Impact of dual tasking on gaze behaviour and locomotor strategies adopted while circumventing virtual pedestrians during a collision avoidance task

Exploring the challenges of avoiding collisions with virtual pedestrians using a dual-task paradigm in individuals with chronic moderate to severe traumatic brain injury

“…The dual-task adaptations observed in healthy controls apparently contrast with a recent study by Bhojwani et al (2022), which used a protocol similar to the one used in the present study [ 45 ] and where no dual-task adaptations in terms of locomotor measures were observed. The healthy individuals included in the present study, however, were aged-matched to the m/sTBI group and older (average 41.8 years, range 24–53) than those tested earlier (24.9 years, range 18–29) [ 45 ]. Age-related changes in sensorimotor and cognitive functions [ 72 – 74 ], as well as in dual-task walking abilities [ 75 , 76 ], likely explain differences between the two studies.…”

“…Data recorded in the Unreal engine were exported to Matlab (MathWorks, USA) and used to calculate the measures related to the locomotor and cognitive tasks. Because participants exhibited very similar behaviour when navigating VRP interferers approaching from the left vs. right, as also seen in other studies [ 45 , 67 , 68 ], data from the left and right VRP directions were combined into a single ‘diagonal’ condition. There was only one missing trial for one participant that was not recorded due to technical issues.…”

“…Research also shows that attentional processes and gaze behaviour (where a person is looking) are closely linked at the neural level, making gaze allocation indicative of an individual’s focus of attention [ 44 ]. In recent locomotor studies, gaze fixation duration was shown to be modulated according to factors such as the location and/or direction of displacement of pedestrians present in the environment [ 8 , 45 ], suggesting that visually acquiring information about the spatial properties of the obstacle plays a role in successful collision avoidance. Additionally, a study involving stepping over an obstacle while performing a cognitive task showed that individuals with m/sTBI, unlike healthy individuals, presented a larger cognitive dual-task cost when performing a visual vs. auditory-based cognitive task [ 42 ].…”

“…The second objective was to characterize gaze behaviour associated with the circumvention task performed in single and dual-task conditions in both groups. In relation to the first objective, it was hypothesized that individuals with m/sTBI would present dual-task costs (DTCs) in both the locomotor and cognitive tasks, while the healthy individuals, based on previous work involving similar obstacle circumvention tasks [ 31 , 47 ], would only show a small cognitive DTC. For the second objective, longer gaze fixations on the approaching VRPs were expected in the dual- vs. single task condition for both groups, but such difference would be more pronounced in the m/sTBI group.…”

Cognitive and visual task effects on gaze behaviour and gait of younger and older adults

“…It is possible that the walking task employed in the current study represented a more challenging motor task than the quiet standing paradigm investigated previously (Walsh 2021a ) and, therefore, participants minimised disruption to the sensory information provided by visual input. Similarly, it has been demonstrated in a walking task requiring participants to avoid collisions that dual task effects were not seen in gait or gaze parameters, indicating participants prioritized the locomotor task at hand (Bhojwani et al 2022 ).…”