Veering in human locomotion: modulatory effect of attention.

Without visual information, human subjects are not able to maintain displacement in a straight line. This tendency to depart from linearity during locomotion is called veering. The purpose of the present experiment was to investigate the extent to which attention could modulate navigation in the absence of visual information. Blindfolded locomotion on linear pathways was assessed under three different conditions. The Distraction condition was intended to divert participants' attention from the walking task, whereas in the Concentration condition, participants deliberately focused on the task. There was also a Control condition in which no particular instruction was provided. Results showed that subjects veered in all conditions. Furthermore, more accurate performances were observed in the Distraction condition compared to the Control condition, while the Concentration condition led to larger deviations.