Dual task walking reduced target fixations and slowed gait in healthy young adults

Adding mental workload narrowed visual exploration, pushed gaze off the path, and made precision stepping less efficient.

When healthy young adults walked while doing a cognitive task, they looked less at future stepping targets and more at irrelevant areas. Their gait also slowed, with longer stance times and lower velocity between targets. Cross-stepping appeared more often in single-task than dual-task walking, challenging the idea that it is always maladaptive.

Quick summary

What the study found: Dual-task walking reduced the number and duration of fixations on stepping targets, increased fixations to outside areas, reduced saccade amplitude, and produced slower, less efficient gait patterns.
Why it matters: Even in young, low-risk walkers, mental workload can disrupt proactive visual planning that supports stable, accurate stepping.
What to be careful about: Several participants and trials were excluded, biomechanical and eye-tracking samples differed, and cross-stepping comparisons were descriptive only.

What was found

In the journal article The cost of dual-task walking: Cognitive demands restrict gaze behaviour and gait planning, participants walked an L-shaped route with raised stepping targets under single-task and dual-task conditions.

During dual-task walking, participants showed longer trial duration and slower average walking speed. They also had longer stance times on key targets and reduced velocity between targets, consistent with a more cautious and less efficient gait strategy.

Eye tracking showed fewer and shorter fixations on task-relevant red targets during both the proactive approach period and the later proximal period. At the same time, participants made more fixations toward outside, task-irrelevant areas.

Saccade amplitude was smaller in dual-task than single-task walking. Saccades are rapid eye movements that shift gaze between locations; smaller amplitudes suggest reduced scanning between near and far regions.

What it means

The pattern points to compromised feedforward planning, meaning planning steps in advance using early visual information rather than relying on last-second corrections. Under mental workload, participants gathered less visual information about upcoming targets.

The authors interpret the increase in outside fixations as consistent with “gazing into thin air,” an active visual disengagement from the walking task. In practical terms, attention may be pulled from the path even when the cognitive task does not require looking away.

Where it fits

Adaptive walking depends on coordinating attention, working memory, and vision to build a usable internal map of “where to step next.” Dual-tasking likely taxes these limited resources, shrinking the bandwidth available for scanning and updating target locations.

The study also complicates assumptions about compensatory strategies. Cross-stepping occurred more often in single-task trials than dual-task trials, and the authors suggest cross-stepping may not be maladaptive in this population.

How to use it

For safety and performance, treat “thinking hard while walking precisely” as a meaningful load, not background noise. When navigating curbs, stairs, crowded platforms, or uneven terrain, reduce cognitive demands by pausing a mental task, finishing a text, or delaying complex decisions.

In training and rehabilitation contexts, progress dual-task demands deliberately. Start with stable routes, then add precision stepping, then add a cognitive task, watching for telltale signs: slowed pace, longer “sticking” in stance, and gaze drifting off the route.

Limits & what we still don’t know

The final samples were 17 for eye tracking and 13 for biomechanics due to exclusions and recording issues. That makes estimates less stable and may limit generalizability.

Difficulty manipulations did not produce broad significant effects on biomechanics or many gaze measures, and cross-step analyses were descriptive without inferential tests. The study also reports mean saccade amplitude, which cannot reveal detailed scan-path patterns.

Closing takeaway

This journal article shows that mental workload can measurably disrupt looking behavior that supports precise stepping, even in healthy young adults. If gaze stops serving the path, gait becomes slower and less efficient. When accuracy matters, protect attention first.

Data in this article is provided by PLOS.

Tagged Adults, Age groups, Anatomy, Attention, Behavior, Biological locomotion, Biomechanics, Body limbs, Cognitive psychology, Cognitive science, Eye movements, Feet, Legs, Neuroscience, Perception, Population groupings, Sensory perception, Sensory physiology, Sensory systems, Vision, Visual system, Walking, Young adults