Roughly 4% of the population are said to have aphantasia (lacking a "mind's eye"). Around 10% (numbers vary) don't have an internal monologue.
Unfortunately there's almost no research on the consequences of things which many would consider prerequisites for evaluating truth-claims about the world around them, but obviously it's not quite so stark, they are capable of abstract reasoning.
So, if someone with aphantasia reads a truth claim 'X is true' and they can't visualise the evidence in their mind, what then? Perhaps they bias their beliefs on social signals in such circumstances. Personally, this makes sense to me as a way to explain why highly socially conformist people perceive the world; they struggle to imagine anything which would get them in to trouble.