Effects of Dual-Task Training on Cognitive-Motor Learning and Cortical Activation in Healthy Young Adults

Abstract

A dual-task (DT) paradigm requires concurrent performance of two tasks, or a cognitive and motor task. Since attention needs to be divided between a cognitive and motor task, limited central processing capacity results in interference and functional performance deficits in either one or both tasks. Numerous studies have investigated the effects of DT training in healthy individuals and individuals with neurological disorders. However, the DTs included are limited to simple tasks that do not involve complex interactions of the various systems required for dynamic postural control. Moreover, there is a paucity of knowledge in understanding the effects of complex DT training on cortical activation. Hence, the purpose of this study is to assess the effects of dynamic stability DT training on cognitive, motor, and DT performance and prefrontal and sensorimotor cortical activation in healthy young adults. Our DT paradigm involves balancing on a dynamic stability platform combined with a simple and complex auditory reaction time task. The motor task requires participants to stand on a dynamic stability platform and keep it as level as possible. The cognitive task requires response to auditory stimuli. Prefrontal and sensorimotor cortical activation are assessed with a neuroimaging technique, functional near-infrared spectroscopy (fNIRS). Baseline testing involves performance of each task, the DT, and measurement of cortical activation by quantifying oxygenated hemoglobin (HbO) while performing single and DTs. 20 adults will receive DT training for 5 consecutive days. Training involves practice of 18 DT trials. Post-training performance on the same baseline measures is assessed immediately after 5 days of training and again 1-week post-training to assess retention effects. Preliminary analysis with 5 participants (2 men, 3 women; mean age: 21.4 years; SD: 1.8 years) showed improved balance performance (motor task), reaction time (cognitive task), and DT performance across visits. Moreover, the prefrontal and sensorimotor cortical activation decreased systematically with DT training under single and DT conditions. The decrease in cortical activation paralleled an improvement in cognitive-motor performance with DT training. These preliminary findings suggest promising effects of DT training in healthy young adults to improve postural stability and reduce cognitive-motor interference.