The nature and role of cortical feedback in perception, imagery, and synesthesia.

In his Discussion Paper, Seth makes the case for counterfactual richness of predictive processing models in explaining perceptual presence and its absence in synesthetic concurrent percepts. Here, we question the relevance of counterfactual richness for these and related phenomena, and we argue that alternative theories of perception that incorporate top-down/bottom-up facilitatory interactions are at no relative disadvantage in addressing them.