Intraindividual variability (IIV) in cognitive speed, or moment-to-moment changes in ability, is a developmental phenomenon indicative of neurological integrity that increases gradually across adulthood. Past research has shown that IIV negatively covaries with cognitive performance, in which higher IIV at one occasion is associated with poorer…

Purpose: Of the three currently recognized variants of primary progressive aphasia, behavioral differentiation between the nonfluent/agrammatic (nfvPPA) and logopenic (lvPPA) variants is particularly difficult. The challenge includes uncertainty regarding diagnosis of apraxia of speech, which is subsumed within criteria for variant classification.…

Currently, the reliance on intelligence tests as the primary criterion for the placement of children in school programs has been challenged. Much of the controversy focuses on the insensitivity of these instruments to individual cognitive styles for different subgroups of children. While the issue of whether intelligence tests measure skill…

A major challenge to developing therapeutic interventions for cognitive loss and dementia in aging individuals with Down syndrome (DS) is the selection of appropriate outcome measures. This report describes the adaptation of the Brief Praxis Test (a nonverbal cognitive test) as a primary outcome measure, as well as the selection of secondary…

After intensively studying for several years the thinking processes of members of a tribal group in Western Africa, the Kpelle, the authors examine the relation between culture and cognitive development. The following issues are discussed: (1) an analysis of the terms "culture" and "cognition"; (2) an ethnographic description of the Kpelle…