Retrieval practice improves memory in patients with schizophrenia: new perspectives for cognitive remediation

Camille Jantzi,Julien Elowe,Nicolas Meyer,Pierre Vidailhet,David Serfaty,Elisabeth Bacon,Fabrice Berna,François Severac,Amaury C Mengin

doi:10.1186/s12888-019-2341-y

Abstract

BackgroundSchizophrenia is associated with severe cognitive deficits, particularly episodic memory deficits, that interfere with patients’ socio-professional functioning. Retrieval practice (also known as testing effect) is a well-established episodic memory strategy that involves taking an initial memory test on a previously learned material. Testing later produces robust long-term memory improvements in comparison to the restudy of the same material both in healthy subjects and in some clinical populations with memory deficits. While retrieval practice might represent a relevant cognitive remediation strategy in patients with schizophrenia, studies using optimal procedures to explore the benefits of retrieval practice in this population are still lacking. Therefore, the purpose of our study was to investigate the benefits of retrieval practice in patients with schizophrenia.MethodsNineteen stabilised outpatients with schizophrenia (DSM-5 criteria) and 20 healthy controls first studied a list of 60 word-pairs (30 pairs with weak semantic association and 30 non associated pairs). Half the pairs were studied again (restudy condition), while only the first word of the pair was presented and the subject had to recall the second word for the other half (retrieval practice condition). The final memory test consisted in a cued-recall which took place 2 days later. Statistical analyses were performed using Bayesian methods.ResultsCognitive performances were globally altered in patients. However, in both groups, memory performances for word-pairs were significantly better after retrieval practice than after restudy (56.1% vs 35.7%, respectively, Pr(RP > RS) > 0.999), and when a weak semantic association was present (64.7% vs 27.1%, respectively; Pr(weak > no) > 0.999). Moreover, the positive effect of RP was observed in all patients but one.ConclusionsOur study is the first to demonstrate that retrieval practice efficiently improves episodic memory in comparison to restudy in patients with schizophrenia. This learning strategy should therefore be considered as a useful tool for cognitive remediation programs. In this perspective, future studies might explore retrieval practice using more ecological material.

Highlights

Schizophrenia is associated with severe cognitive deficits, episodic memory deficits, that interfere with patients’ socio-professional functioning
The comparison between baseline scores and scores at the final test indicated that the improvement of performance observed (improvement of 3.6 and 7.3% of word-pairs recalled at the final test respectively, OR = 1.076, CI95%:1.026 – 1.128; Pr(final > baseline) = 0.998)2 was comparable in both groups (the interaction between the group and time was not relevant (Pr = 0.179)
Univariate analyses showed that word-pairs were better recalled through Retrieval practice (RP) than through RS (56.1% vs 35.7%, respectively; OR = 2.29, CI95%:1.67 – 3.12, Pr(RP > RS) > 0.999) and when a weak semantic association was present (64.7% vs 27.1%, respectively; OR = 5.45, CI95%:4.12 – 7.15, Pr(weak > no) > 0.999)

Summary

Introduction

Schizophrenia is associated with severe cognitive deficits, episodic memory deficits, that interfere with patients’ socio-professional functioning. Schizophrenia is associated with severe cognitive deficits, episodic memory impairment They interfere with patients’ socio-professional functioning [1, 2] and are correlated with occupational engagement, residential independence, and self-care [3]. Different strategies have been identified in the general population to improve memory through a semantic task—grouping items by category, visual repetition, counting words or letters, contextual encoding or sentence generation [7]. The use of these strategies varies with age [8,9,10], education and cognitive impairments [11,12,13,14]. Several studies have demonstrated a deficient use of encoding strategies that can be at least partially reversed when the efficient strategy used is explicitly provided to patients [15,16,17,18]

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