Until recently, gait was generally viewed as a largely automated motor task, requiring minimal higher-level cognitive input. Increasing evidence, however, links alterations in executive function and attention to gait disturbances. This review discusses the role of executive function and attention in healthy walking and gait disorders while summarizing the relevant, recent literature. We describe the variety of gait disorders that may be associated with different aspects of executive function, and discuss the changes occurring in executive function as a result of aging and disease as well the potential impact of these changes on gait. The attentional demands of gait are often tested using dual tasking methodologies. Relevant studies in healthy adults and patients are presented, as are the possible mechanisms responsible for the deterioration of gait during dual tasking. Lastly, we suggest how assessments of executive function and attention could be applied in the clinical setting as part of the process of identifying and understanding gait disorders and fall risk. © 2007 Movement Disorder Society Key words: gait; executive function; attention; Parkinson's disease; Alzheimer's disease; aging; dual task; review article The relationship between higher-level cognitive function and gait disturbances has received considerable attention in recent years. Gait is no longer considered as merely an automated motor activity that utilizes minimal higher-level cognitive input. Instead, the multifaceted neuropsychological influences on walking and the interactions between the control of mobility and related behaviors are increasingly appreciated. This is manifest in part by an individual's awareness of a destination, the ability to appropriately control the limb movements that produce gait, and the ability to navigate within often complex environs to successfully reach the desired location. Studies on cognitive function and gait now include many areas of research, ranging from physiology and biomechanics to brain mapping, physics and neuropsychology. For example, imaging studies have demonstrated frontal and parietal activity during locomotion. 1,2 This review covers the importance and relevance of two specific cognitive functions, executive function (EF) and attention, to the performance of gait during normal walking, as well as in aging and in pathological conditions. We review the physiology underlying these cognitive processes, describe the clinical findings and consequences of these relationships and discuss the physiological mechanisms that are brought into play. Finally, we summarize the implications of these associations for the daily lives of individuals affected by impaired function of one or more or these elements and provide suggestions for applying these insights to augment the diagnosis of gait disorders in the clinic. This review article is based on a systematic literature search for reviews and trials reported in English in the electronic databases of Medline and Psychinfo up to April, 2007. Relevant s...

Background The factors that contribute to the dual task (DT) changes in performance that occur when older adults walk while simultaneously performing other tasks are not well-known. We hypothesized that cognitive and motor reserve (e.g., executive function, EF, postural control, and walking abilities) and affect (e.g., anxiety, depressive symptoms) influence the DT decrements (DTDs) in gait. Methods 228 community-living, healthy older adults (mean: 76.2±4.2 yrs; 59% women) walked with and without dual tasking, e.g., subtracting 7’s, phoneme monitoring. Mobility (e.g., the Dynamic Gait Index), cognitive function (e.g., memory, EF), and affect (e.g., Geriatric Depression Scale) were quantified. Bivariate and multivariate analyses identified factors associated with the DTD in gait speed (a general measure of locomotor function), swing time, (reflecting balance during gait), and swing time variability (a measure of stride-to-stride consistency). Results Gait speed and swing time decreased (p<0.001) and swing time variability increased (became worse) (p<0.001) during all DTs. The DTD in gait speed was correlated with comfortable-walking gait speed, but not with tests of mobility or cognitive function. The DTD in swing time variability was correlated with EF, mobility and affect (e.g., depressive symptoms). Much of the variance in the DTDs was unexplained. Conclusions Usual-walking abilities and cognitive function contribute to the DT effects on gait, but these relationships depend on specifics of the DT, the gait feature being studied, and the particulars of the cognitive domain. Meeting the everyday challenges of walking while dual tasking apparently relies on multiple factors including a consistent gait pattern and EF.

Even among young adults, the effects of secondary, cognitive tasks on gait speed are strongly influenced by prioritization. This finding was less significant in the older adults, suggesting that there is an age-associated decline in the ability to flexibly allocate attention to gait. Somewhat surprisingly, when prioritization was not explicitly instructed, gait speed in both young and older adults most closely resembled that of the condition when they were instructed to focus attention on the cognitive task.