Fig. 2

Intolerance of uncertainty predicts psychophysiology during fear extinction. Bar graphs depicting IU differences ±1 SD from the mean during early and late extinction learning. a SCR magnitude and b pupil dilation. Low IU were associated with significantly greater SCR magnitude responses to CS+ vs. CS− in early extinction and no differences between stimuli in late extinction. High IU scorers showed no differences in SCR magnitude to CS+ and CS− stimuli in early extinction, and delayed discrimination in SCR magnitude to CS+ vs. CS− in late extinction. The pupil dilation results followed a similar pattern to the SCR magnitude results, albeit at trend. SCR magnitude (μS), skin conductance magnitude measured in microSiemens; Pupil dilation (Δmm) measured in delta millimetres