Three trail making tests for use in neuropsychological assessments with brief intertest intervals

Mediating effect of executive function on memory in normal aging adults

OBJECTIVE

We hypothesize that the effect of aging on memory is mediated by executive function.

METHODS

Two hundred and thirty healthy adults (101 male, 129 female) were recruited for the study. We used a promising, newly developed, computerized neuropsychological test for the measurement of executive function and memory. The data were analyzed using structural equation modeling and path analysis.

RESULTS

The full mediation model showed a good fit to the data. However, chi-squared (χ(2)) tests for model comparison indicated that the partial mediation model better fits our data. Thus, the partial mediation model was used as the final model. In terms of auditory-verbal memory, the effect of aging on memory was fully mediated by executive function. However, visuo-spatial memory was significantly affected both indirectly (through executive function) and directly (by aging). Gender differences were not significant in this model.

CONCLUSION

This study demonstrated the importance of executive function in the memory functioning of normal aging adults. It is noteworthy that modality differences were found between auditory-verbal and visuo-spatial memory. Aging is not the only factor that drives memory decline, and its direct, adverse effect on memory was more prominent in the visuo-spatial memory task than auditory-verbal memory task. Since performance in both modalities is fully or partially mediated by executive function, it is important to train normal aging adults in executive control skills, such as planning, strategy formation, and rapid decision making.

Neuropsychological test performance before and after HIV-1 seroconversion: the Multicenter AIDS Cohort Study

The objective of this study is to compare neuropsychological test performance before and after HIV-1 seroconversion in order to identify possible acute changes in psychomotor speed, memory, attention, and concentration secondary to seroconversion. The study utilized mixed effects models to examine longitudinal neuropsychological test data. We conducted a nested cohort study of 362 male HIV-1 seroconverters enrolled in the Multicenter AIDS Cohort Study. We used linear mixed models with random subject effects to compare repeated neuropsychological test outcomes from 5 years before seroconversion to 2 years after seroconversion on the Trail Making Test (parts A and B), Symbol-Digit Test, Grooved Pegboard (dominant and non-dominant hands), Stroop Color-Interference Test, Rey Auditory Verbal Learning Test, and the CalCAP Reaction Time Test. We found no significant changes in the time-dependent score after seroconversion for the majority of neuropsychological tests used in the Multicenter AIDS Cohort Study. There was a significant change in time trend after seroconversion on part B of the Trail Making Test (p=0.042), but the difference only represented a 2 % decrease in performance. We found the following characteristics to be associated with worse neuropsychological test performance: lower education levels, history of depression, older age, and no previous neurocognitive testing (p< .05). Our results suggest that despite a 50 % decrease in CD4 cell count immediately following infection, HIV-1 does not appear to have a measurable effect on psychomotor or complex cognitive processing for up to 2 years following infection, using this set of neurocognitive measures.

Confirmation of a two-factor model for interpretation of the comprehensive trail making test with children

Exploratory factor analyses (EFAs) of the Comprehensive Trail Making Test suggested a possible two-factor solution that might better reflect the differences in Trails 1-3 and Trails 4 and 5 as opposed to a single Composite Index for the total standardization sample. The purpose of this study was to conduct a confirmatory factor analysis (CFA) of the two-factor structure with a subset of the standardization sample ages 18 or younger that had completed all five-trail tasks. The sample included 251 boys and 306 girls, ages 8-18, with a mean age of 12.76 (SD = 3.07). Data were collected across 16 states with representation from all regions of the USA. Standardized scores on each of the trails (1-5) tasks were considered. The results of CFA using M-plus indicated a good fit for the two-factor model, χ(2)(4) = 18.686, p = .0009, root mean-square error of approximation = 0.081, comparative fit index = 0.986 and standardized root-mean-squared residual = 0.021. A one-factor model was not supported. As suggested by the EFA in the manual, Trails 1-3 and Trails 4 and 5, while related, appear to be different in subtle ways that may be most meaningful in conjunction with evaluation of children with neurodevelopmental differences. Implications and possible explanations for this difference are discussed.

The Relationship between Tests of Neurocognition and Performance on a Laparoscopic Simulator

Objective. To estimate if there is a relationship between the results of tests of neurocognition and performance on a laparoscopic surgery simulator. Methods and Materials. Twenty participants with no prior laparoscopic experience had baseline cognitive tests administered (Trail Making Test, Part A and B (TMT-A and TMT-B), Grooved Peg Board Test, Symbol Digit Modalities Test, Symbol Digit Recall Test, and Stroop Interference Test), completed a demographic questionnaire, and then performed laparoscopy using a simulator. We correlated the results of cognitive tests with laparoscopic surgical performance. Results. One cognitive test sensitive to frontal lobe function, TMT-A, significantly correlated with laparoscopic surgical performance on the simulator (correlation coefficient of 0.534 with P < .05). However, the correlation between performance and other cognitive tests (TMT-B, Grooved Peg Board Test, Symbol Digit Modalities Test, Symbol Digit Recall Test, and Stroop Interference Test) was not statistically significant. Conclusion. Laparoscopic performance may be related to measures of frontal lobe function. Neurocognitive tests may predict motor skills abilities and performance on laparoscopic simulator.