Attempts to Suppress Episodic Memories Fail but do Produce Demand: Evidence from the P300-Based Complex Trial Protocol and an Implicit Memory Test
- 283 Downloads
Instructions to voluntarily suppress memories of a mock crime have been reported to result in decreased P300 amplitude during a P300-based concealed information test (CIT) and reduced autobiographical Implicit Association Test (aIAT) D scores, supporting successful suppression. However, one such study, (Hu et al., Psychological science 26(7):1098–1106, 2015) used the P300-based Complex Trial Protocol with a 50–50 target to nontarget ratio, which could impose much response switching and thereby drain cognitive resources, also resulting in reduced P300. The present study replicated Hu et al. (Psychological science 26(7):1098–1106, 2015) with one major variation—a less intrusive 20–80 target to nontarget ratio that required less response switching. Detection rates were high using both the brainwave-based CIT (90% accuracy) and the aIAT (87% accuracy). However we found no significant differences between the suppression and simple guilty groups on the major indices of concealed information detection, which compare probe and irrelevant P300 responses. While we did find that overall P300 amplitude was reduced in the suppression group, this reduction was not specific to probe responses. Additionally, while there were group differences in aIAT hit rates, there were no differences in aIAT D scores. Taken together, these findings suggest that the previously demonstrated reductions in P300 are a reflection of task demand rather than of effective voluntary memory suppression.
KeywordsMemory suppression P300 Concealed information test
Compliance with Ethical Standards
Conflict of interest
The authors, both Ward and Rosenfeld, declare there is no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study, as required by the Northwestern University IRB which approved this study.
- Clark, D. A. (Ed.), (2005). Intrusive thoughts in clinical disorders: Theory, research, and treatment. New York: Guilford Press.Google Scholar
- Cohen, J. (1969). Statistical power analysis for the behavioural sciences. New York: Academic Press.Google Scholar
- Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd edn.). Hillsdale: Lawrence Earlbaum Associates.Google Scholar
- Donchin, E., Kramer, A., & Wickens, C. (1986). Applications of brain event related potentials to problems in engineering psychology. In M. Coles, S. Porges & E. Donchin (Eds.), Psychophysiology: Systems, processes and applications (pp. 702–710). New York: Guilford.Google Scholar
- Hu, X., Bergström, Z. M., Bodenhausen, G. V., & Rosenfeld, J. P. (2015). Suppressing unwanted autobiographical memories reduces their automatic influences evidence from electrophysiology and an implicit autobiographical memory test. Psychological Science, 26(7), 1098–1106.CrossRefPubMedGoogle Scholar
- Keil, A., Debener, S., Gratton, G., Junghöfer, M., Kappenman, E. S., Luck, S. J., Luu, P., Miller, G. A., & Yee, C. M. (2014). Committee report: Publication guidelines and recommendations for studies using electroencephalography and magnetoencephalography. Psychophysiology, 51, 1–21.CrossRefPubMedGoogle Scholar
- Meixner, J. B., Haynes, A., Winograd, M. R., Brown, J., & Rosenfeld, J. P. (2009). Assigned versus random, countermeasure-like responses in the P300 based complex trial protocol for detection of deception: Task demand effects. Applied Psychophysiology and Biofeedback, 34(3), 209–220.CrossRefPubMedGoogle Scholar
- Rosenfeld, J. P. (2011). P300 in detecting concealed information. Memory detection, 63–89.Google Scholar
- Rosenfeld, J. P., Labkovsky, E., Davydova, E., Ward, A., & Rosenfeld, L. (2017a). Financial incentive does not affect P300 to certain episodic and semantic probes in the P300-based Complex Trial Protocol (CTP) in malingering detection. Psychophysiology (in press).Google Scholar
- Rosenfeld, J. P., Ward, A., Drapekin, J., Labkovsky, E., & Tullman, S. (2017b). Instructions to suppress semantic memory enhances or has no effect on P300 in a Concealed Information Test (CIT). International Journal of Psychophysiology (in press).Google Scholar
- Wegner, D. M. (1989). White bears and other unwanted thoughts: Suppression, obsession, and the psychology of mental control. London: The Guilford Press.Google Scholar