Potential of and Problems With New Measures of Psychometric Intelligence After Traumatic Brain Injury
Abstract
ABSTRACT. Examination of the concurrent and criterion validities of the General Ability Measure for Adults (GAMA) and the Wechsler Adult Intelligence Scale—Third Edition (WAIS–III) in patients with traumatic brain injury (TBI). Correlational methods and multivariate analyses of variance. Regional rehabilitation center. Prospective series of consecutive rehabilitation referrals, including 60 adults with TBI and no confounding premorbid histories. GAMA and WAIS–III IQ and factor index scores were obtained within 1 year after injury and were compared with each other and with measures of injury severity. GAMA and WAIS–III summary IQ scores demonstrated substantial covariance (supporting concurrent validity), but neither was sufficiently sensitive to injury severity. The WAIS–III Processing Speed (PS) index was the only measure that clearly demonstrated criterion validity. GAMA and WAIS–III summary IQ scores measure similar abilities but may not be sensitive to degree of injury severity in individuals with TBI. In contrast, the WAIS–III PS index appears to have promise in the evaluation of sequelae of TBI.