By Alli Horning, Health Sciences; Thomas McQuaid, Health Sciences
Advisor: Pierce Boyne
Abstract: Neural control of walking in healthy adults is largely subcortical (automatic), while individuals with gait impairments are thought to increase cortical activity (conscious) when walking. While conscious walking may correct gait deviations caused by neuromuscular abnormalities or the environment, previous studies have suggested it negatively influences advanced motor control (gait symmetry, metabolic cost, comfortable walking speed). However, limited research is available confirming this. The purpose of this study is to identify brain regions responsible for conscious walking. We hypothesize the prefrontal cortex (SFG9m), primary motor cortex (M1F), supplementary motor area (SMA), and premotor cortex (PMd) are more active during conscious walking than automatic walking. Using functional near-infrared spectroscopy (fNIRS) to measure cortical activation, eight healthy adults (ages 21-55) completed 5 cycles of walking, each involving 30 seconds of conscious walking, 30 seconds of rest, and 30 seconds of automatic walking. Participants were instructed to focus on kinematic aspects of their gait during conscious walking, and to avoid doing so during automatic walking. During conscious walking, an increase in SFG9m (T=2.357, p=0.033) and PMd (T=3.079, p=0.008) activation was found, with no significant changes in M1F (T=1.164, p=0.263) or SMA (T=1.182, p=0.257). Conclusively, areas of the frontal and premotor cortices involved with executive function and motor planning were more active during conscious walking. Overactivation of motor planning regions may inhibit motor function as cognitive resources become scarce; therefore, these findings will benefit the design of future studies. Further research is needed to investigate influences of conscious gait control on walking function.