I have aphantasia.

People usually respond to this fact with “how do you X” questions, which I feel helpless to answer, because there isn’t a well-developed language for these things.

1. How do I navigate in familiar spaces? I… erm… “feel” it…? I can just sort of sense the spatial distance between things, without these things having visual representations. It’s a bit like if you were awake, closed your eyes and attempted to navigate a familiar space – my guess is that people don’t imagine the table to be avoided 2 feet ahead of them, rather they have some spatial sense that doesn’t run through visual imagery. If this isn’t your experience, I don’t know what else to tell you.
2. How do I dream? I mostly don’t. When I do, obviously, there is no visual content, nor sound nor speech. It feels like a stream of thoughts and concepts. Any movement through space feels like the above “feeling” of navigating a familiar space. Many people report occasionally waking up from feeling themselves “fall” in a dream – it’s kinda like this, but less severe, and for everything?
3. How do I remember faces/past events/etc.? I sit with the thought of the face/past event/etc. With time, details will surface, but there isn’t an explicit search process and, obviously, I’m not scanning over any visual representation. Sometimes the non-visual navigation of space is helpful, for example when recalling the geometry of a person or building.
4. How do I mentally rehearse future events, such as a presentation? Again, I more or less don’t. If it’s important enough, I will write down thoughts, record myself, or practice with a friend. The vast majority of the time, I wing it.
5. How do I engage with new narratives or descriptions? I just kind of sit with it and hope I absorb the relevant details. Friends have commented that when they describe new ideas, I have this odd habit of mouthing back the words they are saying immediately after they say them. I suspect that this is compensatory behavior.

You can see why describing navigation, dreams, mental arithmetic, recalling physical appearances and so on using the word “feel” is inadequate. (Previously I would have used “imagine,” until learning that most people were using this in a totally crazy way.)

With these experiences in mind (???), here’s a first attempt at an ontology of aphantasia.

1. Spatial proprioception: the ability to sense and manipulate mental representations of space and objects using non-visual cues.
2. Conceptual stream: an experienced stream of thoughts, ideas, and narratives as a continuous flow, without visual or auditory annotation.
3. Embodied cognition: utilizing bodily sensations and physical experiences to process and understand information.
4. Percolatory perception or recall: the process of memories and details absorbing or surfacing, effortlessly albeit noisily, without explicit mental rehearsal.