Social threat perception and the evolution of paranoia

Social brain dysfunctions in schizophrenia: a review of neuroimaging studies

Several studies have indicated that schizophrenic patients show impaired performance in various aspects of social cognition, including theory of mind, emotion processing, and agency judgments. Neuroimaging studies that have compared patients and healthy subjects during such mental activity indicate an abnormal hemodynamic response in the medial prefrontal cortex, the prefrontal cortex, the amygdala, the inferior parietal lobe, i.e., a set of regions known to be critically involved in social cognition. This paper addresses a number of issues raised by schizophrenia research into theory of mind, emotion perception and self-agency with regards to the neural systems that mediate social cognition. In healthy subjects, typical brain patterns are associated with theory of mind, emotion perception and self-agency; some activated clusters overlap, while others are distinct. For instance, activations in the paracingulate gyrus are almost systematically associated with theory of mind tasks, while the amygdala is mainly involved in emotion perception tasks. Additional foci are frequently found activated during those tasks: superior temporal sulcus, inferior frontal area. Moreover, the inferior parietal lobe is thought to contribute to agency judgments. In the light of the data on brain abnormalities and neurochemical dysfunctions in schizophrenia, we discuss the interaction of social cognitive dysfunction with the supposed information processing abnormalities caused by dopamine dysregulation.

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

Numerous studies suggest a cognitive bias for threat-related material in delusional ideation. However, few studies have examined this bias using a memory task. We investigated the influence of delusion-proneness on identity and expression memory for angry and happy faces. Participants high and low in delusion-proneness were presented with happy and angry faces and were later asked to recognise the same faces displaying a neutral expression. They also had to remember what the initial expressions of the faces had been. Remember/know/guess judgments were asked for both identity and expression memory. Results showed that delusion-prone participants better recognised the identity of angry faces compared to non-delusional participants. Also, this difference between the two groups was mainly due to a greater number of remember responses in delusion-prone participants. These findings extend previous studies by showing that delusions are associated with a memory bias for threat-related stimuli.

Individuals with schizophrenia present hypo- and hyperactivation during implicit cueing in an inhibitory task

BACKGROUND

The primary purpose of this investigation was to assess the neural correlates of implicit cueing during an inhibitory task in schizophrenia when performance accuracy was matched with healthy comparison subjects.

METHODS

We compared 17 individuals with chronic schizophrenia (SZ; medicated, 13.9 average years of illness) and 17 healthy comparison subjects (HC) matched for hit and false alarm rates, age, and education on a visual Go/Nogo task during functional magnetic resonance imaging. In this task, one of the go stimuli also served implicitly as a cue predictive of a subsequent inhibitory (Nogo) trial.

CONCLUSIONS

Findings suggest that even when matched for overall performance accuracy, individuals with SZ exhibit difficulties with inhibition and cue processing that may relate to core deficits in cognitive control and stimulus processing. In particular, these findings point towards an important role of the parietal cortex for cued inhibitory processes in healthy populations.

Social cognition in "pure" delusional disorder

Introduction. Delusional disorders are characterised by monothematic, "encapsulated" and incorrigible false beliefs and misinterpretations of social signals. Due to the rarity of cases with "pure" delusional disorder (DD) in clinical settings most studies of social cognition in delusional patients have focused on patients with paranoid schizophrenia. In the present study we sought to examine emotion recognition, theory of mind abilities, and pragmatic language comprehension in patients with delusional disorder. Methods. Social cognition was assessed in 21 patients recruited over a 3-year period who were diagnosed with delusional disorder, paranoid, erotomanic, or jealous type. In addition to an emotion recognition and theory of mind test battery, we included a novel German Proverb Test, which has been found indicative of subtle theory of mind deficits in schizophrenic patients. Executive functioning was assessed using the Wisconsin Card Sorting Test (WCST). Psychopathology was measured using the Positive and Negative Symptoms Scale (PANSS). Patients' task performance was compared to a group of 22 healthy control persons paralleled for verbal intelligence, education, and age. Results. Patients with DD made significantly more perseverative errors in the WCST, they performed more poorly on the theory of mind tasks and the proverb test, but were unimpaired in basic emotion recognition abilities relative to controls. When executive functioning was co-varied out, the group differences in theory of mind disappeared, whereas the greater propensity of patients with DD to interpret proverbs literally remained significant. Conclusions. In "pure" DD the basic social cognitive abilities appear to be preserved. Difficulties in metaphorical speech comprehension and executive functioning could, however, indicate more subtle social cognitive deficits in these patients.

Aberrantly flattened responsivity to emotional pictures in paranoid schizophrenia

To investigate the nature of emotional experience in schizophrenia, we examined emotional responses to affective stimuli. Twenty-one outpatients with schizophrenia (9 paranoid, 12 nonparanoid) and 20 normal controls rated the arousal and valence that they experienced from the presentation of 60 pictures. Schizophrenia patients displayed less emotional responsivity to the positive stimuli and they displayed diverse responsivity to the negative stimuli, which depended upon arousal level. Further analysis, using schizophrenia subtype, indicated that nonparanoid patients reported increased negative responsivity and decreased positive responsivity, regardless of arousal level. However, paranoid schizophrenia patients showed enhanced self-reported experiences of emotion to the low arousing stimuli and diminished responsivity to the high arousing stimuli. This pattern was robust to the negative stimuli. These findings suggest that paranoid schizophrenia patients might suffer from aberrantly flattened responses to negative emotional stimuli, and that this may account for paranoid tendency and secondary social isolation in paranoid schizophrenia.

Greater impairment in negative emotion evaluation ability in patients with paranoid schizophrenia

To explore whether or not patients with schizophrenia display a more profound impairment of negative emotion processing, we assessed the implicit evaluation of positive and negative emotional stimuli. Twenty patients with schizophrenia (9 paranoid, 11 non-paranoid) and 22 normal controls were instructed to classify emotional pictures according to the intrinsic valence if the pictures were black and white. If the stimuli were color-filtered, participants were instructed to press the positive/negative response key according to the extrinsic valence (assigned valence of color). The error rates of the color-filtered stimuli were used as dependent measures. Normal controls made more errors on trials of the positive pictures when the correct response was the negative response key than when the correct response was the positive response key. The reverse was true on trials of the negative pictures. Patients with schizophrenia, especially paranoid schizophrenia, committed more errors in trials of the positive pictures when the correct response key was the negative response key. However, the reverse was not true on trials of the negative pictures. These findings suggest that patients with paranoid schizophrenia might suffer from an impaired ability to evaluate negative emotions and have a loosening of association within their negative emotional networks.

Are you always on my mind? A review of how face perception and attention interact

In this review we examine how attention is involved in detecting faces, recognizing facial identity and registering and discriminating between facial expressions of emotion. The first section examines whether these aspects of face perception are "automatic", in that they are especially rapid, non-conscious, mandatory and capacity-free. The second section discusses whether limited-capacity selective attention mechanisms are preferentially recruited by faces and facial expressions. Evidence from behavioral, neuropsychological, neuroimaging and psychophysiological studies from humans and single-unit recordings from primates is examined and the neural systems involved in processing faces, emotion and attention are highlighted. Avenues for further research are identified.

Culture, ethnicity, and paranoia

This paper defines concepts of culture, ethnicity, and paranoia. It then explores the relationship between culture and ethnicity and the development of paranoia both in mental health settings and in the wider world. The importance of cultural awareness training while dealing with an ethnic population in any multicultural setting is emphasized. When exploring paranoia, proper exploration of its genesis is essential to distinguish between pathological and nonpathological paranoia.

Neural mechanisms of the cognitive control of emotion

BACKGROUND

Emotion regulation involves the initiation of new emotional responses and continual alteration of current emotions in response to rapidly changing environmental and social stimuli. The capacity to effectively implement emotion regulation strategies is essential for psychological health; impairments in the ability to regulate emotions may be critical to the development of clinical levels of depression, anxiety and mania.

OBJECTIVE

This review provides a summary of findings from current research examining the neural mechanisms of emotion regulation by means of conscious cognitive strategies of reappraisal. These findings are considered in the context of related concepts of emotion perception and emotion generation, with discussion of the likely cognitive neuropsychological contributions to emotion regulation and the implications for psychiatric disorders.

RESULTS

Convergent evidence implicates an inhibitory role of prefrontal cortex and cingulate regions upon subcortical and cortical emotion generation systems in the cognitive control of emotional experience. Concurrent modulation of cortical activity by the peripheral nervous system is highlighted by recent studies using simultaneous physiological and neuroimaging techniques. Individual differences in emotion perception, generation of affect and neuropsychological skills are likely to have direct consequences for emotion regulation.

CONCLUSIONS

Emotion regulation relies on synergy within brain stem, limbic and cortical processes that promote the adaptive perception, generation and regulation of affect. Aberrant emotion processing in any of these stages may disrupt this self-sustaining regulatory system, with the potential to manifest in distinct forms of emotion dysregulation as seen in major psychiatric disorders such as depression, bipolar disorder and schizophrenia.

Data gathering: biased in psychosis?

This study examined whether the probabilistic reasoning bias referred to as a "jumping-to-conclusions" (JTC) style of reasoning, which, according to previous research, is associated with particular psychotic symptoms such as delusions, represents a trait that can also be detected in nonpsychotic relatives of patients with schizophrenia and in nonpsychotic individuals with a high level of psychotic experiences. Participants were, in order of level of psychosis liability, 40 patients with schizophrenia or a schizoaffective disorder, 40 first-degree nonpsychotic relatives, 41 participants from the general population with above average expression of psychotic experiences, and 53 participants from the general population with an average level of psychotic experiences. A "jumping-to-conclusions" bias was assessed using the beads task. A dose-response relationship was found in the association between level of psychosis liability and JTC (defined as needing only a single bead to complete the beads task) (odds ratio [OR] linear trend = 1.59, 95% CI: 1.13-2.24), and, independently, alinear association was apparent between JTC and level of delusional ideation (OR linear trend = 2.59, 95% CI: 1.18-5.69). In addition, the association between psychosis liability and JTC was generally much stronger as the level of delusional ideation was higher. JTC is associated with liability to psychosis (trait), in particular if the psychosis phenotype is characterized by delusional ideation (state).

The misattribution of salience in delusional patients with schizophrenia

INTRODUCTION

Delusions may arise from abnormalities in emotional perception. In this study, we tested the hypothesis that delusional schizophrenia patients are more likely than non-delusional schizophrenia patients and healthy participants to assign affective meanings to neutral stimuli.

METHODS

Unpleasant, pleasant, and neutral words were randomly presented to three subject groups--patients with schizophrenia with prominent delusions, patients with schizophrenia without delusions, and healthy participants. Participants performed three tasks: one in which they decided whether a letter string was a word or a non-word (lexical decision) and two affective classification tasks in which they judged whether words were 1) neutral or unpleasant, or 2) neutral or pleasant.

RESULTS

While there were no significant between-group differences in lexical decision performance, patients with delusions showed selective performance deficits in both affective classification tasks. First, delusional patients were significantly more likely than non-delusional patients and healthy participants to classify words as unpleasant. Second, delusional patients took significantly longer than both other groups to correctly classify neutral words in both affective classification tasks.

CONCLUSIONS

Taken together, these findings suggest that delusions are associated with the explicit misattribution of salience to neutral stimuli.

Incautious reasoning as a pathogenetic factor for the development of psychotic symptoms in schizophrenia

Previous studies indicate that schizophrenia patients draw decisions more hastily than controls. The aim of the present study was to obtain convergent evidence with a new paradigm, designed after the Who Wants to Be a Millionaire television game show. Thirty-two schizophrenia patients and 38 healthy subjects were administered 20 knowledge questions, along with 4 response alternatives. Participants were required to provide probability estimates for each alternative. Whenever a subject was confident that one of the alternatives was correct or was wrong, the subject was asked to indicate this via a decision or rejection rating. Thus, probability estimates and decisions were independently assessed, allowing determination of the point at which probability estimates translate into decisions. Patients and controls gave comparable probability estimates for all alternatives. However, patients committed more erroneous responses, owing to their making decisions in the face of low subjective probability ratings and rejecting alternatives despite rather high probability ratings. The results provide further evidence for the claim that schizophrenia patients make strong judgments based on little information. We propose that a lowered threshold for accepting alternatives provides a parsimonious explanation for the data-gathering bias reported in the literature.

ADHD and schizophrenia phenomenology: visual scanpaths to emotional faces as a potential psychophysiological marker?

Commonalities in the clinical phenomenology and psychopharmacology of ADHD and schizophrenia are reviewed. The potential of psychostimulants to produce psychotic symptoms emphasizes the need for objective psychophysiological distinctions between these disorders. Impaired emotion perception in both disorders is discussed. It is proposed that visual scanpaths to facial expressions of emotion might prove a potentially useful psychophysiological distinction between ADHD and schizophrenia. There is consistent evidence that both facial affect recognition and scanpaths to facial expressions are impaired in schizophrenia, with emerging empirical evidence showing that facial affect recognition is impaired in ADHD also. Brain imaging studies show reduced activity in the medial prefrontal and limbic (amygdala) brain regions required to process emotional faces in schizophrenia, but suggest more localized loss of activity in these regions in ADHD. As amygdala activity in particular has been linked to effective visual scanning of face stimuli, it is postulated that condition-specific breakdowns in these brain regions that subserve emotional behavior might manifest as distinct scanpath aberrations to facial expressions of emotion in schizophrenia and ADHD.

Sustained activation of the hippocampus in response to fearful faces in schizophrenia

BACKGROUND

In healthy individuals, the activity of the medial temporal lobe habituates rapidly with the repeated presentation of a stimulus. Using functional magnetic resonance imaging (fMRI), we tested the hypothesis that habituation of the medial temporal lobe is reduced in schizophrenia.

METHODS

During fMRI scanning, fearful and happy faces were presented repeatedly to healthy control subjects (n =16) and patients with schizophrenia (n =18). Habituation of medial temporal lobe structures was measured by comparing the hemodynamic response occurring during the early and late portions of the presentation of each face.

RESULTS

Control subjects demonstrated significant medial temporal lobe habituation to fearful but not to happy faces. In contrast, patients with schizophrenia did not demonstrate medial temporal lobe habituation in response to fearful or happy faces. In a direct, between-group comparison, right hippocampal habituation to fearful faces was significantly greater in control subjects than in the schizophrenia patients. Also, there were no significant differences between the patients and control subjects in the early medial temporal lobe response to fearful faces, suggesting that attenuated hippocampal habituation in schizophrenia is not associated with a reduction in initial activation.

CONCLUSIONS

These findings suggest that there is abnormal modulation of hippocampal responses to fearful faces in schizophrenia.