NONINVASIVE BRAIN STIMULATION INCREASES THE COMPLEXITY OF RESTING-STATE BRAIN NETWORK ACTIVITY IN OLDER ADULTS

Successful completion of cognitive and motor tasks requires functional interactions between numerous brain networks over multiple temporal scales. Biological aging reduces the multi-scale “complexity” of the spontaneous fluctuations in network activity. Still, it is unknown if such “resting-state” complexity is sensitive to functional status, or modifiable via intervention. We hypothesized that resting-state complexity is lower in older adults with functional limitations, and, that it can be increased via repeated exposure to transcranial direct current stimulation (tDCS). Twelve older adults with mild-to-moderate executive dysfunction (i.e., Trail Making Test B time below the 25th percentile of age- and education-based norm) and slow gait (i.e., gait speed 4.7, p4.9, p