Perceptual speed in adulthood: cross-sectional and longitudinal studies.

Cross-sectional data on age differences in perceptual speed are presented from the Seattle Longitudinal Study for the age range 22-91 years (N = 1,620, first assessed in 1977; N = 628, first assessed in 1984). In addition, 838 subjects were followed over the 7-year interval. Markers of perceptual speed were the Identical Pictures and Finding A's tests from the ETS Kit of Factor-Referenced Tests. Significant age differences, age changes, and cohort differences were found at both observed variable and latent construct levels. Cross-lagged correlations examine the role of perceptual speed in predicting later performance on other abilities (Verbal Meaning, Inductive Reasoning, Spatial Orientation, Number, and Word Fluency). When perceptual speed is partialled out of scores for these abilities, aging effects are reduced markedly for all abilities, but least for Spatial Orientation and Inductive Reasoning.