Orbitofrontal Reality Filtering (ORFi) denotes a cognitive process that allows our thoughts and behaviors to be congruent with the ongoing reality. ORFi appears to use a mechanism signaling when an anticipation is now invalid. It intervenes at an early stage of processing, at 200-300 ms, and is associated with activation of the posterior medial OFC. However, situations involving ambiguity may render it difficult to determine when previous anticipations are no longer valid. In the present thesis, we investigate how precisely the brain deals with such ambiguous situations. We first showed that the brain uses at least two distinct processes evaluating the absence of anticipated outcomes with unequivocal or ambiguous behavioral relevance. We next showed that the OFC flexibly adjusts the processing of outcomes depending on whether they require or not behavioral adaptation in the present context.