Proper Names and Common Nouns are differently supported by Cognitive Reserve and Semantic Knowledge in healthy aging

Cognitive reserve refers to acquired learnings that modulate brain resistance to physiological aging or brain damage. One relevant component of cognitive reserve seems to be the richness of connections in the semantic knowledge. We examined the influence of cognitive reserve and semantic knowledge on proper name and common noun retrieval.Sixty-six elderly participants were administered a questionnaire for cognitive reserve, and tests assessing semantic knowledge and proper name and common noun retrieval. Results showed that proper names were more difficult to retrieve than common nouns. Moreover, cognitive reserve and semantic knowledge were linearly and positively associated with common noun retrieval, with additive effects. In contrast, they interacted with each other in predicting the retrieval of proper names: cognitive reserve had a greater impact on proper name retrieval in older adults with weaker semantic profile, while semantic knowledge assisted proper name retrieval in older adults with scarcer cognitive reserve.

Dorsal White Matter Integrity and Name Retrieval in Midlife

Background: Recent findings on retrieval of proper names in cognitively healthy middle- aged persons indicate that Tip-Of-The-Tongue (TOT) states occurring during proper name retrieval implicate inferior frontal (BA 44) and parietal (BA 40) cortical areas. Such findings give rise to the possibility that anatomical connectivity via dorsal white matter may be associated with difficulties in name retrieval in midlife. Objectives & Method: Using Diffusion Tensor Imaging, we examined in vivo microstructural properties of white matter in 72 cognitively healthy Middle-Aged (MA) and 59 Young Adults (YA), comparing their naming abilities as well as testing, for possible associations between dorsal white matter integrity and naming abilities in the MA group. Results: The MA group was better in retrieving correct names (U = 1525.5, p = .006), but they also retrieved more incorrect names than YA believing they had retrieved the correct ones (U = 1265.5, p < .001). Furthermore, despite being more familiar with the tested names than YA (U = 930, p < .001), MA experienced significantly more TOTs relative to YA (U = 1498.5, p = .004). Tract-based spatial statistics showed significant group differences in values of fractional anisotropy (FA), mean diffusivity, axial diffusivity, radial diffusivity, and mode of anisotropy in a range of white matter tracts. In the MA group, FA values in the right Superior Longitudinal Fasciculus (SLF) were positively correlated with “don’t know” scores (rs = .287, p = .014). Conclusion: The association of SLF integrity and name retrieval ability in midlife indicates a need to revisit the models of name retrieval that posit no role for dorsal white matter in proper name retrieval.

Proper name retrieval in cognitive decline

This study explores the retrieval of proper names and the sensitivity of this lexical category to the modulatory effect of cognitive reserve in an aging population. Thirty-two elderly patients, undergoing their first neuropsychological evaluation were matched for age and education to thirty-two healthy controls. All participants were administered the Montreal Cognitive Assessment (MoCA) to measure their global cognitive performance, the Famous Face Naming test to assess proper name retrieval, and the Cognitive Reserve Index (CRI) questionnaire to obtain an index of cognitive reserve. The two groups had comparable CRI total scores, but patients’ performance was worse in both MoCA and Famous Face naming test, compared to healthy controls. Results showed that cognitive reserve predicted global cognitive performance (i.e., MoCA score) in the patients, but not in the healthy participants. Naming proper names was independent from cognitive reserve. This might be due to their lexical nature, which lies in a poor semantic connection between proper names and their bearers.