Demographic Effects on Longitudinal Semantic Processing, Working Memory, and Cognitive Speed

OBJECTIVES To better understand and compare effects of aging and education across domains of language and cognition, we investigated whether 1) these domains show different associations with age and education, 2) these domains show similar patterns of age-related change over time, and 3) education moderates the rate of decline in these domains. METHODS We analyzed data from 306 older adults aged 55-85 at baseline of whom 116 returned for follow-up 4-8 years later. An exploratory factor analysis identified domains of language and cognition across a range of tasks. A confirmatory factor analysis analyzed cross-sectional associations of age and education with these domains. Subsequently, mixed linear models analyzed longitudinal change as a function of age and moderation by education. RESULTS Two language domains, i.e., semantic control and semantic memory efficiency, and two cognitive domains, i.e., working memory and cognitive speed, were identified. Older age negatively affected all domains, but semantic memory efficiency and higher education positively affected all domains except cognitive speed at baseline. In language domains, a steeper age-related decline was observed after age 73-74 compared to younger ages, while cognition declined linearly with age. Greater educational attainment did not protect the rate of decline over time in any domain. DISCUSSION Separate domains show varying effects of age and education at baseline, language versus cognitive domains show dissimilar patterns of age-related change over time, and education does not moderate the rate of decline in these domains. These findings broaden our understanding of age effects on cognitive and language abilities by placing observed age differences in context.Objectives: To better understand and compare effects of aging and education across domains of language and cognition, we investigated whether (a) these domains show different associations with age and education, (b) these do- mains show similar patterns of age-related change over time, and (c) education moderates the rate of decline in these domains. Method: We analyzed data from 306 older adults aged 55–85 at baseline of whom 116 returned for follow-up 4–8 years later. An exploratory factor analysis identified domains of language and cognition across a range of tasks. A confirmatory factor analysis analyzed cross-sectional associations of age and education with these domains. Subsequently, mixed linear models analyzed longitudinal change as a function of age and moderation by education. Results: We identified 2 language domains, that is, semantic control and semantic memory efficiency, and 2 cognitive domains, that is, working memory and cognitive speed. Older age negatively affected all domains except semantic memory efficiency, and higher education positively affected all domains except cognitive speed at baseline. In language domains, a steeper age-related decline was observed after age 73–74 compared to younger ages, while cognition declined linearly with age. Greater educational attainment did not protect the rate of decline over time in any domain. Discussion: Separate domains show varying effects of age and education at baseline, language versus cognitive domains show dissimilar patterns of age-related change over time, and education does not moderate the rate of decline in these domains. These findings broaden our understanding of age effects on cognitive and language abilities by placing observed age differences in context.Peer reviewe

The modulating effect of education on semantic interference during healthy aging

Aging has traditionally been related to impairments in name retrieval. These impairments have usually been explained by a phonological transmission deficit hypothesis or by an inhibitory deficit hypothesis. This decline can, however, be modulated by the educational level of the sample. This study analyzed the possible role of these approaches in explaining both object and face naming impairments during aging. Older adults with low and high educational level and young adults with high educational level were asked to repeatedly name objects or famous people using the semantic-blocking paradigm. We compared naming when exemplars were presented in a semantically homogeneous or in a semantically heterogeneous context. Results revealed significantly slower rates of both face and object naming in the homogeneous context (i.e., semantic interference), with a stronger effect for face naming. Interestingly, the group of older adults with a lower educational level showed an increased semantic interference effect during face naming. These findings suggest the joint work of the two mechanisms proposed to explain age-related naming difficulties, i.e., the inhibitory deficit and the transmission deficit hypothesis. Therefore, the stronger vulnerability to semantic interference in the lower educated older adult sample would possibly point to a failure in the inhibitory mechanisms in charge of interference resolution, as proposed by the inhibitory deficit hypothesis. In addition, the fact that this interference effect was mainly restricted to face naming and not to object naming would be consistent with the increased age-related difficulties during proper name retrieval, as suggested by the transmission deficit hypothesis.This research was supported by grants PSI2013-46033-P to A.M., PSI2015-65502-C2-1-P to M.T.B., PCIN-2015-165-C02-01 to D.P., PSI2017-89324-C2-1-P to DP from the Spanish Ministry of Economy and Competitiveness (http://www.mineco.gob.es/)

Another type of bilingual advantage? Tense-mood-aspect frequency, verb-form regularity and context-governed choice in bilingual vs. monolingual Spanish speakers with agrammatism

Introduction: This study asks whether Spanish-English bilinguals with agrammatism perform better than comparable monolingual Spanish speakers on a test of copular verb production. We chose the Spanish dual-copula system, because its two copula verbs: ser and estar (meaning ‘be’ in English), differ semantically (depending on the context of the sentence), as well as in overall frequency and form-regularity. We asked: Do bilingual Spanish-English speakers with agrammatism perform differently from their monolingual Spanish counterparts on a test comparing the effects of TMA Frequency, VF Regularity and CGC on verb production? Methodology: Participants were asked to complete 130 written sentences orally with the correct verb-form. E.g., “¿Donde ______ la pelota?” (está)- “Where is the ball?” Six sentence types were employed to compare among the three factors: 1) High TMA Frequency/Low VF Regularity (ser in present tense) 2) High TMA Frequency/High VF Regularity (estar in present tense) 3) Low TMA Frequency/Low VF Regularity (ser in imperfect past tense) 4) Low TMA Frequency/High VF Regularity (estar in imperfect past tense) 5) High TMA Frequency/High CGC (sentences requiring either ser or estar in the present tense and result in a semantic change) 6) High TMA Frequency/Low CGC (sentences allowing a choice of either ser or estar in the present tense and do not result in a semantic change) Participants: Six Spanish-speaking participants with agrammatism were tested. Three had been highly proficient bilingual Spanish-English speakers, while the other three were relatively monolingual Spanish speakers. All had suffered left-frontal strokes at least 6 months prior to this study (X= 3.4 years) and were judged agrammatic (in both languages, for bilinguals) based on the effortfulness of their spontaneous speech, short phrase-length, high substantive-word use, omission of functors, and relatively good comprehension. Twelve non-aphasic Spanish-English speakers served as controls, and were matched for language history, age, educational attainment, and relative socio-economic status. Results and Conclusions: In general, participants with agrammatism made markedly more errors on this task (X= 40%) than control participants (X= 4%), thus reinforcing our finding that despite high frequency in daily usage, ser and estar are not resistant to agrammatism (O’Connor Wells, 2011; O’Connor, Obler & Goral, 2007). A mixed-effects logistic regression analysis of the bilingual vs. monolingual data, revealed a trend (p = 0.07) for the mean performance of the bilinguals with agrammatism (65%) to be greater than that of the monolinguals (54%). Although the direction of their performance was the same, the bilinguals with agrammatism outperformed the monolingual ones on all three of our verb factors. These data are consistent with the possibility that bilingualism facilitates language performance among bilinguals in their first language