A Verbal Card Sorting Task to Measure Executive Functions

Abstract

Purpose: The Wisconsin Card Sorting Test (WCST) is commonly used to measure nonverbal executive functions (EFs) in a variety of clinical populations. However, in some clinical populations (e.g., people with aphasia), deficits may be present in more linguistic (or verbal) domains and less pronounced in nonverbal domains. Thus, when determining possible deficits in these individuals, it is critical to assess both verbal and nonverbal cognitive abilities. The purpose of this study was to create a verbal card sorting task (VCST) to complement the WCST. Method: We created the VCST by modifying a computerized version of the WCST, the Berg Card Sorting Task (BCST). We then compared 35 individuals with mild traumatic brain injury (mTBI) and 33 matched controls' performance on each task. We tested the VCST in individuals with mTBI first because they demonstrate impaired EFs but unimpaired language. We therefore expected the mTBI group to perform similarly on the VCST and BCST, suggesting that the two tasks measure EFs similarly. Results: In line with our hypothesis, the mTBI group had unimpaired inhibition and sustained attention but impaired shifting on each task. Component loadings for both tasks were also similar, and participants' inhibition and shifting scores positively correlated across the two tasks. Conclusions: Together, these findings suggest that the VCST is a potentially useful tool for measuring verbal EF deficits. Our results also provide important insights into the EF impairments experienced by individuals with mTBI. Supplemental Material: https://doi.org/10.23641/asha.23230475