Aphantasia subtypes
Aphantasia is heterogeneous: some people have no voluntary imagery in any sense, others lack only visual imagery, some have vivid dreams despite no waking imagery. The field is still sorting out the internal structure.
The single label "aphantasia" covers several empirically distinct patterns. Visual-only aphantasia is an inability to picture while other senses — hearing a tune in your head, recalling a smell, imagining a texture — work normally. Multi-sensory aphantasia is the absence of voluntary imagery in any modality. Partial or low-vividness aphantasia describes people whose imagery is fleeting or dim rather than absent. Some aphantasics report vivid dreams; some do not. Some have involuntary hypnagogic imagery on falling asleep; some do not.
Zeman’s 2025 decade review flags this heterogeneity as one of the open questions the field has not yet settled. A connectivity-based model like the Liu and Bartolomeo 2025 framework plausibly accommodates it — different pairs of brain regions may connect or fail to connect to different degrees in different people — but subtypes have not been cleanly mapped onto brain-network profiles. For a reader, the practical implication is that any single description of aphantasia is a simplification; your own version is allowed to be its own shape.