Abstract
Objective
This study utilized a culturally diverse sample with traumatic brain injury (TBI) to examine effects of ethnicity on the Verbal Comprehension (VCI), Perceptual Reasoning (PRI), Working Memory (WMI), and Processing Speed (PSI) indices of the Wechsler Adult Intelligence Scale-Fourth Edition while controlling for education and injury severity. Hypotheses were that education and ethnicity would significantly influence all indices, the latter to a lesser extent, and injury severity would most strongly affect PSI scores.
Method
Participants were 43 trauma center admissions with documented head injury. Mean age and education were 32.16 and 13.88 years, respectively. There were 14 Euro-, 17 Hispanic-, and 12 African-Americans.
Results
ANCOVAs revealed significant effects for education across indices. Significant effects were found for ethnicity on the VCI and PRI and injury severity on the PSI. Post hoc comparisons indicated Euro- and Hispanic-Americans did not differ on VCI but performed significantly higher than African-Americans. Euro-Americans performed significantly better than African-Americans on the PRI, but comparable performance emerged between Euro- and Hispanic-Americans and between African- and Hispanic-Americans. Groups did not differ on the WMI or PSI.
Conclusions
Education and ethnicity accounted for most of the variance in VCI and PRI. Analysis of the WMI revealed education produced a significant effect, but ethnicity and injury severity did not. On the PSI, education and injury severity had significant effects. PSI was the only composite to which injury severity made a statistically significant contribution. Despite the small sample size, findings have important implications in the intellectual assessment of individuals with TBI.
Detecting malingered performance on the Wechsler Adult Intelligence Scale Validation of Mittenberg's approach in traumatic brain injury
