Anterior insular activity signals perceptual conflicts induced by temporal and spatial context

The signals registered by our senses are inherently ambiguous. Subjective experience, by contrast, is informative: it portrays one interpretation of the sensory environment at a time while discarding competing alternatives. This is exemplified by bistable perception, where ambiguous sensory information induces prolonged intervals of alternating unambiguous perceptual states. According to predictive-processing accounts of bistable perception, perceptual experiences in the recent past constitute a predictive context that stabilizes perception, while sensory information that is in conflict with this predictive context evokes prediction errors. These prediction errors are thought to drive spontaneous perceptual switches. We asked whether this mechanism generalizes to conflicts between other forms of predictive context and sensory information.

To this aim, we investigated the neural correlates of perceptual conflicts with temporal and spatial context during bistable perception using functional magnetic resonance imaging (fMRI). Twenty-six healthy participants viewed serial presentations of ambiguous structure-from-motion stimuli either in isolation (conflict with temporal context) or embedded in a similar but unambiguous surround stimulus (conflict with spatial context). The neural correlates of conflicts with temporal and spatial context overlapped in the anterior insula bilaterally. Model-based analyses similarly yielded common prediction error signals in the anterior insula bilaterally, right inferior frontal gyrus and right inferior parietal lobe. Together, these findings point to a generic role of these frontoparietal regions in detecting perceptual conflict and thus in the construction of unambiguous perceptual experiences.