Detecting feigned high impact experiences: a symptom over-report questionnaire outperforms the emotional Stroop task

Background and objectives - The Modified Stroop Task (MST) effect refers to a prolonged reaction time (RT) in color-naming words related to an individual's disorder. Some authors argue that its absence in people who claim symptoms might be an indication of feigning.

Method - We tested whether the MST effect is robust against feigning attempts and compared its absence as an index of feigning with over-reporting tendencies on a symptom questionnaire (i.e., the Self-Reported Symptom Inventory (SRSI)). We included participants (n = 22) who i) reported current high impact of aversive experiences (High scorers), ii) reported current low impact (Low scorers) of aversive experiences (n = 24), and iii) actors (n = 18) with low impact, but instructed to feign current high psychological impact of aversive life events (Simulators). We administered the MST, including impact-related, neutral, and feigning-related words, and the SRSI.

Results - We found no MST effect for impact-related words in the high scorers group, or for feigning-related words in the simulators. Relative to high scorers and low scorers, simulators exhibited significantly longer RTs on all types of words and they also endorsed significantly more bogus symptoms on the SRSI. Thus, the SRSI was a more sensitive measure of feigning than the absence of an MST effect.

Limitation - Some limitations are related to our reliance on a sub-clinical student sample, whereas others reflect the unresolved issues surrounding the MST. Thus, the generalizability of our results is uncertain.

Conclusion - Our findings add to the doubts on the idea that the MST can be used to differentiate between genuine and feigned complaints.