In 2002, we began to investigate overconfidence errors in psychosis. In two pilot studies conducted in Germany (Moritz, Woodward, & Ruff, 2003) and Canada (Moritz & Woodward, 2002), we required subjects to generate words in response to stimuli presented by the experimenter. Previously presented and self-generated words were read to the participants along with distractor stimuli. Apart from simple recognition (old/new), participants were asked to indicate who they thought had produced the word (source attribution: experimenter or participant) and to estimate their judgment confidence. In both studies, patients with schizophrenia displayed enhanced confidence regarding false responses (feedback regarding the correctness of the decision was given later). As expected, healthy controls made fewer errors and were less confident regarding false responses than patients.
We assume that healthy subjects attach some kind of “not trustworthy” tag to mental events that are not supported by sufficient evidence. Patients with schizophrenia, on the other hand, may have a deficit differentiating correct from incorrect events (replications by Moritz, Woodward, & Chen, 2006; Moritz, Woodward, Cuttler, Whitman, & Watson, 2004; Moritz, Woodward, Whitman, & Cuttler, 2005; Moritz, Woodward, & Rodriguez-Raecke, 2006; Moritz, Woodward, Jelinek, & Klinge, 2008; Moritz & Woodward, 2006a). Importantly, the investigation did not employ any material relevant to delusions; all words produced by the experimenter were neutral, precluding tautological inferences (for a review, see Moritz & Woodward, 2006a). This effect has also been demonstrated for other cognitive domains besides memory (Moritz et al., 2014; Moritz, Woznica, Andreou, & Köther, 2012).
- PD Dr. Christina Andreou
- Dipl.-Psych. Birgit Hottenrott
- Prof. Dr. Steffen Moritz
- Dr. Lukasz Gaweda (Medical University of Warsaw, Warsaw, Poland)
- Dr. Maarten Peters (University of Maastricht, Maastricht, Netherlands)
- Prof. Dr. Todd S. Woodward (University of British Columbia and Riverview Hospital, Vancouver, Canada)
Moritz, S., Göritz, A. S., Van Quaquebeke, N., Andreou, C., Jungclaussen, D., & Peters, M. J. (2014). Knowledge corruption for visual perception in individuals high on paranoia. Psychiatry Research, 30, 700-705.
Moritz, S., & Woodward, T. S. (2002). Memory confidence and false memories in schizophrenia. Journal of Nervous and Mental Disease, 190, 641-643.
Moritz, S., & Woodward, T. S. (2006a). The contribution of metamemory deficits to schizophrenia. Journal of Abnormal Psychology, 115, 15-25.
Moritz, S., & Woodward, T. S. (2006b). Metacognitive control over false memories: A key determinant of delusional thinking. Current Psychiatry Reports, 8, 184-190.
Moritz, S., Woodward, T. S., & Chen, E. (2006). Investigation of metamemory dysfunctions in first-episode schizophrenia. Schizophrenia Research, 81, 247-252.
Moritz, S., Woodward, T. S., Cuttler, C., Whitman, J. C., & Watson, J. M. (2004). False memories in schizophrenia. Neuropsychology, 18, 276-283.
Moritz, S., Woodward, T. S., Jelinek, L., & Klinge, R. (2008). Memory and metamemory in schizophrenia: A liberal acceptance account of psychosis. Psychological Medicine, 38, 825-832.
Moritz, S., Woodward, T. S., & Rodriguez-Raecke, R. (2006). Patients with schizophrenia do not produce more false memories than controls but are more confident in them. Psychological Medicine, 36, 659-667.
Moritz, S., Woodward, T. S., & Ruff, C. C. (2003). Source monitoring and memory confidence in schizophrenia. Psychological Medicine, 33, 131-139.
Moritz, S., Woodward, T. S., Whitman, J. C., & Cuttler, C. (2005). Confidence in errors as a possible basis for delusions in schizophrenia. Journal of Nervous and Mental Disease, 193, 9-16.
Moritz, S., Woznica, A., Andreou, C., & Köther, U. (2012). Response confidence for emotion perception in schizophrenia using a Continuous Facial Sequence Task. Psychiatry Research, 30, 202-207.