Biomaterial Database

Genetic and Environmental Influences on Verbal Fluency in Middle Age: A Longitudinal Twin Study. 2018

Daniel E Gustavson, and Matthew S Panizzon, and Jeremy A Elman, and Carol E Franz, and Asad Beck, and Chandra A Reynolds, and Kristen C Jacobson, and Hong Xian, and Rosemary Toomey, and Michael J Lyons, and William S Kremen

Department of Psychiatry, Center for Behavior Genetics of Aging, University of California, San Diego, 9500 Gilman Dr. (MC 0738), La Jolla, CA, 92093, USA. dgustavson@ucsd.edu.

Mounting evidence suggests that measures of phonemic fluency and semantic fluency are differentially associated with other cognitive and health phenotypes, but few studies have examined their shared and unique variance, especially using genetically-informative designs. In this study, 1464 middle-aged twins completed six fluency subtests at up to two time-points (mean age 56 and 62 years). Confirmatory factor analyses supported a two-factor solution: a General Fluency latent factor explained variation in all six subtests and a Semantic-Specific factor accounted for additional variance in semantic subtests. Both factors were explained primarily by genetic influences at both waves (a2 = 0.57-0.76). There was considerable stability of individual differences over 6 years (r = .90 for General Fluency, r = .81 for Semantic-Specific), especially for genetic influences (rg = .94 and 1.0, respectively). These results suggest that semantic fluency can be viewed as a combination of general and semantic-specific variance, but phonemic fluency is captured entirely by the general factor.

UI	MeSH Term	Description	Entries
D008137	Longitudinal Studies	Studies in which variables relating to an individual or group of individuals are assessed over a period of time.	Bogalusa Heart Study,California Teachers Study,Framingham Heart Study,Jackson Heart Study,Longitudinal Survey,Tuskegee Syphilis Study,Bogalusa Heart Studies,California Teachers Studies,Framingham Heart Studies,Heart Studies, Bogalusa,Heart Studies, Framingham,Heart Studies, Jackson,Heart Study, Bogalusa,Heart Study, Framingham,Heart Study, Jackson,Jackson Heart Studies,Longitudinal Study,Longitudinal Surveys,Studies, Bogalusa Heart,Studies, California Teachers,Studies, Jackson Heart,Studies, Longitudinal,Study, Bogalusa Heart,Study, California Teachers,Study, Longitudinal,Survey, Longitudinal,Surveys, Longitudinal,Syphilis Studies, Tuskegee,Syphilis Study, Tuskegee,Teachers Studies, California,Teachers Study, California,Tuskegee Syphilis Studies
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D008962	Models, Theoretical	Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Experimental Model,Experimental Models,Mathematical Model,Model, Experimental,Models (Theoretical),Models, Experimental,Models, Theoretic,Theoretical Study,Mathematical Models,Model (Theoretical),Model, Mathematical,Model, Theoretical,Models, Mathematical,Studies, Theoretical,Study, Theoretical,Theoretical Model,Theoretical Models,Theoretical Studies
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D003071	Cognition	Intellectual or mental process whereby an organism obtains knowledge.	Cognitive Function,Cognitions,Cognitive Functions,Function, Cognitive,Functions, Cognitive
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging
D014705	Verbal Behavior	Includes both producing and responding to words, either written or spoken.	Behavior, Verbal,Behaviors, Verbal,Verbal Behaviors
D059647	Gene-Environment Interaction	The combined effects of genotypes and environmental factors together on phenotypic characteristics.	Environment-Gene Interaction,Environment Gene Interaction,Environment-Gene Interactions,Gene Environment Interaction,Gene-Environment Interactions,Interaction, Environment-Gene,Interaction, Gene-Environment,Interactions, Environment-Gene,Interactions, Gene-Environment