Right lateral fusiform gyrus dysfunction during facial information processing in schizophrenia

Abnormal connectivity and activation during audiovisual speech perception in schizophrenia

The unconscious integration of vocal and facial cues during speech perception facilitates face-to-face communication. Recent studies have provided substantial behavioural evidence concerning impairments in audiovisual (AV) speech perception in schizophrenia. However, the specific neurophysiological mechanism underlying these deficits remains unknown. Here, we investigated activities and connectivities centered on the auditory cortex during AV speech perception in schizophrenia. Using magnetoencephalography, we recorded and analysed event-related fields in response to auditory (A: voice), visual (V: face) and AV (voice-face) stimuli in 23 schizophrenia patients (13 males) and 22 healthy controls (13 males). The functional connectivity associated with the subadditive response to AV stimulus (i.e., [AV] < [A] + [V]) was also compared between the two groups. Within the healthy control group, [AV] activity was smaller than the sum of [A] and [V] at latencies of approximately 100 ms in the posterior ramus of the lateral sulcus in only the left hemisphere, demonstrating a subadditive N1m effect. Conversely, the schizophrenia group did not show such a subadditive response. Furthermore, weaker functional connectivity from the posterior ramus of the lateral sulcus of the left hemisphere to the fusiform gyrus of the right hemisphere was observed in schizophrenia. Notably, this weakened connectivity was associated with the severity of negative symptoms. These results demonstrate abnormalities in connectivity between speech- and face-related cortical areas in schizophrenia. This aberrant subadditive response and connectivity deficits for integrating speech and facial information may be the neural basis of social communication dysfunctions in schizophrenia.

Neural circuit disruptions of eye gaze processing in autism spectrum disorder and schizophrenia: An activation likelihood estimation meta-analysis

BACKGROUND

Impairment in social cognition, particularly eye gaze processing, is a shared feature common to autism spectrum disorder (ASD) and schizophrenia. However, it is unclear if a convergent neural mechanism also underlies gaze dysfunction in these conditions. The present study examined whether this shared eye gaze phenotype is reflected in a profile of convergent neurobiological dysfunction in ASD and schizophrenia.

METHODS

Activation likelihood estimation (ALE) meta-analyses were conducted on peak voxel coordinates across the whole brain to identify spatial convergence. Functional coactivation with regions emerging as significant was assessed using meta-analytic connectivity modeling. Functional decoding was also conducted.

RESULTS

Fifty-six experiments (n = 30 with schizophrenia and n = 26 with ASD) from 36 articles met inclusion criteria, which comprised 354 participants with ASD, 275 with schizophrenia and 613 healthy controls (1242 participants in total). In ASD, aberrant activation was found in the left amygdala relative to unaffected controls during gaze processing. In schizophrenia, aberrant activation was found in the right inferior frontal gyrus and supplementary motor area. Across ASD and schizophrenia, aberrant activation was found in the right inferior frontal gyrus and right fusiform gyrus during gaze processing. Functional decoding mapped the left amygdala to domains related to emotion processing and cognition, the right inferior frontal gyrus to cognition and perception, and the right fusiform gyrus to visual perception, spatial cognition, and emotion perception. These regions also showed meta-analytic connectivity to frontoparietal and frontotemporal circuitry.

CONCLUSION

Alterations in frontoparietal and frontotemporal circuitry emerged as neural markers of gaze impairments in ASD and schizophrenia. These findings have implications for advancing transdiagnostic biomarkers to inform targeted treatments for ASD and schizophrenia.

Association of cortical thickness and cognition with schizophrenia treatment resistance

AIM

Approximately a third of patients with schizophrenia fail to adequately respond to antipsychotic medications, a condition known as treatment resistance (TR). We aimed to assess cognitive and cortical thickness deficits and their relationship to TR in schizophrenia.

METHOD

We recruited patients with schizophrenia (n = 127), including patients at treatment initiation (n = 45), treatment-responsive patients (n = 40) and TR patients (n = 42), and healthy controls (n = 83). Clinical symptoms, neurocognitive function, and structural images were assessed. We performed group comparisons, and explored association of cortical thickness and cognition with TR.

RESULTS

The TR patients showed significantly more severe clinical symptoms and cognitive impairment relative to the treatment-responsive group. Compared to healthy controls, 56 of 68 brain regions showed significantly reduced cortical thickness in patients with schizophrenia. Reductions in five regions were significantly associated with TR (reduction in TR relative to treatment-responsive patients), i.e. in the right caudal middle frontal gyrus, superior frontal cortex, fusiform gyrus, pars opercularis of the inferior frontal cortex, and supramarginal cortex. Cognition deficits were also significantly correlated with cortical thickness in these five regions in patients with schizophrenia. Cortical thickness of the right caudal middle frontal gyrus, superior frontal cortex and pars opercularis of the inferior frontal cortex also significantly mediated effects of cognitive deficits on TR.

CONCLUSION

Treatment resistance in schizophrenia was associated with reduced thickness in the right caudal middle frontal gyrus, superior frontal cortex, fusiform gyrus, pars opercularis of the inferior frontal cortex, and supramarginal cortex. Cortical abnormalities further mediate cognitive deficits known to be associated with TR.

Evidence From Imaging Resilience Genetics for a Protective Mechanism Against Schizophrenia in the Ventral Visual Pathway

INTRODUCTION

Illuminating neurobiological mechanisms underlying the protective effect of recently discovered common genetic resilience variants for schizophrenia is crucial for more effective prevention efforts. Current models implicate adaptive neuroplastic changes in the visual system and their pro-cognitive effects as a schizophrenia resilience mechanism. We investigated whether common genetic resilience variants might affect brain structure in similar neural circuits.

METHOD

Using structural magnetic resonance imaging, we measured the impact of an established schizophrenia polygenic resilience score (PRSResilience) on cortical volume, thickness, and surface area in 101 healthy subjects and in a replication sample of 33 224 healthy subjects (UK Biobank).

FINDING

We observed a significant positive whole-brain correlation between PRSResilience and cortical volume in the right fusiform gyrus (FFG) (r = 0.35; P = .0004). Post-hoc analyses in this cluster revealed an impact of PRSResilience on cortical surface area. The replication sample showed a positive correlation between PRSResilience and global cortical volume and surface area in the left FFG.

CONCLUSION

Our findings represent the first evidence of a neurobiological correlate of a genetic resilience factor for schizophrenia. They support the view that schizophrenia resilience emerges from strengthening neural circuits in the ventral visual pathway and an increased capacity for the disambiguation of social and nonsocial visual information. This may aid psychosocial functioning, ameliorate the detrimental effects of subtle perceptual and cognitive disturbances in at-risk individuals, and facilitate coping with the cognitive and psychosocial consequences of stressors. Our results thus provide a novel link between visual cognition, the vulnerability-stress concept, and schizophrenia resilience models.

Ketamine disrupts gaze patterns during face viewing in the common marmoset

Faces are stimuli of critical importance for primates. The common marmoset (Callithrix jacchus) is a promising model for investigations of face processing, as this species possesses oculomotor and face-processing networks resembling those of macaques and humans. Face processing is often disrupted in neuropsychiatric conditions such as schizophrenia (SZ), and thus, it is important to recapitulate underlying circuitry dysfunction preclinically. The N-methyl-d-aspartate (NMDA) noncompetitive antagonist ketamine has been used extensively to model the cognitive symptoms of SZ. Here, we investigated the effects of a subanesthetic dose of ketamine on oculomotor behavior in marmosets during face viewing. Four marmosets received systemic ketamine or saline injections while viewing phase-scrambled or intact videos of conspecifics' faces. To evaluate effects of ketamine on scan paths during face viewing, we identified regions of interest in each face video and classified locations of saccade onsets and landing positions within these areas. A preference for the snout over eye regions was observed following ketamine administration. In addition, regions in which saccades landed could be significantly predicted by saccade onset region in the saline but not the ketamine condition. Effects on saccade control were limited to an increase in saccade peak velocity in all conditions and a reduction in saccade amplitudes during viewing of scrambled videos. Thus, ketamine induced a significant disruption of scan paths during viewing of conspecific faces but limited effects on saccade motor control. These findings support the use of ketamine in marmosets for investigating changes in neural circuits underlying social cognition in neuropsychiatric disorders.NEW & NOTEWORTHY Face processing, an important social cognitive ability, is impaired in neuropsychiatric conditions such as schizophrenia. The highly social common marmoset model presents an opportunity to investigate these impairments. We administered subanesthetic doses of ketamine to marmosets to model the cognitive symptoms of schizophrenia. We observed a disruption of scan paths during viewing of conspecifics' faces. These findings support the use of ketamine in marmosets as a model for investigating social cognition in neuropsychiatric disorders.

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.

Cortical Pathways or Mechanism in the Face Inversion Effect in Patients with First-Episode Schizophrenia

OBJECTIVE

Impaired face perception is considered as a hallmark of social disability in schizophrenia. It is widely believed that inverted faces and upright faces are processed by distinct mechanisms. Previous studies have identified that individuals with schizophrenia display poorer face processing than controls. However, the mechanisms underlying the face inversion effect (FIE) in patients with first-episode schizophrenia (FSZ) remain unclear.

METHODS

We designed an fMRI task to investigate the FIE mechanism in patients with schizophrenia. Thirty-four patients with FSZ and thirty-five healthy controls (CON) underwent task-related fMRI scanning, clinical assessment, anhedonia experience examination, and social function and cognitive function evaluation.

RESULTS

The patients with FSZ exhibited distinct functional activity regarding upright and inverted face processing within the cortical face and non-face network. These results suggest that the differences in quantitative processing might mediate the FIE in schizophrenia. Compared with controls, affected patients showed impairments in processing both upright and inverted faces; and for these patients with FSZ, upright face processing was associated with more severe and broader impairment than inverted face processing. Reduced response in the left middle occipital gyrus for upright face processing was related to poorer performance of social function outcomes evaluated using the Personal and Social Performance Scale.

CONCLUSION

Our data suggested that patients with FSZ exhibited similar performance in processing inverted faces and upright faces, but were less efficient than controls; and for these patients, inverted faces are processed less efficiently than upright faces. We also provided a clue that the mechanism under abnormal FIE might be related to an aberrant activation of non-face-selective areas instead of abnormal activation of face-specific areas in patients with schizophrenia. Finally, our study indicated that the neural pathway for upright recognition might be relevant in determining the functional outcomes of this devastating disorder.

Effect of Risperidone Monotherapy on Dynamic Functional Connectivity of Insular Subdivisions in Treatment-Naive, First-Episode Schizophrenia

OBJECTIVE

The insula consists of functionally diverse subdivisions, and each division plays different roles in schizophrenia neuropathology. The current study aimed to investigate the abnormal patterns of dynamic functional connectivity (dFC) of insular subdivisions in schizophrenia and the effect of antipsychotics on these connections.

METHODS

Longitudinal study of the dFC of insular subdivisions was conducted in 42 treatment-naive first-episode patients with schizophrenia at baseline and after 8 weeks of risperidone treatment based on resting-state functional magnetic resonance image (fMRI).

RESULTS

At baseline, patients showed decreased dFC variance (less variable) between the insular subdivisions and the precuneus, supplementary motor area and temporal cortex, as well as increased dFC variance (more variable) between the insular subdivisions and parietal cortex, compared with healthy controls. After treatment, the dFC variance of the abnormal connections were normalized, which was accompanied by a significant improvement in positive symptoms.

CONCLUSIONS

Our findings highlighted the abnormal patterns of fluctuating connectivity of insular subdivision circuits in schizophrenia and suggested that these abnormalities may be modified after antipsychotic treatment.

Functional disconnection between the visual cortex and right fusiform face area in schizophrenia

Patients with schizophrenia show impairment in processing faces, including facial affect and face detection, but the underlying mechanisms are unknown. We used functional magnetic resonance imaging (fMRI) to characterize resting state functional connectivity between an independent component analysis (ICA)-defined early visual cortical network (corresponding to regions in V1, V2, V3) and a priori defined face-processing regions (fusiform face area [FFA], occipital face area [OFA], superior temporal sulcus [STS] and amygdala) using dual regression in 20 schizophrenia patients and 26 healthy controls. We also investigated the association between resting functional connectivity and neural responses (fMRI) elicited by a face detection paradigm in a partially overlapping sample (Maher et al., 2016) that used stimuli equated for lower-level perceptual abilities. Group differences in functional connectivity were found in right FFA only; controls showed significantly stronger functional connectivity to an early visual cortical network. Functional connectivity in right FFA was associated with (a) neural responses during face detection in controls only, and (b) perceptual detection thresholds for faces in patients only. The finding of impaired functional connectivity for right FFA (but not other queried domain-specific regions) converges with findings investigating face detection in an overlapping sample in which dysfunction was found exclusively for right FFA in schizophrenia during face detection.

Neutral face and complex object neurophysiological processing deficits in long-term schizophrenia and in first hospitalized schizophrenia-spectrum individuals

BACKGROUND

Face processing is impaired in long-term schizophrenia as indexed by a reduced face-related N170 event-related potential (ERP) that corresponds with volumetric decreases in right fusiform gyrus. Impairment in face processing may constitute an object-specific deficit in schizophrenia that relates to social impairment and misattribution of social signs in the disease, or the face deficit may be part of a more general deficit in complex visual processing. Further, it is not clear the degree to which face and complex object processing deficits are present early in disease course. To that end, the current study investigated face- and object-elicited N170 in long-term schizophrenia and the first hospitalized schizophrenia-spectrum.

METHODS

ERPs were collected from 32 long-term schizophrenia patients and 32 matched controls, and from 31 first hospitalization patients and 31 matched controls. Subjects detected rarely presented butterflies among non-target neutral faces and automobiles.

RESULTS

For both patient groups, the N170s to all stimuli were significantly attenuated. Despite this overall reduction, the increase in N170 amplitude to faces was intact in both patient samples. Symptoms were not correlated with N170 amplitude or latency to faces.

CONCLUSIONS

Information processing of complex stimuli is fundamentally impaired in schizophrenia, as reflected in attenuated N170 ERPs in both first hospitalized and long-term patients. This suggests the presence of low-level visual complex object processing deficits near disease onset that persist with disease course.

Intact prioritisation of unconscious face processing in schizophrenia

INTRODUCTION

Faces provide a rich source of social information, crucial for the successful navigation of daily social interactions. People with schizophrenia suffer a wide range of social-cognitive deficits, including abnormalities in face perception. However, to date, studies of face perception in schizophrenia have primarily employed tasks that require patients to make judgements about the faces. It is, thus, unclear whether the reported deficits reflect an impairment in encoding visual face information, or biased social-cognitive evaluative processes.

METHODS

We assess the integrity of early unconscious face processing in 21 out-patients diagnosed with Schizophrenia or Schizoaffective Disorder (15M/6F) and 21 healthy controls (14M/7F). In order to control for any direct influence of higher order cognitive processes, we use a behavioural paradigm known as breaking continuous flash suppression (b-CFS), where participants simply respond to the presence and location of a face. In healthy adults, this method has previously been used to show that upright faces gain rapid and privileged access to conscious awareness over inverted faces and other inanimate objects.

RESULTS

Here, we report similar effects in patients, suggesting that the early unconscious stages of face processing are intact in schizophrenia.

CONCLUSION

Our data indicate that face processing deficits reported in the literature must manifest at a conscious stage of processing, where the influence of mentalizing or attribution biases might play a role.

Stimuli may have little impact on the deficit of visual working memory accuracy in first-episode schizophrenia

PURPOSE

Working memory (WM) deficits have been observed in people with schizophrenia (SZ) and are considered a core cognitive dysfunction in these patients. However, little is known about how stimuli and memory load influence visual WM deficits.

PATIENTS AND METHODS

In the present study, we adopted a match-to-sample task to examine the visual WM in 18 first-episode patients with SZ and 18 healthy controls (HCs). Faces and houses were used as the stimuli, and there were two levels of memory load - one item and two items; the average accuracy (ACC) and reaction time were calculated for each condition. The Positive and Negative Syndrome Scale and the Personal and Social Performance scale were used to assess the psychiatric symptoms and social function, respectively.

RESULTS

The results showed equivalent levels of WM deficit when using face and house stimuli. Moreover, the WM deficits were not related to the duration of illness, medication, or SZ symptoms.

CONCLUSION

These results demonstrate that stimuli may have little impact on ACC in WM tasks in people with SZ. In addition, the memory load may have little impact on WM ACC when the load is relatively low.

Schizophrenia patients have higher-order language and extralinguistic impairments

INTRODUCTION

The extralinguistic and paralinguistic aspects of the language refer to higher-order language functions such as lexical-semantic processes, prosody, indirect speech acts or discourse comprehension and production. Studies suggest that these processes are mediated by the Right Hemisphere (RH) and there is also some evidence of RH dysfunctions in schizophrenia. The aim of the paper is to investigate the extralinguistic and paralinguistic processing mediated by Right Hemisphere in schizophrenia patients using a validated and standardized battery of tests.

METHODS

Two groups of participants were examined: a schizophrenia sample (40 participants) and a control group (39 participants). Extralinguistic and paralinguistic processing was assessed in all subjects by the Polish version of the Right Hemisphere Language Battery (RHLB-PL), which measures comprehension of implicit information, naming, understanding humor, inappropriate remarks and comments, explanation and understanding of metaphors, understanding emotional and language prosody and discourse understanding.

RESULTS

Schizophrenia patients scored significantly lower than controls in subtests measuring comprehension of implicit information, interpretation of humor, explanation of metaphors, inappropriate remarks and comments, discernment of emotional and language prosody and comprehension of discourse. No differences were observed in naming, understanding metaphors or in processing visuo-spatial information.

CONCLUSIONS

Extralinguistic and paralinguistic dysfunctions appear to be present in schizophrenia patients and they suggest that RH processing may be disturbed in that group of patients. As the disturbances of higher-order language processes mediated by the RH may cause serious impairments in the social communication of patients, it is worth evaluating them during clinical examination.

Disordered high-frequency oscillation in face processing in schizophrenia patients

Schizophrenia is a complex disorder characterized by marked social dysfunctions, but the neural mechanism underlying this deficit is unknown. To investigate whether face-specific perceptual processes are influenced in schizophrenia patients, both face detection and configural analysis were assessed in normal individuals and schizophrenia patients by recording electroencephalogram (EEG) data. Here, a face processing model was built based on the frequency oscillations, and the evoked power (theta, alpha, and beta bands) and the induced power (gamma bands) were recorded while the subjects passively viewed face and nonface images presented in upright and inverted orientations. The healthy adults showed a significant face-specific effect in the alpha, beta, and gamma bands, and an inversion effect was observed in the gamma band in the occipital lobe and right temporal lobe. Importantly, the schizophrenia patients showed face-specific deficits in the low-frequency beta and gamma bands, and the face inversion effect in the gamma band was absent from the occipital lobe. All these results revealed face-specific processing in patients due to the disorder of high-frequency EEG, providing additional evidence to enrich future studies investigating neural mechanisms and serving as a marked diagnostic basis.

Schizophrenia and Category-Selectivity in the Brain: Normal for Faces but Abnormal for Houses

Face processing is regularly found to be impaired in schizophrenia (SZ), thus suggesting that social malfunctioning might be caused by dysfunctional face processing. Most studies focused on emotional face processes, whereas non-emotional face processing received less attention. While current reports on abnormal face processing in SZ are mixed, examinations of non-emotional face processing compared to adequate control stimuli may clarify whether SZ is characterized by a face-processing deficit. Patients with SZ (n = 28) and healthy controls (n = 30) engaged in an fMRI scan where images of non-emotional faces and houses were presented. A simple inverted-picture detection task warranted the participants' attention. Region of interest (ROI) analyses were conducted on face-sensitive regions including the fusiform face area, the occipital face area, and the superior temporal sulcus. Scene-sensitivity was assessed in the parahippocampal place area (PPA) and served as control condition. Patients did not show aberrant face-related neural processes in face-sensitive regions. This finding was also evident when analyses were done on individually defined ROIs or on in-house-localizer ROIs. Patients revealed a decreased specificity toward house stimuli as reflected in decreased neural response toward houses in the PPA. Again, this result was supported by supplementary analyses. Neural activation toward neutral faces was not found to be impaired in SZ, therefore speaking against an overall face-processing deficit. Aberrant activation in scene-sensitive PPA is also found in assessments of memory processes in SZ. It is up to future studies to show how impairments in PPA relate to functional outcome in SZ.

Differential inter-subject correlation of brain activity when kinship is a variable in moral dilemma

Previous behavioural studies have shown that humans act more altruistically towards kin. Whether and how knowledge of genetic relatedness translates into differential neurocognitive evaluation of observed social interactions has remained an open question. Here, we investigated how the human brain is engaged when viewing a moral dilemma between genetic vs. non-genetic sisters. During functional magnetic resonance imaging, a movie was shown, depicting refusal of organ donation between two sisters, with subjects guided to believe the sisters were related either genetically or by adoption. Although 90% of the subjects self-reported that genetic relationship was not relevant, their brain activity told a different story. Comparing correlations of brain activity across all subject pairs between the two viewing conditions, we found significantly stronger inter-subject correlations in insula, cingulate, medial and lateral prefrontal, superior temporal, and superior parietal cortices, when the subjects believed that the sisters were genetically related. Cognitive functions previously associated with these areas include moral and emotional conflict regulation, decision making, and mentalizing, suggesting more similar engagement of such functions when observing refusal of altruism from a genetic sister. Our results show that mere knowledge of a genetic relationship between interacting persons robustly modulates social cognition of the perceiver.

Face-related visual search deficits in first-episode schizophrenia

Schizophrenia is considered a complex illness with multiple cognitive dysfunctions, including a deficit in visual processing. However, whether the deficiency of visual processing in schizophrenia is general across stimuli or stimulus-specific remains the subject of debate. In the current study, eighteen first-episode schizophrenic patients and eighteen healthy controls participated in three visual search tasks in which they were asked to search a specific target of a triangle, face identity or facial affect. The results showed that, compared to healthy controls, the accuracies for face identity and facial affect searches were significantly lower in schizophrenic patients, while the performance of the triangle search was the same. Furthermore, the accuracy of the facial affect search was negatively correlated to negative symptoms in schizophrenia. These results revealed a face-related deficit in schizophrenia and suggest that visual processing deficits in schizophrenia were stimuli-specific.

Modeling a linkage between blood transcriptional expression and activity in brain regions to infer the phenotype of schizophrenia patients

Hundreds of genetic loci participate to schizophrenia liability. It is also known that impaired cerebral connectivity is directly related to the cognitive and affective disturbances in schizophrenia. How genetic susceptibility and brain neural networks interact to specify a pathological phenotype in schizophrenia remains elusive. Imaging genetics, highlighting brain variations, has proven effective to establish links between vulnerability loci and associated clinical traits. As previous imaging genetics works in schizophrenia have essentially focused on structural DNA variants, these findings could be blurred by epigenetic mechanisms taking place during gene expression. We explored the meaningful links between genetic data from peripheral blood tissues on one hand, and regional brain reactivity to emotion task assayed by blood oxygen level-dependent functional magnetic resonance imaging on the other hand, in schizophrenia patients and matched healthy volunteers. We applied Sparse Generalized Canonical Correlation Analysis to identify joint signals between two blocks of variables: (i) the transcriptional expression of 33 candidate genes, and (ii) the blood oxygen level-dependent activity in 16 region of interest. Results suggested that peripheral transcriptional expression is related to brain imaging variations through a sequential pathway, ending with the schizophrenia phenotype. Generalization of such an approach to larger data sets should thus help in outlining the pathways involved in psychiatric illnesses such as schizophrenia.

IMAGING

SEARCHING FOR LINKS TO AID DIAGNOSIS: Researchers explore links between the expression of genes associated with schizophrenia in blood cells and variations in brain activity during emotion processing. El Chérif Ibrahim and Eric Fakra at Aix-Marseille Université, France, and colleagues have developed a method to relate the expression levels of 33 schizophrenia susceptibility genes in blood cells and functional magnetic resonance imaging (fMRI) data obtained as individuals carry out a task that triggers emotional responses. Although they found no significant differences in the expression of genes between the 26 patients with schizophrenia and 26 healthy controls they examined, variations in activity in the superior temporal gyrus were strongly linked to schizophrenia-associated gene expression and presence of disease. Similar analyses of larger data sets will shed further light on the relationship between peripheral molecular changes and disease-related behaviors and ultimately, aid the diagnosis of neuropsychiatric disease.

Differential sensory fMRI signatures in autism and schizophrenia: Analysis of amplitude and trial-to-trial variability

Autism and schizophrenia share multiple phenotypic and genotypic markers, and there is ongoing debate regarding the relationship of these two disorders. To examine whether cortical dynamics are similar across these disorders, we directly compared fMRI responses to visual, somatosensory and auditory stimuli in adults with autism (N=15), with schizophrenia (N=15), and matched controls (N=15). All participants completed a one-back letter detection task presented at fixation (to control attention) while task-irrelevant sensory stimulation was delivered to the different modalities. We focused specifically on the response amplitudes and the variability in sensory fMRI responses of the two groups, given the evidence of greater trial-to-trial variability in adults with autism. Both autism and schizophrenia individuals showed weaker signal-to-noise ratios (SNR) in sensory-evoked responses compared to controls (d>0.42), but for different reasons. For the autism group, the fMRI response amplitudes were indistinguishable from controls but were more variable trial-to-trial (d=0.47). For the schizophrenia group, response amplitudes were smaller compared to autism (d=0.44) and control groups (d=0.74), but were not significantly more variable (d<0.29). These differential group profiles suggest (1) that greater trial-to-trial variability in cortical responses may be specific to autism and is not a defining characteristic of schizophrenia, and (2) that blunted response amplitudes may be characteristic of schizophrenia. The relationship between the amplitude and the variability of cortical activity might serve as a specific signature differentiating these neurodevelopmental disorders. Identifying the neural basis of these responses and their relationship to the underlying genetic bases may substantially enlighten the understanding of both disorders.

The Core Brain Region for Face Processing in Schizophrenia Lacks Face Selectivity

BACKGROUND

Face perception impairment in schizophrenia has long been recognized. However, brain mechanisms underlying this socially important perceptual deficit are not well understood. Previous magnetic resonance imaging (MRI) studies have shown that patients have altered structure in brain regions responsible for processing face information, but functional properties of these brain regions are not clearly determined. A key functional property of the face-processing system--face selectivity--has yet to be evaluated in schizophrenia.

METHODS

We used functional MRI (fMRI) to examine face selectivity of 3 core face-processing regions--fusiform face area (FFA), occipital face area (OFA), and superior temporal sulcus (STS)--in schizophrenia patients (n = 24) and healthy controls (n = 23). To disassociate face-specific processing from general perceptual processing, we compared cortical activations during performance of perceptually equated face and tree detection tasks.

RESULTS

Activation levels of the 3 putative face-processing regions during face detection did not differ between patients and controls, being similar for FFA and OFA and absent for STS. However, face selectivity, indexed by the difference in cortical activation between face and tree detection, was significantly reduced in patients for FFA, especially for low-contrast stimuli. FFA activation and perceptual performance during face detection were associated in patients.

CONCLUSIONS

These results show a lack of face-specific processing in the schizophrenic brain region presumably subserving face perception. This finding suggests boosting visual salience of face images as a potential therapeutic venue for improving face perception in this psychiatric disorder.

Efficacy of identifying neural components in the face and emotion processing system in schizophrenia using a dynamic functional localizer

Schizophrenia is associated with deficits in face perception and emotion recognition. Despite consistent behavioural results, the neural mechanisms underlying these cognitive abilities have been difficult to isolate, in part due to differences in neuroimaging methods used between studies for identifying regions in the face processing system. Given this problem, we aimed to validate a recently developed fMRI-based dynamic functional localizer task for use in studies of psychiatric populations and specifically schizophrenia. Previously, this functional localizer successfully identified each of the core face processing regions (i.e. fusiform face area, occipital face area, superior temporal sulcus), and regions within an extended system (e.g. amygdala) in healthy individuals. In this study, we tested the functional localizer success rate in 27 schizophrenia patients and in 24 community controls. Overall, the core face processing regions were localized equally between both the schizophrenia and control group. Additionally, the amygdala, a candidate brain region from the extended system, was identified in nearly half the participants from both groups. These results indicate the effectiveness of a dynamic functional localizer at identifying regions of interest associated with face perception and emotion recognition in schizophrenia. The use of dynamic functional localizers may help standardize the investigation of the facial and emotion processing system in this and other clinical populations.

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.

Visual and associated affective processing of face information in schizophrenia: A selective review

Perception of facial features is crucial in social life. In past decades, extensive research showed that the ability to perceive facial emotion expression was compromised in schizophrenia patients. Given that face perception involves visual/cognitive and affective processing, the roles of these two processing domains in the compromised face perception in schizophrenia were studied and discussed, but not clearly defined. One particular issue was whether face-specific processing is implicated in this psychiatric disorder. Recent investigations have probed into the components of face perception processes such as visual detection, identity recognition, emotion expression discrimination and working memory conveyed from faces. Recent investigations have further assessed the associations between face processing and basic visual processing and between face processing and social cognitive processing such as Theory of Mind. In this selective review, we discuss the investigative findings relevant to the issues of cognitive and affective association and face-specific processing. We highlight the implications of multiple processing domains and face-specific processes as potential mechanisms underlying compromised face perception in schizophrenia. These findings suggest a need for a domain-specific therapeutic approach to the improvement of face perception in schizophrenia.

Abnormalities in personal space and parietal-frontal function in schizophrenia

Schizophrenia is associated with subtle abnormalities in day-to-day social behaviors, including a tendency in some patients to “keep their distance” from others in physical space. The neural basis of this abnormality, and related changes in social functioning, is unknown. Here we examined, in schizophrenic patients and healthy control subjects, the functioning of a parietal–frontal network involved in monitoring the space immediately surrounding the body (“personal space”). Using fMRI, we found that one region of this network, the dorsal intraparietal sulcus (DIPS), was hyper-responsive in schizophrenic patients to face stimuli appearing to move towards the subjects, intruding into personal space. This hyper-responsivity was predicted both by the size of personal space (which was abnormally elevated in the schizophrenia group) and the severity of negative symptoms. In contrast, in a second study, the activity of two lower-level visual areas that send information to DIPS (the fusiform face area and middle temporal area) was normal in schizophrenia. Together, these findings suggest that changes in parietal–frontal networks that support the sensory-guided initiation of behavior, including actions occurring in the space surrounding the body, contribute to social dysfunction and negative symptoms in schizophrenia.

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A parietal–frontal network in the primate brain monitors the space near the body.

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“Personal space”, a person's “comfort zone”, is influenced by this network.

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Patients with schizophrenia show an abnormal enlargement of personal space.

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This enlargement correlates with negative symptom levels.

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This enlargement also correlates with parietal responses to personal space intrusions.

Response of schizophrenic patients to dynamic facial expressions: an event-related potentials study

OBJECTIVE

Patients with schizophrenia have an impaired ability to respond to faces and may specifically show an impaired response to dynamic facial expressions. Here we investigated the responses of schizophrenic patients and healthy controls to dynamic facial images using event-related potentials (ERPs).

METHODS

We showed 13 schizophrenic patients and 13 healthy controls visual stimuli comprising facial expressions that continually changed from neutral to emotional.

RESULTS

N200 latencies and P100-N200 peak-to-peak amplitudes in controls were prolonged or greater for dynamic emotions in comparison with those for static stimuli, but the group with schizophrenia showed no significant differences in responses to dynamic and static emotions. A significant negative correlation was observed between N200 latencies for dynamic negative emotion and PANSS (positive and negative syndrome scale) general psychopathology scale scores.

CONCLUSIONS

A combination of hypersensitivity to static emotions and hyposensitivity to dynamic emotions in people with schizophrenia might underlie the absence of differences in response to these stimuli. A tendency in the schizophrenic group to hypersensitivity to static emotions might arise from the enhanced fear and arousal characteristics of this group; their hyposensitivity to dynamic emotions might result from controlled attentional bias away from facial expressions to reduce fear and anxiety.

Involvement of the dorsolateral prefrontal cortex and superior temporal sulcus in impaired social perception in schizophrenia

BACKGROUND

Schizophrenia is a mental disorder characterized by impairments in diverse thinking and emotional responses, which are related to social perception dysfunction. This fMRI study was designed to investigate a neurobiological basis of social perception deficits of patients with schizophrenia in various social situations of daily life and their relationship with clinical symptoms and social dysfunction.

METHODS

Seventeen patients and 19 controls underwent functional magnetic resonance imaging, during which participants performed a virtual social perception task, containing an avatar's speech with positive, negative or neutral emotion in a virtual reality space. Participants were asked to determine whether or not the avatar's speech was appropriate to each situation.

RESULTS

The significant group×appropriateness interaction was seen in the left dorsolateral prefrontal cortex (DLPFC), resulting from lower activity in patients in the inappropriate condition, and left DLPFC activity was negatively correlated with the severity of negative symptoms and positively correlated with the level of social functioning. The significant appropriateness×emotion interaction observed in the left superior temporal sulcus (STS) was present in controls, but absent in patients, resulting from the existence and absence of a difference between the inappropriate positive and negative conditions, respectively.

CONCLUSIONS

These findings indicate that dysfunction of the DLPFC-STS network may underlie patients' abnormal social perception in various social situations of daily life. Abnormal functioning of this network may contribute to increases of negative symptoms and decreases of social functioning.

Face recognition in schizophrenia disorder: A comprehensive review of behavioral, neuroimaging and neurophysiological studies

Facial emotion processing has been extensively studied in schizophrenia patients while general face processing has received less attention. The already published reviews do not address the current scientific literature in a complete manner. Therefore, here we tried to answer some questions that remain to be clarified, particularly: are the non-emotional aspects of facial processing in fact impaired in schizophrenia patients? At the behavioral level, our key conclusions are that visual perception deficit in schizophrenia patients: are not specific to faces; are most often present when the cognitive (e.g. attention) and perceptual demands of the tasks are important; and seems to worsen with the illness chronification. Although, currently evidence suggests impaired second order configural processing, more studies are necessary to determine whether or not holistic processing is impaired in schizophrenia patients. Neural and neurophysiological evidence suggests impaired earlier levels of visual processing, which might involve the deficits in interaction of the magnocellular and parvocellular pathways impacting on further processing. These deficits seem to be present even before the disorder out-set. Although evidence suggests that this deficit may be not specific to faces, further evidence on this question is necessary, in particularly more ecological studies including context and body processing.

Hippocampal dysfunction during declarative memory encoding in schizophrenia and effects of genetic liability

Declarative memory (DM) impairments are reported in schizophrenia and in unaffected biological relatives of patients. However, the neural correlates of successful and unsuccessful encoding, mediated by the medial temporal lobe (MTL) memory system, and the influence of disease-related genetic liability remain under explored. This study employed an event-related functional MRI paradigm to compare activations for successfully and unsuccessfully encoded associative face-name stimuli between 26 schizophrenia patients (mean age: 33, 19m/7f), 30 controls (mean age: 29, 24m/6f), and 14 unaffected relatives of patients (mean age: 40, 5m/9f). Compared to controls or unaffected relatives, patients showed hyper-activations in ventral visual stream and temporo-parietal cortical association areas when contrasting successfully encoded events to fixation. Follow-up hippocampal regions-of-interest analysis revealed schizophrenia-related hyper-activations in the right anterior hippocampus during successful encoding; contrasting successful versus unsuccessful events produced schizophrenia-related hypo-activations in the left anterior hippocampus. Similar hippocampal hypo-activations were observed in unaffected relatives during successful versus unsuccessful encoding. Post hoc analyses of hippocampal volume showed reductions in patients, but not in unaffected relatives compared to controls. Findings suggest that DM encoding deficits are attributable to both disease-specific and genetic liability factors that impact different components of the MTL memory system. Hyper-activations in temporo-occipital and parietal regions observed only in patients suggest the influence of disease-related factors. Regional hyper- and hypo-activations attributable to successful encoding occurring in both patients and unaffected relatives suggest the influence of schizophrenia-related genetic liability factors.

An fMRI study of facial emotion processing in children and adolescents with 22q11.2 deletion syndrome

BACKGROUND

22q11.2 deletion syndrome (22q11DS, velo-cardio-facial syndrome [VCFS]) is a genetic disorder associated with interstitial deletions of chromosome 22q11.2. In addition to high rates of neuropsychiatric disorders, children with 22q11DS have impairments of face processing, as well as IQ-independent deficits in visuoperceptual function and social and abstract reasoning. These face-processing deficits may contribute to the social impairments of 22q11DS. However, their neurobiological basis is poorly understood.

METHODS

We used event-related functional magnetic resonance imaging (fMRI) to examine neural responses when children with 22q11DS (aged 9-17 years) and healthy controls (aged 8-17 years) incidentally processed neutral expressions and mild (50%) and intense (100%) expressions of fear and disgust. We included 28 right-handed children and adolescents: 14 with 22q11DS and 14 healthy (including nine siblings) controls.

RESULTS

Within groups, contrasts showed that individuals significantly activated 'face responsive' areas when viewing neutral faces, including fusiform-extrastriate cortices. Further, within both groups, there was a significant positive linear trend in activation of fusiform-extrastriate cortices and cerebellum to increasing intensities of fear. There were, however, also between-group differences. Children with 22q11DS generally showed reduced activity as compared to controls in brain regions involved in social cognition and emotion processing across emotion types and intensities, including fusiform-extrastriate cortices, anterior cingulate cortex (Brodmann area (BA) 24/32), and superomedial prefrontal cortices (BA 6). Also, an exploratory correlation analysis showed that within 22q11DS children reduced activation was associated with behavioural impairment-social difficulties (measured using the Total Difficulties Score from the Strengths and Difficulties Questionnaire [SDQ]) were significantly negatively correlated with brain activity during fear and disgust processing (respectively) in the left precentral gyrus (BA 4) and in the left fusiform gyrus (FG, BA 19), right lingual gyrus (BA 18), and bilateral cerebellum.

CONCLUSIONS

Regions involved in face processing, including fusiform-extrastriate cortices, anterior cingulate gyri, and superomedial prefrontal cortices (BA 6), are activated by facial expressions of fearful, disgusted, and neutral expressions in children with 22q11DS but generally to a lesser degree than in controls. Hypoactivation in these regions may partly explain the social impairments of children with 22q11DS.

Social-Cognitive Deficits in Schizophrenia

Patients with schizophrenia not only suffer from prototypical psychotic symptoms such as delusions and hallucinations and from cognitive deficits, but also from tremendous deficits in social functioning. However, little is known about the interplay between the cognitive and the social-cognitive deficits in schizophrenia. Our chapter gives an overview on behavioral, as well as functional imaging studies on social cognition in schizophrenia. Main findings on cognitive and motivational deficits in schizophrenia are reviewed and introduced within the context of the dopamine hypothesis of schizophrenia. The reviewed findings suggest that disturbed "social brain" functioning in schizophrenia, depending on the specific context, can either lead to a neglect of the emotions and intentions of others or to the false attribution of these emotions and intentions in an emotionally neutral social content. We integrate these findings with the current knowledge about aberrant dopaminergic firing in schizophrenia by presenting a comprehensive model explaining core symptoms of the disorder. The main implication of the presented model is that neither cognitive-motivational, nor social-cognitive deficits alone cause schizophrenia symptoms, but that symptoms only emerge by the interplay of disturbed social brain functioning with aberrant dopaminergic firing.

Subsequent memory effects in schizophrenia

Differential neural activation at encoding can predict which stimuli will be subsequently remembered or forgotten, and memory deficits are pronounced in schizophrenia. We used event-related functional magnetic resonance imaging (fMRI) to investigate subsequent memory (SM) effects for visual fractals in patients with schizophrenia (n=26) and healthy controls (n=28). Participants incidentally encoded the fractals during an oddball task and 10 min later they made old/new recognition memory judgments on 30 target fractals and 30 foil fractals. We found evidence for subsequent memory (SM, subsequently remembered>subsequently forgotten) effects on regional brain activation in both groups but with distinct patterns. Region of interest (ROI) analyses in controls demonstrated SM activation in both medial temporal lobe (MTL) and fusiform cortex (FF), whereas patients showed SM effects only in the FF. There were no significant between group differences in MTL activation; however, patients demonstrated greater FF activation than controls. Notably, greater FF activation during successful encoding was associated with more severe negative symptoms. Exploratory whole brain analyses in patients demonstrated SM activation in the occipital pole, lateral occipital cortex, left inferior temporal gyrus, and fusiform cortex; whereas in controls there was no significant activation that survived correction for multiple comparisons. Our findings suggest that patients, particularly those with prominent negative symptoms, may activate FF as a compensatory strategy to promote successful encoding, with relatively less reliance on MTL recruitment.

Facial emotion identification in early-onset psychosis

Facial emotion identification (FEI) deficits are common in patients with chronic schizophrenia and are strongly related to impaired functioning. The objectives of this study were to determine whether FEI deficits are present and emotion specific in people experiencing early-onset psychosis (EOP), and related to current clinical symptoms and functioning. Patients with EOP (n=34, mean age=14.11, 53% female) and healthy controls (HC, n=42, mean age 13.80, 51% female) completed a task of FEI that measured accuracy, error pattern and response time. Relative to HC, patients with EOP (i) had lower accuracy for identifying facial expressions of emotions, especially fear, anger and disgust, (ii) were more likely to misattribute other emotional expressions as fear or disgust, and (iii) were slower at accurately identifying all facial expressions. FEI accuracy was not related to clinical symptoms or current functioning. Deficits in FEI (especially for fear, anger and disgust) are evident in EOP. Our findings suggest that while emotion identification deficits may reflect a trait susceptibility marker, functional deficits may represent a sequelae of illness.

Facial emotion identification in early-onset and first-episode psychosis: a systematic review with meta-analysis

OBJECTIVE

Patients with chronic schizophrenia are characterized by deficits in identifying facial expressions of emotion, and these deficits relate to impaired social and occupational function. It is not yet known if these deficits are trait-like and present at the onset of psychosis, preceding a subsequent diagnosis of schizophrenia. Our objective was to systematically review and analyze the extant literature to assess if there is a consistent profile of emotion identification problems in early-onset and first-episode psychosis.

METHODS

We conducted a systematic review and meta-analysis of 12 peer-reviewed studies of facial emotion identification in early-onset and first-episode psychosis, published between 1980 and March 2013. We examined the average mean difference between patients and controls on measures of facial emotion identification.

RESULTS

Findings suggest that patients with early-onset and first-episode psychosis have impairment in identifying facial expressions of biologically salient emotion. Across the 12 studies, the onset of psychosis was distinguished by a generalized effect of significantly poorer accuracy for identifying facial expressions of emotion than healthy controls, and this difference had a substantial effect size (d=-0.88, N=378, 95% CI=-1.42 to -0.32). Within this general effect some emotions were also harder for patients to identify than others, with the magnitude of impairment found to be (i) large for disgust, fear and surprise, and (ii) medium for sadness, and happiness. No between groups mean differences were found for anger or neutral facial expressions.

CONCLUSIONS

Deficits in facial emotion identification are evident at first onset of a psychotic episode. The findings suggest that, over and above a generalized deficit in identifying facial emotion, patients may find some emotions harder to identifying than others. This reflects findings with chronic schizophrenia populations and suggests that emotion identification impairment represents a trait susceptibility marker, rather than a sequeale of illness. They signal the urgent need to treat emotion identification deficits at the onset of illness, which could improve functional outcomes.

Positive and negative symptom scores are correlated with activation in different brain regions during facial emotion perception in schizophrenia patients: a voxel-based sLORETA source activity study

Schizophrenia is one of the most devastating of all mental illnesses, and has dimensional characteristics that include both positive and negative symptoms. One problem reported in schizophrenia patients is that they tend to show deficits in face emotion processing, on which negative symptoms are thought to have stronger influence. In this study, four event-related potential (ERP) components (P100, N170, N250, and P300) and their source activities were analyzed using EEG data acquired from 23 schizophrenia patients while they were presented with facial emotion picture stimuli. Correlations between positive and negative syndrome scale (PANSS) scores and source activations during facial emotion processing were calculated to identify the brain areas affected by symptom scores. Our analysis demonstrates that PANSS positive scores are negatively correlated with major areas of the left temporal lobule for early ERP components (P100, N170) and with the right middle frontal lobule for a later component (N250), which indicates that positive symptoms affect both early face processing and facial emotion processing. On the other hand, PANSS negative scores are negatively correlated with several clustered regions, including the left fusiform gyrus (at P100), most of which are not overlapped with regions showing correlations with PANSS positive scores. Our results suggest that positive and negative symptoms affect independent brain regions during facial emotion processing, which may help to explain the heterogeneous characteristics of schizophrenia.

Reduced habituation in patients with schizophrenia

BACKGROUND

Neural habituation, the decrease in brain response to repeated stimulation, is a basic form of learning. There is strong evidence for behavioral and physiological habituation deficits in schizophrenia, and one previous study found reduced neural habituation within the hippocampus. However, it is unknown whether neural habituation deficits are specific to faces and limited to the hippocampus. Here we studied habituation of several brain regions in schizophrenia, using both face and object stimuli. Post-scan memory measures were administered to test for a link between hippocampal habituation and memory performance.

METHODS

During an fMRI scan, 23 patients with schizophrenia and 21 control subjects viewed blocks of a repeated neutral face or neutral object, and blocks of different neutral faces and neutral objects. Habituation in the hippocampus, primary visual cortex and fusiform face area (FFA) was compared between groups. Memory for faces, words, and word pairs was assessed after the scan.

RESULTS

Patients showed reduced habituation to faces in the hippocampus and primary visual cortex, but not the FFA. Healthy control subjects exhibited a pattern of hippocampal discrimination that distinguished between repeated and different images for both faces and objects, and schizophrenia patients did not. Hippocampal discrimination was positively correlated with memory for word pairs.

CONCLUSION

Patients with schizophrenia showed reduced habituation of the hippocampus and visual cortex, and a lack of neural discrimination between old and new images in the hippocampus. Hippocampal discrimination correlated with memory performance, suggesting reduced habituation may contribute to the memory deficits commonly observed in schizophrenia.

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.

Neural basis of implicit memory for socio-emotional information in schizophrenia

Individuals with schizophrenia are impaired in processing social signals such as facial expressions of emotion. Perceiving facial expressions is a complex process that depends on a distributed neural network of regions involved in affective, cognitive, and visual processing. We examined repetition priming, a non-conscious form of perceptual learning, to explore the visual-perceptual processes associated with perceiving facial expression in people with schizophrenia. Functional magnetic resonance imaging (fMRI) was also employed to probe the sensitivity of face-responsive regions in the ventral pathway to the repetition of stimuli. Subjects viewed blocks of novel and repeated faces displaying fear expressions and neutral expressions and identified each face as male or female. Gender decisions were faster for repeated encoding relative to initial encoding of faces, indicating significant priming for facial expressions. Priming was normal in schizophrenia patients, but, as expected, recognition memory for the expressions was impaired. Neuroimaging findings showed that priming-related activation for patients was reduced in the left fusiform gyrus, relative to controls, regardless of facial expression. The findings suggest that schizophrenia patients have altered neural sensitivity in regions of the ventral visual processing stream that underlie early perceptual learning of objects and faces.

Speed of facial affect intensity recognition as an endophenotype of first-episode psychosis and associated limbic-cortical grey matter systems

BACKGROUND

Psychotic disorders are highly heritable such that the unaffected relatives of patients may manifest characteristics, or endophenotypes, that are more closely related to risk genes than the overt clinical condition. Facial affect processing is dependent on a distributed cortico-limbic network that is disrupted in psychosis. This study assessed facial affect processing and related brain structure as a candidate endophenotype of first-episode psychosis (FEP).

METHOD

Three samples comprising 30 FEP patients, 30 of their first-degree relatives and 31 unrelated healthy controls underwent assessment of facial affect processing and structural magnetic resonance imaging (sMRI) data. Multivariate analysis (partial least squares, PLS) was used to identify a grey matter (GM) system in which anatomical variation was associated with variation in facial affect processing speed.

RESULTS

The groups did not differ in their accuracy of facial affect intensity rating but differed significantly in speed of response, with controls responding faster than relatives, who responded faster than patients. Within the control group, variation in speed of affect processing was significantly associated with variation of GM density in amygdala, lateral temporal cortex, frontal cortex and cerebellum. However, this association between cortico-limbic GM density and speed of facial affect processing was absent in patients and their relatives.

CONCLUSIONS

Speed of facial affect processing presents as a candidate endophenotype of FEP. The normal association between speed of facial affect processing and cortico-limbic GM variation was disrupted in FEP patients and their relatives.

Social cognition in schizophrenia: from social stimuli processing to social engagement

Social cognition consists of several skills which allow us to interact with other humans. These skills include social stimuli processing, drawing inferences about others' mental states, and engaging in social interactions. In recent years, there has been growing evidence of social cognitive impairments in patients with schizophrenia. Apparently, these impairments are separable from general neurocognitive impairments, such as attention, memory, and executive functioning. Moreover, social cognition seems to be a main determinant of functional outcome and could be used as a guide to elaborate new pharmacological and psychological treatments. However, most of these studies focus on individual mechanisms and observational perspectives; only few of them study schizophrenic patients during interactive situations. We first review evidences of social cognitive impairments both in social stimuli processing and in mental state attribution. We focus on the relationship between these functions and both general cognitive impairments and functional outcome. We next review recent game theory approaches to the study of how social engagement occurs in schizophrenic patients. The advantage of using game theory is that game-oriented tasks can assess social decision making in an interactive everyday situation model. Finally, we review proposed theoretical models used to explain social alterations and their underlying biological mechanisms. Based on interactive studies, we propose a framework which takes into account the dynamic nature of social processes. Thus, understanding social skills as a result of dynamical systems could facilitate the development of both basic research and clinical applications oriented to psychiatric populations.

Neurophysiological impairment in emotional face processing is associated with low extraversion in schizophrenia

Patients with schizophrenia have low extraversion and high neuroticism. These personality traits affect the everyday life of patients with schizophrenia, making it important to investigate neurobiological basis of personality traits. In healthy people, extraversion is associated with hemodynamic responses in the amygdala and electrophysiological brain activity such as event-related potential and event-related desynchronization during emotional face processing. Patients with schizophrenia show abnormal neural activity during emotional face processing, such as an N170 amplitude reduction. However, few studies to date have reported an association between personality traits and neural activity during emotional face processing in schizophrenia. In the present study, we examined N170 during emotional face processing, and association with personality traits in patients with schizophrenia. Fifteen male patients with chronic schizophrenia and 15 healthy male subjects participated in this study. Patients with schizophrenia had reduced N170 amplitudes (p=0.007). While healthy subjects had increased N170 amplitudes in response to emotional faces compared with neutral faces (p=0.003), patients with schizophrenia showed no difference in N170 amplitudes between emotional and neutral faces (p=0.60). Reduced N170 amplitude in response to neutral faces was correlated with low extraversion scores in patients with schizophrenia (r(s)=-0.69, p=0.005). The abnormal N170 and its association with extraversion in schizophrenia were found at the right rather than the left posterior temporal electrode. An abnormal N170 in schizophrenia may reflect impairments in the structural encoding of emotional faces, and indiscrimination between emotional and neutral faces at this stage of information processing. The association between abnormal N170 amplitudes and extraversion suggests that abnormal neural activity in the early stages of emotional face processing may underlie low extraversion characteristic of schizophrenia.

Publication bias in neuroimaging research: implications for meta-analyses

Neuroimaging and the neurosciences have made notable advances in sharing activation results through detailed databases, making meta-analysis of the published research faster and easier. However, the effect of publication bias in these fields has not been previously addressed or accounted for in the developed meta-analytic methods. In this article, we examine publication bias in functional magnetic resonance imaging (fMRI) for tasks involving working memory in the frontal lobes (Brodmann Areas 4, 6, 8, 9, 10, 37, 45, 46, and 47). Seventy-four studies were selected from the literature and the effect of publication bias was examined using a number of regression-based techniques. Pearson's r correlation coefficient and Cohen's d effect size estimates were computed for the activation in each study and compared to the study sample size using Egger's regression, Macaskill's regression, and the 'Trim and Fill' method. Evidence for publication bias was identified in this body of literature (p < 0.01 for each test), generally, though was neither task- nor sub-region-dependent. While we focused our analysis on this subgroup of brain mapping studies, we believe our findings generalize to the brain imaging literature as a whole and databases seeking to curate their collective results. While neuroimaging databases of summary effects are of enormous value to the community, the potential publication bias should be considered when performing meta-analyses based on database contents.

["Theory of mind" and its neuronal correlates in forensically relevant disorders]

Theory of mind (ToM), the ability to recognize mental states of others, and empathy are crucial cognitive-emotional processes for appropriate social interactions. Deficits in these processes can lead to maladjusted social behavior or even to aggressive or criminal behavior. ToM and empathy deficits have been found in different forensically relevant disorders, such as schizophrenia, pedophilia but especially in autism and psychopathy according to Hare. Most notably, autistic and psychopathic patients differ in their type of deficits and in their neuronal correlates. While autistic individuals lack the ability to take the perspective of others, psychopaths lack empathy. The aim of this article is to provide a better understanding of the pathophysiology of ToM and empathy deficits in forensically relevant disorders by reviewing and discussing the findings of neuroimaging and lesion studies and to highlight crucial implications for neuropsychotherapy according to Grawe.

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.

The benefit of directly comparing autism and schizophrenia for revealing mechanisms of social cognitive impairment

Autism and schizophrenia share a history of diagnostic conflation that was not definitively resolved until the publication of the DSM-III in 1980. Though now recognized as heterogeneous disorders with distinct developmental trajectories and dissociative features, much of the early nosological confusion stemmed from apparent overlap in certain areas of social dysfunction. In more recent years, separate but substantial literatures have accumulated for autism and schizophrenia demonstrating that abnormalities in social cognition directly contribute to the characteristic social deficits of both disorders. The current paper argues that direct comparison of social cognitive impairment can highlight shared and divergent mechanisms underlying pathways to social dysfunction, a process that can provide significant clinical benefit by informing the development of tailored treatment efforts. Thus, while the history of diagnostic conflation between autism and schizophrenia may have originated in similarities in social dysfunction, the goal of direct comparisons is not to conflate them once again but rather to reveal distinctions that illuminate disorder-specific mechanisms and pathways that contribute to social cognitive impairment.

Brain dysfunctions during facial discrimination in schizophrenia: selective association to affect decoding

Schizophrenia patients exhibit impaired facial affect perception, yet the exact nature of this impairment remains unclear. We investigated neural activity related to processing facial emotional and non-emotional information and complex images in 12 schizophrenia patients and 15 healthy controls using functional magnetic resonance imaging. All subjects performed a facial information processing task with three conditions: matching facial emotion, matching facial identity, and matching complex visual patterns. Patients and controls showed comparable behavioral performance in all task conditions. The neural activation patterns in schizophrenia patients and healthy controls were distinctly different while processing affect-related facial information but not other non-emotional facial features. During emotion matching, orbital frontal cortex and left amydala activations were found in controls but not in patients. When comparing emotion versus identity matching, controls activated the fusiform and middle temporal gyri, left superior temporal gyrus, and right inferior and middle frontal gyrus, whereas schizophrenia patients only activated the middle and inferior frontal gyri, the frontal operculi and the right insular cortex. Our findings suggest that schizophrenia patients and healthy controls may utilize different neural networks when processing facial emotional information.

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.

Increased fusiform area activation in schizophrenia during processing of spatial frequency-degraded faces, as revealed by fMRI

BACKGROUND

People with schizophrenia demonstrate perceptual organization impairments, and these are thought to contribute to their face processing difficulties.

METHOD

We examined the neural substrates of emotionally neutral face processing in schizophrenia by investigating neural activity under three stimulus conditions: faces characterized by the full spectrum of spatial frequencies, faces with low spatial frequency information removed [high spatial frequency (HSF) condition], and faces with high spatial frequency information removed [low spatial frequency (LSF) condition]. Face perception in the HSF condition is more reliant on local feature processing whereas perception in the LSF condition requires greater reliance on global form processing. Past studies of perceptual organization in schizophrenia indicate that patients perform relatively more poorly with degraded stimuli but also that, when global information is absent, patients may perform better than controls because of their relatively increased ability to initially process individual features. Therefore, we hypothesized that people with schizophrenia (n=14) would demonstrate greater face processing difficulties than controls (n=13) in the LSF condition, whereas they would demonstrate a smaller difference or superior performance in the HSF condition.

RESULTS

In a gender-discrimination task, behavioral data indicated high levels of accuracy for both groups, with a trend toward an interaction involving higher patient performance in the HSF condition and poorer patient performance in the LSF condition. Patients demonstrated greater activity in the fusiform gyrus compared to controls in both degraded conditions.

CONCLUSIONS

These data suggest that impairments in basic integration abilities may be compensated for by relatively increased activity in this region.