Congenital aphantasia: what we (think we) know, what we thought we knew but were mistaken about, and what we don't know

Congenital Aphantasia initially described a lifelong inability to visualise. But it is now understood to manifest as imaginative inabilities that can encompass multiple sensory modalities (e.g. vision, audio, movement, taste, touch, smell). Congenital Aphantasia has become a focus of a dynamic multidisciplinary field of research. Amongst researchers, there are some points of agreement, such that the phenomenon arises when distributed brain regions fail to act in concert. There are, however, also points of disagreement. These include whether the primary visual cortex makes a necessary causal contribution to imagery when people can visualise, if Congenital Aphantasia is specific to the imagery of objects, and whether visualisations can be subliminal. We argue that some conceptual confusions have contributed to these debates, such as what constitutes an objective measure of imagery. We argue for a framework wherein imagined sensations are understood to be conscious phenomenal experiences that arise as an emergent property of coordinated activity from across a broad network of brain regions. These imagined experiences cannot, therefore, be subliminal and will naturally be characterised by variability across the general population. As Congenital Aphantasia is characterised by deficits of phenomenal experience, we believe it represents a promising empirical avenue to uncover fundamental truths about how human brains generate conscious sensations.