Associative Memory Impairments Are Associated With Functional Alterations Within the Memory Network in Schizophrenia Patients and Their Unaffected First-Degree Relatives: An fMRI Study.

Viola Oertel,Christian Knöchel,Silke Matura,Michael Stäblein,Helena Storchak,Denisa Ghinea,Andreas Reif,David Prvulovic,David E J Linden,Robert A Bittner,Gilberto Alves,Dominik Kraft

doi:10.3389/fpsyt.2019.00033

Abstract

Memory impairments are a major characteristic of schizophrenia (SZ). In the current study, we used an associative memory task to test the hypothesis that SZ patients and first-degree relatives have altered functional patterns in comparison to healthy controls. We analyzed the fMRI activation pattern during the presentation of a face-name task in 27 SZ patients, 23 first-degree relatives, and 27 healthy controls. In addition, we performed correlation analyses between individual psychopathology, accuracy and reaction time of the task and the beta scores of the functional brain activations. We observed a lower response accuracy and increased reaction time during the retrieval of face-name pairs in SZ patients compared with controls. Deficient performance was accompanied by abnormal functional activation patterns predominantly in DMN regions during encoding and retrieval. No significant correlation between individual psychopathology and neuronal activation during encoding or retrieval of face-name pairs was observed. Findings of first-degree relatives indicated slightly different functional pattern within brain networks in contrast to controls without significant differences in the behavioral task. Both the accuracy of memory performance as well as the functional activation pattern during retrieval revealed alterations in SZ patients, and, to a lesser degree, in relatives. The results are of potential relevance for integration within a comprehensive model of memory function in SZ. The development of a neurophysiological model of cognition in psychosis may help to clarify and improve therapeutic options to improve memory and functioning in the illness.

Highlights

Schizophrenia (SZ) is a severe mental disease, with patients suffering from “positive” and “negative” symptoms [1], and from various cognitive deficits
We included 27 healthy control subjects (CON) {Mage(mean) = 34.22 years (SD[standard deviation] = ±11.38)}, 27 patients (SZ) (Mage = 37.22 years [SD = ±9.14]) with the diagnosis of SZ according to DSM IV [20] and 23 first-degree relatives of SZ patients with no history of psychiatric disorders (REL) (Mage = 43.56 years [SD = ±14.25])
Relatives showed slightly higher reaction times and slightly lower accuracy compared to controls. fMRI pattern indicated a network related to cognition and visual perception/(occipital lobe) to be active during the association of faces to names

Summary

Introduction

Schizophrenia (SZ) is a severe mental disease, with patients suffering from “positive” (e.g., delusions, hallucinations, disturbances of thoughts) and “negative” symptoms (e.g., loss of energy, flattened affect) [1], and from various cognitive deficits. According to Sperling et al [13] and Kirwan and Stark [14], activation of the anterior HC is closely associated with successful memory encoding. During encoding, schizophrenia patients showed decreased activation of the left inferior PFC, the right middle frontal gyrus, the right medial frontal gyrus, and the right posterior HC. During retrieval, they identified lower activation in SZ compared with controls in several frontal regions, in the right subgenual region, in the thalamus bilaterally, in the left anterior HC, in the right fusiform gyrus and in the cerebellum bilaterally. The authors identified higher functional activation in the right anterior MTL in SZ patients compared to controls

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Results

Discussion

Conclusion