RESUMO
Uncertainty about the emotional impact of future events is a common part of everyday life. However, relatively little is known about whether the level of uncertainty about the affective nature of an upcoming visual image influences anticipatory neurocognitive processes. To investigate this, participants viewed a series of negative and neutral pictures, which were preceded by abstract anticipatory cues. Neural activity was measured using event-related potentials (ERPs). In the 'uncertain' cue condition, the cue could be followed by either a negative or a neutral picture with equal probability; in the 'fairly uncertain' condition the cue was followed by a negative picture on 70% of trials, and by a neutral picture on 30% of trials. In the 'certain' condition, the cue was always followed by a negative picture. For the P200 component, reflecting early stages of selective attention, there was no amplitude difference between cue conditions. At later stages of processing, the early posterior negativity (EPN) amplitude was enhanced for cues indicating a greater level of certainty, and the late positive potential (LPP) amplitude was greater for certain, compared to fairly uncertain and uncertain cues. The stimulus preceding negativity (SPN), an index of anticipatory processing, was more negative for certain cues compared to fairly uncertain and uncertain cues. For the SPN there was no difference between fairly uncertain and uncertain cues. These results provide evidence that the level of uncertainty regarding the affective nature of an upcoming picture influenced several stages of processing during the anticipation of the stimulus.
