The neuropsychology of emerging psychosis and the role of working memory in episodic memory encoding

Marlon O Pflueger; Pasquale Calabrese; Erich Studerus; Ronan Zimmermann; Ute Gschwandtner; Stefan Borgwardt; Jacqueline Aston; Rolf-Dieter Stieglitz; Anita Riecher-Rössler

doi:10.2147/PRBM.S149425

The neuropsychology of emerging psychosis and the role of working memory in episodic memory encoding

Psychol Res Behav Manag. 2018 May 10:11:157-168. doi: 10.2147/PRBM.S149425. eCollection 2018.

Authors

Marlon O Pflueger¹, Pasquale Calabrese², Erich Studerus³, Ronan Zimmermann⁴, Ute Gschwandtner⁴, Stefan Borgwardt⁵, Jacqueline Aston³, Rolf-Dieter Stieglitz⁶, Anita Riecher-Rössler³

Affiliations

¹ Department of Forensic Psychiatry, University of Basel Psychiatric Clinics, Basel, Switzerland.
² Division of Molecular and Cognitive Neuroscience, University of Basel, Basel, Switzerland.
³ Center for Gender Research and Early Detection, University of Basel Psychiatric Hospital, Basel, Switzerland.
⁴ Department of Neurology and Neurosurgery, Hospital of the University of Basel, Basel, Switzerland.
⁵ Department of Psychiatry (UPK), University of Basel, Basel, Switzerland.
⁶ Division of Clinical Psychology and Psychiatry, University of Basel, Basel, Switzerland.

Abstract

Background: Episodic memory encoding and working memory (WM) deficits are among the first cognitive signs and symptoms in the course of schizophrenia spectrum disorders. However, it is not clear whether the deficit pattern is generalized or specific in nature. We hypothesized that encoding deficits at an early stage of the disease might be due to the more fundamental WM deficits.

Methods: We examined episodic memory encoding and WM by administering the California Verbal Learning Test, a 2-back task, and the Wisconsin Card Sorting Test in 90 first-episode psychosis (FE) patients and 116 individuals with an at-risk mental state for psychosis (ARMS) compared to 57 healthy subjects.

Results: Learning progress, but not span of apprehension, was diminished to a similar extent in both the ARMS and the FE. We showed that this was due to WM impairment by applying a structural equation approach.

Conclusion: Thus, we conclude that verbal memory encoding deficits are secondary to primary WM impairment in emerging psychosis.

Keywords: 2-back task; at-risk mental state; cognition; first-episode psychosis; rate of learning; recency; semantic cluster ratio; serial position effect.