Median-IQR strategies. Relationship between ΔMedian and ΔIQR of MTC for young adults (left panels A, B) and elderly adults (right panels C, D) during the change of slopes from 0° to +3° (up) and slopes from 0° to -3° (down). Significant correlation (p < 0.01) was found in the young group. ρ = Correlation coefficient. (See text for details).