TBI and Nonverbal Executive Functioning: Examination of a Modified Design Fluency Test's Psychometric Properties and Sensitivity to Focal Frontal Injury

Abstract

The purpose of this study was to investigate a modified version of the Design Fluency Test (DFT; Jones-Gotman & Milner, 1977) to establish its psychometric properties and clinical sensitivity to frontal traumatic brain injury (TBI). Twenty-five participants with moderate-to-severe TBI and focal frontal injury confirmed on magnetic resonance imaging or computed tomography, and 25 participants with TBI and nonfrontal focal injury were administered a modified fixed version of the DFT (Russell & Starkey, 1993). Analyses revealed that this modified DFT demonstrated excellent interrater agreement and consistency. This measure also demonstrated modest convergent validity with established measures of executive function abilities and discriminant validity with measures of other cognitive domains. Lastly, participants with frontal TBI generated significantly fewer novel designs compared with participants with nonfrontal focal injury. However, no significant differences were detected with regard to the total number of errors committed. Collectively, these results suggest that this fixed version of the DFT is a reliable measure of nonverbal executive functioning sensitive to frontal TBI.

Key words:

• design fluency
• neuropsychological assessment
• nonverbal executive functioning
• psychometrics
• traumatic brain injury

Acknowledgments

This material is the result of work supported with the use of facilities at the James A. Haley Veterans Hospital in Tampa, FL. The views expressed herein are those of the authors and do not necessarily reflect the views or the official policy of the Department of the Army, Department of Defense, Department of Veterans Affairs, or the U.S. Government.

Notes

Note. IQ estimate is based on predictions in the Wechsler Test of Adult Reading (WTAR) manual (WTAR performance plus demographic-based prediction). Unlike the other variables, there were six patients who had missing data on this variable. Due to the overall low number of errors committed, the repetition and rule violation errors were combined and are referred to as “total errors” for all analyses.

Note. The classification values presented here were based on the interpretation guidelines outlined by Cicchetti and Sparrow (1981).

Note. × represent timed measures. TMT-B = Trail-Making Test Part B; D-KEFS = Delis-Kaplan Executive Function System; WCST-64 = Wisconsin Card Sorting Test–64-Card Version; CVLT-II = California Verbal Learning Test-Second Edition; WAIS-III = Wechsler Adult Intelligence Scale-Third Edition; TMT-A = Trail-Making Test Part A.

*p < .05. **p < .01.

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