Conscious Control of Gait Increases with Task Difficulty and Can Be Mitigated by External Focus Instruction.

We aimed to address whether increased task difficulty is sufficient to induce heightened conscious control and influence gait performance in older adults through the manipulations of either task difficulty or attentional focus. Fifty older adults, split into high- (HR) and low-reinvestor (LR) groups, performed a walking task on a 7.4 m straight walkway in two conditions: firm level-ground surface (GW) and foam surface (FW). They subsequently performed the same walking task under two attentional focus conditions: Internal focus (IF) and External focus (EF). Electroencephalography (EEG) T3-Fz and T4-Fz coherences were used to indicate real-time conscious motor control and visual-spatial control, respectively. We observed significantly higher T3-Fz and T4-Fz coherences under FW compared to GW. HR reduced their gait speed at a greater extent than LR under FW. Significantly lower T3-Fz coherence and faster gait were demonstrated under EF compared to IF. LR walked slower under IF compared to Baseline while gait speed of HR did not differ. Visual-spatial and conscious movement processing increase as a function of task difficulty during gait. Our findings also advocate the use of external focus instructions in clinical settings, with the potential to reduce conscious control and promote movement automaticity, even in relatively complex gait tasks.