy measures (e.g. education, occupation, leisure activities, head circumference) are associated with parameters such as brain size or volume, or cerebral blood flow or glucose metabolism patterns as well as brain network utilization during cognitive demands [37]. With this techniques is possible to study the different aspects of reserve mechanisms.…”