Impairment in basal limbic function in schizophrenia during affect recognition

The role of cognitive control in the positive symptoms of psychosis

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Mechanisms underlying positive symptoms in psychosis are unclear.

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Differential fMRI activity present in left amygdala, pallidum and thalamus in high positive symptom patients compared to low.

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Lower activity in SMA/pre-SMA also present in high symptom patients.

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We suggest poor integration of social-emotional information with reward feedback.

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Results may be important for guiding treatment strategies to prevent chronic illness.

Background

Positive symptoms of psychosis (e.g., hallucinations) often limit everyday functioning and can persist despite adequate antipsychotic treatment. We investigated whether poor cognitive control is a mechanism underlying these symptoms.

Methods

97 patients with early psychosis (30 with high positive symptoms (HS) and 67 with low positive symptoms (LS)) and 40 healthy controls (HC) underwent fMRI whilst performing a reward learning task with two conditions; low cognitive demand (choosing between neutral faces) and high cognitive demand (choosing between angry and happy faces – shown to induce an emotional bias). Decision and feedback phases were examined.

Results

Both patient groups showed suboptimal learning behaviour compared to HC and altered activity within a core reward network including occipital/lingual gyrus (decision), rostral Anterior Cingulate Cortex, left pre-central gyrus and Supplementary Motor Cortex (feedback). In the low cognitive demand condition, HS group showed significantly reduced activity in Supplementary Motor Area (SMA)/pre-SMA during the decision phase whilst activity was increased in LS group compared to HC. Recruitment of this region suggests a top-down compensatory mechanism important for control of positive symptoms. With additional cognitive demand (emotional vs. neutral contrast), HS patients showed further alterations within a subcortical network (increased left amygdala activity during decisions and reduced left pallidum and thalamus activity during feedback) compared to LS patients.

Conclusions

The findings suggest a core reward system deficit may be present in both patient groups, but persistent positive symptoms are associated with a specific dysfunction within a network needed to integrate social-emotional information with reward feedback.

Abnormalities in hemispheric lateralization of intra- and inter-hemispheric white matter connections in schizophrenia

Hemispheric lateralization is a prominent feature of the human brain and is grounded into intra- and inter-hemispheric white matter (WM) connections. However, disruptions in hemispheric lateralization involving both intra- and inter-hemispheric WM connections in schizophrenia is still unclear. Hence, a quantitative measure of the hemispheric lateralization of intra- and inter-hemispheric WM connections could provide new insights into schizophrenia. This work performed diffusion tensor imaging on 50 patients and 58 matched healthy controls. Using graph theory, the global and nodal efficiencies were computed for both intra- and inter-hemispheric networks. We found that patients with schizophrenia showed significantly decrease in both global and nodal efficiency of hemispheric networks relative to healthy controls. Specially, deficits in intra-hemispheric integration and inter-hemispheric communication were revealed in frontal and temporal regions for schizophrenia. We also found disrupted hemispheric asymmetries in brain regions associated with emotion, memory, and visual processes for schizophrenia. Moreover, abnormal hemispheric asymmetry of nodal efficiency was significantly correlated with the symptom of the patients. Our finding indicated that the hemispheric WM lateralization of intra- and inter-hemispheric connections could serve as a potential imaging biomarker for schizophrenia.

Neural correlates of emotional processing in psychosis risk and onset - A systematic review and meta-analysis of fMRI studies

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The neural bases of altered emotion processing in psychosis are still unclear.

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Systematic review indicated widespread activation decreases to emotion in first-episode psychosis.

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Evidence in people at clinical high-risk for psychosis lacked convergence.

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These findings were corroborated by image-based meta-analyses.

Aberrant emotion processing is a well-established component of psychotic disorders and is already present at the first episode of psychosis (FEP). However, the role of emotion processing abnormalities in the emergence of psychosis and the underlying neurobiology remain unclear. Here, we systematically reviewed functional magnetic resonance studies that used emotion processing task paradigms in FEP patients, and in people at clinical high-risk for psychosis (CHRp). Image-based meta-analyses with Seed-based d Mapping on available studies (n = 6) were also performed. Compared to controls, FEP patients showed decreased neural responses to emotion, particularly in the amygdala and anterior cingulate cortex. There were no significant differences between CHRp subjects and controls, but a high degree of heterogeneity was identified across studies. The role of altered emotion processing in the early phase of psychosis may be clarified through more homogenous experimental designs, particularly in the CHRp population.

Attentional biases to emotional scenes in schizophrenia: An eye-tracking study

Attentional biases to emotional information may play a key role in the onset and course of schizophrenia. The aim of this experiment was to examine the attentional processing of four emotional scenes in competition (happy, neutral, sad, threatening) in 53 patients with schizophrenia and 51 controls. The eye movements were recorded in a 20-seconds free-viewing task. The results were: (i) patients showed increased attention on threatening scenes, compared to controls, in terms of attentional engagement and maintenance; (ii) patients payed less attention to happy scenes than controls, in terms of attentional maintenance; (iii) whereas positive symptoms were associated with a late avoidance of sad scenes, negative symptoms were associated with heightened attention to threat. The findings suggest that a threat-related bias and a lack of sensitivity to positive information may represent an underlying psychological mechanism of schizophrenia. Importantly, schizophrenia symptoms modulated the attentional biases, which has aetiological and therapeutic implications.

Economization of cerebral activation under training: The inverse U- shaped function revisited

As already observed as early as 1967 by Ingvar and Risberg in their pioneering work, effects of practice of working memory on cerebral functions have been confirmed repeatedly in a number of neuroimaging studies using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). Accordingly, initial performance gains are typically accompanied by increased cerebral activation, while consolidation of such performance gains goes along with a subsequent decrease in activation resembling an inverse U-shaped function. This observed pattern can be interpreted as an economization of cerebral functioning as tasks are being accomplished with relatively lower effort and may also apply to other cognitive domains. However, the economization of cerebral activation under training may depend on task difficulty and training characteristics on the one hand and individual factors, including age, intelligence, cognitive reserve, education, physical and mental health on the other. These findings bear important implications for the design of neuroimaging studies and stimulation protocols, in which similar tasks are routinely repeated.

Polygenic risk for autism spectrum disorder affects left amygdala activity and negative emotion in schizophrenia

Although the diagnoses based on phenomenology have many practical advantages, accumulating evidence shows that schizophrenia and autism spectrum disorder (ASD) share some overlap in genetics and clinical presentation. It remains largely unknown how ASD-associated polygenetic risk contributes to the pathogenesis of schizophrenia. In the present study, we calculated high-resolution ASD polygenic risk scores (ASD PRSs) and selected optimal ten ASD PRS with minimal P values in the association analysis of PRSs, with schizophrenia to assess the effect of ASD PRS on brain neural activity in schizophrenia cases and controls. We found that amplitude of low-frequency fluctuation in left amygdala was positively associated with ASD PRSs in our cohort. Correlation analysis of ASD PRSs with facial emotion recognition test identified the negative correlation of ASD PRSs with negative emotions in schizophrenia cases and controls. Finally, functional enrichment analysis of PRS genes revealed that neural system function and development, as well as signal transduction, were mainly enriched in PRS genes. Our results provide empirical evidence that polygenic risk for ASD contributes to schizophrenia by the intermediate phenotypes of left amygdala function and emotion recognition. It provides a promising strategy to understand the relationship between phenotypes and genotypes shared in mental disorders.

Psychobiology of threat appraisal in the context of psychotic experiences: A selective review

A key factor in the transition to psychosis is the appraisal of anomalous experiences as threatening. Cognitive models of psychosis have identified attentional and interpretative biases underlying threat-based appraisals. While much research has been conducted into these biases within the clinical and cognitive literature, little examination has occurred at the neural level. However, neurobiological research in social cognition employing threatening stimuli mirror cognitive accounts of maladaptive appraisal in psychosis. This review attempted to integrate neuroimaging data regarding social cognition in psychosis with the concepts of attentional and interpretative threat biases. Systematic review methodology was used to identify relevant articles from Medline, PsycINFO and EMBASE, and PubMed databases. The selective review showed that attentional and interpretative threat biases relate to abnormal activation of a range of subcortical and prefrontal structures, including the amygdala, insula, hippocampus, anterior cingulate, and prefrontal cortex, as well as disrupted connectivity between these regions, when processing threatening and neutral or ambiguous stimuli. Notably, neural findings regarding the misattribution of threat to neutral or ambiguous stimuli presented a more consistent picture. Overall, however, the findings for any specific emotion were mixed, both in terms of the specific brain areas involved and the direction of effects (increased/decreased activity), possibly owing to confounds including small sample sizes, varying experimental paradigms, medication, and heterogeneous, in some cases poorly characterised, patient groups. Further neuroimaging research examining these biases by employing experimentally induced anomalous perceptual experiences and well-characterised large samples is needed for greater aetiological specificity.

Abnormal brain activation during threatening face processing in schizophrenia: A meta-analysis of functional neuroimaging studies

Impairment of face perception in schizophrenia is a core aspect of social cognitive dysfunction. This impairment is particularly marked in threatening face processing. Identifying reliable neural correlates of the impairment of threatening face processing is crucial for targeting more effective treatments. However, neuroimaging studies have not yet obtained robust conclusions. Through comprehensive literature search, twenty-one whole brain datasets were included in this meta-analysis. Using seed-based d-Mapping, in this voxel-based meta-analysis, we aimed to: 1) establish the most consistent brain dysfunctions related to threating face processing in schizophrenia; 2) address task-type heterogeneity in this impairment; 3) explore the effect of potential demographic or clinical moderator variables on this impairment. Main meta-analysis indicated that patients with chronic schizophrenia demonstrated attenuated activations in limbic emotional system along with compensatory over-activation in medial prefrontal cortex (MPFC) during threatening faces processing. Sub-task analyses revealed under-activations in right amygdala and left fusiform gyrus in both implicit and explicit tasks. The remaining clusters were found to be differently involved in different types of tasks. Moreover, meta-regression analyses showed brain abnormalities in schizophrenia were partly modulated by age, gender, medication and severity of symptoms. Our results highlighted breakdowns in limbic-MPFC circuit in schizophrenia, suggesting general inability to coordinate and contextualize salient threat stimuli. These findings provide potential targets for neurotherapeutic and pharmacological interventions for schizophrenia.

Music-evoked emotions in schizophrenia

BACKGROUND/OBJECTIVES

Previous studies have reported that people with schizophrenia have impaired musical abilities. Here we developed a simple music-based assay to assess patient's ability to associate a minor chord with sadness. We further characterize correlations between impaired musical responses and psychiatric symptoms.

METHOD

We exposed participants sequentially to two sets of sound stimuli, first a C-major progression and chord, and second a C-minor progression and chord. Participants were asked which stimulus they associated with sadness, the first set, the second set, or neither. The severity of psychiatric symptoms was assessed using the Positive and Negative Syndrome Scale (PANSS). Study participants were 29 patients diagnosed with schizophrenia and 29 healthy volunteers matched in age, gender and musical background.

RESULT

37.9% (95% confidence interval [CI]:19.1-56.7) of patients with schizophrenia associated the minor chord set as sad, compared with 97.9% (95%CI: 89.5-103.6) of controls. Four patients were diagnosed with treatment-resistant schizophrenia, and all four failed to associate the minor chord with sadness. Patients who did not recognize minor chords as sad had significantly higher scores on all PANSS subscales.

CONCLUSIONS

A simple test allows music-evoked emotions to be assessed in schizophrenia patient, and may show potential relationships between music-evoked emotions and psychiatric symptoms.

Neural markers of emotional face perception across psychotic disorders and general population

There is considerable variation in negative and positive symptoms of psychosis, global functioning, and emotional face perception (EFP), not only in schizophrenia but also in other psychotic disorders and healthy individuals. However, EFP impairment and its association with worse symptoms and global functioning have been examined largely in the domain of schizophrenia. The present study adopted a dimensional approach to examine the association of behavioral and neural measures of EFP with symptoms of psychosis and global functioning across individuals with schizophrenia spectrum (SZ; N = 28) and other psychotic (OP; N = 29) disorders, and never-psychotic participants (NP; N = 21). Behavioral and functional MRI data were recorded as participants matched emotional expressions of faces and geometrical shapes. Lower accuracy and increased activity in early visual regions, hippocampus, and amygdala during emotion versus shape matching were associated with higher negative, but not positive, symptoms and lower global functioning, across all participants. This association remained even after controlling for group-related (SZ, OP, and NP) variance, dysphoria, and antipsychotic medication status, except in amygdala. Furthermore, negative symptoms mediated the relationship between behavioral and brain EFP measures and global functioning. This study provides some of the first evidence supporting the specific relationship of EFP measures with negative symptoms and global functioning across psychotic and never-psychotic samples, and transdiagnostically across different psychotic disorders. Present findings help bridge the gap between basic EFP-related neuroscience research and clinical research in psychosis, and highlight EFP as a potential symptom-specific marker that tracks global functioning. (PsycINFO Database Record

Social Cognition in Schizophrenia: Cognitive and Neurobiological Aspects

Social cognition in schizophrenia is currently one of the major fields of interest in studies of this disorder. It is commonly conceptualised as a set of mental operations underlying social interactions, and therefore related to the ability to interpret and predict the behaviour of others in different social contexts. The research community has defined the functional areas that constitute the domain of social cognition, including, at least, the theory of mind, sensory perception, social perception, and attributional bias. Different bodies of evidence have shown that alterations in these functions in patients with schizophrenia are linked to some of their main psychopathological dysfunctions, such as defects in sensory perception, insight and attributional origin, and authorship of human acts. These behavioural alterations have been linked to structural and functional disturbances in the constituents of the so-called social brain. This includes a set of medial parietal, temporal, and pre-frontal areas that have been associated with some anomalies in the theory of mind, the perception of emotions, and the ability to consider the perspective of others, phenomena commonly found in schizophrenia. Future research in the domain of social cognition should be aimed at clarifying its relationship with the social brain and neurocognition.

The Functional Significance of Affect Recognition, Neurocognition, and Clinical Symptoms in Schizophrenia

OBJECTIVES

The complex relationship and exact extent of the contribution of plausible indictors to social functional outcome in schizophrenia remain unclear. The present study aimed to explore the functional significance of clinical symptoms, neurocognition, and affect recognition simultaneously in schizophrenia.

METHODS

The clinical symptoms, basic neurocognition, facial emotion recognition, and social functioning of 154 subjects, including 74 with schizophrenia and 80 nonclinical comparisons, were assessed.

RESULTS

We observed that various subdomains of social functioning were extensively related to general intelligence, basic neurocognition, facial emotion recognition, and clinical symptoms, with different association patterns. Multivariate regression analyses revealed that years of education, age, sustained attention, working memory, and facial emotion recognition were significantly associated with global social functioning in schizophrenia.

CONCLUSION

Our findings suggest that affect recognition combined with nonsocial neurocognition demonstrated a crucial role in predicting global social function in schizophrenia.

Functional deficit of the medial prefrontal cortex during emotional sentence attribution in schizophrenia

BACKGROUND

Functional brain imaging research has already demonstrated that patients with schizophrenia had difficulties with emotion processing, namely in facial emotion perception and emotional prosody. However, the moderating effect of social context and the boundary of perceptual categories of emotion attribution remain unclear. This study investigated the neural bases of emotional sentence attribution in schizophrenia.

METHODS

Twenty-one schizophrenia patients and 25 healthy subjects underwent an event-related functional magnetic resonance imaging paradigm including two tasks: one to classify sentences according to their emotional content, and the other to classify neutral sentences according to their grammatical person.

RESULTS

First, patients showed longer response times as compared to controls only during the emotion attribution task. Second, patients with schizophrenia showed reduction of activation in bilateral auditory areas irrespective of the presence of emotions. Lastly, during emotional sentences attribution, patients displayed less activation than controls in the medial prefrontal cortex (mPFC).

CONCLUSIONS

We suggest that the functional abnormality observed in the mPFC during the emotion attribution task could provide a biological basis for social cognition deficits in patients with schizophrenia.

Corticolimbic dysfunction during facial and prosodic emotional recognition in first-episode psychosis patients and individuals at ultra-high risk

Emotional processing dysfunction is widely reported in patients with chronic schizophrenia and first-episode psychosis (FEP), and has been linked to functional abnormalities of corticolimbic regions. However, corticolimbic dysfunction is less studied in people at ultra-high risk for psychosis (UHR), particularly during processing prosodic voices. We examined corticolimbic response during an emotion recognition task in 18 UHR participants and compared them with 18 FEP patients and 21 healthy controls (HC). Emotional recognition accuracy and corticolimbic response were measured during functional magnetic resonance imaging (fMRI) using emotional dynamic facial and prosodic voice stimuli. Relative to HC, both UHR and FEP groups showed impaired overall emotion recognition accuracy. Whilst during face trials, both UHR and FEP groups did not show significant differences in brain activation relative to HC, during voice trials, FEP patients showed reduced activation across corticolimbic networks including the amygdala. UHR participants showed a trend for increased response in the caudate nucleus during the processing of emotionally valenced prosodic voices relative to HC. The results indicate that corticolimbic dysfunction seen in FEP patients is also present, albeit to a lesser extent, in an UHR cohort, and may represent a neural substrate for emotional processing difficulties prior to the onset of florid psychosis.

Altered amygdala-prefrontal connectivity during emotion perception in schizophrenia

Individuals with schizophrenia evidence impaired emotional functioning. Abnormal amygdala activity has been identified as an etiological factor underlying affective impairment in this population, but the exact nature remains unclear. The current study utilized psychophysiological interaction analyses to examine functional connectivity between the amygdala and medial prefrontal cortex (mPFC) during an emotion perception task. Participants with schizophrenia (SZ) and healthy controls (HC) viewed and rated positive, negative, and neutral images while undergoing functional neuroimaging. Results revealed a significant group difference in right amygdala-mPFC connectivity during perception of negative versus neutral images. Specifically, HC participants demonstrated positive functional coupling between the amygdala and mPFC, consistent with co-active processing of salient information. In contrast, SZ participants evidenced negative functional coupling, consistent with top-down inhibition of the amygdala by the mPFC. A significant positive correlation between connectivity strength during negative image perception and clinician-rated social functioning was also observed in SZ participants, such that weaker right amygdala-mPFC coupling during negative compared to neutral image perception was associated with poorer social functioning. Overall, results suggest that emotional dysfunction and associated deficits in functional outcome in schizophrenia may relate to abnormal interactions between the amygdala and mPFC during perception of emotional stimuli. This study adds to the growing literature on abnormal functional connections in schizophrenia and supports the functional disconnection hypothesis of schizophrenia.

Adjunctive selective estrogen receptor modulator increases neural activity in the hippocampus and inferior frontal gyrus during emotional face recognition in schizophrenia

Estrogen has been implicated in the development and course of schizophrenia with most evidence suggesting a neuroprotective effect. Treatment with raloxifene, a selective estrogen receptor modulator, can reduce symptom severity, improve cognition and normalize brain activity during learning in schizophrenia. People with schizophrenia are especially impaired in the identification of negative facial emotions. The present study was designed to determine the extent to which adjunctive raloxifene treatment would alter abnormal neural activity during angry facial emotion recognition in schizophrenia. Twenty people with schizophrenia (12 men, 8 women) participated in a 13-week, randomized, double-blind, placebo-controlled, crossover trial of adjunctive raloxifene treatment (120 mg per day orally) and performed a facial emotion recognition task during functional magnetic resonance imaging after each treatment phase. Two-sample t-tests in regions of interest selected a priori were performed to assess activation differences between raloxifene and placebo conditions during the recognition of angry faces. Adjunctive raloxifene significantly increased activation in the right hippocampus and left inferior frontal gyrus compared with the placebo condition (family-wise error, P<0.05). There was no significant difference in performance accuracy or reaction time between active and placebo conditions. To the best of our knowledge, this study provides the first evidence suggesting that adjunctive raloxifene treatment changes neural activity in brain regions associated with facial emotion recognition in schizophrenia. These findings support the hypothesis that estrogen plays a modifying role in schizophrenia and shows that adjunctive raloxifene treatment may reverse abnormal neural activity during facial emotion recognition, which is relevant to impaired social functioning in men and women with schizophrenia.

Deficits in Early Stages of Face Processing in Schizophrenia: A Systematic Review of the P100 Component

INTRODUCTION

Schizophrenia is associated with deficits in face and affect recognition, which contribute to broader social functioning deficits. The present aim was to conduct a meta-analysis of early face processing in schizophrenia, as indexed by the P100 event-related potential component.

METHODS

Twelve studies (n = 328 patients with schizophrenia, n = 330 healthy controls) of the P100 component during face processing were evaluated by calculating Cohen's d for each study and overall weighted mean effect size (ES). In additional exploratory analyses, moderating influences of method and design were investigated, and the P100 component during face processing was evaluated based on valence: 5 studies (n = 225 patients, n = 225 controls) included neutral stimuli, 5 studies (n = 225 patients, n = 225 controls) included happy stimuli, and 4 studies (n = 209 patients, n = 209 controls) included fearful stimuli.

RESULTS

The amplitude of the P100 to face stimuli was smaller in patients relative to controls (ES = .41, P < .01). Methodological or design differences did not account for heterogeneity in ES. When split by valence, results indicate smaller P100 in patients relative to control subjects in response to neutral (ES = .32, P < .001) and happy (ES = .21, P < .05) stimuli, whereas there was no difference in response to fearful faces (ES = .09, P > .05).

DISCUSSION

The results indicate that P100 amplitude in response to faces is smaller in patients with schizophrenia, showing that socially relevant visual processing deficits begin earlier in processing than previously suggested. Additionally, the exploratory analyses suggest emotional specificity in these deficits. Ramifications for our understanding of face processing deficits and treatment development are discussed.

Precentral and inferior prefrontal hypoactivation during facial emotion recognition in patients with schizophrenia: A functional near-infrared spectroscopy study

Although patients with schizophrenia demonstrate abnormal processing of emotional face recognition, the neural substrates underlying this process remain unclear. We previously showed abnormal fronto-temporal function during facial expression of emotions, and cognitive inhibition in patients with schizophrenia using functional near-infrared spectroscopy (fNIRS). The aim of the current study was to use fNIRS to identify which brain regions involved in recognizing emotional faces are impaired in patients with schizophrenia, and to determine the neural substrates underlying the response to emotional facial expressions per se, and to facial expressions with cognitive inhibition. We recruited 19 patients with schizophrenia and 19 healthy controls, statistically matched on age, sex, and premorbid IQ. Brain function was measured by fNIRS during emotional face assessment and face identification tasks. Patients with schizophrenia showed lower activation of the right precentral and inferior frontal areas during the emotional face task compared to controls. Further, patients with schizophrenia were slower and less accurate in completing tasks compared to healthy participants. Decreasing performance was associated with increasing severity of the disease. Our present and prior studies suggest that the impaired behavioral performance in schizophrenia is associated with different mechanisms for processing emotional facial expressions versus facial expressions combined with cognitive inhibition.

F-18 fluorodeoxyglucose positron emission tomography study of impaired emotion processing in first episode schizophrenia

BACKGROUND

Schizophrenia cases have been consistently shown to have behavioural and neurofunctional abnormalities but studies during early course are scarce. The present work assesses the performance of acute first episode schizophrenia cases on correlation of a facial emotion perception task with brain function using fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET).

METHODS

Twenty First episode schizophrenia cases and 20 matched healthy controls living in the community were enrolled. For cases, longest duration of illness was one year and treatment with neuroleptic did not exceed two weeks on the day of scan. To measure facial emotion perception (FEP) both groups were administered the Emotion battery from the Penn Computerized Battery followed by PET acquisition. SPM 8 analysis for group differences at p<0.001 was performed.

RESULTS

Schizophrenia subjects showed hypoactivation of bilateral prefrontal cortices and fusiform gyrii, with significant hyperactivation of bilateral basal ganglia and left precuneus. Positive correlation of metabolism in prefrontal cortex and performance indices on emotions domain was seen. No correlation of chlorpromazine equivalent days with metabolism in basal ganglia was observed.

CONCLUSIONS

The performance of schizophrenia cases on FEP task was significantly impaired in comparison to the control group. Brain regions implicated in emotion processing showed hypometabolism in cases as compared to controls. Failure of schizophrenia cases to optimally recruit brain circuitry may be contributing to deficits on FEP task. These findings suggest inherent deficits in neural circuitry of emotion processing in schizophrenia; devoid of confounding effects of neuroleptics and duration of illness.

Abnormal cortico-limbic connectivity during emotional processing correlates with symptom severity in schizophrenia

BACKGROUND

Impaired emotional processing is a core feature of schizophrenia (SZ). Consistent findings suggested that abnormal emotional processing in SZ could be paralleled by a disrupted functional and structural integrity within the fronto-limbic circuitry. The effective connectivity of emotional circuitry in SZ has never been explored in terms of causal relationship between brain regions. We used functional magnetic resonance imaging and Dynamic Causal Modeling (DCM) to characterize effective connectivity during implicit processing of affective stimuli in SZ.

METHODS

We performed DCM to model connectivity between amygdala (Amy), dorsolateral prefrontal cortex (DLPFC), ventral prefrontal cortex (VPFC), fusiform gyrus (FG) and visual cortex (VC) in 25 patients with SZ and 29 HC. Bayesian Model Selection and average were performed to determine the optimal structural model and its parameters.

RESULTS

Analyses revealed that patients with SZ are characterized by a significant reduced top-down endogenous connectivity from DLPFC to Amy, an increased connectivity from Amy to VPFC and a decreased driving input to Amy of affective stimuli compared to HC. Furthermore, DLPFC to Amy connection in patients significantly influenced the severity of psychopathology as rated on Positive and Negative Syndrome Scale.

CONCLUSIONS

Results suggest a functional disconnection in brain network that contributes to the symptomatic outcome of the disorder. Our findings support the study of effective connectivity within cortico-limbic structures as a marker of severity and treatment efficacy in SZ.

Prefrontal activity measured by functional near infrared spectroscopy during probabilistic inference in subjects with persecutory delusions

Jumping to conclusions (JTC) is a probabilistic reasoning bias and is thought to contribute to delusion formation. Neurobiological correlates of the JTC bias are not known. We aimed to examine the rostral prefrontal cortex (rPFC) activity with functional near ınfrared spectroscopy during a modified version of the Beads in a Jar Task (BIJT) in subjects with persecutory delusions (N=25). In BIJT participants are presented beads either drawn from one of the two jars with opposite probability ratios (PRs) of colored beads and are required to decide from which jar beads are being drawn. We administered the BIJT with 90/10 and 55/45 PRs. Compared to healthy controls (N=20), patients reached a decision earlier in both conditions. While the medial rPFC regions were more active in the 90/10 condition in controls compared to patients, lateral rPFC activation was higher in the 55/45 condition in patients than controls. Only in the control group, there was a marked decline in the lateral rPFC activation in the 55/45 condition compared to the 90/10 condition. The activity in the lateral rPFC was negatively correlated with the amount of beads drawn in healthy controls but not in subjects with persecutory delusions. Our results suggest that during the BIJT, rPFC does not function as a single unit and rather consists of functional subunits that are organized differently in patients and controls. The failure to deactivate the lateral rPFC may be associated with earlier decisions in subjects with persecutory delusions.

Neural basis of anhedonia as a failure to predict pleasantness in schizophrenia

OBJECTIVES

Anhedonia in schizophrenia results from a deficit in anticipatory pleasure rather than consummatory pleasure. This study aimed to determine the neural basis of the predictive and experiential components of anticipatory pleasure in schizophrenia.

METHODS

A hedonic rating task was performed by 15 patients with schizophrenia and 17 controls while undergoing functional magnetic resonance imaging. Participants evaluated the level of pleasantness for the preview/predictive phase, comprising a narration and adjunctive audiovisual stimuli for pleasurable experience, and the subsequent viewing/experiential phase, comprising a video clip for a pleasant event.

RESULTS

A significant group-by-phase interaction was seen in the rostral anterior cingulate cortex (ACC) and caudate, resulting from reduced activations in patients during the preview phase. Patients showed significantly reduced activation in the frontopolar cortex and rostral ACC during the preview phase. The signal changes in the caudate and frontopolar cortex were associated with increase in hedonic response during the sequential pleasure experiences.

CONCLUSIONS

Augmentation of hedonic enjoyment between the predictive and experiential stages of anticipatory pleasure is reduced in schizophrenia because of diminished activity in the reward-related regions during the prediction of pleasure. During cued-emotional experiences of anticipatory pleasure, patients seem to have difficulties in the integration of emotional information.

The impact of social content and negative symptoms on affective ratings in schizophrenia

The anhedonia paradox has been a topic of ongoing study in schizophrenia. Previous research has found that schizophrenia patients report less enjoyment from various activities when compared to their healthy counterparts; however, the two groups appear to have similar in-the-moment emotional ratings of these events (Gard et al., 2007; Herbener et al., 2007; Horan et al., 2006). This study examined these in-the-moment experiences further, by assessing whether they differed between social and non-social experiences. The data were collected from 38 individuals with schizophrenia and 53 matched healthy controls in the greater Chicago area. In-the-moment emotional experience was measured by self-reported arousal and valence ratings for social and non-social stimuli taken from the International Affective Picture System (IAPS). Clinical ratings for patients were gathered by the Positive and Negative Syndrome Scale. A series of ANOVAs revealed that controls were more aroused by the social than nonsocial unpleasant stimuli, whereas patients did not show this distinction. Further, regression analyses revealed that negative symptom severity uniquely predicted lower arousal responses to unpleasant social, but not nonsocial, stimuli. Our results indicate that both subject and stimulus factors appear to contribute to differences in emotional responses in individuals with schizophrenia.

Altered medial prefrontal activity during dynamic face processing in schizophrenia spectrum patients

BACKGROUND

Processing the emotional content of faces is recognised as a key deficit of schizophrenia, associated with poorer functional outcomes and possibly contributing to the severity of clinical symptoms such as paranoia. At the neural level, fMRI studies have reported altered limbic activity in response to facial stimuli. However, previous studies may be limited by the use of cognitively demanding tasks and static facial stimuli. To address these issues, the current study used a face processing task involving both passive face viewing and dynamic social stimuli. Such a task may (1) lack the potentially confounding effects of high cognitive demands and (2) show higher ecological validity.

METHODS

Functional MRI was used to examine neural activity in 25 patients with a DSM-IV diagnosis of schizophrenia/schizoaffective disorder and 21 age- and gender-matched healthy controls while they participated in a face processing task, which involved viewing videos of angry and neutral facial expressions, and a non-biological baseline condition.

RESULTS

While viewing faces, patients showed significantly weaker deactivation of the medial prefrontal cortex, including the anterior cingulate, and decreased activation in the left cerebellum, compared to controls. Patients also showed weaker medial prefrontal deactivation while viewing the angry faces relative to baseline.

DISCUSSION

Given that the anterior cingulate plays a role in processing negative emotion, weaker deactivation of this region in patients while viewing faces may contribute to an increased perception of social threat. Future studies examining the neurobiology of social cognition in schizophrenia using fMRI may help establish targets for treatment interventions.

Limbic activity in antipsychotic naïve first-episode psychotic subjects during facial emotion discrimination

The aim of this study was to determine brain activation during facial emotion discrimination in first-episode of psychosis. Eighteen patients underwent an fMRI while performing a facial emotion discrimination task during the acute episode, before starting antipsychotic drugs. A second fMRI and clinical evaluation were performed after evident clinical improvement. An equivalent control group underwent the same two fMRIs with a similar period of time between exams. The voxel-wise approach showed pre-treatment hypoactivation in ventro-limbic regions (cluster including right hippocampus and left amygdala; cluster size 528; p cluster <0.004) and facial perception involved in ventral-posterior regions (bilateral lingual gyrus, calcarine fissure and occipital superior gyrus, (k = 1,508, p < 0.001) and fronto-temporal regions. The region of interest approach also confirmed hypoactivation in right and left amygdala (cluster corrected p = 0.035 and 0.043, respectively). After treatment and clinical improvement, the voxel-wise approach showed a significant increase in activity in lingual gyrus and calcarine fissure in the group of patients. The regions of interest analysis showed an increase in amygdala activity during anger discrimination also in the group of patients. The results suggest a state-dependent model depicting a flattened and aberrant response of amygdala to emotion discrimination that could explain the seemingly contradictory previous findings of hypo- and hyper-amygdala activation.

Evidence for altered amygdala activation in schizophrenia in an adaptive emotion recognition task

Deficits in social cognition seem to present an intermediate phenotype for schizophrenia, and are known to be associated with an altered amygdala response to faces. However, current results are heterogeneous with respect to whether this altered amygdala response in schizophrenia is hypoactive or hyperactive in nature. The present study used functional magnetic resonance imaging to investigate emotion-specific amygdala activation in schizophrenia using a novel adaptive emotion recognition paradigm. Participants comprised 11 schizophrenia outpatients and 16 healthy controls who viewed face stimuli expressing emotions of anger, fear, happiness, and disgust, as well as neutral expressions. The adaptive emotion recognition approach allows the assessment of group differences in both emotion recognition performance and associated neuronal activity while also ensuring a comparable number of correctly recognized emotions between groups. Schizophrenia participants were slower and had a negative bias in emotion recognition. In addition, they showed reduced differential activation during recognition of emotional compared with neutral expressions. Correlation analyses revealed an association of a negative bias with amygdala activation for neutral facial expressions that was specific to the patient group. We replicated previous findings of affected emotion recognition in schizophrenia. Furthermore, we demonstrated that altered amygdala activation in the patient group was associated with the occurrence of a negative bias. These results provide further evidence for impaired social cognition in schizophrenia and point to a central role of the amygdala in negative misperceptions of facial stimuli in schizophrenia.

Individuals diagnosed with schizophrenia assign emotional importance to neutral stimuli: an FMRI study

The majority of functional neuroimaging studies investigating neural correlates of emotion processing in schizophrenia report a significant deficit in limbic structures activation in patients relative to control participants. Recently it has been suggested that this apparent "deficit" could be due to an enhanced sensitivity of the neutral material in individuals diagnosed with schizophrenia, rather than due to their inefficiency in emotion processing. The purpose of the present study was to test this supposition and verify if the potential effect is present in both men and women diagnosed with schizophrenia. In order to do that we examined the pattern of cerebral activation associated with processing of neutral stimuli in schizophrenia. Thirty-seven schizophrenia patients and 37 healthy controls viewed neutral and emotional images while in a functional magnetic resonance imaging scanner. Schizophrenia patients rated the neutral images as more emotionally salient than controls. Additionally, patients showed significant activation during processing of neutral images in limbic and prefrontal regions; similar areas were underactivated in patients relative to controls during processing of emotional information. Investigation of sex differences revealed that the enhanced responsiveness to the emotionally neutral material was attributed primarily to men with schizophrenia.

Altered amygdala activation in schizophrenia patients during emotion processing

Dysfunctional emotion processing in patients suffering from schizophrenia is a prominent clinical feature of great importance for social functioning and subjective well-being. The neurobiological underpinnings are still poorly understood. Here we investigated a large sample of schizophrenia patients and matched healthy controls with an event-related fMRI task during emotion processing using emotional pictures from the International Affective Picture System (IAPS). Schizophrenia patients revealed stronger right amygdala activation during negative and attenuated response during positive affective picture processing compared to healthy controls. Further analysis indicated that medication status influences activation of the ventral anterior cingulate cortex during negative affective stimuli processing. These results might represent a correlate of altered emotional experience in schizophrenia patients who are known to report less positive and more negative affective states in daily life situations.

Functional similarity of facial emotion processing between people with a first episode of psychosis and healthy subjects

BACKGROUND

Neurofunctional and behavioral abnormalities in facial emotion processing (FEmoP) have been consistently found in schizophrenia patients, but studies assessing brain functioning in early phases are scarce and the variety of experimental paradigms in current literature make comparisons difficult. The present work focuses on assessing FEmoP in people experiencing a psychotic episode for the first time with different experimental paradigm approaches.

METHODS

Twenty-two patients with a first psychotic episode (FPe) (13 males) took part in a functional magnetic resonance imaging study (1.5T) examining neural responses to explicit and implicit processing of fearful and happy facial expressions presented at two different intensities: 50% and 100%. Their brain activation was compared to that of 31 healthy subjects (15 males).

RESULTS

Control subjects show differential patterns of brain activation regarding the task demands (implicit or explicit processing), the emotional content (happy or fear) and the intensities of the emotion (50% or 100%); such differences are not found in participants with a first psychotic episode (FPe). No interaction or group effects are seen between control and FPe participants with any of the emotional tasks assessed, although FPe subjects show worse behavioral performance.

CONCLUSIONS

No brain areas recruited for FEmoP emerge as significantly different between people with a FPe and healthy subjects, independently on the demands of the task, the emotion processed, or the intensity of the emotion; but FPe participants show a limited recruitment of differential brain regions that could be associated with poor emotional processing in the short term. Our results outline the need of investigating the underlying processes that lead FPe participants to worse FEmoP performance.

Social perception in schizophrenia: evidence of temporo-occipital and prefrontal dysfunction

Individuals with schizophrenia evidence deficits in social functioning such as difficulties in communication, maintaining employment, and functioning as a member of the community. Impairment in such functions has been linked with higher order social cognitive deficits, which, in turn, have been associated with abnormal brain function. However, it is unclear whether brain abnormalities are found specifically for higher order social cognitive functioning, or whether "lower order" social processing, such as perceiving social stimuli, might demonstrate abnormalities at the neural level. The current study used functional magnetic resonance imaging to explore the neural correlates of social perception in schizophrenia. Individuals with schizophrenia (n=14) and healthy comparison participants (n=14) viewed social (i.e., faces, people) and nonsocial (i.e., scenes, objects) images that varied in affective content (emotional, neutral). Schizophrenia patients showed decreased brain activation, compared to controls, in occipital and temporal regions associated with early visual processing, as well as increased cingulate activity, in response to emotional social relative to nonsocial images. Results indicate aberrant neural response during early stages of visual processing of social information, which may contribute to higher order social cognitive deficits characteristic of this population.

Evidence of diagnostic specificity in the neural correlates of facial affect processing in bipolar disorder and schizophrenia: a meta-analysis of functional imaging studies

BACKGROUND

Schizophrenia (SZ) and bipolar disorder (BD) may overlap in etiology and phenomenology but differ with regard to emotional processing. We used facial affect as a probe for emotional processing to determine whether there are diagnosis-related differences between SZ and BD in the function of the underlying neural circuitry.

METHOD

Functional magnetic resonance imaging (fMRI) studies published up to 30 April 2012 investigating facial affect processing in patients with SZ or BD were identified through computerized and manual literature searches. Activation foci from 29 studies encompassing 483 healthy individuals, 268 patients with SZ and 267 patients with BD were subjected to voxel-based quantitative meta-analysis using activation likelihood estimation (ALE).

RESULTS

Compared to healthy individuals, when emotional facial stimuli were contrasted to neutral stimuli, patients with BD showed overactivation within the parahippocampus/amygdala and thalamus and reduced engagement within the ventrolateral prefrontal cortex (PFC) whereas patients with SZ showed underactivation throughout the entire facial affect processing network and increased activation in visual processing regions within the cuneus. Patients with BD showed greater thalamic engagement compared to patients with SZ; in the reverse comparison, patients with SZ showed greater engagement in posterior associative visual cortices.

CONCLUSIONS

During facial affect processing, patients with BD show overactivation in subcortical regions and underactivation in prefrontal regions of the facial affect processing network, consistent with the notion of reduced emotional regulation. By contrast, overactivation within visual processing regions coupled with reduced engagement of facial affect processing regions points to abnormal visual integration as the core underlying deficit in SZ.

Indeterminacy of translation and impaired intersubjectivity in schizophrenia

Impaired intersubjectivity in schizophrenia has been subject to debate in clinical psychiatry and psychotherapy. In this paper, we will discuss recent perspectives on disordered intersubjectivity among the core symptoms of schizophrenic psychoses. Based on symptoms crucial for communication deficits in schizophrenia, we address indeterminacy of translation as a potential default in the therapeutic setting. The concept of indeterminacy of translation reviewed here assumes that no reference for translation of languages is given, but principles to substitute this non-referring space of unknown terms are to be demonstrated: firstly, a maxim of indulgence which requires that as many true considerations as possible have to be achieved by the final interpretation of a proposition, and secondly, a coherence which is given when the considerations are deductable and not contradictory. Indulgence and coherence are hypothesized as reflecting an approximation process of reconstructing intersubjectivity in conditions where it is severely disturbed such as schizophrenia.

Emotion effects on attention, amygdala activation, and functional connectivity in schizophrenia

Emotional abnormalities are a critical clinical feature of schizophrenia (SCZ), but complete understanding of their underlying neuropathology is lacking. Numerous studies have examined amygdala activation in response to affective stimuli in SCZ, but no consensus has emerged. However, behavioral studies examining 'in-the-moment' processing of affect have suggested intact emotional processing in SCZ. To examine which aspects of emotional processing may be impaired in SCZ, we combined behavior and neuroimaging to investigate effects of aversive stimuli during minimal cognitive engagement, at the level of behavior, amygdala recruitment, and its whole-brain task-based functional connectivity (tb-fcMRI) because impairments may manifest when examining across-region functional integration. Twenty-eight patients and 24 matched controls underwent rapid event-related fMRI at 3 T while performing a simple perceptual decision task with negative or neutral distraction. We examined perceptual decision slowing, amygdala activation, and whole-brain amygdala tb-fcMRI, while ensuring group signal-to-noise profile matching. Following scanning, subjects rated all images for experienced arousal and valence. No significant group differences emerged for negative vs neutral reaction time, emotional ratings across groups, or amygdala activation. However, even in the absence of behavioral or activation differences, SCZ subjects demonstrated significantly weaker amygdala-prefrontal cortical coupling, specifically during negative distraction. Whereas in-the-moment perception, behavioral response, and amygdala recruitment to negative stimuli during minimal cognitive load seem to be intact, there is evidence of aberrant amygdala-prefrontal integration in SCZ subjects. Such abnormalities may prove critical for understanding disturbances in patients' ability to use affective cues when guiding higher level cognitive processes needed in social interactions.

Comparison of brain and blood gene expression in an animal model of negative symptoms in schizophrenia

OBJECTIVES

To investigate the potential of white blood cells as probes for central processes we have measured gene expression in both the anterior cingulate cortex and white blood cells using a putative animal model of negative symptoms in schizophrenia.

METHODS

The model is based on the capability of ketamine to induce psychotic symptoms in healthy volunteers and to worsen such symptoms in schizophrenic patients. Classical fear conditioning is used to assess emotional processing and cognitive function in animals exposed to sub-chronic ketamine vs. controls. Gene expression was measured using a commercially sourced whole genome rat gene array. Data analyses were performed using ANOVA (Systat 11).

RESULTS

In both anterior cingulate cortex and white blood cells a significant interaction between ketamine and fear conditioning could be observed. The outcome is largely supported by our subsequent metagene analysis. Moreover, the correlation between gene expression in brain and blood is about constant when no ketamine is present (r~0.4). With ketamine, however, the correlation becomes very low (r~0.2) when there is no fear, but it increases to ~0.6 when fear and ketamine are both present. Our results show that under normal conditions ketamine lowers gene expression in the brain, but this effect is completely reversed in combination with fear conditioning, indicating a stimulatory action.

CONCLUSION

This paradoxical outcome indicates that extreme care must be taken when using gene expression data from white blood cells as marker for psychiatric disorders, especially when pharmacological and environmental interactions are at play.

Hippocampus and nucleus accumbens activity during neutral word recognition related to trait physical anhedonia in patients with schizophrenia: an fMRI study

Emotional memory dysfunction may be associated with anhedonia in schizophrenia. This study aimed to investigate the neurobiological basis of emotional memory and its relationship with anhedonia in schizophrenia specifically in emotional memory relate brain regions of interest (ROIs) including the amygdala, hippocampus, nucleus accumbens, and ventromedial prefrontal cortex. Fourteen patients with schizophrenia and 16 healthy subjects performed a word-image associative encoding task, during which a neutral word was presented with a positive, neutral, or control image. Subjects underwent functional magnetic resonance imaging while performing the recognition task. Correlation analyses were performed between the percent signal change (PSC) in the ROIs and the anhedonia scores. We found no group differences in recognition accuracy and reaction time. The PSC of the hippocampus in the positive and neutral conditions, and the PSC in the nucleus accumbens in the control condition, appeared to be negatively correlated with the Physical Anhedonia Scale (PAS) scores in patients with schizophrenia, while significant correlations with the PAS scores were not observed in healthy subjects. This study provides further evidences of the role of the hippocampus and nucleus accumbens in trait physical anhedonia and possible associations between emotional memory deficit and trait physical anhedonia in patients with schizophrenia.

No amygdala attenuation in schizophrenic patients treated with atypical antipsychotics

Functional magnetic resonance (fMRI) imaging was used to measure amygdala activation in an emotional valence discrimination task in clinically stable patients with schizophrenia treated with atypical antipsychotics and healthy controls. No difference was detected between patients with schizophrenia and controls.

Amygdala recruitment in schizophrenia in response to aversive emotional material: a meta-analysis of neuroimaging studies

Emotional dysfunction has long been established as a critical clinical feature of schizophrenia. In the past decade, there has been extensive work examining the potential contribution of abnormal amygdala activation to this dysfunction in patients with schizophrenia. A number of studies have demonstrated under-recruitment of the amygdala in response to emotional stimuli, while others have shown intact recruitment of this region. To date, there have been few attempts to synthesize this literature using quantitative criteria or to use a formal meta-analytic approach to examine which variables may moderate the magnitude of between-group differences in amygdala activation in response to aversive emotional stimuli. We conducted a meta-analysis of amygdala activation in patients with schizophrenia, using a bootstrapping approach to investigate: (a) evidence for amygdala under-recruitment in schizophrenia and (b) variables that may moderate the magnitude of between-group differences in amygdala activation. We demonstrate that patients with schizophrenia show statistically significant, but modest, under-recruitment of bilateral amygdala (mean effect size = -0.20 SD). However, present findings indicate that this under-recruitment is dependent on the use of a neutral vs emotion interaction contrast and is not apparent if amygdala activation by patients and controls is evaluated in a negative emotional condition only.

Facial emotion processing in patients with schizophrenia and their non-psychotic siblings: a functional magnetic resonance imaging study

BACKGROUND

Previous studies have shown that patients with schizophrenia show abnormalities in brain activation when processing emotional faces. However, very few studies have examined if such abnormalities are also found in non-western patient samples and in at-risk individuals. The current study explored whether patients with schizophrenia and siblings of patients in China would show abnormal brain activation during processing of emotional faces.

METHODS

Thirty-six participants (three groups of twelve each of patients with schizophrenia, nonpsychotic siblings, and healthy controls) took part in the study. They were administered a task to judge emotional valence of three types of faces (viz., happy, fearful, and neutral), during fMRI scanning.

RESULTS

Results of this study demonstrated that patients with schizophrenia showed abnormalities in the social brain neural circuit during facial emotion processing, in comparison with nonpsychotic siblings and healthy controls. Patients with schizophrenia demonstrated lower activation right superior and middle frontal gyrus, left precentral gyrus, left middle temporal gyrus and left insula in comparison with healthy controls; and showed abnormal activation in bilateral inferior and middle frontal gyri, right orbital frontal gyrus, left superior and middle temporal gyrus, bilateral insula, and right superior parietal gyrus/postcentral gyrus when compared with their nonpyschotic siblings. Meanwhile, patients with schizophrenia showed greater activation in left middle frontal gyrus than healthy controls, and overactivation in bilateral middle frontal gyri, right orbital frontal gyrus and left middle temporal gyrus than their nonpsychotic siblings during processing of fearful faces. Moreover, nonpsychotic siblings seemed to share some similar dysfunctions in processing facial expressions as their psychotic probands, the two groups both showed abnormal activation in precentral and superior frontal gyri, and such abnormal activation lied between patients with schizophrenia and healthy controls.

CONCLUSIONS

The current findings support the universality of emotion perception impairments in schizophrenia, and also suggest that facial emotion perception might be a potential endophenotype of schizophrenia.

Meta-analysis of functional neuroimaging studies of emotion perception and experience in schizophrenia

BACKGROUND

Neuroimaging studies of emotion in schizophrenia have reported abnormalities in amygdala and other regions, although divergent results and heterogeneous paradigms complicate conclusions from single experiments. To identify more consistent patterns of dysfunction, a meta-analysis of functional imaging studies of emotion was undertaken.

METHODS

Searching Medline and PsycINFO databases through January 2011, 88 potential articles were identified, of which 26 met inclusion criteria, comprising 450 patients with schizophrenia and 422 healthy comparison subjects. Contrasts were selected to include emotion perception and emotion experience. Foci from individual studies were subjected to a voxelwise meta-analysis using multilevel kernel density analysis.

RESULTS

For emotional experience, comparison subjects showed greater activation in the left occipital pole. For emotional perception, schizophrenia subjects showed reduced activation in bilateral amygdala, visual processing areas, anterior cingulate cortex, dorsolateral frontal cortex, medial frontal cortex, and subcortical structures. Schizophrenia subjects showed greater activation in the cuneus, parietal lobule, precentral gyrus, and superior temporal gyrus. Combining across studies and eliminating studies that did not balance on effort and stimulus complexity eliminated most differences in visual processing regions as well as most areas where schizophrenia subjects showed a greater signal. Reduced reactivity of the amygdala appeared primarily in implicit studies of emotion, whereas deficits in anterior cingulate cortex activity appeared throughout all contrasts.

CONCLUSIONS

Processing emotional stimuli, schizophrenia patients show reduced activation in areas engaged by emotional stimuli, although in some conditions, schizophrenia patients exhibit increased activation in areas outside those traditionally associated with emotion, possibly representing compensatory processing.

Social appraisal in chronic psychosis: role of medial frontal and occipital networks

Persons with schizophrenia often appraise other individuals as threatening or persecutory. To evaluate social appraisal in schizophrenia, we probed brain networks with a task in which subjects judged whether or not they liked face stimuli with emotional expressions. We predicted that appraising negative expressions would engage patients, more than controls, and negative faces would be related to higher levels of negative affect and produce increased activity in the medial frontal cortex, an area involved in social appraisal. Twenty-one stable outpatients with chronic non-affective psychosis (16 schizophrenic, 5 schizoaffective) and 21 healthy subjects underwent functional magnetic resonance imaging. Compared with the control subjects, patients were slower to respond, but particularly slow when they judged negatively-valenced faces, a slowness correlated with negative affect in the psychosis patients. Appraisal activated the medial prefrontal cortex (mPFC) across all face valences. For negative expressions, patients exhibited greater activation of the dorsal anterior cingulate cortex (dACC). A psychophysiological interaction analysis of the dACC revealed co-modulation of the mPFC in controls, significantly less in patients, and a trend for co-modulation of occipital cortex in the patients. Activity in occipital cortex correlated with poor social adjustment and impaired social cognition, and co-modulation of the occipital gyrus by the dACC was correlated with poorer social cognition. The findings link appraisal of negative affect with aberrant activation of the medial frontal cortex, while early sensory processing of this social cognitive task was linked with poor social function, reflecting either top-down or bottom-up influences.

Selective emotional processing deficits to social vignettes in schizophrenia: an ERP study

Schizophrenia is associated with abnormalities in emotional processing and social cognition. However, it remains unclear whether patients show abnormal neurophysiological responses during fast, online appraisals of the emotional meaning of social information. To examine this question, event-related potentials (ERPs) were collected while 18 schizophrenia patients and 18 demographically matched controls evaluated 2-sentence vignettes describing negative, positive, or neutral social situations. ERPs were time locked to a critical word (CW) in the second sentence that conferred emotional valence. A late positivity effect to emotional (vs neutral) CWs was seen in both groups (in controls, to negative and positive CWs; in patients, to negative CWs only). However, the controls showed a greater late positivity effect to the negative and positive (vs neutral) CWs than the schizophrenia patients at mid-posterior (negative vs neutral) and at right posterior peripheral (positive vs neutral) sites. These between-group differences arose from reduced amplitudes of the late positivity to the negative and positive CWs in the patients relative to the controls; there was no difference between the 2 groups in the amplitude of the late positivity to the neutral CWs. These findings suggest that schizophrenia is associated with a specific neural deficit during the online evaluation of emotionally valent, socially relevant information.

Abnormal structure or function of the amygdala is a common component of neurodevelopmental disorders

The amygdala, perhaps more than any other brain region, has been implicated in numerous neuropsychiatric and neurodevelopmental disorders. It is part of a system initially evolved to detect dangers in the environment and modulate subsequent responses, which can profoundly influence human behavior. If its threshold is set too low, normally benign aspects of the environment are perceived as dangers, interactions are limited, and anxiety may arise. If set too high, risk taking increases and inappropriate sociality may occur. Given that many neurodevelopmental disorders involve too little or too much anxiety or too little of too much social interaction, it is not surprising that the amygdala has been implicated in many of them. In this chapter, we begin by providing a brief overview of the phylogeny, ontogeny, and function of the amygdala and then appraise data from neurodevelopmental disorders which suggest amygdala dysregulation. We focus on neurodevelopmental disorders where there is evidence of amygdala dysregulation from postmortem studies, structural MRI analyses or functional MRI. However, the results are often disparate and it is not totally clear whether this is due to inherent heterogeneity or differences in methodology. Nonetheless, the amygdala is a common site for neuropathology in neurodevelopmental disorders and is therefore a potential target for therapeutics to alleviate associated symptoms.

Neuronal correlates of affective theory of mind in schizophrenia out-patients: evidence for a baseline deficit

BACKGROUND

Schizophrenia out-patients have deficits in affective theory of mind (ToM) but also on more basal levels of social cognition, such as the processing of neutral and emotional expressions. These deficits are associated with changes in brain activation in the amygdala and the superior temporal sulcus (STS). However, until now there have been no studies that examined these different levels of social cognition and their neurobiological underpinnings in patients within one design.

METHOD

Sixteen medicated schizophrenia out-patients and 16 matched healthy controls were studied with functional magnetic resonance imaging (fMRI) during a social cognition task that allows the investigation of affective ToM (aToM), emotion recognition and the processing of neutral facial expressions.

RESULTS

Patients showed a deficit in emotion recognition and a more prominent deficit in aToM. The performance in aToM and in emotion recognition was correlated in the control group but not in the schizophrenia group. Region-of-interest analysis of functional brain imaging data revealed no difference between groups during aToM, but a hyperactivation in the schizophrenia group in the left amygdala and right STS during emotion recognition and the processing of neutral facial expressions.

CONCLUSIONS

The results indicate that schizophrenia out-patients have deficits at several levels of social cognition and provide the first evidence that deficits on higher-order social cognitive processes in schizophrenia may be traced back to an aberrant processing of faces per se.

Facial emotion processing in schizophrenia: a meta-analysis of functional neuroimaging data

BACKGROUND

People with schizophrenia have difficulty with emotion perception. Functional imaging studies indicate regional brain activation abnormalities in patients with schizophrenia when processing facial emotion. However, findings have not been entirely consistent across different studies.

METHODS

Activation likelihood estimation (ALE) meta-analyses were conducted to examine brain activation during facial emotion processing in patients with schizophrenia, controls, and patients compared with controls. Secondary meta-analyses were performed to assess the contribution of task design and illness chronicity to the results reported.

RESULTS

When processing facial expressions of emotions, both patients with schizophrenia and healthy controls activated the bilateral amygdala and right fusiform gyri. However, the extent of activation in these regions was generally much more limited in the schizophrenia samples. When directly compared with controls, the extent of activation in bilateral amygdala, parahippocampal gyrus and fusiform gyrus, right superior frontal gyrus, and lentiform nucleus was significantly less in patients. Patients with schizophrenia, but not controls, activated the left insula. A relative failure to recruit the amygdala in patients occurred regardless of whether the task design was explicit or implicit, while differences in fusiform activation were evident in explicit, not implicit, tasks. Restricting the analysis to patients with chronic illness did not substantially change the results.

CONCLUSIONS

A marked underrecruitment of the amygdala, accompanied by a substantial limitation in activation throughout a ventral temporal-basal ganglia-prefrontal cortex "social brain" system may be central to the difficulties patients experience when processing facial emotion.

Neural correlates of emotion recognition in schizophrenia

The following fMRI study aimed to characterize the neural correlates of explicit emotion discrimination in 17 patients with schizophrenia and 17 matched healthy controls. In patients, emotion recognition impairments were found to be paralleled by cerebral dysfunctions in the affective division of the anterior cingulate cortex, the bilateral dorsomedial prefrontal cortex, the right superior temporal gyrus and the right fusiform gyrus. While the patients' responses to emotional faces were characterized predominantly by hypoactivations, the neutral faces elicited hyperactivations mainly in the frontal and cingulate areas, and the basal ganglia, along with misattribution errors. The decreased activation in the fusiform face area during responses to both emotional and neutral stimuli may be indicative of general face processing deficits. Similar although less pronounced deficits have been observed in subjects at high risk of psychosis as well as in patients with early onset. In adult schizophrenia, the evidence of an imbalanced cerebral network appears early in the course of the illness, with the dysfunctions, as indicated by correlations here, becoming more pronounced in patients with longer illness duration.

Impaired facial emotion perception in schizophrenia: a meta-analysis

Research into facial emotion perception in schizophrenia has burgeoned over the past several decades. The evidence is mixed regarding whether patients with schizophrenia have a general facial emotion perception deficit (a deficit in facial emotion perception plus a more basic deficit in facial processing) or specific facial emotion perception deficits (deficits only in facial emotion perception tasks). A meta-analysis is conducted of 28 facial emotion perception studies that include control tasks. These studies use differential deficit designs to examine whether patients with schizophrenia demonstrate a general deficit or specific deficit in facial emotion perception. A significant mean effect size is found for total facial emotion perception (d=-0.85). Patients with schizophrenia demonstrate impaired ability to perform corresponding control tasks, and the mean effect size is -0.70. The current findings suggest that patients with schizophrenia have moderately to severely impaired perception of facial emotion.