A neuropsychological profile has been proposed for AS;[29] if verified, it could differentiate between AS and HFA and aid in differential diagnosis. Relative to HFA, people with AS have deficits in nonverbal skills such as visual-spatial problem solving and visual-motor coordination,[30] along with stronger verbal abilities.[31] Several studies have found AS with a neuropsychologic profile of assets and deficits consistent with a nonverbal learning disability, but several other studies have failed to replicate this.[30] The literature review did not reveal consistent findings of "nonverbal weaknesses or increased spatial or motor problems relative to individuals with HFA", leading some researchers to argue that increased cognitive ability is evidenced in AS relative to HFA regardless of differences in verbal and nonverbal ability.[32]