Testing central executive functioning with a pencil-and-paper test, A. Baddeley et al; theory and methodology in executive function research, P.W. Burgess; executive and non-executive functions in normal and pathological ageing - a neuroimaging investigation, J.K. Foster et al; sustained attention and the frontal lobes, T. Manley, I.H. Robertson; how specific are memory and other cognitive deficits caused by frontal lobe lesions? A.R. Mayes, I. Daum; normal age-related memory loss and its relation to frontal lobe dysfunction, A. J. Parkin; do frontal tests measure executive function? - issues and assessment and evidence from fluency tests, L.H. Phillips; a neural systems approach to the cognitive psychology of ageing - studies with CANTAB on large samples of the normal elderly population, T.W. Robbins et al; studies of executive function in normal old age, C. Askew, P. Rabbitt; behavioural assessment of the dysexecutive syndrome, B.A. Wilson.This volume reflects the pressure to develop useful models and methodologies to study executive behaviour - the ability to update information in working memory in order to control selective attention to formulate plans of action and to monitor their efficient execution. Many models are based on the concept of a single central executive that manges these functions; others propose a number of independent working memory systems that each serve one task or activity but not others.; This book is a collection of essays by active researchers who discuss their own work on the definition of executive or controlled behaviours, and on the relation of these behaviours to specific areas of the frontal cortex. The papers are particularly concerned with logical difficulties that arise in defining these functions that lead, in turn, to methodological difficulties in studying them. In particular, they discuss such problems as the low test-re-test reliability of tasks that have been used to define and explore executive behaviours, thel3%