Examination of a Novel Cognitive-motor Weight-bearing Dual-task Intervention in Older Adults

In order to functionally move through one's community, it is vital to be able to perform simultaneous motor and cognitive tasks (cognitive-motor dual-task). This allows us to talk to another person, scan the environment for oncoming traffic, and avoid objects that are in our path when walking. This even allows high level sporting participation, such as predicting an opponents' path when sprinting and cutting to score a goal. Unfortunately, aging is associated with increased difficulty in performing cognitive-motor tasks. A classical example is when older adults stop walking in order to talk to another person. Several studies have established that an increase in age is associated with increased cognitive resources required to perform normally automatic motor tasks. Deficits in cognitive-motor dual-task capabilities have been observed not only in older adults, but also in those with neuromuscular compromise due to factors such as stroke and Parkinson's, and even with altered cognition in mild cognitive impairment and Attention Deficit Disorder.

Although these early investigations suggest a relationship between physical and cognitive capabilities, little is known regarding the appropriate level of cognitive task difficulty that will result in improvements or delays in learning a motor task. Conflicting results are noted in the few studies that have investigated this line of research. Some support that a concurrent cognitive task provides a context that facilitates motor learning, while other show that cognitive load prevents individuals from fully learning the motor task . Further, there are very few studies that investigate the effect of cognitive load on the transfer of motor learning to new task conditions for weight-bearing activities. Early evidence suggests that generalizability of learning diminishes the further participants are from the initial task conditions. Interestingly, cognition has been suggested to play a vital role in motor learning, performance, and dual-task capability. Working memory capacity, or the process that allows the maintenance and manipulation of information over a short period of time, has been shown to strongly relate to the rate at which younger adults learn motor sequences, and moderately relate the motor learning of older adults. Executive function, or the properties of cognitive flexibility, problem-solving, and response maintenance, also plays a role in motor learning and performance. Decrements in executive function has been shown to precede mobility limitations, and might even predict gains in mobility from a physical intervention. Executive function may also predict a large portion of the variability when under the context of simultaneously having a cognitive load. There continues to be a lack of understanding of what cognitive capacity is required to perform simultaneous mobility and cognitive tasks with the least risk of injury, and what dose of intervention in both physical and cognitive realms are necessary to induce an improvement in function of both systems.

Purpose: To determine the impact an intervention using simultaneous cognitive and motor tasks on the capacity of healthy adults to improve in functional mobility and cognition.

Research Question: Does a cognitive-motor intervention impact functional mobility and cognition of healthy older adults?

Following obtaining consent from the subject, testing will take place three times a week for 8 weeks. Subjects are randomly assigned to one of each of the three groups: control group, simple cognitive group, or complex cognitive group.