Psycho-Metric Curve Parameters.

Individual maximum likelihood (ML) estimated threshold (PSE fit), intercept and slope ± SE obtained by Logit glm fit describing the percentage of positive answers as function of upward force level. R2 psy values describe the explained variance of the Logit function used to describe psychophysical decisions per each subject. PSE stair values were obtained by averaging the force levels associated with the last 10 reversals of the up-down staircase method. Bold values are those considered for further analysis. Either PSE fit or PSE stairs were used whether individual R2 psy were higher (as well as equal) or lower than 0.60, respectively.