26 Cognitive Correlates of Functional Assessment Tool in Veterans with Mild Traumatic Brain Injury

Abstract

Objective:Limitations of traditional neuropsychological assessment include testing in a highly controlled environment designed to minimize distraction. While informative, it may not fully capture real-world cognitive functioning. This may be particularly important for individuals with mild traumatic brain injury (mTBI), a subset of whom report subtle challenges with complex cognitive functioning that are not consistently captured by neuropsychological assessment. The objective of this study was to extend previous work examining cognitive correlates of performance on functional assessment tool, the Goal Processing Sale (GPS), in a larger sample of Veterans with mTBI.Participants and Methods:46 Veterans with chronic mTBI completed GPS and neuropsychological measures (mean age = 43.5; education = 15 years; 89% male). 93% of participants had clinically significant PTSD (PCL-M > 31). The GPS is an ecologically valid assessment in which participants plan and execute a complex task following specified rules under a time constraint. Performance is rated on a 0 (not able) to 10 (absolutely not a problem) scale in 8 domains: 1) Planning, 2) Initiation, 3) Self-Monitoring, 4) Maintenance of Attention, 5) Sequencing and Switching of Attention, 6) Flexible Problem Solving, 7) Task Execution, and 8) Learning and Memory. The GPS Overall Performance is average of 8 domain scores. Neuropsychological assessment data were scored using standardized norms and transformed into z-scores. Scores were averaged into 2 domains: 1) Overall Attention/Executive Function (4 subdomains: Working Memory [Auditory Consonant Trigrams, WAIS-III Letter Number Sequencing], Sustained Attention [Digit Vigilance Test], Inhibition [D-KEFS Stroop Inhibition], Mental Flexibility [Trail Making Test B, D-KEFS Stroop Inhibition Switching, Design Fluency Switching, Verbal Fluency Switching]) and 2) Overall Memory (2 subdomains: Total Recall [HVLT-R, BVMT-R], and Delayed Recall [HVLT-R, BVMT-R]).Pearson correlation coefficients were used to determine relation between overall GPS and overall executive function performance, as well as 8 GPS subdomain and 8 neuropsychological domain/subdomain scores. To adjust for multiple comparisons, p < .01 was used.Results:Overall GPS performance was statistically significantly related to Overall Attention/Executive Functioning and Overall Memory. Investigating further, multiple significant subdomain relations emerged. GPS Planning was related to Inhibition. GPS Self-Monitoring and GPS Task Execution were related to Mental Flexibility. GPS Maintenance of Attention and GPS Flexible Problem Solving were related to Mental Flexibility and Inhibition. GPS Sequencing and Switching of Attention was related to Mental Flexibility and Total Recall.GPS Learning and Memory was related to Working Memory, Mental Flexibility, and Inhibition. GPS Initiation was not related to neuropsychological measures.Conclusions:Current findings build upon prior work establishing validity of GPS functional assessment measure (Novakovic-Agopian et al., 2012). Seven of 8 GPS subdomains were related to at least one aspect of executive functioning assessed with neuropsychological measures, with the majority related to mental flexibility. Taken together, findings suggest that the GPS converges with traditional measures, offering a method to capture multiple aspects of executive functioning applied together. Further, it may also be useful tool capturing aspects of executive functioning in complex, ecologically-valid settings often not captured with traditional neuropsychological assessment.