Increased amygdala activation during automatic processing of facial emotion in schizophrenia

BLA-involved circuits in neuropsychiatric disorders

The basolateral amygdala (BLA) is the subregion of the amygdala located in the medial of the temporal lobe, which is connected with a wide range of brain regions to achieve diverse functions. Recently, an increasing number of studies have focused on the participation of the BLA in many neuropsychiatric disorders from the neural circuit perspective, aided by the rapid development of viral tracing methods and increasingly specific neural modulation technologies. However, how to translate this circuit-level preclinical intervention into clinical treatment using noninvasive or minor invasive manipulations to benefit patients struggling with neuropsychiatric disorders is still an inevitable question to be considered. In this review, we summarized the role of BLA-involved circuits in neuropsychiatric disorders including Alzheimer's disease, perioperative neurocognitive disorders, schizophrenia, anxiety disorders, depressive disorders, posttraumatic stress disorders, autism spectrum disorders, and pain-associative affective states and cognitive dysfunctions. Additionally, we provide insights into future directions and challenges for clinical translation.

Cognitive control enhancement in attention deficit hyperactivity disorder (ADHD) and neurotypical individuals

Cognitive control, which has been localized to the right inferior frontal gyrus (rIFG) based on functional imaging and brain lesion studies, is impaired in patients with ADHD. The present study aims to investigate whether transcranial direct current stimulation (tDCS) over the rIFG might improve cognitive control in ADHD subjects. We hypothesized poorer performance in a cognitive control task, but not in a control language task, in the ADHD subjects. Crucially, following tDCS, we expected the ADHD group to improve their cognitive control. In a double-blind randomized control trial, 42 participants performed the stop signal task (SST) to index their cognitive control level and the language task. Half of them were randomly assigned to the anodal stimulation condition and half to the sham stimulation. The anodal or sham stimulation was applied over the right IFG. Following the stimulation, the participants reset the two tasks to see whether stimulation improved the (predicted) weaker performance in the ADHD group. Stimulation significantly enhanced cognitive control for both groups, with or without ADHD, in the SST task, but no significant stimulation effects were found for the control task. tDCS seems as a promising tool to improve cognitive control in the general population.

Amygdala signal abnormality and cognitive impairment in drug-naïve schizophrenia

BACKGROUND

Recently studies had showed that the amygdala may take part in the cognitive impairment in schizophrenia (SC). However, the mechanism is still unclear, so we explored the relationship between the amygdala resting state magnetic resonance imaging (rsMRI) signal and cognitive function, to provide a reference for the follow-up study.

METHODS

We collected 59 drug-naïve SCs and 46 healthy controls (HCs) from the Third People's Hospital of Foshan. The rsMRI technique and automatic segmentation tool were used to extract the volume and functional indicators of the SC's amygdala. The Positive and Negative Syndrome Scale (PANSS) was used to assess the severity of the disease, and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess cognitive function. Pearson correlation analysis was used to compare the relationship between the structural and functional indicators of the amygdala and PANSS and RBANS.

RESULTS

(1) There was no significant difference between SC and HC in age, gender and years of education. Compared with HC, the PANSS score of SC increased and the RBANS score decreased significantly. Meanwhile, the left amygdala volume decreased (t=-3.675, p < 0.001), and the Fractional amplitude of low-frequency fluctuations (FALFF) values of bilateral amygdala increased (t_L=3.916, p < 0.001; t_R=3.131, p = 0.002). (2) The volumes of the left amygdala were negatively correlated with the PANSS score (r_L=-0.243, p = 0.039). While the FALFF values of the bilateral amygdala were positively correlated with the PANSS score (r_L=0.257, p = 0.026; r_R=0.259, p = 0.026). Bilateral amygdala volumes and FALFF values were positively correlated (r_L=0.445, p < 0.001; r_R=0.326, p = 0.006) and negatively correlated with RBANS score (r_L=-0.284, p = 0.014; r_R=-0.272, p = 0.020), respectively.

CONCLUSION

The abnormal volume and function of the amygdala play important roles in the disease process of SC, and are closely related to cognitive impairment.

Slower access to visual awareness but otherwise intact implicit perception of emotional faces in schizophrenia-spectrum disorders

Schizophrenia-spectrum disorders are characterized by deficits in social domains. Extant research has reported an impaired ability to perceive emotional faces in schizophrenia. Yet, it is unclear if these deficits occur already in the access to visual awareness. To investigate this question, 23 people with schizophrenia or schizoaffective disorder and 22 healthy controls performed a breaking continuous flash suppression task with fearful, happy, and neutral faces. Response times were analysed with generalized linear mixed models. People with schizophrenia-spectrum disorders were slower than controls in detecting faces, but did not show emotion-specific impairments. Moreover, happy faces were detected faster than neutral and fearful faces, across all participants. Although caution is needed when interpreting the main effect of group, our findings may suggest an elevated threshold for visual awareness in schizophrenia-spectrum disorders, but an intact implicit emotion perception. Our study provides a new insight into the mechanisms underlying emotion perception in schizophrenia-spectrum disorders.

Amygdala connectivity during emotional face perception in psychotic disorders

Emotional face perception (EFP) deficits have been identified as a significant feature of psychotic disorders and are associated with symptoms and real-world functioning in these disorders. The amygdala is frequently implicated in EFP and bears extensive structural connectivity with other brain regions supporting EFP. Amygdala functional connectivity during attentional control of implicitly processed emotional faces in psychotic disorders is well examined. However, it is unclear whether amygdala functional connectivity while explicitly processing emotional faces contributes to EFP deficits in psychotic disorders. Further, it is unclear whether these connectivity differences are associated with symptoms or functioning and if these relationships are transdiagnostic across psychotic disorders. We used functional magnetic resonance imaging (fMRI) and seed-based functional connectivity analyses to examine connectivity of amygdala to other regions of the face processing network during an EFP task. The sample consisted of 55 cases with psychotic disorders and 29 participants with no history of psychosis (NP). Results indicated that, compared to NP, cases showed worse accuracy, greater inferior frontal gyrus (IFG) activation, and greater amygdala-insula connectivity while matching emotional and neutral faces. Additionally, worse accuracy, greater IFG activation, greater amygdala-insula and amygdala-IFG connectivity during emotional vs. neutral faces was associated with worse negative symptoms and greater deficits in social and global functioning in cases. Importantly, these relationships transcended diagnostic categories, and applied across psychotic disorders. The present study presents compelling evidence relating alterations in amygdala functional connectivity during explicit EFP with clinical and functioning deficits seen across psychotic disorders.

Altered brain responses to specific negative emotions in schizophrenia

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Scenic stimuli might offer a better understanding of emotional processing than faces.

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Emotional scenes were presented to schizophrenia patients and healthy controls.

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Schizophrenia patients tend to misclassify emotional images as fear.

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Schizophrenia patients hyperactivated regions involved in fear and disgust processing.

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Patients’ brain response did not differ from controls in response to happy and sad scenes.

Deficits in emotion processing are a core feature of schizophrenia, but their neurobiological bases are poorly understood. Previous research, mainly focused on emotional face processing and emotion recognition deficits, has shown controverted results. Furthermore, the use of faces has been questioned for not entailing an appropriate stimulus to study emotional processing. This highlights the importance of investigating emotional processing abnormalities using evocative stimuli. For the first time, we have studied the brain responses to scenic stimuli in patients with schizophrenia. We selected scenes from the IAPS that elicit fear, disgust, happiness, and sadness. Twenty-six patients with schizophrenia and thirty age-, sex- and premorbid IQ-matched healthy controls were included. Behavioral task results show that patients tended to misclassify disgust and sadness as fear. Brain responses in patients were different from controls in images eliciting disgust and fear. In response to disgust images, patients hyperactivated the right temporal cortex, which was not activated by the controls. With fear images, hyperactivation was observed in brain regions involved in fear processing, including midline regions from the medial frontal cortex to the anterior cingulate cortex, the superior frontal gyrus, inferior and superior temporal cortex, and visual areas. These results suggest that schizophrenia is characterized by hyper-responsivity to stimuli evoking high-arousal, negative emotions, and a bias towards fear in emotion recognition.

Limbic Hyperactivity in Response to Emotionally Neutral Stimuli in Schizophrenia: A Neuroimaging Meta-Analysis of the Hypervigilant Mind

OBJECTIVE

It has long been assumed that paranoid ideation may stem from an aberrant limbic response to threatening stimuli. However, results from functional neuroimaging studies using negative emotional stimuli have failed to confirm this assumption. One of the potential reasons for the lack of effect is that study participants with psychosis may display aberrant brain responses to neutral material rather than to threatening stimuli. The authors conducted a functional neuroimaging meta-analysis to test this hypothesis.

METHODS

A literature search was performed with PubMed, Google Scholar, and Embase to identify functional neuroimaging studies examining brain responses to neutral material in patients with psychosis. A total of 23 studies involving schizophrenia patients were retrieved. Using t-maps of peak coordinates to calculate effect sizes, a random-effects model meta-analysis was performed with the anisotropic effect-size version of Seed-based d Mapping software.

RESULTS

In schizophrenia patients relative to healthy control subjects, increased activations were observed in the left and right amygdala and parahippocampus and the left putamen, hippocampus, and insula in response to neutral stimuli.

CONCLUSIONS

Given that several limbic regions were found to be more activated in schizophrenia patients than in control subjects, the results of this meta-analysis strongly suggest that these patients confer aberrant emotional significance to nonthreatening stimuli. In theory, this abnormal brain reactivity may fuel delusional thoughts. Studies are needed in individuals at risk of psychosis to determine whether aberrant limbic reactivity to neutral stimuli is an early neurofunctional marker of psychosis vulnerability.

Oxytocin increases eye gaze in schizophrenia

Abnormal eye gaze is common in schizophrenia and linked to functional impairment. The hypothalamic neuropeptide oxytocin modulates visual attention to social stimuli, but its effects on eye gaze in schizophrenia are unknown. We examined visual scanning of faces in men with schizophrenia and neurotypical controls to quantify oxytocin effects on eye gaze. In a randomized, double-blind, crossover study, 33 men with schizophrenia and 39 matched controls received one dose of intranasal oxytocin (40 IU) and placebo on separate testing days. Participants viewed 20 color photographs of faces while their gaze patterns were recorded. We tested for differences in fixation time on the eyes between patients and controls as well as oxytocin effects using linear mixed-effects models. We also tested whether attachment style, symptom severity, and anti-dopaminergic medication dosage moderated oxytocin effects. In the placebo condition, patients showed reduced fixation time on the eyes compared to controls. Oxytocin was associated with an increase in fixation time among patients, but a decrease among controls. Higher attachment anxiety and greater symptom severity predicted increased fixation time on the eyes on oxytocin versus placebo. Anti-dopaminergic medication dosage and attachment avoidance did not impact response to oxytocin. Consistent with findings that oxytocin optimizes processing of social stimuli, intranasal oxytocin enhanced eye gaze in men with schizophrenia. Further work is needed to determine whether changes in eye gaze impact social cognition and functional outcomes. Both attachment anxiety and symptom severity predicted oxytocin response, highlighting the importance of examining potential moderators of oxytocin effects in future studies.

Different levels of facial expression recognition in patients with first-episode schizophrenia: A functional MRI study

Background

The impairment of facial expression recognition has become a biomarker for early identification of first-episode schizophrenia, and this kind of research is increasing.

Aims

To explore the differences in brain area activation using different degrees of disgusted facial expression recognition in antipsychotic-naïve patients with first-episode schizophrenia and healthy controls.

Methods

In this study, facial expression recognition tests were performed on 30 first-episode, antipsychotic-naïve patients with schizophrenia (treatment group) and 30 healthy subjects (control group) with matched age, educational attainment and gender. Functional MRI was used for comparing the differences of the brain areas of activation between the two groups.

Results

The average response time difference between the patient group and the control group in the ‘high degree of disgust’ facial expression recognition task was statistically significant (1.359 (0.408)/2.193 (0.625), F=26.65, p<0.001), and the correct recognition rate of the treatment group was lower than that of the control group (41.05 (22.25)/59.84 (13.91, F=19.81, p<0.001). Compared with the control group, the left thalamus, right lingual gyrus and right middle temporal gyrus were negatively activated in the patients with first-episode schizophrenia in the ‘high degree of disgust’ emotion recognition, and there was a significant activation in the left and right middle temporal gyrus and the right caudate nucleus. However, there was no significant activation difference in the ‘low degree of disgust’ recognition.

Conclusions

In patients with first-episode schizophrenia, the areas of facial recognition impairment are significantly different in different degrees of disgust facial expression recognition.

Transdiagnostic deviant facial recognition for implicit negative emotion in autism and schizophrenia

Impaired facial affect recognition (FAR) is observed in schizophrenia and autism spectrum disorder (ASD) and has been linked to amygdala and fusiform gyrus dysfunction. ASD patient's impairments seem to be more pronounced during implicit rather than explicit FAR, whereas for schizophrenia data are inconsistent. However, there are no studies comparing both patient groups in an identical design. The aim of this three-group study was to identify (i) whether FAR alterations are equally present in both groups, (ii) whether they are present rather during implicit or explicit FAR, (iii) and whether they are conveyed by similar or disorder-specific neural mechanisms. Using fMRI, we investigated neural activation during explicit and implicit negative and neutral FAR in 33 young-adult individuals with ASD, 20 subjects with paranoid-schizophrenia and 25 IQ- and gender-matched controls individuals. Differences in activation patterns between each clinical group and controls, respectively were found exclusively for implicit FAR in amygdala and fusiform gyrus. In addition, the ASD group additionally showed reduced activations in medial prefrontal cortex (PFC), bilateral dorso-lateral PFC, ventro-lateral PFC, posterior-superior temporal sulcus and left temporo-parietal junction. Although subjects with ASD showed more widespread altered activation patterns, a direct comparison between both patient groups did not show disorder-specific deficits in neither patient group. In summary, our findings are consistent with a common neural deficit during implicit negative facial affect recognition in schizophrenia and autism spectrum disorders.

Automatic processing of emotional facial expressions as a function of social anhedonia

Anhedonia is an important feature of major depression and schizophrenia-spectrum disorders. Few neuroimaging studies have investigated neural alterations in high anhedonia, isolated from other psychopathological variables, by including only participants without clinical diagnoses. The present study examined healthy individuals scoring high (N = 18) vs. low (N = 19) in social anhedonia, who were carefully selected from a sample of N = 282 participants. To examine differences in automatic brain responses to social-affective stimuli between high vs. low social anhedonia participants, we used functional magnetic resonance imaging. To assess early, automatic stages of emotion processing, we administered a paradigm presenting brief (33ms), backward-masked happy, sad, and neutral facial expressions. Individuals high in social anhedonia demonstrated increased activation in the bilateral thalamus and left red nucleus in response to masked sad faces relative to individuals low in social anhedonia. No significant group differences in brain activation emerged in other regions known to be involved in emotion and reward processing, including the amygdala and nucleus accumbens. Our results suggest that high social anhedonia in otherwise healthy individuals is associated with exaggerated automatic reactivity in the thalamus, which is a brain structure that has been implicated in the mediation of attentional processes.

Influence of facial feedback during a cooperative human-robot task in schizophrenia

Rapid progress in the area of humanoid robots offers tremendous possibilities for investigating and improving social competences in people with social deficits, but remains yet unexplored in schizophrenia. In this study, we examined the influence of social feedbacks elicited by a humanoid robot on motor coordination during a human-robot interaction. Twenty-two schizophrenia patients and twenty-two matched healthy controls underwent a collaborative motor synchrony task with the iCub humanoid robot. Results revealed that positive social feedback had a facilitatory effect on motor coordination in the control participants compared to non-social positive feedback. This facilitatory effect was not present in schizophrenia patients, whose social-motor coordination was similarly impaired in social and non-social feedback conditions. Furthermore, patients' cognitive flexibility impairment and antipsychotic dosing were negatively correlated with patients' ability to synchronize hand movements with iCub. Overall, our findings reveal that patients have marked difficulties to exploit facial social cues elicited by a humanoid robot to modulate their motor coordination during human-robot interaction, partly accounted for by cognitive deficits and medication. This study opens new perspectives for comprehension of social deficits in this mental disorder.

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

Decreased Numbers of Somatostatin-Expressing Neurons in the Amygdala of Subjects With Bipolar Disorder or Schizophrenia: Relationship to Circadian Rhythms

BACKGROUND

Growing evidence points to a key role for somatostatin (SST) in schizophrenia (SZ) and bipolar disorder (BD). In the amygdala, neurons expressing SST play an important role in the regulation of anxiety, which is often comorbid in these disorders. We tested the hypothesis that SST-immunoreactive (IR) neurons are decreased in the amygdala of subjects with SZ and BD. Evidence for circadian SST expression in the amygdala and disrupted circadian rhythms and rhythmic peaks of anxiety in BD suggest a disruption of rhythmic expression of SST in this disorder.

METHODS

Amygdala sections from 12 SZ, 15 BD, and 15 control subjects were processed for immunocytochemistry for SST and neuropeptide Y, a neuropeptide partially coexpressed in SST-IR neurons. Total numbers (Nt) of IR neurons were measured. Time of death was used to test associations with circadian rhythms.

RESULTS

SST-IR neurons were decreased in the lateral amygdala nucleus in BD (Nt, p = .003) and SZ (Nt, p = .02). In normal control subjects, Nt of SST-IR neurons varied according to time of death. This pattern was altered in BD subjects, characterized by decreases of SST-IR neurons selectively in subjects with time of death corresponding to the day (6:00 am to 5:59 pm). Numbers of neuropeptide Y-IR neurons were not affected.

CONCLUSIONS

Decreased SST-IR neurons in the amygdala of patients with SZ and BD, interpreted here as decreased SST expression, may disrupt responses to fear and anxiety regulation in these individuals. In BD, our findings raise the possibility that morning peaks of anxiety depend on a disruption of circadian regulation of SST expression in the amygdala.

Decreased response inhibition to sad faces during explicit and implicit tasks in females with depression: Evidence from an event-related potential study

The present study aimed to investigate neural substrates of response inhibition to sad faces across explicit and implicit tasks in depressed female patients. Event-related potentials were obtained while participants performed modified explicit and implicit emotional go/no-go tasks. Compared to controls, depressed patients showed decreased discrimination accuracy and amplitudes of original and nogo-go difference waves at the P3 interval in response inhibition to sad faces during explicit and implicit tasks. P3 difference wave were positively correlated with discrimination accuracy and were independent of clinical assessment. The activation of right dorsal prefrontal cortex was larger for the implicit than for the explicit task in sad condition in health controls, but was similar for the two tasks in depressed patients. The present study indicated that selectively impairment in response inhibition to sad faces in depressed female patients occurred at the behavior inhibition stage across implicit and explicit tasks and may be a trait-like marker of depression. Longitudinal studies are required to determine whether decreased response inhibition to sad faces increases the risk for future depressive episodes so that appropriate treatment can be administered to patients.

Decreased neural response for facial emotion processing in subjects with high genetic load for schizophrenia

BACKGROUND

Patients with schizophrenia show impairment in facial emotion processing which is essential for successful social cognition. Using a functional magnetic resonance imaging (fMRI), this study aimed to investigate the implicit facial emotion recognition processing in participants with high genetic load for schizophrenia (GHR) as a possible trait marker of developing schizophrenia.

METHODS

Block design fMRI of implicit facial emotion processing was used in 20 participants with GHR aged 16-35, and 17 age, sex, and education year-matched healthy controls (HC). During the facial emotional processing for fearful, happy, and neutral face stimuli, participants were asked to explicitly determine the gender per stimuli.

RESULTS

Occipito-temporo-limbic area in fearful face condition and involvement of broader region including prefrontal cortex in neutral face condition revealed significant attenuation of BOLD signal activation in GHR compared to HC. The GHR demonstrated less activity in right amygdala during fearful and neutral face condition.

CONCLUSION

The study presented that GHR displayed abnormal brain activity in occipito-temporo-limbic-frontal network implicated in facial emotion processing. It indicates that abnormal facial emotion processing may be influenced by a genetic factor and could be a trait marker in schizophrenia.

Non-Conscious Perception of Emotions in Psychiatric Disorders: The Unsolved Puzzle of Psychopathology

Psychophysiological and functional neuroimaging studies have frequently and consistently shown that emotional information can be processed outside of the conscious awareness. Non-conscious processing comprises automatic, uncontrolled, and fast processing that occurs without subjective awareness. However, how such non-conscious emotional processing occurs in patients with various psychiatric disorders requires further examination. In this article, we reviewed and discussed previous studies on the non-conscious emotional processing in patients diagnosed with anxiety disorder, schizophrenia, bipolar disorder, and depression, to further understand how non-conscious emotional processing varies across these psychiatric disorders. Although the symptom profile of each disorder does not often overlap with one another, these patients commonly show abnormal emotional processing based on the pathology of their mood and cognitive function. This indicates that the observed abnormalities of emotional processing in certain social interactions may derive from a biased mood or cognition process that precedes consciously controlled and voluntary processes. Since preconscious forms of emotional processing appear to have a major effect on behaviour and cognition in patients with these disorders, further investigation is required to understand these processes and their impact on patient pathology.

Emotionally Neutral Stimuli Are Not Neutral in Schizophrenia: A Mini Review of Functional Neuroimaging Studies

Reliable evidence shows that schizophrenia patients tend to experience negative emotions when presented with emotionally neutral stimuli. Similarly, several functional neuroimaging studies show that schizophrenia patients have increased activations in response to neutral material. However, results are heterogeneous. Here, we review the functional neuroimaging studies that have addressed this research question. Based on the 36 functional neuroimaging studies that we retrieved, it seems that the increased brain reactivity to neutral stimuli is fairly common in schizophrenia, but that the regions involved vary considerably, apart from the amygdala. Prefrontal and cingulate sub-regions and the hippocampus may also be involved. By contrasts, results in individuals at risk for psychosis are less consistent. In schizophrenia patients, results are less consistent in the case of studies using non-facial stimuli, explicit processing paradigms, and/or event-related designs. This means that human faces may convey subtle information (e.g., trustworthiness) other than basic emotional expressions. It also means that the aberrant brain reactivity to neutral stimuli is less likely to occur when experimental paradigms are too cognitively demanding as well as in studies lacking statistical power. The main hypothesis proposed to account for this increased brain reactivity to neutral stimuli is the aberrant salience hypothesis of psychosis. Other investigators propose that the aberrant brain reactivity to neutral stimuli in schizophrenia results from abnormal associative learning, untrustworthiness judgments, priming effects, and/or reduced habituation to neutral stimuli. In the future, the effects of antipsychotics on this aberrant brain reactivity will need to be determined, as well as the potential implication of sex/gender.

Affective Flattening in Patients with Schizophrenia: Differential Association with Amygdala Response to Threat-Related Facial Expression under Automatic and Controlled Processing Conditions

OBJECTIVE

Early neuroimaging studies have demonstrated amygdala hypoactivation in schizophrenia but more recent research based on paradigms with minimal cognitive loads or examining automatic processing has observed amygdala hyperactivation. Hyperactivation was found to be related to affective flattening. In this study, amygdala responsivity to threat-related facial expression was investigated in patients as a function of automatic versus controlled processing and patients' flat affect.

METHODS

Functional magnetic resonance imaging was used to measure amygdala activation in 36 patients with schizophrenia and 42 healthy controls. During scanning, a viewing task with masked and unmasked fearful and neutral faces was presented.

RESULTS

Patients exhibited increased amygdala response to unmasked fearful faces. With respect to masked fearful faces, no between-group differences emerged for the sample as a whole but a subsample of patients with flat affect showed heightened amygdala activation. The amygdala response to masked fearful faces was positively correlated with the degree of flat affect. Conversely, amygdala response to unmasked fearful faces was negatively correlated to the severity of affective flattening. In patients, amygdala responses to masked and unmasked fearful faces showed an inverse correlation.

CONCLUSION

Our findings suggest that amygdala hyperresponsivity to unmasked fearful faces might be a functional characteristic of schizophrenia. Amygdala hyperresponsivity to masked fearful faces might be a specific characteristic of patients with affective flattening. A model of flat affect as a response mechanism to emotional overload is proposed.

NCAN Cross-Disorder Risk Variant Is Associated With Limbic Gray Matter Deficits in Healthy Subjects and Major Depression

Genome-wide association studies have reported an association between NCAN rs1064395 genotype and bipolar disorder. This association was later extended to schizophrenia and major depression. However, the neurobiological underpinnings of these associations are poorly understood. NCAN is implicated in neuronal plasticity and expressed in subcortical brain areas, such as the amygdala and hippocampus, which are critically involved in dysfunctional emotion processing and regulation across diagnostic boundaries. We hypothesized that the NCAN risk variant is associated with reduced gray matter volumes in these areas. Gray matter structure was assessed by voxel-based morphometry on structural MRI data in two independent German samples (healthy subjects, n=512; depressed inpatients, n=171). All participants were genotyped for NCAN rs1064395. Hippocampal and amygdala region-of-interest analyses were performed within each sample. In addition, whole-brain data from the combined sample were analyzed. Risk (A)-allele carriers showed reduced amygdala and hippocampal gray matter volumes in both cohorts with a remarkable spatial overlap. In the combined sample, genotype effects observed for the amygdala and hippocampus survived correction for entire brain volume. Further effects were also observed in the left orbitofrontal cortex and the cerebellum/fusiform gyrus. We conclude that NCAN genotype is associated with limbic gray matter alterations in healthy and depressed subjects in brain areas implicated in emotion perception and regulation. The present data suggest that NCAN forms susceptibility to neurostructural deficits in the amygdala, hippocampus, and prefrontal areas independent of disease, which might lead to disorder onset in the presence of other genetic or environmental risk factors.

Losing the sugar coating: potential impact of perineuronal net abnormalities on interneurons in schizophrenia

Perineuronal nets (PNNs) were shown to be markedly altered in subjects with schizophrenia. In particular, decreases of PNNs have been detected in the amygdala, entorhinal cortex and prefrontal cortex. The formation of these specialized extracellular matrix (ECM) aggregates during postnatal development, their functions, and association with distinct populations of GABAergic interneurons, bear great relevance to the pathophysiology of schizophrenia. PNNs gradually mature in an experience-dependent manner during late stages of postnatal development, overlapping with the prodromal period/age of onset of schizophrenia. Throughout adulthood, PNNs regulate neuronal properties, including synaptic remodeling, cell membrane compartmentalization and subsequent regulation of glutamate receptors and calcium channels, and susceptibility to oxidative stress. With the present paper, we discuss evidence for PNN abnormalities in schizophrenia, the potential functional impact of such abnormalities on inhibitory circuits and, in turn, cognitive and emotion processing. We integrate these considerations with results from recent genetic studies showing genetic susceptibility for schizophrenia associated with genes encoding for PNN components, matrix-regulating molecules and immune system factors. Notably, the composition of PNNs is regulated dynamically in response to factors such as fear, reward, stress, and immune response. This regulation occurs through families of matrix metalloproteinases that cleave ECM components, altering their functions and affecting plasticity. Several metalloproteinases have been proposed as vulnerability factors for schizophrenia. We speculate that the physiological process of PNN remodeling may be disrupted in schizophrenia as a result of interactions between matrix remodeling processes and immune system dysregulation. In turn, these mechanisms may contribute to the dysfunction of GABAergic neurons.

Training of Affect Recognition impacts electrophysiological correlates of facial affect recognition in schizophrenia: Analyses of fixation-locked potentials

OBJECTIVES

Training of Affect Recognition (TAR) is a useful approach to restoring cognitive function in schizophrenic patients. Along with improving visual exploration of faces and altering central information processing in relevant brain areas, TAR attenuates impairments in facial affect recognition. In the present study, we investigate the effects of TAR on early electrophysiological correlates of facial affect recognition in schizophrenia.

METHODS

The study population comprised 12 schizophrenic patients and 14 healthy controls. In each individual, we carried out EEG, concomitant measurements of scanning eye movements and fixation-based low resolution electromagnetic tomography (sLORETA) analyses of brain electric activity. All analyses were performed at baseline and after participation in TAR.

RESULTS

In patients, brain activation patterns significantly changed after completing the TAR. Functional improvements were particularly pronounced in the superior parietal and inferior parietal lobes, where trained patients showed a larger increase in activation than untrained healthy controls.

CONCLUSIONS

The TAR activates compensatory brain processes involved in the perception, attention and evaluation of emotional stimuli. This may underlie the established behavioral effects of the TAR in schizophrenic patients, which include improvements in facial affect recognition and alterations of visual exploration strategies.

Negative symptoms in schizophrenia show association with amygdala volumes and neural activation during affective processing

OBJECTIVES

Negative symptoms in schizophrenia have been associated with structural and functional alterations of the amygdala. We hypothesised that there would be between-group differences in amygdala volume and neural activation patterns during processing of affective stimuli among patients with schizophrenia and healthy controls. We further hypothesised correlations between neuroimaging metrics and clinical ratings of negative symptoms in patients with schizophrenia.

METHODS

We used structural and functional magnetic resonance imaging to assess volume and neural activation of the amygdala in 28 patients with schizophrenia and 28 healthy controls.

RESULTS

We found no between-group differences in amygdala volume or neural activation. However, we found a significant negative correlation between emotional blunting and neural activation in the left amygdala during processing of positive affect. We also found a significant negative correlation between stereotyped thinking and the volume of right amygdala.

CONCLUSION

Our findings implicate the amygdala in a subgroup of negative symptoms in schizophrenia that are characterised by reduced expression with blunted affect and stereotyped thinking.

Bidirectional regulation of synaptic plasticity in the basolateral amygdala induced by the D1-like family of dopamine receptors and group II metabotropic glutamate receptors

Competing mechanisms of long-term potentiation (LTP) and long-term depression (LTD) in principal neurons of the basolateral amygdala (BLA) are thought to underlie the acquisition and consolidation of fear memories, and their subsequent extinction. However, no study to date has examined the locus of action and/or the cellular mechanism(s) by which these processes interact. Here, we report that synaptic plasticity in the cortical pathway onto BLA principal neurons is frequency-dependent and shows a transition from LTD to LTP at stimulation frequencies of ∼10 Hz. At the crossover point from LTD to LTP induction we show that concurrent activation of D1 and group II metabotropic glutamate (mGluR2/3) receptors act to nullify any net change in synaptic strength. Significantly, blockade of either D1 or mGluR2/3 receptors unmasked 10 Hz stimulation-induced LTD and LTP, respectively. Significantly, prior activation of presynaptic D1 receptors caused a time-dependent attenuation of mGluR2/3-induced depotentiation of previously induced LTP. Furthermore, studies with cell type-specific postsynaptic transgene expression of designer receptors activated by designer drugs (DREADDs) suggest that the interaction results via bidirectional modulation of adenylate cyclase activity in presynaptic glutamatergic terminals. The results of our study raise the possibility that the temporal sequence of activation of either presynaptic D1 receptors or mGluR2/3 receptors may critically regulate the direction of synaptic plasticity in afferent pathways onto BLA principal neurons. Hence, the interaction of these two neurotransmitter systems may represent an important mechanism for bidirectional metaplasticity in BLA circuits and thus modulate the acquisition and extinction of fear memory.

Transdiagnostic dimensions of anxiety and depression moderate motivation-related brain networks during goal maintenance

BACKGROUND

Advancing research on the etiology, prevention, and treatment of psychopathology requires the field to move beyond modular conceptualizations of neural dysfunction toward understanding disturbance in key brain networks. Although some studies of anxiety and depression have begun doing so, they typically suffer from several drawbacks, including: (1) a categorical approach ignoring transdiagnostic processes, (2) failure to account for substantial anxiety and depression comorbidity, (3) examination of networks at rest, which overlooks disruption manifesting only when networks are challenged. Accordingly, the present study examined relationships between transdiagnostic dimensions of anxiety/depression and patterns of functional connectivity while goal maintenance was challenged.

METHODS

Participants (n = 179, unselected community members and undergraduates selected to be high/low on anxiety/depression) performed a task in which goal maintenance was challenged (color-word Stroop) while fMRI data were collected. Analyses examined moderation by anxiety/depression of condition-dependent coupling between regions of dorsolateral prefrontal cortex (dlPFC) previously associated with approach and avoidance motivation and amygdala/orbitofrontal cortex (OFC).

RESULTS

Anxious arousal was positively associated with amygdala↔right dlPFC coupling. Depression was positively associated with OFC↔right dlPFC coupling and negatively associated with OFC↔left dlPFC coupling.

CONCLUSIONS

Findings advance the field toward an integrative model of the neural instantiation of anxiety/depression by identifying specific, distinct dysfunctions associated with anxiety and depression in networks important for maintaining approach and avoidance goals. Specifically, findings shed light on potential neural mechanisms involved in attentional biases in anxiety and valuation biases in depression and underscore the importance of examining transdiagnostic dimensions of anxiety/depression while networks are challenged.

Event-related brain potentials to emotional images and gonadal steroid hormone levels in patients with schizophrenia and paired controls

Prominent disturbances in the experience, expression, and emotion recognition in patients with schizophrenia have been relatively well documented over the last few years. Furthermore, sex differences in behavior and brain activity, associated with the processing of various emotions, have been reported in the general population and in schizophrenia patients. Others proposed that sex differences should be rather attributed to testosterone, which may play a role in the etiology of schizophrenia. Also, it had been suggested that estradiol may play a protective role in schizophrenia. Surprisingly, few studies investigating this pathology have focused on both brain substrates and gonadal steroid hormone levels, in emotional processing. In the present study, we investigated electrocortical responses related to emotional valence and arousal as well as gonadal steroid hormone levels in patients with schizophrenia. Event-Related Potentials (ERP) were recorded during exposition to emotional pictures in 18 patients with schizophrenia and in 24 control participants paired on intelligence, manual dominance and socioeconomic status. Given their previous sensitivity to emotional and attention processes, the P200, N200 and the P300 were selected for analysis. More precisely, emotional valence generally affects early components (N200), which reflect early process of selective attention, whereas emotional arousal and valence both influences the P300 component, which is related to memory context updating, and stimulus categorization. Results showed that, in the control group, the amplitude of the N200 was significantly more lateralized over the right hemisphere, while there was no such lateralization in patients with schizophrenia. In patients with schizophrenia, significantly smaller anterior P300 amplitude was observed to the unpleasant, compared to the pleasant. That anterior P300 reduction was also correlated with negative symptoms. The N200 and P300 amplitudes were positively correlated with the estradiol level in all conditions, revealing that the N200 and the P300 were reduced, when estradiol level was higher. Conversely, only the P300 amplitude showed positive correlation with the testosterone level.

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.

Not all distraction is bad: working memory vulnerability to implicit socioemotional distraction correlates with negative symptoms and functional impairment in psychosis

This study investigated implicit socioemotional modulation of working memory (WM) in the context of symptom severity and functional status in individuals with psychosis (N = 21). A delayed match-to-sample task was modified wherein task-irrelevant facial distracters were presented early and briefly during the rehearsal of pseudoword memoranda that varied incrementally in load size (1, 2, or 3 syllables). Facial distracters displayed happy, sad, or emotionally neutral expressions. Implicit socioemotional modulation of WM was indexed by subtracting task accuracy on nonfacial geometrical distraction trials from facial distraction trials. Results indicated that the amount of implicit socioemotional modulation of high WM load accuracy was significantly associated with negative symptoms (r = 0.63, P < 0.01), role functioning (r = -0.50, P < 0.05), social functioning (r = -0.55, P < 0.01), and global assessment of functioning (r = -0.53, P < 0.05). Specifically, greater attentional distraction of high WM load was associated with less severe symptoms and functional impairment. This study demonstrates the importance of the WM-socioemotional interface in influencing clinical and psychosocial functional status in psychosis.

Hyperactivation balances sensory processing deficits during mood induction in schizophrenia

While impairments in emotion recognition are consistently reported in schizophrenia, there is some debate on the experience of emotion. Only few studies investigated neural correlates of emotional experience in schizophrenia. The present functional magnetic resonance imaging study compared a standard visual mood induction paradigm with an audiovisual method aimed at eliciting emotions more automatically. To investigate the interplay of sensory, cognitive and emotional mechanisms during emotion experience, we examined connectivity patterns between brain areas. Sixteen schizophrenia patients and sixteen healthy subjects participated in two different mood inductions (visual and audiovisual) that were administered for different emotions (happiness, sadness and neutral). Confirming the dissociation of behavioral and neural correlates of emotion experience, patients rated their mood similarly to healthy subjects but showed differences in neural activations. Sensory brain areas were activated less, increased activity emerged in higher cortical areas, particularly during audiovisual stimulation. Connectivity was increased between primary and secondary sensory processing areas in schizophrenia. These findings support the hypothesis of a deficit in filtering and processing sensory information alongside increased higher-order cognitive effort compensating for perception deficits in the affective domain. This may suffice to recover emotion experience in ratings of clinically stable patients but may fail during acute psychosis.

The role of cannabinoid transmission in emotional memory formation: implications for addiction and schizophrenia

Emerging evidence from both basic and clinical research demonstrates an important role for endocannabinoid (ECB) signaling in the processing of emotionally salient information, learning, and memory. Cannabinoid transmission within neural circuits involved in emotional processing has been shown to modulate the acquisition, recall, and extinction of emotionally salient memories and importantly, can strongly modulate the emotional salience of incoming sensory information. Two neural regions in particular, the medial prefrontal cortex (PFC) and the basolateral nucleus of the amygdala (BLA), play important roles in emotional regulation and contain high levels of cannabinoid receptors. Furthermore, both regions show profound abnormalities in neuropsychiatric disorders such as addiction and schizophrenia. Considerable evidence has demonstrated that cannabinoid transmission functionally interacts with dopamine (DA), a neurotransmitter system that is of exceptional importance for both addictive behaviors and the neuropsychopathology of disorders like schizophrenia. Research in our laboratory has focused on how cannabinoid transmission both within and extrinsic to the mesolimbic DA system, including the BLA → mPFC circuitry, can modulate both rewarding and aversive emotional information. In this review, we will summarize clinical and basic neuroscience research demonstrating the importance of cannabinoid signaling within this neural circuitry. In particular, evidence will be reviewed emphasizing the importance of cannabinoid signaling within the BLA → mPFC circuitry in the context of emotional salience processing, memory formation and memory-related plasticity. We propose that aberrant states of hyper or hypoactive ECB signaling within the amygdala-prefrontal cortical circuit may lead to dysregulation of mesocorticolimbic DA transmission controlling the processing of emotionally salient information. These disturbances may in turn lead to emotional processing, learning, and memory abnormalities related to various neuropsychiatric disorders, including addiction and schizophrenia-related psychoses.

Automatic amygdala response to facial expression in schizophrenia: initial hyperresponsivity followed by hyporesponsivity

BACKGROUND

It is well established that the amygdala is crucially involved in the processing of facial emotions. In schizophrenia patients, a number of neuroimaging findings suggest hypoactivation of the amygdala in response to facial emotion, while others indicate normal or enhanced recruitment of this region. Some of this variability may be related to the baseline condition used and the length of the experiment. There is evidence that schizophrenia patients display increased activation of the amygdala to neutral faces and that this is predominantly observed during early parts of the experiment. Recent research examining the automatic processing of facial emotion has also reported amygdala hyperactivation in schizophrenia. In the present study, we focused on the time-course of amygdala activation during the automatic processing of emotional facial expression. We hypothesized that in comparison to healthy subjects, patients would initially show hyperresponsivity of the amygdala to masked emotional and neutral faces. In addition, we expected amygdala deactivation in response to masked facial emotions from the first to the second phase to be more pronounced in patients than in controls.

RESULTS

Amygdala activation in response to angry, happy, neutral, and no facial expression (presented for 33 ms) was measured by functional magnetic resonance imaging in 30 schizophrenia patients and 35 healthy controls. Across all subjects, the bilateral amygdala response to faces (relative to the no facial expression condition) was larger in the initial phase (first half of trials) than in the second phase (second half of trials). During the initial phase, schizophrenia patients exhibited an increased right amygdala response to all faces and an increased left amygdala response to neutral faces compared with controls. During the second phase, controls manifested a higher right amygdala response for all faces and a higher left amygdala response to angry faces than patients.

CONCLUSIONS

Schizophrenia patients are characterized by high initial amygdala responsivity to facial expressions at an automatic processing level, which substantially decreases with time. Amygdala deactivation over time might reflect an automatic mechanism by which schizophrenia patients suppress the processing of facial stimuli. This blocking mechanism could help patients avoid overstimulation during social interactions.

Neural circuitry of masked emotional face processing in youth with bipolar disorder, severe mood dysregulation, and healthy volunteers

Youth with bipolar disorder (BD) and those with severe, non-episodic irritability (severe mood dysregulation, SMD) show face-emotion labeling deficits. These groups differ from healthy volunteers (HV) in neural responses to emotional faces. It is unknown whether awareness is required to elicit these differences. We compared activation in BD (N=20), SMD (N=18), and HV (N=22) during "Aware" and "Non-aware" priming of shapes by emotional faces. Subjects rated how much they liked the shape. In aware, a face (angry, fearful, happy, neutral, blank oval) appeared (187 ms) before the shape. In non-aware, a face appeared (17 ms), followed by a mask (170 ms), and shape. A Diagnosis-by-Awareness-by-Emotion ANOVA was not significant. There were significant Diagnosis-by-Awareness interactions in occipital regions. BD and SMD showed increased activity for non-aware vs. aware; HV showed the reverse pattern. When subjects viewed angry or neutral faces, there were Emotion-by-Diagnosis interactions in face-emotion processing regions, including the L precentral gyrus, R posterior cingulate, R superior temporal gyrus, R middle occipital gyrus, and L medial frontal gyrus. Regardless of awareness, BD and SMD differ in activation patterns from HV and each other in multiple brain regions, suggesting that BD and SMD are distinct developmental mood disorders.

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.

Odor naming and interpretation performance in 881 schizophrenia subjects: association with clinical parameters

BACKGROUND

Olfactory function tests are sensitive tools for assessing sensory-cognitive processing in schizophrenia. However, associations of central olfactory measures with clinical outcome parameters have not been simultaneously studied in large samples of schizophrenia patients.

METHODS

In the framework of the comprehensive phenotyping of the GRAS (Göttingen Research Association for Schizophrenia) cohort, we modified and extended existing odor naming (active memory retrieval) and interpretation (attribute assignment) tasks to evaluate them in 881 schizophrenia patients and 102 healthy controls matched for age, gender and smoking behavior. Associations with emotional processing, neuropsychological test performance and disease outcome were studied.

RESULTS

Schizophrenia patients underperformed controls in both olfactory tasks. Odor naming deficits were primarily associated with compromised cognition, interpretation deficits with positive symptom severity and general alertness. Contrasting schizophrenia extreme performers of odor interpretation (best versus worst percentile; N=88 each) and healthy individuals (N=102) underscores the obvious relationship between impaired odor interpretation and psychopathology, cognitive dysfunctioning, and emotional processing (all p<0.004).

CONCLUSIONS

The strong association of performance in higher olfactory measures, odor naming and interpretation, with lead symptoms of schizophrenia and determinants of disease severity highlights their clinical and scientific significance. Based on the results obtained here in an exploratory fashion in a large patient sample, the development of an easy-to-use clinical test with improved psychometric properties may be encouraged.

Mood-congruent amygdala responses to subliminally presented facial expressions in major depression: associations with anhedonia

BACKGROUND

Anhedonia has long been recognized as a key feature of major depressive disorders, but little is known about the association between hedonic symptoms and neurobiological processes in depressed patients. We investigated whether amygdala mood-congruent responses to emotional stimuli in depressed patients are correlated with anhedonic symptoms at automatic levels of processing.

METHODS

We measured amygdala responsiveness to subliminally presented sad and happy facial expressions in depressed patients and matched healthy controls using functional magnetic resonance imaging. Amygdala responsiveness was compared between patients and healthy controls within a 2 (group) x 2 (emotion) design. In addition, we correlated patients' amygdala responsiveness to sad and happy facial stimuli with self-report questionnaire measures of anhedonia.

RESULTS

We included 35 patients and 35 controls in our study. As in previous studies, we observed a strong emotion x group interaction in the bilateral amygdala: depressed patients showed greater amygdala responses to sad than happy faces, whereas healthy controls responded more strongly to happy than sad faces. The lack of automatic right amygdala responsiveness to happy faces in depressed patients was associated with higher physical anhedonia scores.

LIMITATIONS

Almost all depressed patients were taking antidepressant medications.

CONCLUSION

We replicated our previous finding of depressed patients showing automatic amygdala mood-congruent biases in terms of enhanced reactivity to negative emotional stimuli and reduced activity to positive emotional stimuli. The altered amygdala processing of positive stimuli in patients was associated with anhedonia scores. The results indicate that reduced amygdala responsiveness to positive stimuli may contribute to anhedonic symptoms due to reduced/inappropriate salience attribution to positive information at very early processing levels.

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.

Trait and state positive emotional experience in schizophrenia: a meta-analysis

BACKGROUND

Prior meta-analyses indicated that people with schizophrenia show impairment in trait hedonic capacity but retain their state hedonic experience (valence) in laboratory-based assessments. Little is known about what is the extent of differences for state positive emotional experience (especially arousal) between people with schizophrenia and healthy controls. It is also not clear whether negative symptoms and gender effect contribute to the variance of positive affect.

METHODS AND FINDINGS

The current meta-analysis examined 21 studies assessing state arousal experience, 40 studies measuring state valence experience, and 47 studies assessing trait hedonic capacity in schizophrenia. Patients with schizophrenia demonstrated significant impairment in trait hedonic capacity (Cohen's d = 0.81). However, patients and controls did not statistically differ in state hedonic (valence) as well as exciting (arousal) experience to positive stimuli (Cohen's d = -0.24 to 0.06). They also reported experiencing relatively robust state aversion and calmness to positive stimuli compared with controls (Cohen's d = 0.75, 0.56, respectively). Negative symptoms and gender contributed to the variance of findings in positive affect, especially trait hedonic capacity in schizophrenia.

CONCLUSIONS

Our findings suggest that schizophrenia patients have no deficit in state positive emotional experience but impairment in "noncurrent" hedonic capacity, which may be mediated by negative symptoms and gender effect.

Childhood maltreatment is associated with an automatic negative emotion processing bias in the amygdala

Major depression has been repeatedly associated with amygdala hyper-responsiveness to negative (but not positive) facial expressions at early, automatic stages of emotion processing using subliminally presented stimuli. However, it is not clear whether this "limbic bias" is a correlate of depression or represents a vulnerability marker preceding the onset of the disease. Because childhood maltreatment is a potent risk factor for the development of major depression in later life, we explored whether childhood maltreatment is associated with amygdalar emotion processing bias in maltreated but healthy subjects. Amygdala responsiveness to subliminally presented sad and happy faces was measured by means of fMRI at 3 T in N = 150 healthy subjects carefully screened for psychiatric disorders. Childhood maltreatment was assessed by the 25-item childhood trauma questionnaire (CTQ). A strong association of CTQ-scores with amygdala responsiveness to sad, but not happy facial expressions emerged. This result was further qualified by an interaction of emotional valence and CTQ-scores and was not confounded by trait anxiety, current depression level, age, gender, intelligence, education level, and more recent stressful life-events. Childhood maltreatment is apparently associated with detectable changes in amygdala function during early stages of emotion processing which resemble findings described in major depression. Limbic hyper-responsiveness to negative facial cues could be a consequence of the experience of maltreatment during childhood increasing the risk of depression in later life.

LIMITATION

the present association of limbic bias and maltreatment was demonstrated in the absence of psychopathological abnormalities, thereby limiting strong conclusions.

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.

Early sensory-perceptual processing deficits for affectively valenced inputs are more pronounced in schizophrenia patients with a history of violence than in their non-violent peers

Individuals with schizophrenia are more prone to violent behaviors than the general population. It is increasingly recognized that processing of emotionally valenced stimuli is impaired in schizophrenia, a deficit that may play a role in aggressive behavior. Our goal was to establish whether patients with a history of violence would show more severe deficits in processing emotionally valenced inputs than non-violent patients. Using event-related potentials, we measured how early during processing of emotional valence, evidence of aberrant function was observed. A total of 42 schizophrenia patients (21 with history of violence; 21 without) and 28 healthy controls were tested. Participants performed an inhibitory control task, making speeded responses to pictorial stimuli. Pictures occasionally repeated twice and participants withheld responses to these repeats. Valenced pictures from the International Affective Picture System were presented. Results in controls showed modulations during the earliest phases of sensory processing (<100 ms) for negatively valenced pictures. A cascade of modulations ensued, involving sensory and perceptual processing stages. In contrast, neither schizophrenia group showed early differentiation. Non-violent patients showed earliest modulations beginning ∼150 ms. For violent patients, however, earliest modulations were further delayed and highly attenuated. The current study reveals sensory-perceptual processing dysfunction for negatively valenced inputs, which is particularly pronounced in aggressive patients.

Autism spectrum disorders and schizophrenia: meta-analysis of the neural correlates of social cognition

Context

Impaired social cognition is a cardinal feature of Autism Spectrum Disorders (ASD) and Schizophrenia (SZ). However, the functional neuroanatomy of social cognition in either disorder remains unclear due to variability in primary literature. Additionally, it is not known whether deficits in ASD and SZ arise from similar or disease-specific disruption of the social cognition network.

Objective

To identify regions most robustly implicated in social cognition processing in SZ and ASD.

Data Sources

Systematic review of English language articles using MEDLINE (1995–2010) and reference lists.

Study Selection

Studies were required to use fMRI to compare ASD or SZ subjects to a matched healthy control group, provide coordinates in standard stereotactic space, and employ standardized facial emotion recognition (FER) or theory of mind (TOM) paradigms.

Data Extraction

Activation foci from studies meeting inclusion criteria (n = 33) were subjected to a quantitative voxel-based meta-analysis using activation likelihood estimation, and encompassed 146 subjects with ASD, 336 SZ patients and 492 healthy controls.

Results

Both SZ and ASD showed medial prefrontal hypoactivation, which was more pronounced in ASD, while ventrolateral prefrontal dysfunction was associated mostly with SZ. Amygdala hypoactivation was observed in SZ patients during FER and in ASD during more complex ToM tasks. Both disorders were associated with hypoactivation within the Superior Temporal Sulcus (STS) during ToM tasks, but activation in these regions was increased in ASD during affect processing. Disease-specific differences were noted in somatosensory engagement, which was increased in SZ and decreased in ASD. Reduced thalamic activation was uniquely seen in SZ.

Conclusions

Reduced frontolimbic and STS engagement emerged as a shared feature of social cognition deficits in SZ and ASD. However, there were disease- and stimulus-specific differences. These findings may aid future studies on SZ and ASD and facilitate the formulation of new hypotheses regarding their pathophysiology.

Sex-specific associations between peripheral oxytocin and emotion perception in schizophrenia

BACKGROUND

We previously reported that higher levels of peripheral oxytocin are associated with lower levels of positive, general, and overall symptoms in women but not in men with schizophrenia. Here we investigate the influence of sex, sex steroid hormone fluctuations, and peripheral oxytocin levels on emotional processing in men and women with schizophrenia.

METHOD

Twenty-two women with schizophrenia and 31 female controls completed the Penn Emotion Acuity Test (PEAT), a facial emotion recognition and perception task, during two menstrual cycle phases: 1) early follicular (Days 2-4; low estrogen/progesterone) and 2) midluteal (Days 20-22; high estrogen/progesterone). Twenty-six males with schizophrenia and 26 male controls completed testing at comparable intervals. We obtained plasma hormone assays of estrogen, progesterone, testosterone, and oxytocin.

RESULTS

No sex differences were noted on the PEAT. Plasma oxytocin levels did not fluctuate across phases of the menstrual cycle. However, female patients and controls more accurately identified facial emotions during the early follicular versus midluteal phase (p<0.05). Higher oxytocin levels related to perceiving faces as happier in both female patients (r=-0.46, p=0.04) and controls (r=-0.40, p=0.04) but not in men.

CONCLUSION

Like healthy women, women with schizophrenia demonstrate menstrual-cycle dependent fluctuations in recognizing emotional cues. Like healthy women, female patients with higher levels of oxytocin perceived faces as happier. Future studies need to address whether this sex-specific relationship is associated with trust and other positive emotions, and whether exogenous oxytocin might enhance mood states and social interaction in female or all schizophrenia patients.

Neural correlates of social approach and withdrawal in patients with major depression

Successful human interaction is based on correct recognition, interpretation, and appropriate reaction to facial affect. In depression, social skill deficits are among the most restraining symptoms leading to social withdrawal, thereby aggravating social isolation and depressive affect. Dysfunctional approach and withdrawal tendencies to emotional stimuli have been documented, but the investigation of their neural underpinnings has received limited attention. We performed an fMRI study including 15 depressive patients and 15 matched, healthy controls. All subjects performed two tasks, an implicit joystick task as well as an explicit rating task, both using happy, neutral, and angry facial expressions. Behavioral data analysis indicated a significant group effect, with depressed patients showing more withdrawal than controls. Analysis of the functional data revealed significant group effects for both tasks. Among other regions, we observed significant group differences in amygdala activation, with patients showing less response particularly during approach to happy faces. Additionally, significant correlations of amygdala activation with psychopathology emerged, suggesting that more pronounced symptoms are accompanied by stronger decreases of amygdala activation. Hence, our results demonstrate that depressed patients show dysfunctional social approach and withdrawal behavior, which in turn may aggravate the disorder by negative social interactions contributing to isolation and reinforcing cognitive biases.

Exaggerated brain activation during emotion processing in unaffected siblings of patients with schizophrenia

BACKGROUND

Schizophrenia is characterized by impaired social cognition, including emotion processing. Behavioral studies have reported impaired performance on various emotion processing tasks, and imaging studies in patients have observed aberrant activity within the underlying neural circuitry. Also, subjects at increased genetic risk of developing schizophrenia, including unaffected siblings of patients, show behavioral impairments in emotion processing. It is unclear, however, whether and how the underlying neural system is disrupted in these subjects. In this study, we investigated whether siblings of patients with schizophrenia show abnormal brain activation during basic emotion processing.

METHODS

Brain activity was measured using functional magnetic resonance imaging in 24 unaffected siblings of patients with schizophrenia and 25 healthy control subjects while they viewed and rated neutral, positive, and negative pictures. None of the subjects had a psychiatric disorder, and the two groups did not differ in age, gender, or level of own, paternal, or maternal education.

RESULTS

Compared with control subjects, siblings showed increased activity within the amygdala, hippocampus, medial prefrontal cortex, posterior and anterior cingulate cortex, and middle temporal gyrus in response to emotionally arousing pictures relative to neutral pictures. No activation differences between the groups were found during the neutral stimuli, indicating that the observed hyperactivity is likely caused by abnormal emotion processing rather than impaired visuoattentional processing.

CONCLUSIONS

Our findings of hyperactivity in siblings during emotion processing suggest that functional abnormalities within the neural circuitry of emotion processing are related to the genetic risk for developing schizophrenia.

Sex-specific associations between peripheral oxytocin and emotion perception in schizophrenia

BACKGROUND

We previously reported that higher levels of peripheral oxytocin are associated with lower levels of positive, general, and overall symptoms in women but not in men with schizophrenia. Here we investigate the influence of sex, sex steroid hormone fluctuations, and peripheral oxytocin levels on emotional processing in men and women with schizophrenia.

METHOD

Twenty-two women with schizophrenia and 31 female controls completed the Penn Emotion Acuity Test (PEAT), a facial emotion recognition and perception task, during two menstrual cycle phases: 1) early follicular (Days 2-4; low estrogen/progesterone) and 2) midluteal (Days 20-22; high estrogen/progesterone). Twenty-six males with schizophrenia and 26 male controls completed testing at comparable intervals. We obtained plasma hormone assays of estrogen, progesterone, testosterone, and oxytocin.

RESULTS

No sex differences were noted on the PEAT. Plasma oxytocin levels did not fluctuate across phases of the menstrual cycle. However, female patients and controls more accurately identified facial emotions during the early follicular versus midluteal phase (p<0.05). Higher oxytocin levels related to perceiving faces as happier in both female patients (r=-0.46, p=0.04) and controls (r=-0.40, p=0.04) but not in men.

CONCLUSION

Like healthy women, women with schizophrenia demonstrate menstrual-cycle dependent fluctuations in recognizing emotional cues. Like healthy women, female patients with higher levels of oxytocin perceived faces as happier. Future studies need to address whether this sex-specific relationship is associated with trust and other positive emotions, and whether exogenous oxytocin might enhance mood states and social interaction in female or all schizophrenia patients.