The Effects of Repeated Exposure on the Vocational Multitasking Test
Authors:   , Navarro Gabriella Y. , Schultheis Maria Teresa 
Published: September 2022

Objective: Traditional neuropsychological assessments have proven to be useful tools, allowing clinicians to use them to make functional recommendations. However, traditional assessments have several limitations that preclude them from making accurate inferences about everyday dysfunction. Consequently, there has been more of a focus on developing performance-based assessments that represent real world behaviors, termed ecologically valid tests. The Vocational Multitasking Test, a performance-based assessment, was developed as an ecologically valid assessment to assess multitasking that mimics a workplace environment. At this time, there has yet to be a study that examined the test-retest reliability or the sensitivity to practice effects within this novel task. Consequently, this study aimed to evaluate the extent of practice effects, identify key cognitive and demographic variables related to practice effects and establish test re-test reliability within the VMT. Methods: A total of 26 individuals who met inclusion/exclusion criteria completed a total of two testing sessions (Baseline and Follow Up), each lasting approximately 1.5 hours Prior to testing, participants were randomly assigned to either undergo the follow-up VMT administration one-week post-baseline ("Week 1" group) or two weeks post-baseline ("Week 2" group). During the VMT Pre Screener was administered, followed by the baseline VMT and neuropsychological assessments. During the follow up session (1 or 2 weeks later), participants were administered the VMT, followed by the VMT Post Screener. Result: A follow up analysis of a paired samples t-test was conducted to assess for change in performance independent of group. There was a significant difference in the score from baseline (M = 37.12, SD = 10.85) to follow up (M = 42.5, SD = 11.02) scores suggesting the presence of practice effects (t (25) = -4.41, p < .01, d = .86). A correlation analysis evaluating test-retest reliability yielded a significant positive correlation indicating strong test-retest reliability (r = .84, p < .01). Correlational analyses demonstrated that VMT was not significantly correlated with age (r = -.10, p = .63), education (r = .21, p = .31), verbal memory (r = -.03, p = .89) and visual memory (r_s = -.26, p = .21), or processing speed (r_s = -.15, p = .47). Discussion: Results suggested that individuals' performance increased from baseline to follow up administration, suggesting the presence of practice effects. When distinguishing which group had more robust practice effects, the groups did not differ significantly. This indicates that a comparable degree of practice effects with either one or two weeks elapsing between administrations. Thus, practice effects do not need to be differentially considered when using these timepoints clinically. The secondary aim of this study was to establish test-retest reliability. Furthermore, the combined results of this study suggest that the practice effects between test and administration influence all participants to a similar degree. Failure to understand practice effects can lead to inaccurate conclusions in a variety of areas (McCaffrey et al., 1995; McCaffrey, Ortega, & Haase, 1993; Heilbronner, 2010). In other studies, the VMT is being examined as a rehabilitation tool for neurological populations who are either in the workforce or planning to re-enter the workforce. Participants complete the VMT at baseline and after two weeks with an intervention designed to increase VMT performance. The strong test-retest reliability reinforces that it is appropriate to re-administer the VMT. However, without this study, inaccurate conclusions about the intervention could be drawn.