Fig 1.
Experimental pieces of apparatus.
Fig 2.
Flowchart of fNIRS signals processing.
SNR = signal noise ratio; OD = optical density; MBLL = modified Beer-Lambert law.
Fig 3.
Array and subregions mapping: Dorsolateral PFC (yellow); Frontopolar PFC (red); Ventrolateral PFC (green); Orbitofrontal PFC (blue).
Fig 4.
Reference lines for torso kinematics.
Lines are superimposed on a representative body segments skeleton derived from the motion capture system.
Table 1.
ANOVAs applied to oxyhemoglobin data.
Fig 5.
Oxyhemoglobin concentrations (ΔO2HbAVG) for the first slip trial.
Average values across all participants (N = 10) for left and right prefrontal cortex (PFC) subregions (top to bottom panels) as a function of the period (standing, walking, recovery): A) Left and right dorsolateral PFC (DLPFCL/R); B) Left and right ventrolateral PFC (VLPFCL/R); C) Left and right frontopolar FPFC (FPFCL/R); D) Left and right orbitofrontal cortex (OFCL/R). Error bars indicate standard error of the corresponding means. Asterisks: significant differences (* p < 0.05, ** p < 0.01, *** p < 0.0001).
Fig 6.
Oxyhemoglobin concentrations (ΔO2HbAVG) as a function of trials.
Average values across all participants (N = 10) for left () and right (
) prefrontal cortex (PFC) subregions (top to bottom panels) as a function of the trial number: A) Left and right dorsolateral PFC (DLPFCL/R); B) Left and right ventrolateral PFC (VLPFCL/R); C) Left and right frontopolar PFC (FPFCL/R); D) Left and right orbitofrontal cortex (OFCL/R). Error bars correspond to the standard error of the corresponding means. Piecewise linear regressions (---) use trial 3 as the break point (see bottom graph and text for justification). *** p < 0.0001.
Table 2.
Comparisons of piecewise and single linear regressions.
Fig 7.
Kinematic variations for the first trial.
Average values across all participants (N = 10) as a function of period: A) Trunk angular dispersion (TAD); B) trunk range of motion (TROM); C) center of mass range of motion (COM ROM); D) Minimum of COM (Min COM). Error bars indicate standard error of the corresponding means. Asterisks: significant differences (* p < 0.05, ** p < 0.01, *** p < 0.0001).
Fig 8.
Kinematic variations and response time as a function of trials.
Average values across all participants (N = 10). From top to bottom: TAD = Trunk angular dispersion; TROM = Trunk range of motion; COM ROM = Center of mass range of motion; Min ROM = Minimum of COM; Step Time = first response step time. Error bars correspond to the standard error of the corresponding means. Piecewise linear regressions (---) use trial 3 as the break point (see Fig 5 and text for justification).
Table 3.
PFC (DL,VL,F)—kinematics correlations.