Discrimination within Recognition Memory in Schizophrenia.

Kathryn Mcguire,Melanie Blahnik,Scott Sponheim

doi:10.3390/bs3020273

Abstract

Episodic memory is one of the most affected cognitive domains in schizophrenia. First-degree biological relatives of individuals with schizophrenia also have been found to exhibit a similar, but milder, episodic memory deficit. Unlike most studies that focus on the percent of previously presented items recognized, the current investigation sought to further elucidate the nature of memory dysfunction associated with schizophrenia by examining the discrimination of old and new material during recognition (measured by d') to consider false recognition of new items. Using the Recurring Figures Test and the California Verbal Learning Test (CVLT), we studied a sample of schizophrenia probands and the first-degree biological relatives of patients with schizophrenia, as well as probands with bipolar disorder and first-degree biological relatives to assess the specificity of recognition memory dysfunction to schizophrenia. The schizophrenia sample had poorer recognition discrimination in both nonverbal and verbal modalities; no such deficits were identified in first-degree biological relatives or bipolar disorder probands. Discrimination in schizophrenia and bipolar probands failed to benefit from the geometric structure in the designs in the manner that controls did on the nonverbal test. Females performed better than males in recognition of geometric designs. Episodic memory dysfunction in schizophrenia is present for a variety of stimulus domains and reflects poor use of item content to increase discrimination of old and new items.

Highlights

It has been well-established in the literature that neurocognitive dysfunction is associated with schizophrenia, a focus with historical roots dating back to the Kraepelinian era of “dementia praecox”(a term Emil Kraepelin derived from a Latin translation of Benedict Morel’s French term “demence precoce”) [1]
The comparison of patients allowed examination of the diagnostic specificity of recognition memory discrimination deficits, while the contrast of relatives tested whether any recognition abnormalities were specific to the genetic liability for schizophrenia
The benefit from nameable geometric structures that appeared greater for females with schizophrenia than males with the disorder suggests that they are better able to compensate for episodic memory deficits by using semantic strategies in encoding and retrieval. t-tests of d' scores within groups revealed that female probands with schizophrenia performed significantly better than male probands with schizophrenia on delayed recognition of geometric designs, t(38) = 2.06, p = 0.046, while performing to their male counterparts in the three other conditions

Summary

Introduction

It has been well-established in the literature that neurocognitive dysfunction is associated with schizophrenia, a focus with historical roots dating back to the Kraepelinian era of “dementia praecox”(a term Emil Kraepelin derived from a Latin translation of Benedict Morel’s French term “demence precoce”) [1]. Research findings suggest that neuropsychological deficits are associated with genetically influenced brain structure and function that predisposes individuals to psychosis [10,11,12,13,14]. This area of study is immediately relevant to the daily lives of people with schizophrenia, as cognitive functioning has been shown to be a reliable predictor of community functioning [15] and knowledge of deficient cognitive processes may lead to more effective psychosocial interventions and cognitive remediation for the disorder.

Objectives

Methods

Results

Discussion

Conclusion