Effects of walking on bilateral differences in spatial attention control: a cross-over design

Background: Walking requires a high attentional cost for balance control and interferes with the control of attention. However, it is unclear whether the performance of visual spatial attention control, which is one of the functions of attention control, is also decreased during walking. In addition, although previous studies have shown right-hemispheric dominance and lower ability of left side visual spatial attention control during sitting, it remains unknown whether walking accentuates bilateral differences in visual spatial attention control. We tested the hypothesis that walking interferes with visual spatial attention control on both sides and accentuates its bilateral differences. Methods: Twenty healthy right-handed subjects (24.3 ± 2.0 years) participated in this study. Subjects performed a random stimulus–response compatibility (SRC) task during both sitting and walking situations. To evaluate the effects of walking, reaction time was measured on both sides for the two situations. In comparison to the both situations (sitting and walking), the amount of change of the SRC effect on both sides was used. In the comparing the bilateral difference (left and right), the difference of the SRC effect was evaluated in each situation. The paired t-test was applied to both comparisons for statistical analysis. Results: The SRC effect on both sides during walking was significantly larger than during sitting (P < 0.05). In addition, walking significantly accentuated the bilateral differences in visual spatial attention control (P < 0.05). Conclusions: These results suggest that walking affects the performance of visual spatial attention control on both sides and accentuates its bilateral differences. These results have implications for development of practice methods of gait disorder with higher brain dysfunction.