In the mind's eye: The late positive potential to negative and neutral mental imagery and intolerance of uncertainty.

There are many advantages to human beings' ability to generate and sustain mental imagery in the absence of exteroceptive stimuli; however, this ability may also underlie emotional disorders characterized by worry, rumination, or excessive concern about the future. For instance, fear-based disorders may be characterized by heightened ERPs to negative imagery. On the other hand, distress disorders may be characterized by attempts to avoid engaging with negative mental imagery, and therefore reduced electrocortical response. Prior ERP work has used negative and neutral pictorial stimuli to establish the parameters of response in healthy individuals, before taking these paradigms to clinical samples to assess aberrant emotion processing. Yet despite its clinical relevance, no study to date has elicited a late positive potential (LPP), a robust measure of emotion processing, to standardized negative imagined scenes. Here, participants listened to audio descriptions of negative and neutral scenes, and were asked to imagine these scenes as vividly as possible. Results showed that negative imagined scenes elicited an increased LPP, lasting approximately 10 s after audio description offset, as well as heightened ratings of arousal and unpleasantness. Moreover, participants with greater self-reported cognitive concerns about uncertain future events (higher prospective intolerance of uncertainty) showed reduced emotional modulation of the LPP. These data provide the first evidence of sustained electrocortical processing of standardized negative imagery elicited in the absence of salient visual cues, and suggest that cognitive risk for anxiety in an unselected sample may be represented phenotypically by blunted LPPs to negative imagery.