Genetic variance in processing speed drives variation in aging of spatial and memory abilities.
Previous analyses have identified a genetic contribution to the correlation between declines with age in processing speed and higher cognitive abilities. The goal of the current analysis was to apply the biometric dual change score model to consider the possibility of temporal dynamics underlying the genetic covariance between aging trajectories for processing speed and cognitive abilities. Longitudinal twin data from the Swedish Adoption/Twin Study of Aging, including up to 5 measurement occasions covering a 16-year period, were available from 806 participants ranging in age from 50 to 88 years at the 1st measurement wave. Factors were generated to tap 4 cognitive domains: verbal ability, spatial ability, memory, and processing speed. Model-fitting indicated that genetic variance for processing speed was a leading indicator of variation in age changes for spatial and memory ability, providing additional support for processing speed theories of cognitive aging.
Finkel
Deborah
D
Department of Psychology, Indiana University Southeast, New Albany, IN 47150, USA. dfinkel@ius.edu
Reynolds
Chandra A
CA
McArdle
John J
JJ
Hamagami
Fumiaki
F
Pedersen
Nancy L
NL
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics* / Q000523:psychology; D001076:Aptitude; D005260:Female; D005838:Genotype; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D015233:Models, Statistical; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D009949:Orientation; D011594:Psychometrics; D011930:Reaction Time / Q000235:genetics*; D013548:Sweden; D014427:Twins / Q000235:genetics* / Q000523:psychology