Gait and Eye Tracking in Healthy Adults

Participants were recruited via a TU-Chemnitz online mailing list and could participate if they had self-reported normal or corrected-to-normal vision (≤ ± 7 dpt when uncorrected, contact lenses were permitted), no neurological or walking impairments, and a body mass of 130 kg or less. Visual and body mass-based exclusion criteria were based on the device limits of the eye tracker and the treadmill, respectively. All participants reported being sufficiently rested and focused in a questionnaire prior to the experiment, were naïve to the hypotheses and debriefed after the experiment. We aimed for a power of 80% (Cohen 1988 ) which, given $\alpha =.05$ and Cohen’s $f=0.25$ (a realistic estimate based on previous work, Kopiske et al. 2021 (link)), required a sample size of $N=24$ . A total of 27 participated, as after inspecting data quality, but prior to any hypothesis-related analysis, data of three participants had to be excluded due to a high proportion of missing eye-tracking data (> 20% missing values, same cutoff as used in Kopiske et al. 2021 (link)).
The analyzed sample of N = 24 included 14 women and 10 men with an average age of 24.3 years (between 19 and 34), average height 173 cm ± 9 cm (standard deviation), average body mass 68 kg ± 15 kg and average leg length 94 cm ± 6 cm. These biometric measurements were required for modeling motion tracking. For participation, participants received either course credit or a monetary reimbursement of 8€/h. All experimental procedures were approved by the Chemnitz University of Technology, Faculty of Behavioral and Social Sciences ethics committee (case no.: V-314-PHKP-WETGRAIL01-17012019). Participant data were protected following the guidelines for data management and data sharing of the German DGPs (Gollwitzer et al. 2020 ).