Adapted by Carleton, R. N., Norton, M. A., & Asmundson, G.J. G. (2007) from the original, longer scale (Freeston, M., Rhéaume, J., Letarte, H., Dugas, M. J., & Ladouceur, R., 1994). IUS scores are strongly related to anxiety and depression, and will be used in comparison to exploitative reward behaviors as assessed in our neuroimaging task. The IUS assesses two sub-scales of uncertainty: prospective (i.e., avoidance) and inhibitory (response to uncertainty).