title: Age-related difference in relationships between cognitive processing speed and general cognitive status.
abstract: General cognitive status (GCS) is a composite of cognitive abilities reflecting full function. The literature suggests a relationship between cognitive processing speed and GCS, as well as age-related changes of processing speed on cognitive performance. Therefore, this study recruited 34 younger and 39 older adults to verify age-related differences in relationships between cognitive processing speed and GCS. We measured cognitive processing speed with the Processing Speed Index of the Wechsler Adult Intelligence Scale. Findings indicated that cognitive processing speed predicted GCS in older but not younger adults. Future research may be needed to verify the training effect of processing speed on GCS. This study also further examined cognitive factors related to processing speed in aging and the relationships between cognitive processing speed and verbal fluency, cognitive inhibition, and divided attention. A stepwise regression analysis indicated that only verbal fluency contributed significantly to cognitive processing speed in older adults, accounting for 21% of the variance. These observations suggest that age-related changes of prefrontal regions may not fully explain age-related decline in cognitive processing speed.
authors.affiliation: a Laboratory of Neuropsychology, Laboratory of Cognitive Affective Neuroscience, and Institute of Clinical Neuropsychology , The University of Hong Kong , Hong Kong.
authors.forename: Helena M K
authors.initials: HM
authors.lastname: Tam
authors.forename: Charlene L M
authors.initials: CL
authors.lastname: Lam
authors.forename: Haixia
authors.initials: H
authors.lastname: Huang
authors.forename: Baolan
authors.initials: B
authors.lastname: Wang
authors.forename: Tatia M C
authors.initials: TM
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D001288:Attention; D003071:Cognition; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D014705:Verbal Behavior; D014888:Wechsler Scales; D055815:Young Adult
keywords: Montreal Cognitive Assessment; cognitive processing speed; frontal functions; general cognitive status; verbal fluency