Effect of emotional cues on prospective memory performance in patients with schizophrenia and major depressive disorder

Emotion and prospective memory: effects of emotional targets and contexts

Event-based prospective memory (PM) refers to the ability to remember to perform a delayed and intended action when an event is encountered in the future. Whether emotional targets promote PM performance is still controversial. The reason for these inconsistent findings may be related to the degree of target arousal and context valence (the valence of ongoing task trials) in the previous studies. This study aimed to investigate the separate and combined effects of target valence, arousal, and context valence on event-based PM through two experiments. The results showed that the participants were faster and more accurate in responding to positive, negative, and high-arousal PM targets. Interestingly, an interaction effect of target valence, arousal, and context valence was observed, implying that their individual effects on PM performance cannot be understood in isolation. These findings demonstrate that positive, negative, and high-arousal PM targets can enhance PM performance. In addition, the results provided support for both the emotion enhancement account and the emotion-saliency account, depending upon whether the valence of the PM target matched or did not match the valence of the context. Moreover, context valence can modulate the effect of arousal on PM across different target valences.

The benefits of emotionally salient cues on event-based prospective memory in bipolar patients and schizophrenia patients

Prospective memory (PM) refers to the ability to remember to carry out a delayed intention in the future. Evidence suggests that emotionally salient cues can enhance PM functions in healthy population, but whether the benefit exists in schizophrenia and bipolar patients remains unclear. This study aimed to examine and compare the potential enhancement effect of emotional PM cues in schizophrenia patients and bipolar patients. Twenty-eight clinically stable schizophrenia participants, 26 euthymic bipolar participants and 29 controls completed a computerized PM task involving PM cues with different types of valences (i.e., positive, neutral and negative). All the three groups showed better PM performance when negative PM cues were presented compared with positive and neutral PM cues. The sizes of the enhancement effects of negative PM cues were large (all Cohen's d ≥ 1.00) and comparable across three groups. Our findings suggested that patients with schizophrenia and bipolar disorders could benefit from negative PM cues to an extent similar to healthy individuals, thus extended the notion of psychosis continuum to the important area of emotion-cognition interaction.

Brief report: A randomized controlled trial of a compensatory cognitive training to improve prospective memory performance in people with schizophrenia or depression

People with schizophrenia or depression have prospective memory (PM) deficits, which affect their daily living. Given the paucity of research into training to correct PM deficits, we subjected a group of participants to a Chinese version of the PM module of the Cognitive Compensatory Training (CCT-C-PM) intervention to study its effect on their PM performance. Specifically, we independently randomized two diagnostic cohorts (schizophrenia and depression) into control groups (occupational therapy only) or experimental groups (CCT-C-PM and occupational therapy). The schizophrenia cohort had 17 participants in its control group and 23 participants in its experimental group. The depression cohort had 10 participants in its control group and 12 participants in its experimental group. The sociodemographic information of the participants was collected. Their symptoms and PM performances were measured at baseline and after treatment (after the completion of the CCT-C-PM intervention in the experimental group and the same timeframe in the control group). The treatment effects were examined by a repeated measure analysis of variance/analysis of covariance and a post hoc Scheffé test. The effect sizes (Cohen's d) of treatments against the controls were also calculated. There was no difference between the experimental and control groups in either cohort in terms of sociodemographic data, symptoms, and PM measures at baseline. The sex combination differed across the groups in the depression cohort. We found that the CCT-C-PM improved PM, especially event-based PM, for which large effect sizes were seen. The effect on time-based PM was unclear and requires future study. Our findings suggest that the CCT-C-PM is a viable training method for improving PM.

Emotional Stop Cues Facilitate Inhibitory Control in Schizophrenia

OBJECTIVE

Inhibitory control is a key deficit in patients with schizophrenia. This study aims to test whether emotions can facilitate inhibition in patients with schizophrenia when they increase attention to inhibitory process.

METHOD

A total of 36 patients with schizophrenia and 36 healthy controls completed an emotional stop-signal task. The task involved selective responses to "Go" stimuli and stopped response when emotional or neutral stop cues occurred.

RESULTS

In all conditions, patients with schizophrenia took longer time to inhibit response compared with healthy controls, indicating an overall impairment in response inhibition. Importantly, patients with schizophrenia and controls acquired similar size of benefit from the negative stop cues, showing as reduced reaction time to negative than neutral stop cues. However, the negative stop cues impaired subsequent Go performance only in patients with schizophrenia, indicating additional cost of the negative stop cues for patients with schizophrenia. In both groups, the positive stop cues did not have any significant influence on response inhibition.

CONCLUSIONS

These findings provide novel evidence for the benefit of emotional stop cues on inhibitory control in patients with schizophrenia and reveal different after-effects of emotional enhancement effect in patients and healthy populations. The findings may help develop effective interventions for improving inhibitory control in patients with schizophrenia and other clinical populations.

A comparison of different types of prospective memory reminders in schizophrenia

People with schizophrenia often experience difficulties with prospective memory (PM), but few empirical studies have directly compared the effectiveness of different types of reminders in remediating these difficulties. In the present study, two distinct types of reminders were compared to a standard (no reminder) condition in outpatients with schizophrenia (n = 30) and controls (n = 30). Using an adapted version of the well-validated laboratory PM measure, Virtual Week, participants were asked to complete three different conditions (counterbalanced), in which they were (i) provided with access to self-initiated reminders, (ii) provided with experimenter-initiated reminders, and (iii) completed a standard (no-reminder) condition. Both groups benefited from the provision of reminders, but self-initiated reminders were the most beneficial, particularly for time-based tasks. These data align with a broader literature that shows PM can be enhanced by the use of reminders. However, it extends this literature in an important way by showing that these benefits are equivalent for people with schizophrenia, and may be greatest where access to reminders is self-initiated. The implications of these data for the development of rehabilitative interventions are discussed.

The Time Course of Dorsal and Rostral-Ventral Anterior Cingulate Cortex Activity in the Emotional Stroop Experiment Reveals Valence and Arousal Aberrant Modulation in Patients with Schizophrenia

This paper aims to investigate the temporal dynamics within the dorsal anterior cingulate cortex (dACC) and the rostral-ventral (rv) ACC during the interaction of emotional valence and arousal with cognitive control in patients with Schizophrenia (SZ). Although cognitive deficits in SZ are highly relevant and emotional disturbances are common, the temporal relationship of brain regions involved in the interaction of emotional and cognitive processing in SZ is yet to be determined. To address this issue, the reaction time (RT), event-related potential (ERP) and temporal dynamics of the dACC and rvACC activity were compared between SZ subjects and healthy controls (HC), using a modified emotional Stroop experiment (with factors namely congruence, arousal and valence). EEG was recorded with 64 channels and source localisation was performed using the sLORETA software package. We observed slower initial increase and lower peaks of time course activity within the dACC and rvACC in the SZ group. In this particular group, the dACC activity during late negativity was negatively correlated with a significantly higher RT in the high arousal conflict condition. In contrast to HC subjects, at the N450 window, there was no significant valence (ERP and rvACC ROI) modulation effect in the SZ subjects. Using high density EEG and source localisation, it was possible to distinguish various disturbances within the dACC and rvACC in patients with SZ, during emotion–cognition processing.