Constricted expressiveness and psychophysiological reactivity in schizophrenia

Voice patterns in schizophrenia: A systematic review and Bayesian meta-analysis

Voice atypicalities have been a characteristic feature of schizophrenia since its first definitions. They are often associated with core negative symptoms such as flat affect and alogia, and with the social impairments seen in the disorder. This suggests that voice atypicalities may represent a marker of clinical features and social functioning in schizophrenia. We systematically reviewed and meta-analyzed the evidence for distinctive acoustic patterns in schizophrenia, as well as their relation to clinical features. We identified 46 articles, including 55 studies with a total of 1254 patients with schizophrenia and 699 healthy controls. Summary effect sizes (Hedges'g and Pearson's r) estimates were calculated using multilevel Bayesian modeling. We identified weak atypicalities in pitch variability (g = -0.55) related to flat affect, and stronger atypicalities in proportion of spoken time, speech rate, and pauses (g's between -0.75 and -1.89) related to alogia and flat affect. However, the effects were mostly modest (with the important exception of pause duration) compared to perceptual and clinical judgments, and characterized by large heterogeneity between studies. Moderator analyses revealed that tasks with a more demanding cognitive and social component showed larger effects both in contrasting patients and controls and in assessing symptomatology. In conclusion, studies of acoustic patterns are a promising but, yet unsystematic avenue for establishing markers of schizophrenia. We outline recommendations towards more cumulative, open, and theory-driven research.

The Fragile Brain: Stress Vulnerability, Negative Affect and GABAergic Neurocircuits in Psychosis

Persons with schizophrenia exhibit sensitivity to stress and negative affect (NA), both strongly correlated with poor functional outcome. This theoretical review suggests that NA reflects a "fragile brain," ie, vulnerable to stress, including events not experienced as stressful by healthy individuals. Based on postmortem evidence of altered gamma-aminobutyric acid (GABA) function in parvalbumin positive interneurons (PVI), animal models of PVI abnormalities and neuroimaging data with GABAergic challenge, it is suggested that GABAergic disruptions weaken cortical regions, which leads to stress vulnerability and excessive NA. Neurocircuits that respond to stressful and salient environmental stimuli, such as the hypothalamic-pituitary-adrenal axis and the amygdala, are highly dysregulated in schizophrenia, exhibiting hypo- and hyper-activity. PVI abnormalities in lateral prefrontal cortex and hippocampus have been hypothesized to affect cognitive function and positive symptoms, respectively; in the medial frontal cortex (dorsal anterior cingulate cortex and dorsal medial prefrontal cortex), these abnormalities may lead to vulnerability to stress, NA and dysregulation of stress responsive systems. Given that postmortem PVI disruptions have been identified in other conditions, such as bipolar disorder and autism, stress vulnerability may reflect a transdiagnostic dimension of psychopathology.

The specific social costs of expressive negative symptoms in schizophrenia: reduced smiling predicts interactional outcome

OBJECTIVE

We tested whether people with schizophrenia and prominent expressive negative symptoms (ENS) show reduced facial expressions in face-to-face social interactions and whether this expressive reduction explains negative social evaluations of these persons.

METHOD

We compared participants with schizophrenia with high ENS (n = 18) with participants with schizophrenia with low ENS (n = 30) and with healthy controls (n = 39). Participants engaged in an affiliative role-play that was coded for the frequency of positive and negative facial expression and rated for social performance skills and willingness for future interactions with the respective role-play partner.

RESULTS

Participants with schizophrenia with high ENS showed significantly fewer positive facial expressions than those with low ENS and controls and were also rated significantly lower on social performance skills and willingness for future interactions. Participants with schizophrenia with low ENS did not differ from controls on these measures. The group difference in willingness for future interactions was significantly and independently mediated by the reduced positive facial expressions and social performance skills.

CONCLUSION

Reduced facial expressiveness in schizophrenia is specifically related to ENS and has negative social consequences. These findings highlight the need to develop aetiological models and targeted interventions for ENS and its social consequences.

Mirroring the self: testing neurophysiological correlates of disturbed self-experience in schizophrenia spectrum

BACKGROUND

Self-disorders (SDs) have been described as a core schizophrenia spectrum vulnerability phenotype, both in classic and contemporary psychopathological literature. However, such a core phenotype has not yet been investigated adopting a trans-domain approach that combines the phenomenological and the neurophysiological levels of analysis. The aim of this study is to investigate the relation between SDs and subtle, schizophrenia-specific impairments of emotional resonance that are supposed to reflect abnormalities in the mirror neurons mechanism. Specifically, we tested whether electromyographic response to emotional stimuli (i.e. a proxy for subtle changes in facial mimicry and related motor resonance mechanisms) would predict the occurrence of anomalous subjective experiences (i.e. SDs).

SAMPLING AND METHODS

Eighteen schizophrenia spectrum (SzSp) patients underwent a comprehensive psychopathological examination and were contextually tested with a multimodal paradigm, recording facial electromyographic activity of muscles in response to positive and negative emotional stimuli. Experiential anomalies were explored with the Bonn Scale for the Assessment of Basic Symptoms (BSABS) and then condensed into rational subscales mapping SzSp anomalous self-experiences.

RESULTS

SzSp patients showed an imbalance in emotional motor resonance with a selective bias toward negative stimuli, as well as a multisensory integration impairment. Multiple regression analysis showed that electromyographic facial reactions in response to negative stimuli presented in auditory modality specifically and strongly correlated with SD subscore.

CONCLUSIONS

The study confirms the potential of SDs as target phenotype for neurobiological research and encourages research into disturbed motor/emotional resonance as possible body-level correlate of disturbed subjective experiences in SzSp.

Dimensional information-theoretic measurement of facial emotion expressions in schizophrenia

Altered facial expressions of emotions are characteristic impairments in schizophrenia. Ratings of affect have traditionally been limited to clinical rating scales and facial muscle movement analysis, which require extensive training and have limitations based on methodology and ecological validity. To improve reliable assessment of dynamic facial expression changes, we have developed automated measurements of facial emotion expressions based on information-theoretic measures of expressivity of ambiguity and distinctiveness of facial expressions. These measures were examined in matched groups of persons with schizophrenia (n = 28) and healthy controls (n = 26) who underwent video acquisition to assess expressivity of basic emotions (happiness, sadness, anger, fear, and disgust) in evoked conditions. Persons with schizophrenia scored higher on ambiguity, the measure of conditional entropy within the expression of a single emotion, and they scored lower on distinctiveness, the measure of mutual information across expressions of different emotions. The automated measures compared favorably with observer-based ratings. This method can be applied for delineating dynamic emotional expressivity in healthy and clinical populations.

Facial reactions in response to dynamic emotional stimuli in different modalities in patients suffering from schizophrenia: a behavioral and EMG study

Emotional facial expression is an important low-level mechanism contributing to the experience of empathy, thereby lying at the core of social interaction. Schizophrenia is associated with pervasive social cognitive impairments, including emotional processing of facial expressions. In this study we test a novel paradigm in order to investigate the evaluation of the emotional content of perceived emotions presented through dynamic expressive stimuli, facial mimicry evoked by the same stimuli, and their functional relation. Fifteen healthy controls and 15 patients diagnosed with schizophrenia were presented with stimuli portraying positive (laugh), negative (cry) and neutral (control) emotional stimuli in visual, auditory modalities in isolation, and congruently or incongruently associated. Participants where requested to recognize and quantitatively rate the emotional value of the perceived stimuli, while electromyographic activity of Corrugator and Zygomaticus muscles was recorded. All participants correctly judged the perceived emotional stimuli and prioritized the visual over the auditory modality in identifying the emotion when they were incongruently associated (Audio-Visual Incongruent condition). The neutral emotional stimuli did not evoke any muscle responses and were judged by all participants as emotionally neutral. Control group responded with rapid and congruent mimicry to emotional stimuli, and in Incongruent condition muscle responses were driven by what participants saw rather than by what they heard. Patient group showed a similar pattern only with respect to negative stimuli, whereas showed a lack of or a non-specific Zygomaticus response when positive stimuli were presented. Finally, we found that only patients with reduced facial mimicry (Internalizers) judged both positive and negative emotions as significantly more neutral than controls. The relevance of these findings for studying emotional deficits in schizophrenia is discussed.

Cognition-emotion dysinteraction in schizophrenia

Evolving theories of schizophrenia emphasize a "disconnection" in distributed fronto-striatal-limbic neural systems, which may give rise to breakdowns in cognition and emotional function. We discuss these diverse domains of function from the perspective of disrupted neural circuits involved in "cold" cognitive vs. "hot" affective operations and the interplay between these processes. We focus on three research areas that highlight cognition-emotion dysinteractions in schizophrenia: First, we discuss the role of cognitive deficits in the "maintenance" of emotional information. We review recent evidence suggesting that motivational abnormalities in schizophrenia may in part arise due to a disrupted ability to "maintain" affective information over time. Here, dysfunction in a prototypical "cold" cognitive operation may result in "affective" deficits in schizophrenia. Second, we discuss abnormalities in the detection and ascription of salience, manifest as excessive processing of non-emotional stimuli and inappropriate distractibility. We review emerging evidence suggesting deficits in some, but not other, specific emotional processes in schizophrenia - namely an intact ability to perceive emotion "in-the-moment" but poor prospective valuation of stimuli and heightened reactivity to stimuli that ought to be filtered. Third, we discuss abnormalities in learning mechanisms that may give rise to delusions, the fixed, false, and often emotionally charged beliefs that accompany psychosis. We highlight the role of affect in aberrant belief formation, mostly ignored by current theoretical models. Together, we attempt to provide a consilient overview for how breakdowns in neural systems underlying affect and cognition in psychosis interact across symptom domains. We conclude with a brief treatment of the neurobiology of schizophrenia and the need to close our explanatory gap between cellular-level hypotheses and complex behavioral symptoms observed in this illness.

Cognition-emotion dysinteraction in schizophrenia

Evolving theories of schizophrenia emphasize a "disconnection" in distributed fronto-striatal-limbic neural systems, which may give rise to breakdowns in cognition and emotional function. We discuss these diverse domains of function from the perspective of disrupted neural circuits involved in "cold" cognitive vs. "hot" affective operations and the interplay between these processes. We focus on three research areas that highlight cognition-emotion dysinteractions in schizophrenia: First, we discuss the role of cognitive deficits in the "maintenance" of emotional information. We review recent evidence suggesting that motivational abnormalities in schizophrenia may in part arise due to a disrupted ability to "maintain" affective information over time. Here, dysfunction in a prototypical "cold" cognitive operation may result in "affective" deficits in schizophrenia. Second, we discuss abnormalities in the detection and ascription of salience, manifest as excessive processing of non-emotional stimuli and inappropriate distractibility. We review emerging evidence suggesting deficits in some, but not other, specific emotional processes in schizophrenia - namely an intact ability to perceive emotion "in-the-moment" but poor prospective valuation of stimuli and heightened reactivity to stimuli that ought to be filtered. Third, we discuss abnormalities in learning mechanisms that may give rise to delusions, the fixed, false, and often emotionally charged beliefs that accompany psychosis. We highlight the role of affect in aberrant belief formation, mostly ignored by current theoretical models. Together, we attempt to provide a consilient overview for how breakdowns in neural systems underlying affect and cognition in psychosis interact across symptom domains. We conclude with a brief treatment of the neurobiology of schizophrenia and the need to close our explanatory gap between cellular-level hypotheses and complex behavioral symptoms observed in this illness.

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

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

Physiological reactivity and facial expression to emotion-inducing films in patients with schizophrenia

The present study aimed to investigate the physiological reactivity and recognition to emotional stimuli in outpatients with schizophrenia and in healthy controls. Skin conductance response, skin conductance level, heart rate, respiration, corrugator muscle, and orbicularis muscle were all measured using five emotion-eliciting film clips. The patients reported lower intensity of experienced anger and disgust than controls. The patient and control groups did not differ in accuracy to recognize emotions except anger. Anger, fear, amusement, and sadness had a discriminative effect on physiological responses in the two groups. These findings provide helpful physiological evidence influenced by harmful or favorable emotional stimuli. Future directions may include to clarify how physiological reactivity and subject experience to emotion are related to their functioning.

Sustained gamma-band EEG following negative words in depression and schizophrenia

INTRODUCTION

Sustained and elaborative emotional information processing in depression and decreased affective elaboration in schizophrenia are considered hallmarks of these disorders but have not been directly measured. Gamma-band (35-45 Hz) EEG has been associated with semantic functions such as feature binding and may index these elaborative processing. This study examined whether there were group differences in baseline and sustained gamma-band EEG following emotional stimuli in healthy adults as well as adults with depression and schizophrenia.

METHODS

24 never-depressed healthy controls, 14 patients with DSM-IV unipolar major depressive disorder, and 15 patients with DSM-IV schizophrenia completed a lexical emotion identification task during EEG assessment. Gamma-band (35-45 Hz) EEG in response to negative words was the primary dependent measure.

RESULTS

As predicted, depressed individuals displayed sustained and increased gamma-band EEG throughout the task, and particularly in the seconds following negative words. Individuals with schizophrenia displayed decreased gamma-band activity throughout the task.

CONCLUSIONS

These data suggest that gamma-band EEG, measured over several seconds, may serve as a useful index of sustained semantic information processing. Depressed individuals appear to engage in sustained elaboration following emotional stimuli, whereas individuals with schizophrenia are not as prone to this type of elaborative processing.

Empathic abilities in people with schizophrenia

Although the existence of empathy deficits in schizophrenia is generally accepted, very few studies have directly investigated the issue. The nature of empathy deficits in healthy subjects and psychiatric patients is an understudied subject. The performances of the 30 outpatients with schizophrenia on a psychometric measure, the Empathy Quotient (EQ), were compared with those of 30 control subjects matched for age, duration of education and gender. The relatives or spouses of the patients also filled out the EQ. A neuropsychological battery, including emotion recognition, emotional reasoning and theory of mind tasks, was also administered. Schizophrenia patients had severe empathy dysfunction based on their relative EQ ratings. There was a serious discrepancy between the self and relative/spouse assessments of the empathic skills of schizophrenia patients. Consistent with the previous findings schizophrenia patients were impaired in nearly all cognitive tasks. The empathy deficits of schizophrenia patients were associated with their impairments in other social cognitive tasks. Studies focusing on dysfunctional brain networks underlying empathy deficits and studies using more experimental measures of empathy should be helpful to unravel the true nature of the empathic failure in patients with schizophrenia.

Accuracy and intensity of posed emotional expressions in unmedicated schizophrenia patients: vocal and facial channels

This study investigated the ability of schizophrenia patients to volitionally display various emotional expressions. Accuracy and intensity of facial and vocal emotional expression were rated in 26 unmedicated male schizophrenia patients and 20 non-patient male controls while posing emotional facial and vocal expressions. Results indicate that schizophrenia patients, compared to non-patient controls, had deficits in their ability to portray some, but not all, emotions. Accuracy and intensity of posed facial and vocal expressions were inversely correlated with negative symptoms in the patient group. We conclude that observable flattened affect in schizophrenia during posed expression is not evident across all emotions. Furthermore, substantial disruption in the ability to portray posed emotions may be largely driven by the presence of negative symptoms.

Computerized measurement of facial expression of emotions in schizophrenia

Deficits in the ability to express emotions characterize several neuropsychiatric disorders and are a hallmark of schizophrenia, and there is need for a method of quantifying expression, which is currently done by clinical ratings. This paper presents the development and validation of a computational framework for quantifying emotional expression differences between patients with schizophrenia and healthy controls. Each face is modeled as a combination of elastic regions, and expression changes are modeled as a deformation between a neutral face and an expressive face. Functions of these deformations, known as the regional volumetric difference (RVD) functions, form distinctive quantitative profiles of expressions. Employing pattern classification techniques, we have designed expression classifiers for the four universal emotions of happiness, sadness, anger and fear by training on RVD functions of expression changes. The classifiers were cross-validated and then applied to facial expression images of patients with schizophrenia and healthy controls. The classification score for each image reflects the extent to which the expressed emotion matches the intended emotion. Group-wise statistical analysis revealed this score to be significantly different between healthy controls and patients, especially in the case of anger. This score correlated with clinical severity of flat affect. These results encourage the use of such deformation based expression quantification measures for research in clinical applications that require the automated measurement of facial affect.

A review of emotion deficits in schizophrenia

Emotion deficits in schizophrenia have been described since the time of Kraepelin. However, no comprehensive review of clinical emotion studies has ever been conducted, in this work, studies that used diagnostic criteria and were published in English were selected from an extensive PubMed search. Fifty-five studies on emotion expression repeatedly showed that individuals with schizophrenia (IWSs) display fewer overt expressions than non patient comparison subjects (NCSs) in verbal, facial, and acoustic channels. No clear differences were found between IWSs and depressed subjects. Sixty-nine studies examined emotion experience in schizophrenia. IWSs report higher anhedonia, and they tend to show more negative emotions in real-life event studies. In evocative studies, they report a similar degree of pleasantness and a similar or higher degree of unpleasantness. From 110 studies, ii can be concluded that emotion recognition is impaired in schizophrenia in all channels. These deficits in social perception are correlated with neurocognitive deficits and some social skills. IWSs show dysfunction in the three domains of emotion expression, emotion experience, and emotion recognition, and these dysfunctions appear to be independent of each other across domains. These deficits in basic emotion processing may be linked to psychopathology and functional outcomes.

Emotional processing in schizophrenia

INTRODUCTION

Persons with schizophrenia have impaired emotional processing, involving experience, expression, and recognition of emotions.

METHODS

This article reviews the historical descriptions and more recent work on emotion processing in schizophrenia.

RESULTS

Although abilities of emotional processing relate directly to interpersonal communication and psychosocial functioning, methodological issues exist in the current body of studies and resultant knowledge, which limit translation to novel treatment options.

CONCLUSIONS

Further improvement in emotion processing in persons with stable schizophrenia are unlikely to result from conventional pharmacotherapy of psychosis. New treatment modalities and behavioural interventions offer possible improvements in quality of life and psychosocial functioning.

Neural correlates of sad feelings in schizophrenia with and without blunted affect

OBJECTIVE

There have been reports that patients with schizophrenia have decreased activity in the prefrontal cortex during emotion processing. However, findings have been confounded by sample nonspecificity and explicit cognitive task interference with emotion processing. We aimed to further investigate this by examining the ventrolateral prefrontal cortex (VLPFC) activation in response to the passive viewing of sad film excerpts.

METHODS

We presented film excerpts depicting sad and neutral social situations to 25 schizophrenia patients (14 with blunted affect [BA+] and 11 without blunted affect [BA-]) in an implicit perception task to evoke prefronto-limbic activity illustrated by blood oxygenation level-dependent functional magnetic resonance imaging.

RESULTS

A random-effects analysis (2-sample t test) using statistical parametric mapping indicated that BA+ patients differed from BA- patients at a 0.05 level (P corrected for multiple comparisons). Consistent with our a priori hypothesis, BA- patients (relative to BA+ patients) showed significant activation in the right VLPFC. An exploratory analysis revealed the following loci of activation: caudate nucleus, VLPFC, middle prefrontal cortex, medial prefrontal cortex, anterior cingulate cortex, and anterior temporal pole in the BA- group; and hippocampus, cerebellum, anterior temporal pole, and midbrain in the BA+ group.

CONCLUSIONS

We observed not only hypofrontality in the BA+ group but also dysfunctional circuitry distributed throughout the brain. The temporal and midbrain activation seen in the BA+ group may indicate that these brain regions were working harder to compensate for inactivation in other regions. These distributed dysfunctional circuits may form the neural basis of blunted affect through impairment of emotion processing in the brain that prevents it from processing input efficiently and producing output effectively, thereby leading to symptoms such as blunted affect.

Brain activity during emotionally negative pictures in schizophrenia with and without flat affect: an fMRI study

The aim of this functional magnetic resonance imaging (fMRI) study was to compare regional brain activity in schizophrenia subjects with (FA+) and without (FA-) flat affect during the viewing of emotionally negative pictures. Thirteen FA+ subjects and 11 FA- subjects were scanned while being presented with a series of emotionally negative and neutral pictures. Experientially, the viewing of the negative pictures induced a negative emotional state whose intensity was significantly greater in the FA- group than in the FA+ group. Neurally, the Negative minus Neutral contrast revealed, in the FA- group, significant loci of activation in the midbrain, pons, anterior cingulate cortex, insula, ventrolateral orbitofrontal cortex, anterior temporal pole, amygdala, medial prefrontal cortex, and extrastriate visual cortex. In the FA+ group, this contrast produced significant loci of activation in the midbrain, pons, anterior temporal pole, and extrastriate visual cortex. When the brain activity measured in the FA+ group was subtracted from that measured in the FA- group, only the lingual gyrus was significantly activated. Perhaps in FA+ subjects an amygdaloid malfunction rendered the amygdala unable to correctly evaluate the emotional meaning of the pictures presented, thus preventing effective connectivity linking the amygdala to the brain regions implicated in the physiological and experiential dimensions of emotion. Alternatively, a disturbance of effective connectivity in the neural networks linking the midbrain and the medial prefrontal system may have been responsible for the quasi absence of emotional reaction in FA+ subjects, and the abnormal functioning of the medial prefrontal cortex and anterior cingulate cortex in the FA+ group.

Prosody and lexical accuracy in flat affect schizophrenia

To test the hypothesis that flat affect in schizophrenia involves a motor-expressive deficiency, but not an emotional deficiency, we compared the acoustic properties of speech that are used to express emotion with the emotional content of the words. DSM-III-R schizophrenic patients were divided into flat (N=20) and non-flat affect (N=26) groups on the basis of rating-scale scores. Twenty normal subjects also were included. Subjects were recorded on audio tape as they described a happy and a sad experience for about 10 min. The recordings were analyzed acoustically for fluency and for two types of prosody: inflection and emphasis. Words from transcriptions of the recordings were sorted by content analysis software into psychologically meaningful categories; we compared 'pleasure' and 'distress' word categories. Patients with flat affect spoke with less inflection, and were less fluent. However, they were similar to the other groups in the rate at which they used 'pleasure' words to describe happy experiences and 'distress' words to describe sad experiences. The behavioral deficiency in flat affect appears to be restricted to reduced activity in communicative motor channels. Other aspects of emotion processing seem intact.

Dissociation of affect recognition and mood state from blunting in patients with schizophrenia

The present study was designed to investigate the relationships between expression, perception, and experience of emotion in schizophrenic patients with and without affective blunting. Cognitive processing speed, emotional perception, and emotional experience were assessed in 25 schizophrenic patients grouped according to scores on a measure of overt emotional expression (Rating Scale for Emotional Blunting). Results showed dissociation of emotional expression from emotional perception and emotional experience. Blunted schizophrenic patients were no more impaired in the perception of emotion (Profile of Nonverbal Sensitivity) than non-blunted schizophrenic patients. In addition, groups did not differ in intensity of emotional experience as quantified on the self-report of arousal state (Positive and Negative Affect Scales). Accuracy of perception and reported experience of emotion did not differ between groups as a function of emotional valence. Cognitive processing speed (Symbol Digit Modalities Test; SDMT) was related to blunting score and to perception accuracy, although the SDMT did not differ between groups. Results are discussed in terms of a neuropathological basis for impairment of emotional expression.