86 The Examination Between Credible and Non-Credible Groups on Embedded PVT Tests

Abstract

Objective:

Performance validity tests (PVTs) are included in neuropsychological testing to ensure examinees are performing to the best of their abilities. There are two types of PVTs: embedded and free standing. Embedded PVTs are tests that are derived from standard neuropsychological tests of various cognitive domains. Freestanding PVTs are tests that are designed with the intention of being a PVT. Research studies show that undergraduate samples do not always performed to the best of their abilities. The purpose of this study was to cross-validate previous research on the topic of performance validity in a college sample. It was predicted that the non-credible group would demonstrate higher failure rates on embedded PVTs compared to the credible group.

Participants and Methods:

The sample consisted of 198 neurologically and psychologically healthy undergraduate students with a mean age of 19.69 (SD = 2.11). Participants were broken into two groups: non-credible (i.e., participants that failed two or more PVTs) and credible (i.e., participants that did not failed two or more PVTs). The Rey-Osterrith copy test, Comalli Stroop part A (CSA), B (CSB), and C (CSC), Trail Making Test part A and B, Symbol Digit Modalities Test written (SDMT-W) and oral (SDMT-O) parts, Controlled Oral Word Association Test (COWAT) letter fluency, and Finger Tapping Test were used to evaluate failure rates in our sample. PVT cutoff scores were use from previously validated in the literature. Chi-square analysis was used to evaluate failure rates between the groups.

Results:

Chi-square analysis revealed significant failure rate differences between groups on several PVTs. Results revealed that 15% of the non-credible group failed the CSA compared to 1% of the credible group, X2=14.77, p=.000. Meanwhile, 26% of the non-credible group failed the CSB compared to 2% of the credible group, X2=24.72, p=.000. Furthermore, results showed that 11% of the non-credible group failed the CSC compared to 1% of the credible group, X2=13.05, p=.000.Next, 48% of the non-credible group failed the Trail Making Test part A compared to 8% of the credible group, X2=31.61, p=.000. We also found that 15% of the non-credible group failed the SDMT-W part compared to 1% of the credible group,X2=19.18, p=.000. Meanwhile, on the SDMT-O part 19% of the non-credible group failed compared to 1% of the credible group, X2=25.52, p =.000. On the COWAT letter fluency task 74% of the non-credible group failed compared to 19% of the credible group, X2=36.90, p=.000. Finally, results revealed on the Finger Tapping Test 19% of the non-credible group failed compared to 3% of the credible group, X2=10.01, p=.002.

Conclusions:

As expected, the non-credible participants demonstrated significantly higher PVT failure rates compared to credible participants. A possible explanation driving higher failure rates in our sample can be due to cultural variables (e.g., bilingualism). It was suggested by researchers that linguistic factors may be impacting higher PVT failure rates and developing a false-positive error. Future research using undergraduate samples need to identify which PVT’s are being impacted by linguist factors.