title: Examination of the processing speed account in a population-based longitudinal study with narrow age cohort design.
abstract: The processing speed account suggests that general slowing of mental processing speed results in an overall decline, especially age-related decline, in other cognitive domains. Support for the speed account comes mainly from cross-sectional studies with participants that vary in age (age-heterogeneous samples). This study investigated how well variations in processing speed predict change of episodic recall in a longitudinal framework and examined with the Narrow Age Cohort (NAC) design. Data were obtained from Betula, a population-based longitudinal study. Both 5-year (n= 490; Time 3 - Time 4) and 10-year follow-up results (n= 608; Time 1 - Time 3) were used. In both samples, which were subjected to prospective dementia screening, we found considerably weaker associations in longitudinal data compared to cross-sectional, and also weaker associations in age-homogeneous than in age-heterogeneous samples. The results provide little support for the speed account.
authors.affiliation: Department of Psychology, Stockholm University, Sweden. ola.sternang@psychology.su.se
authors.forename: Ola
authors.initials: O
authors.lastname: Sternäng
authors.forename: Ake
authors.initials: A
authors.lastname: Wahlin
authors.forename: Lars-Göran
authors.initials: LG
authors.lastname: Nilsson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007206:Individuality; D008137:Longitudinal Studies; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D011930:Reaction Time; D021641:Recognition, Psychology; D012153:Retention, Psychology; D013548:Sweden