When I "imagine" something while I awake, it is not remotely like seeing. There is no image overlaid on the "real world" whether obscuring the black behind my eyelids or anything else when they are open. I can't tell shapes, or colours. If my eyes are closed, I just see the inside of my eyelids, nothing more.
My one experience of seeing something while awake during meditation was like being inside a movie. Everything was as clear as if I had been walking around in that setting for real.
I don't know what it will take to make you sure, but for me, I have experienced three entirely different "modes" of imagining things, ranging from no visuals, to shifting and unclear visual, to crystal clear images, and the distinction is stark and obvious - there's no ambiguity in it.
for me, it's much less detailed unless I focus my imagination on the less detailed part.
The two experiences are different, most of the time, yes, but only "completely 100% different" IMO to aphantasics, or those who are high in aphantasia. I.e. hyperphantasia is a thing, and a normal thing for most people in altered states (and schizophrenia might be seen as involving an extreme form of hyperphantasia intruding where it shouldn't, in some cases).
See also my post below: https://news.ycombinator.com/item?id=49707079
I invite you to feed your own friendly AI these references then ask it to analyze the recent papers trying to study aphantasia and come to your own conclusions about whether they're actually doing all that much. My own suggested that while there are some improvements since the papers I cited that it is still difficult to say that they've solved the problems in those studies.
Still, directionally, while inferring from "brain activations" to qualia is a difficult path, if there was enough data to show big and consistent correlations that would tend to satisfy me that maybe there is some sort of real difference and we're not just talking past each other. It's not such a shocking claim that I need truly shocking evidence to believe it, just some support.
This is fairly conclusively disproven by far more than just fMRI / brain-imaging studies. E.g. aphantasics have problem with visual memory recall, visual priming, pupil dilatory and skin conductance responses when imagining light and/or fearful stimuli, and many other results (especially acquired aphantasia) that don't depend on brain imaging and obviously rule out semantic explanations. Likewise, rejecting the reality of the phenomenon also seems to require believing an extraordinary amount of error and/or conspiracy on the part of highly educated and insightful people that explicitly are saying the issue is not one of semantics / description. This is also not to mention the rich history of visualization practices in much of the worlds religions and esoteric practices (which make basically zero sense if this is all metaphor). See e.g. the discussion in a previous HN thread (https://news.ycombinator.com/item?id=49464414).
> I invite you to feed your own friendly AI these references then ask it to analyze the recent papers [...]
Likewise, an unbiased AI prompt (or two prompts in separate sessions, with opposite biases) will clearly reveal the "semantics denialist" case has very little to stand on here. Yes, there are communication and linguistic issues, but these only cover a subset of ambiguous cases. Rejecting or denying the reality of aphantasia is an extremely strong indicator you are aphantasic, to some considerable degree.
One easy answer up there with "more study is needed" in terms of being a bit cliche, but cliche because it's often true, is that there may be a richer spectrum or something that isn't even 1-dimensional then we're currently able to grasp, which will become more clear over time and more study. Perhaps it's less rare than we think and the rareness is only those we can talk into agreeing their qualia really is different from others. Or the way we are describing it leads people in the "1-2 out of 5" category to declare themselves aphantastic on HN when they aren't really properly so.
I agree this is an annoying confound, and also that it feels highly intuitive that being able to consciously visualize ought to correlate with better visuospatial (and thus much mathematical) cognitive ability.
I think the solution is recognizing that the reason cognitive deficits are mostly unobserved (visual memory recall studies aside) is recognizing that aphantasia is almost certainly a conscious access problem, i.e. most aphantasics are still using imagery too, just unawares. Last I checked, this is the leading hypothesis / explanation.
Also, plasticity and the ingenuity of the brain is clearly such that an aphantasic can also find other ways (e.g. other sensory modality imagery, pure logical relations, etc) of representing the problems that seem like they should rely on visualization. It seems obvious to me that these other ways can be both advantageous/disadvantageous, depending on the situation / phenomenon.
I know the vast chasm between the two states from direct first hand experience.
So do many others.
Also the well-documented cases of acquired aphantasia are especially troubling for the skeptical "semantic disagreement" cases, given that acquired aphantasia is entirely within-person.