Results by Maher et al. (1987) and Spitzer (1993) suggest that formal thought-disordered schizophrenia patients share a defect in the automatic processing of associations. This has been modelled as an abnormal speed of spreading activation among nodes within a semantic network. Disorganized thinking, tangential speech, and associative loosening are viewed as resulting from this disinhibition. Evidence for this theory has been mainly derived from semantic priming studies. We were able to replicate Spitzer’s findings in several studies (Moritz, Mersmann, Jacobsen, et al., 2001; Moritz, Mersmann, Kloss, et al., 2001; Moritz, Woodward, Küppers, Lausen, & Schickel, 2003) and also demonstrated that (a) abnormalities are detectable in individuals scoring high on schizotypy (Moritz et al., 1999) and (b) effects are not confined to lexical decision tasks. A study of patients with bipolar disorder also provided tentative evidence that disinhibited semantic activation might be specific to the symptom of disorganized thinking (Andreou, Bozikas, Ramnalis, Giannakou, & Fokas, 2013).

Moreover, in a computerized priming procedure, we found that formal thought-disordered schizophrenia patients prefer the inferior meaning of homographs (e.g., bank: money (superior) vs. river (inferior) relative to psychiatric controls and healthy subjects (Moritz, Mersmann, Jacobsen, et al., 2001; for a pilot study, see Moritz, Mersmann, Quast, & Andresen, 2001). At present, we are trying to collect convergent data with alternative paradigms (the source memory and false memories paradigms). Using masked repetition priming, we again found a large positive semantic priming effect in formal thought-disordered patients with schizophrenia (Wentura, Moritz, & Frings, 2008).

Research Team

  • PD Dr. Christina Andreou
  • Prof. Dr. Steffen Moritz
  • Dr. Todd S. Woodward (University of British Columbia and Riverview Hospital, Vancouver, Canada)

Cooperating Partners

  • Dr. Christian Frings (Department of Psychology, Saarbrücken, Germany)
  • Dr. Daniela Roesch-Ely (Hospital for Psychiatry, Heidelberg, Germany)
  • Prof. Dr. Dr. Manfred Spitzer (Hospital for Psychiatry and Psychotherapy, Ulm, Germany)
  • Dr. Matthias Weisbrod (Hospital for Psychiatry, Heidelberg, Germany)
  • Prof. Dirk Wentura (Department of Psychology, Saarbrücken, Germany)

References

Andreou, C., Bozikas, V. P., Ramnalis, A., Giannakou, M., & Fokas, K. (2013). Semantic priming in remitted patients with bipolar disorder. Journal of Behavior Therapy and Experimental Psychiatry, 44, 48-52.

Moritz, S., Andresen, B., Domin, F., Martin, T., Probsthein, E., Kretschmer, G., & Krausz, M. Naber, D. & Spitzer, M. (1999). Increased automatic spreading activation in healthy subjects with elevated scores in a scale assessing schizophrenic language disturbances. Psychological Medicine, 29, 161-170.

Moritz, S., Mersmann, K., Jacobsen, D., Kloss, M., Andresen, B., Pawlik, K., & Naber, D. (2001). Enhanced semantic priming in thought-disordered schizophrenic patients using a word pronunciation task. Schizophrenia Research, 48, 301-305.

Moritz, S., Mersmann, K., Kloss, M., Jacobsen, D., Wilke, U., Andresen, B., Naber, D. & Pawlik, K. (2001). Further evidence for ‘hyper-priming’ in thought-disordered schizophrenics. Psychological Medicine, 31, 221-229.

Moritz, S., Mersmann, K., Quast, C., & Andresen, B. (2001). Assoziationsnormen für 68 deutsche Homonyme [Association norms for 68 German homonymes]. Zeitschrift für Experimentelle Psychologie, 48, 226-238.

Moritz, S., Woodward, T. S., Küppers, D., Lausen, A., & Schickel, M. (2003). Increased automatic spreading of activation in thought disordered schizophrenic patients. Schizophrenia Research, 59, 181-186.

Wentura, D., Moritz, S., & Frings, C. (2008). Further evidence for “hyper-priming” in thought-disordered schizophrenic patients using repeated masked category priming. Schizophrenia Research, 102, 69-75.