B - 51 Are my Constructs Bass-Ackwards? A Hierarchical Approach to Neuropsychological Factors in Traumatic Brain Injury

Abstract Objective This study examined neuropsychological measures within a hierarchical framework in a traumatic brain injury (TBI) sample. Methods 270 individuals (M = 32 years old, SD = 14.8; 70% male, 94% white) with mixed TBI severity (73.7% mild TBI) completed the Meyers Neuropsychological Battery (MNB). Principal Components Analyses (PCAs) were conducted using Goldberg’s (2006) “bass-ackwards” hierarchical approach commonly used to evaluate “stratum” in personality and psychopathology. This involves an iterative top-down approach extracting a single general factor, then using the same data to extract two factors, then three factors, and continues as long as theoretically feasible. Extracted factors are saved as factor scores and correlated to reveal pathways between stratum. Results Iterative PCAs revealed a 4-stratum model. The first unrotated principal component (FUPC) was defined by loadings for Arithmetic, AVLT, RCFT, and Block Design. The second stratum factors were defined by AVLT and BNT (factor 1) and RCFT and Block Design (factor 2). The third stratum was defined by RCFT, Block Design, and Finger Localization nondominant (factor 1); Information and BNT (factor 2); and AVLT, Coding, and Finger Tapping dominant (factor 3). Stratum 4 was RCFT and Block Design (factor 1); AVLT (factor 2); Sentence Repetition, Similarities, and Information (factor 3); and Finger Tapping bilateral, Coding, and Trails Making Test (factor 4). Correlational pathways between factors ranged from 0.50 to 0.98. Conclusion Factors at lower stratum generally aligned with functions for cortical lobes. For example, Stratum 4 can be conceptualized as right temporoparietal (factor 1), left temporal (factor 2), left frontotemporal (factor 3), and bilateral frontal (factor 4).