Normative data from the CANTAB. I: development of executive function over the lifespan.

The study of executive function within a developmental framework has proven integral to the advancement of knowledge concerning the acquisition and decline of higher skill processes. Still in its early stages, there exists a discontinuity in the literature between the exploration of executive capacity in young children and the elderly. Research of age-related differences utilising a lifespan approach has been restricted by the lack of assessment tools for the measurement of executive skills that are applicable across all age levels. This paper addresses these issues using the computer-based Cambridge Neuropsychological Test Automated Battery (CANTAB) to identify periods of development in executive capacities using a normative sample of 194 participants ranging in age from 8 to 64 years. Findings of executive function in children as young as 8 years of age were extended, with functional gains found in the efficiency of working memory capacity, planning and problem-solving abilities, between the ages of 15 and 19 years and again at 20-29 years of age. Cognitive flexibility was assessed at adult-levels in even the youngest children. Declines in performance on all tasks were revealed for the 50-64 year old sample, providing support for the vulnerability of executive skills to normal aging.