Abstract

Objective: We extended the research analyzing the atypical longer Digit Span backwards (DSB) than forward DS (DSF) profile by examining this pattern on a test purported to assess similar executive functions, the Trail Making Test A & B (TMT A & B). We compared the overall cognitive performance of better TMTB > TMTA. Though clinical lore indicates worse performance on a simpler task (TMTA) represents pathology, we hypothesized that similarly to better DSB > DSF, TMTB > TMTA would predict better cognitive performance. Method: Archival data from individuals (N = 1131) completing an intelligence scale & TMT A & B were utilized. Most were Caucasian (85%) and half were female (50.6%), with a mean age of 22.7 years (SD = 6.12) and mean education of 13.7 years (SD = 2.0). We utilized correlations, regression, ANOVA, & nonparametric Kruskal-Wallis tests. Results: Nonparametric analyses indicated that full scale intelligence (FSIQ) & working memory index (WMI) significantly differentiated between TMT groups (p = .003 & .011, respectively). ANOVA also exhibited significant differences between TMTB > TMTA & TMTA > TMTB performances on FSIQ (p = .002) & WMI (p = .037). The better TMTB > TMTA group always scored higher than the TMTA > TMTB group. FSIQ was significantly correlated with TMTB > TMTA (r = .332, p = .000), as was WMI (r = .357, p = .000). Conclusion(s): Our results indicate that atypical TMTB > TMTA profile does not indicate pathology. We believe this profile results from individuals who fail to engage in simpler tasks like TMTA but fully engage in more challenging tasks such as TMTB. Further, these findings implicitly validate that similarly to DSB, TMTB taps into the underlying executive functions.