This thesis is an investigation of the cognitive mechanisms underlying human navigation of obstacles in their path, through responses to incoming visual information. Nineteen young adults performed an online obstacle avoidance strategy adjustment two steps prior to a 50 cm wide, 15% leg length high obstacle while responding to a simultaneous auditory Stroop task. Participants demonstrated adjusted obstacle crossing but not obstacle circumvention behaviors when dual-tasking and required greater time to respond to the Stroop task when performing an online strategy adjustment compared to trials where no adjustment was required. Performing an online circumvention strategy adjustment increased the latency and magnitude of center of mass lateral deviations. These results confirm the complexity of these online maneuvers;​ and that input from the cognitive system is required for their execution. There may be greater implications for populations with reduced mobility or cognitive capabilities.