The effects of angry and happy expressions on recognition memory for unfamiliar faces in delusion-prone individuals

Memory of my victory and your defeat: Contributions of reward- and memory-related regions to the encoding of winning events in competitions with others

Social interactions enhance human memories, but little is known about how the neural mechanisms underlying episodic memories are modulated by rewarding outcomes in social interactions. To investigate this, fMRI data were recorded while healthy young adults encoded unfamiliar faces in either a competition or a control task. In the competition task, participants encoded opponents' faces in the rock-paper-scissors game, where trial-by-trial outcomes of Win, Draw, and Lose for participants were shown by facial expressions of opponents (Angry, Neutral, and Happy). In the control task, participants encoded faces by assessing facial expressions. After encoding, participants recognized faces previously learned. Behavioral data showed that emotional valence for opponents' Angry faces as the Win outcome was rated positively in the competition task, whereas the rating for Angry faces was rated negatively in the control task, and that Angry faces were remembered more accurately than Neutral or Happy faces in both tasks. fMRI data showed that activation in the medial orbitofrontal cortex (mOFC) paralleled the pattern of valence ratings, with greater activation for the Win than Draw or Lose conditions of the competition task, and the Angry condition of the control task. Moreover, functional connectivity between the mOFC and hippocampus was increased in Win compared to Angry, and the mOFC-hippocampus functional connectivity predicted individual differences in subsequent memory performance only in Win of the competition task, but not in any other conditions of the two tasks. These results demonstrate that the memory enhancement by context-dependent social rewards involves interactions between reward- and memory-related regions.

Characteristics of memories of delusion-like experiences within the psychosis continuum: Pilot studies providing new insight on the relationship between self and delusions

BACKGROUND AND OBJECTIVES

Delusions are usually anchored in past events associated with abnormal experiences or delusional interpretations of personal events. The characteristics of the memory of these experiences may contribute to maintain delusional beliefs by providing confirmatory evidence for the delusions. However, these aspects have not been investigated properly.

METHOD

Seventeen patients with schizophrenia were examined in study 1 during a face-to-face interview. The second study used a web-based design and included 83 participants without a psychotic disorder. Participants were asked to rate the vividness, emotional intensity and valence, and the centrality to the self of memories of delusion-like experiences (that were cued by means of the Peters et al. Delusional Inventory, PDI; Peters, Joseph, Day, & Garety, 2004) and positive and negative memories used as comparators.

RESULTS

In both studies, the memories of delusion-like experiences were less vivid, less emotionally intense than positive (but not negative) memories and emotionally neutral. Their centrality to the self did not differ from that of positive and negative memories. Moreover, the severity of delusions in study 1 and delusion-proneness in study 2 were significantly correlated with vividness, emotional intensity, and centrality of memories of delusion-like experiences.

LIMITATIONS

The accuracy of memories of delusion-like experiences could not be checked making it difficult to distinguish them from delusional memories. The sample size was small in study 1.

CONCLUSIONS

Our results point to reciprocal relationships between delusions, self, and autobiographical memories of delusion-like experiences that are similar within the psychosis continuum and that may be involved in the maintenance of delusions.

Disconnection Between Amygdala and Medial Prefrontal Cortex in Psychotic Disorders

Distracting emotional information impairs attention more in schizophrenia (SCZ) than in never-psychotic individuals. However, it is unclear whether this impairment and its neural circuitry is indicative generally of psychosis, or specifically of SCZ, and whether it is even more specific to certain SCZ symptoms (eg, deficit syndrome). It is also unclear if this abnormality contributes to impaired behavioral performance and real-world functioning. Functional imaging data were recorded while individuals with SCZ, bipolar disorder with psychosis (BDP) and no history of psychotic disorders (CON) attended to identity of faces while ignoring their emotional expressions. We examined group differences in functional connectivity between amygdala, involved in emotional evaluation, and sub-regions of medial prefrontal cortex (MPFC), involved in emotion regulation and cognitive control. Additionally, we examined correlation of this connectivity with deficit syndrome and real-world functioning. Behaviorally, SCZ showed the worst accuracy when matching the identity of emotional vs neutral faces. Neurally, SCZ showed lower amygdala-MPFC connectivity than BDP and CON. BPD did not differ from CON, neurally or behaviorally. In patients, reduced amygdala-MPFC connectivity during emotional distractors was related to worse emotional vs neutral accuracy, greater deficit syndrome severity, and unemployment. Thus, reduced amygdala-MPFC functional connectivity during emotional distractors reflects a deficit that is specific to SCZ. This reduction in connectivity is associated with worse clinical and real-world functioning. Overall, these findings provide support for the specificity and clinical utility of amygdala-MPFC functional connectivity as a potential neural marker of SCZ.

Recall of threat material is modulated by self or other referencing in people with high or low levels of non-clinical paranoia

BACKGROUND AND OBJECTIVES

Biased processing of negatively valenced, and particularly threat-related material plays an important role in the development of paranoid thinking. This has been demonstrated by superior memory for threat-related information in patients with persecutory delusions and in non-clinical paranoia-prone participants. This study examined how emotional material was recalled having been encoded in relation to one self or to another person, in people high or low in paranoid ideation. It was predicted that people high in paranoia would recall more threat related material about others than people low in paranoia owing to being particularly alert to threats from other people.

METHODS

Participants who reported high (N = 30) or low (N = 30) levels of sub-clinical paranoid thinking were presented with a series of threat-related and positive words and were asked to process them in terms of the self, or in terms of a fictional character.

RESULTS

As predicted, when words were processed in terms of another person, the high paranoia group recalled more threat-related words than positive words, but when words had been processed in terms of the self, recall of threat-related and positive words did not differ. In contrast, there was no interaction between word-valence and referent in the low paranoia group.

LIMITATIONS

These findings are drawn from an analogue sample. Replication in a sample of clinical participants who report persecutory delusions is required.

CONCLUSIONS

People high in sub-clinical paranoid ideation recalled threat preferentially in relation to other people. Such information processing biases may help understand the development and maintenance of persecutory beliefs.

Neural mechanisms underlying the effects of face-based affective signals on memory for faces: a tentative model

In our daily lives, we form some impressions of other people. Although those impressions are affected by many factors, face-based affective signals such as facial expression, facial attractiveness, or trustworthiness are important. Previous psychological studies have demonstrated the impact of facial impressions on remembering other people, but little is known about the neural mechanisms underlying this psychological process. The purpose of this article is to review recent functional MRI (fMRI) studies to investigate the effects of face-based affective signals including facial expression, facial attractiveness, and trustworthiness on memory for faces, and to propose a tentative concept for understanding this affective-cognitive interaction. On the basis of the aforementioned research, three brain regions are potentially involved in the processing of face-based affective signals. The first candidate is the amygdala, where activity is generally modulated by both affectively positive and negative signals from faces. Activity in the orbitofrontal cortex (OFC), as the second candidate, increases as a function of perceived positive signals from faces; whereas activity in the insular cortex, as the third candidate, reflects a function of face-based negative signals. In addition, neuroscientific studies have reported that the three regions are functionally connected to the memory-related hippocampal regions. These findings suggest that the effects of face-based affective signals on memory for faces could be modulated by interactions between the regions associated with the processing of face-based affective signals and the hippocampus as a memory-related region.

Do patients with schizophrenia have a general or specific deficit in the perception of social threat? A meta-analytic study

This study investigates whether social cognitive deficits found in patients with schizophrenia are specific to social threat stimuli, and whether the deficits increase across the delusion spectrum from a subclinical sample to clinical manifestation. The authors presented the meta-analytic review of the published literature on social threat perception performance in three kinds of group comparisons: a subclinical group and a healthy control group, a schizophrenia group and a healthy control group, and a schizophrenia with delusion symptoms group and a healthy control group. The meta-analysis of 20 studies yielded six weighted effect sizes. The largest differences were found between the schizophrenia with delusion group and the healthy controls in both the threat and non-threat conditions. No differences were found between the effect sizes in the threat-related condition and the non-threat condition in any of the three group comparisons. Age was found to be significantly correlated with the effect sizes. The performance differences in both the threat and non-threat conditions reflect a generalized performance deficit, rather than a specific deficit, in the perception of social threat stimuli among patients with schizophrenia.

Neuropsychological aspects of delusional disorder

Delusional disorders (DDs) are clinically rare syndromes characterized by false beliefs that are held with firm conviction despite counterevidence. The neuropsychology of DDs is poorly understood. Two partially opposing models--a cognitive bias model and a cognitive deficit model--have received mixed empiric support, partly because most research has been carried out in patients with paranoid schizophrenia, with which the nosologic association of DDs is unknown. Based on these models, we review empiric findings concerning the neuropsychology of DDs (narrowly defined). We conclude that DDs can best be seen as extreme variations of cognitive mechanisms involved in rapid threat detection and defensive harm avoidance. From this viewpoint, the two models seem to be complementary in explanatory power rather than contradictory. Future research may help to clarify the question of gene-environment interaction involvement in the formation of delusional beliefs.

Measuring psychosis proneness in a nonclinical Korean population: is the Peters et al Delusions Inventory useful for assessing high-risk individuals?

OBJECTIVES

We examined the psychometric properties of the Korean version of the Peters et al Delusions Inventory (PDI) 40 and investigated the distribution of delusional ideation in a nonclinical population. We also used the item response theory to evaluate the usefulness of the PDI in measuring the risk for psychosis.

METHODS

A total of 310 nonclinical individuals completed the Korean PDI-40, the Magical Ideation Scale (MIS), and the Schizotypal Personality Scale (STA). In addition, 60 psychotic inpatients with delusions completed the PDI-40. Among 310 individuals, 124 participated in a follow-up study 6 months after completing their original questionnaire.

RESULTS

The PDI-40 revealed a slightly skewed distribution, but the score range was similar to that of the British population. Scores were negatively correlated with age, but no sex differences were found. The Korean PDI-40 exhibited good internal consistency and test-retest reliability. The PDI was significantly correlated with the MIS and the STA. Ten components were extracted through a principal component analysis with varimax rotation. The test results using item response theory revealed 39 items as the items which individuals with very high level of psychosis proneness will answer as "yes." Moreover, all items yielded "above moderate" discrimination in terms of psychosis proneness.

CONCLUSIONS

We confirmed the reliability and validity of the Korean PDI-40. The usefulness of the PDI-40 in a nonclinical population was replicated in the Korean sample. The PDI-40 can be used as an informative device when investigating "psychosis proneness" in a group at high risk for psychosis.