A normative‐developmental study of executive function: A window on prefrontal function in children

Abstract

Normative‐developmental performance on a battery of executive function tasks was investigated. Executive function was defined as goal‐directed behavior, including planning, organized search, and impulse control. Measures were drawn from clinical neuropsychology (visual search, verbal fluency, motor sequencing, and Wisconsin Card Sorting Task [WCST]) and from developmental psychology (Tower of Hanoi [TOH] and Matching Familiar Figures Test [MFFT]). A discriminant task, recognition memory, was administered, and IQ scores were available on a subset of the sample. One hundred subjects ranging from 3 to 12 years old participated; an adult group was also studied. Three major results were found: (a) adult‐level performance on different subsets of the executive function tasks was achieved at three different ages—6 years old, 10 years old, and adolescence; (b) the measures clustered into three different factors reflecting speeded responding, set maintenance, and planning; and (c) most of the executive function tasks were uncorrelated with IQ. The implications of these results for our understanding of the development of prefrontal lobe functions are discussed.