Gray Matter Volume and Cognitive Performance During Normal Aging. A Voxel-Based Morphometry Study.

Normal aging is characterized by decline in cognitive functioning in conjunction with extensive gray matter (GM) atrophy. A first aim of this study was to determine GM volume differences related to aging by comparing two groups of participants, middle-aged group (MAG, mean age 41 years, = 16) and older adults (OG, mean age 71 years, = 14) who underwent an magnetic resonance images (MRI) voxel-based morphometry (VBM) evaluation. The VBM analyses included two optimized pipelines, for the cortex and for the cerebellum.

Aging modulates fronto-temporal cortical interactions during lexical production. A dynamic causal modeling study.

In this dynamic causal modeling (DCM) study, we evaluated the effect of age on the effective connectivity of a cerebral network involved in lexical production. Younger and older adults performed an object naming task during fMRI. The DCM was used to explore the interactions between four regions of interest: the occipital cortex, OC; the lateral temporal cortex, LTC; the medial temporal cortex, MTC; and the inferior frontal cortex, IFC.

Effect of social leisure activities on object naming in healthy aging A multimodal approach.

Environmental factors contribute to the constitution and maintenance of the cognitive reserve and partially explain the variability of cognitive performance in older individuals. We assessed the role of leisure activities - social and individual - on the access to lexico-semantic representations evaluated through a task of object naming (ON). We hypothesize that compared to individual, social leisure activities explain better the ON performance in the older adults, which is explained by a mechanism of neural reserve.

Aging Modulates the Hemispheric Specialization during Word Production.

Although older adults exhibit normal accuracy in performing word retrieval and generation (lexical production; e.g., object naming), they are generally slower in responding than younger adults.

Modulation of the inter-hemispheric processing of semantic information during normal aging. A divided visual field experiment.

We evaluated the effect of normal aging on the inter-hemispheric processing of semantic information by using the divided visual field (DVF) method, with words and pictures. Two main theoretical models have been considered, (a) the HAROLD model which posits that aging is associated with supplementary recruitment of the right hemisphere (RH) and decreased hemispheric specialization, and (b) the RH decline theory, which assumes that the RH becomes less efficient with aging, associated with increased LH specialization. Two groups of subjects were examined, a Young Group (YG) and an Old Group (OG), while participants performed a semantic categorization task (living vs.