Abstract
[Purpose] The purpose of this study was to determine the change of allocation of attention caused by a difference in gait phase and gait speed. We also determined the relationship between attentional demand and gait automaticity change caused by the gait speed alteration. [Subjects and Methods] Ten male participated. Participants were instructed to perform the probe reaction time (RT) task during treadmill walking in four different gait speed conditions (60%, 80%, 100%, and 120% of preferred speed). Walking ratio in each gait speed conditions were calculated, and RTs and walking ratios were compared in each gait speed condition and in the single-support and double-support gait phase. [Results] RTs were significantly delayed with decline of gait speed. Walking ratio was significantly decreased in proportion of decrement of gait speed. There was no difference of gait phase between single-support and double-support phase. [Conclusion] This study showed that relationship between attentional load and deficit of gait automaticity. While gait phase didn't influence attentional demand, and this result showed the characteristics of treadmill gait.