here are your proofs
a decent part of humans lack ability to join concepts together, they can only repeat tasks, never come up with anything on their own
>as many as 18% of modern individuals exhibit PFS disability
https://riojournal.com/article/38546/
>An inability to produce a novel mental image [...] Such an individual [...] would not be able to follow instructions to draw a novel object such as a five-headed horse, as this process relies on mental synthesis of a never-before-seen image in the mind’s eye.
>Crucially, the mental synthesis disability does not derive from a lack of semantic understanding, since the subject is tested in a non-verbal setting. Rather, the disability derives from a general inability of the lateral PFC to construct novel images in the mind’s eye.
https://riojournal.com/article/13239/