Correlation between errors on the Wisconsin Card Sorting Test and the availability of striatal dopamine transporters in healthy volunteers

Abstract

Although studies have indicated that the frontal lobe plays an important role in performance on the Wisconsin Card Sorting Test (WCST) and that basal ganglia play a specific role in frontal lobe function, the role of striatal dopamine (DA) activity in performance on the WCST remains unclear. We assessed the relation between the availability of striatal dopamine transporters (DATs) and performance on the WCST as a measure of executive function in healthy individuals. We approximated the availability of DATs in 53 healthy volunteers aged 19-61 years by use of single photon emission computed tomography with technetium-99m (99mTc)-TRODAT-1 as the ligand. The WCST was administered to all participants. The availability of DAT was significantly negatively correlated with perseverative errors on the WCST, both before and after adjustment for body mass index (r(before) = -0.39, p = 0.004; r(after) = -0.39, p = 0.005). This was an association study; thus, a causal relation between DAT availability and performance cannot be confirmed. Our results suggest that striatal DAT availability may play a role in executive function as measured by the WCST.