The concurrent performance of two attention-demanding tasks requires the ability to divide attention, prioritize, and share cognitive resources. Among older adults, dual-tasking abilities when standing or walking reflect a risk of falls and are associated with future cognitive decline. A fall can have many severe and undesirable consequences for older adults. This research examined the benefits of very low intensity, non-invasive electrical stimulation of various parts of the brain, hoping that this might improve the ability of older adults to perform both tasks simultaneously in a safer manner.
Subjects were evaluated before and after 4 different treatments: sham, designed not to have any influence at all, but to rule out any placebo effects; stimulation of a cognitive area of the brain (DLPFC) that is responsible for dividing attention; stimulation of a sensory-motor area of the brain which contributes to the regulation of walking process; and simultaneous stimulation of both areas – motor and cognitive – together. Each treatment included non-invasive stimulation using a very low-intensity electric current for 20 minutes. Immediately upon the conclusion of the treatment, the walking and standing sway of each subject were evaluated, with and without the request to also perform a cognitive task.
Stimulation of the cognitive area of the brain (i.e., the DLPFC), whether alone or together with the stimulation of the motor area, reduced the negative effects of the cognitive task on walking and standing stability by about 50%. On the other hand, stimulation of the sensory-motor area alone and sham stimulation did not improve the subjects’ performance. These results demonstrate that a low-level, ’gentle‘ stimulation of a specific cognitive area of the brain can improve the performance of older adults when they walk or stand in place while at the same time performing a cognitive task, at least within the immediate time range. Positive results over a more protracted period may help to diminish the risks of falling, and perhaps also enhance cognitive function among the elderly population.
Researchers: Junhong Zhou, Brad Manor, Wanting Yu, On-Yee Lo, Natalia Gouskova, Ricardo Salvador, Racheli Katz, Pablo Cornejo Thumm, Marina Brozgol, Giulio Ruffini, Alvaro Pascual-Leon, Lewis A. Lipsitz, Jeffrey M. Hausdorff