Using lexical familiarity judgments to assess verbally mediated intelligence in aphasia.

In this study, a task using forced-choice lexical familiarity judgments of irregular versus archaic words (a newly developed measure called the Lexical Orthographic Familiarity Test; LOFT) was compared to a standardized oral word-reading measure (the Wechsler Test of Adult Reading; WTAR) in a group of 35 aphasic adults and a comparison group of 125 community dwelling, nonbrain damaged adults. When compared to the comparison group, aphasics had significantly lower scores on the WTAR but not the LOFT. Although both the WTAR and LOFT were significantly correlated with education in the nonbrain-damaged group, only the LOFT was correlated with education and also with the Barona full scale IQ index in the aphasic group. Lastly, WTAR performance showed a significantly greater relationship to the severity of language disorder in the aphasic group than did the LOFT. These results have both theoretical and clinical implications for the assessment of language-disordered adults, as they indicate that patients with aphasia may retain aspects of verbally mediated intelligence, and that the LOFT may provide a better estimate of premorbid functioning in aphasia than other currently available measures.