The relationships among types of social support and different facets of subjective well-being (i.e., life satisfaction, positive affect, and negative affect) were examined in a sample of 1,111 individuals between the ages of 18 and 95. Using structural equation modeling we found that life satisfaction was predicted by enacted and perceived support, positive affect was predicted by family embeddedness and provided support, and negative affect was predicted by perceived support. When personality variables were included in a subsequent model, the influence of the social support variables were generally reduced. Invariance analyses conducted across age groups indicated that there were no substantial differences in predictors of the different types of subjective well-being across age.

We administered four prospective memory tasks to 330 adults between 18 and 89 years of age to investigate the relationship among the measures of performance in the four tasks, as well as the relationship of the prospective memory measures to age, other cognitive abilities, and noncognitive factors. The four prospective memory variables were found to exhibit both convergent and discriminant validity, indicating that prospective memory ability appears to represent a distinct dimension of individual differences. The prospective memory construct was significantly related to other cognitive abilities, such as executive functioning, fluid intelligence, episodic memory, and perceptual speed, but it was only weakly related to self-ratings of (primarily retrospective) memory and to personality traits. Although a substantial proportion of the age-related variance on the prospective memory construct was shared with other cognitive abilities, we also found some evidence of unique, statistically independent, age-related influences on prospective memory.

Objective-White matter hyperintensities (WMH), visualized on T2-weighted MRI, are thought to reflect small-vessel vascular disease. Much like other markers of brain disease, the association between WMH and cognition is imperfect. The concept of reserve may account for this imperfect relationship. The purpose of this study was to test the reserve hypothesis in the association between WMH severity and cognition. We hypothesized that individuals with higher amounts of reserve would be able to tolerate greater amounts of pathology than those with lower reserve.Methods-Neurologically healthy older adults (n=717) from a community-based study received structural MRI, neuropsychological assessment, and evaluation of reserve. WMH volume was Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Conclusions-For any given level of cognitive function, those with higher reserve had more pathology in the form of WMH, suggesting that they are better able to cope with pathology than those with lower reserve. Both brain reserve and cognitive reserve appear to mitigate the impact of pathology on cognition. NIH Public Access

Background The retrogenesis hypothesis postulates that late-myelinated white matter fibers are most vulnerable to age- and disease-related degeneration, which in turn mediate cognitive decline. While recent evidence supports this hypothesis in the context of Alzheimer’s disease, it has not been tested systematically in normal cognitive aging. Methods In the current study, we examined the retrogenesis hypothesis in a group (n=282) of cognitively normal individuals ranging in age from 7 to 87 years from the Brain Resource International Database. Participants were evaluated with a comprehensive neuropsychological battery and were imaged with diffusion tensor imaging. Fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (DA), measures of white matter coherence, were computed in two prototypical early-myelinated fiber tracts (posterior limb of the internal capsule, cerebral peduncles) and two prototypical late-myelinated fiber tracts (superior longitudinal fasciculus, inferior longitudinal fasciculus) chosen to parallel previous studies; mean summary values were also computed for other early- and late-myelinated fiber tracts. We examined age-associated differences in FA, RD, and DA in the developmental trajectory (ages 7 to 30 years) and degenerative trajectory (ages 31 to 87 years), and tested whether the measures of white matter coherence mediated age-related cognitive decline in the older group. Results FA and DA values were greater for early-myelinated fibers than for late-myelinated fibers, and RD values were lower for early-myelinated than late-myelinated fibers. There were age-associated differences in FA, RD, and DA across early- and late-myelinated fiber tracts in the younger group, but the magnitude of differences did not vary as a function of early or late myelinating status. FA and RD in most fiber tracts showed reliable age-associated differences in the older age group, but the magnitudes were greatest for the late-myelinated tract summary measure, inferior longitudinal fasciculus (late fiber tract), and cerebral peduncles (early fiber tract). Finally, FA in the inferior longitudinal fasciculus and cerebral peduncles and RD in the cerebral peduncles mediated age-associated differences in an executive functioning factor. Discussion Taken together, the findings highlight the importance of white matter coherence in cognitive aging and provide some, but not complete, support for the white matter retrogenesis hypothesis in normal cognitive aging.

Cognitive reserve is a hypothetical construct that has been used to inform models of cognitive aging, and is presumed to be indicative of life experiences that may mitigate the effects of brain pathology. The purpose of this study was to evaluate the construct validity of cognitive reserve by examining both its convergent and discriminant validity across three different samples of participants using structural equation modeling. The cognitive reserve variables were found to correlate highly with one another (thereby providing evidence of convergent validity) but demanding tests of discriminant validity indicated that, in two of the samples, the cognitive reserve construct was highly related to an executive functioning construct. KeywordsConstruct validity; cognition; cognitive reserve; executive functioning; neuropsychology; structural equation modelingThe concept of reserve emerged as a mechanism to explain why there is not a perfect relationship between brain pathology post-mortem and the severity of a clinical condition, such as vascular dementia (VaD) or Alzheimer dementia. Research has indicated that individuals with the same amount of brain pathology may have very different clinical manifestations of dementia. Increased reserve is hypothesized to be associated with protection against clinical expression of dementia because those individuals with higher reserve may be more efficient or better able to compensate for the pathological changes accumulating in the brain. An initial model of reserve indicated the existence of two classifications of reserve-brain reserve and cognitive reserve. Both brain reserve and cognitive reserve are hypothetical constructs that have been used to inform models of aging. Our purpose here is to examine whether it is *Correspondence to Yaakov Stern, 630 W 168 th St, New York, NY 10032, phone 212-342-1350, fax 212-342-1838 NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript meaningful to refer to cognitive reserve as a distinct construct that represents a unique dimension of individual differences.Although brain reserve is an important theoretical construct in its own right, in this paper we are primarily concerned with the concept of cognitive reserve that, Stern (2002) has argued, is an active model of reserve comprised of two main components-neural reserve and neural compensation. The neural reserve component of cognitive reserve refers to the efficiency or capacity of the brain prior to pathological damage. The neural compensation component of cognitive reserve refers to the recruitment of brain areas not typically used by individuals without brain damage to compensate for brain pathology.Cognitive reserve is typically operationalized with variables that are reflective of lifetime experiences that may provide individuals with a set of skills to better manage pathological brain damage, as seen in diseases like AD and VaD. To that end, education level, literacy, occupational attainment, and performance on tests of knowledge (such as vocabulary) hav...