Intolerance of uncertainty enhances generalisation of cued conditioned threat: An event-related potential study

Overgeneralisation is one of the aetiologies of anxiety disorders and is closely associated with elevated intolerance of uncertainty (IU) levels. However, the underlying mechanisms are unclear. Considering the inconsistency of previous results and the high sensitivity of IU to uncertainty, the present study investigated the effect of IU on threat generalisation in predictable and unpredictable conditions. We compared self-reported unconditioned stimuli (US) expectancy and event-related potentials (ERPs) during generalisation in high IU (n = 34) and low IU (n = 35) participants. The results indicated that high IU was associated with higher US expectancy for generalisation stimuli (GS) than with low IU. At the electrophysiological level, compared to low IU, high IU showed increased P1 to ambiguous GS as well as decreased early late positive potential (LPP) to GS in unpredictable conditions, and no differential response to GS in late LPP in predictable conditions. These findings suggest that IU enhances threat generalisation and may be related to increased early automatic attention to ambiguous stimulus and inadequate late elaborate processing in a high uncertainty context. These findings might contribute to the treatment of mood disorders characterized by high IU.