Exploring the sociodemographic, clinical and neuropsychological factors associated with relational memory in schizophrenia.

INTRODUCTION: The Transverse Patterning (TP) task has been used to measure episodic relational memory (RM) deficits in clinical populations. Individuals with schizophrenia often fail to learn TP with standard, and sometimes extensive training. Identifying the differences between TP learners and non-learners can improve our understanding of successful TP performance and its underlying mechanisms, which may help improve interventions aimed at ameliorating RM performance. We investigated sociodemographic, clinical and neuropsychological factors associated with TP performance in schizophrenia. METHODS: Sixty-six participants with schizophrenia completed a semantically rich and a relational-binding dependent version of the TP task and reported on their task awareness and strategy use. RESULTS: Twenty-six participants failed to learn the task rules after extensive training. Learners had superior verbal, visual and working memory, executive functions and overall cognitive functioning compared to non-learners. Learners also had superior awareness of task rules and pairs relationships and used elaborated cognitive strategies more often. CONCLUSIONS: Our results support previous findings that some individuals with schizophrenia show RM impairment even with extensive TP training. We shed light on neuropsychological and metacognitive factors associated with TP performance. This knowledge could enhance interventions targeted to improve relational memory in schizophrenia when extensive training fails.

The Relational Trip Task, a novel ecological measure of relational memory: data from a schizophrenia sample.

INTRODUCTION: Relational memory (RM) is severely impaired in schizophrenia. Unitisation can circumvent RM impairments in clinical populations as measured by the transverse-patterning (TP) task, a well-established measure of RM capacity. We compared memory performance on a new ecological RM measure, the Relational Trip Task (RTT), to that of TP at baseline and examined the effects of a unitisation intervention in RTT performance. RTT involves learning relational information of real-life stimuli, such as the relationship between people and places or objects. METHODS: TP and RTT performances were examined in 45 individuals with schizophrenia. TP-impaired participants (n = 22) were randomised to either the intervention or an active control group. TP and RTT were administered again after unitisation training. Task validity and reliability were assessed. Intervention group's pre- and post-RTT accuracies were compared and contrasted to that in the control group. RESULTS: RTT and TP were moderately correlated. TP non-learners had inferior performance in RTT at baseline. Improvement in RTT performance after unitisation training was observed in the intervention group; no pre-post improvement was observed in the control group. CONCLUSION: RTT has an acceptable criterion validity and excellent alternate-form reliability. Unitisation seemed to be successfully generalized to support associations of real-life stimuli.

A Feasibility Study on the Use of the Method of Loci for Improving Episodic Memory Performance in Schizophrenia and Non-clinical Subjects.

We investigated the feasibility of a short intervention using the Method of Loci (MoL), a well-known visuospatial mnemonic, to improve episodic memory recall performance in schizophrenia. The MoL training protocol comprised encoding and recall of two lists of items (words and images), a training session and practice with MoL. Then, participants had the opportunity to put into practice the newly learned MoL and were instructed to encode and recall two new lists of items using. This approach was first validated with healthy individuals (N = 71). Subsequently, five individuals with schizophrenia completed the protocol. Improvement in healthy individuals was observed for the word list (Wilcoxon effect size r = 0.15). No significant memory improvement was denoted in the schizophrenia group, possibly due to participants' difficulties using the method efficiently and due to fatigue. The MoL seems to require episodic memory, working memory monitoring and executive functions, making it suboptimal for a population with impairments in all those domains. Future research should examine the use of other strategies, better suited for individuals with cognitive impairments like those found in schizophrenia.