Figure 2. The preference for C-Tactile targeted touch and overall touch pleasantness are unaffected by anterolateral cordotomy.

(a) Raw touch pleasantness rating data for the pain-affected and control sides in the pre-cordotomy as well as post-cordotomy states. Group data for the pain affected side pre-cordotomy and post-cordotomy are shown in (b). Group data for the control side pre-cordotomy and post-cordotomy are shown in (c). Ratings of touch pleasantness are not significantly affected by anterolateral cordotomy. Dot plots of the mean individual ratings for touch pleasantness on the pain-affected side in the pre-cordotomy and post-cordotomy state are shown in (d). The lines of best fit with 95% confidence intervals are shown. The vertical dotted line indicates the position of a velocity of 1 cm s-1 on the logarithmic scale. Intercept values were defined as the value of where this 1 cm s-1 line is crossed by the line of best fit. The equations for the fitted curves, R² as well as F-test results for the pre-cordotomy and post-cordotomy states are (y = -2.07x² + 1.88x + 6.22; R² = 0.22; F_{2, 56} = 7.432, p=0.001) and (y = -1.95x² + 1.75x + 6.34; R² = 0.19; F_{2, 56} = 6.211, p=0.004) respectively. F-test results for a linear fit were not statistically significant (p=0.756 and p=0.749 for pre-cordotomy and post-cordotomy states respectively). Dot plots of individual values for β₂ and intercept pre-cordotomy and post-cordotomy states for both the pain-affected and control side are shown in (e) and (f). Group data are presented as mean + standard error mean.