and gait is mostly derived from studies that measured and reported EF as a composite score [12,18,19]. Relatively few studies have focused on the age-related deficits in specific components of executive function and most of these studies were based on a traditional set of tests of executive function, without detailing specific components. The conclusions drawn from these studies might, therefore, be limited by their methodologies. The putative executive measures might not load on a single executive construct, and might overlap with each other [20,21]. The differential breakdown for the executive functioning performance across patients with chronic schizophrenia, for example, suggests that the fractionation of central executive functioning occurs in schizophrenia and not all EF.
