Impaired emotion perception in schizophrenia: a differential deficit

We investigated previously reported contradictory findings regarding the nature of deficits in emotion perception among patients with schizophrenia. Some studies have concluded that such deficits are due to a generalized impairment in visual processing of faces, while others have found it to be restricted to facial emotional expressions. We examined 37 patients and 32 healthy controls, matched on age and education, using three computerized tests: matching facial identity, matching facial emotional expressions, and discrimination of subtle differences in the valence of facial emotional expressions. Our results showed impaired matching of emotions in patients with schizophrenia. This impairment did not manifest on tasks that depended on perceiving the identity of faces or cues of the relative valence of facial emotional expressions. Our findings support the differential deficit hypothesis of emotion perception in schizophrenia.     

Facial recognition deficits and cognition in schizophrenia

Previous investigations have found impaired recognition of facial affect and cognition in schizophrenia. We compared patients with schizophrenia and healthy control volunteers on computerized tasks of emotion recognition, to determine whether emotion processing deficits were correlated with neurocognitive performance. A Computerized Neuropsychological Test Battery (CNP) was administered to 40 patients (25 male, 15 female, mean age+/-S.D. 30.4+/-8.1) with schizophrenia (DSM-IV, 15 first episode and 25 chronically ill patients) treated with atypical neuroleptics and 43 healthy volunteers. A German version of the PENN Facial Discrimination, Differentiation and Memory Test, including happy, sad and neutral faces was used. Additionally, all patients were tested with a standard neuropsychological battery and rated for positive and negative symptoms. Patients with schizophrenia performed worse than control subjects on all emotion recognition tasks (p<0.01). We found higher error rates for discrimination of emotion in happy (p<0.02) and happy female faces (p<0.01), for differentiation of sad versus happy faces (p<0.001) and for facial memory (p<0.04). Poorer performance in emotion discrimination and facial memory correlated with severity of negative symptoms, abstraction-flexibility (p<0.001), verbal memory (p<0.01) and language processing (p<0.001). The study did not reveal a specific deficit for emotion recognition in schizophrenia. These findings lend support to the notion that difficulties in emotion recognition are associated in schizophrenia with key cognitive deficits.     

An fMRI study of facial emotion processing in patients with schizophrenia

OBJECTIVE: Emotion processing deficits are notable in schizophrenia. The authors evaluated cerebral blood flow response in schizophrenia patients during facial emotion processing to test the hypothesis of diminished limbic activation related to emotional relevance of facial stimuli. METHOD: Fourteen patients with schizophrenia and 14 matched comparison subjects viewed facial displays of happiness, sadness, anger, fear, and disgust as well as neutral faces. Functional magnetic resonance imaging was used to measure blood-oxygen-level-dependent signal changes as the subjects alternated between tasks of discriminating emotional valence (positive versus negative) and age (over 30 versus under 30) of the faces with an interleaved crosshair reference condition. RESULTS: The groups did not differ in performance on either task. For both tasks, healthy participants showed activation in the fusiform gyrus, occipital lobe, and inferior frontal cortex relative to the resting baseline condition. The increase was greater in the amygdala and hippocampus during the emotional valence discrimination task than during the age discrimination task. In the patients with schizophrenia, minimal focal response was observed for all tasks relative to the resting baseline condition. Contrasting patients and comparison subjects on the emotional valence discrimination task revealed voxels in the left amygdala and bilateral hippocampus in which the comparison subjects had significantly greater activation. CONCLUSIONS: Failure to activate limbic regions during emotional valence discrimination may explain emotion processing deficits in patients with schizophrenia. While the lack of limbic recruitment did not significantly impair simple valence discrimination performance in this clinically stable group, it may impact performance of more demanding tasks.     

Symptom Correlates of Static and Dynamic Facial Affect Processing in Schizophrenia: Evidence of a Double Dissociation?

Schizophrenia patients have been shown to be compromised in their ability to recognize facial emotion. This deficit has been shown to be related to negative symptoms severity. However, to date, most studies have used static rather than dynamic depictions of faces. Nineteen patients with schizophrenia were compared with seventeen controls on 2 tasks; the first involving the discrimination of facial identity, emotion, and butterfly wings; the second testing emotion recognition using both static and dynamic stimuli. In the first task, the patients performed more poorly than controls for emotion discrimination only, confirming a specific deficit in facial emotion recognition. In the second task, patients performed more poorly in both static and dynamic facial emotion processing. An interesting pattern of associations suggestive of a possible double dissociation emerged in relation to correlations with symptom ratings: high negative symptom ratings were associated with poorer recognition of static displays of emotion, whereas high positive symptom ratings were associated with poorer recognition of dynamic displays of emotion. However, while the strength of associations between negative symptom ratings and accuracy during static and dynamic facial emotion processing was significantly different, those between positive symptom ratings and task performance were not. The results confirm a facial emotion-processing deficit in schizophrenia using more ecologically valid dynamic expressions of emotion. The pattern of findings may reflect differential patterns of cortical dysfunction associated with negative and positive symptoms of schizophrenia in the context of differential neural mechanisms for the processing of static and dynamic displays of facial emotion.     

The face and its emotion: right N170 deficits in structural processing and early emotional discrimination in schizophrenic patients and relatives

Previous studies have reported facial emotion recognition impairments in schizophrenic patients, as well as abnormalities in the N170 component of the event-related potential. Current research on schizophrenia highlights the importance of complexly-inherited brain-based deficits. In order to examine the N170 markers of face structural and emotional processing, DSM-IV diagnosed schizophrenia probands (n=13), unaffected first-degree relatives from multiplex families (n=13), and control subjects (n=13) matched by age, gender and educational level, performed a categorization task which involved words and faces with positive and negative valence. The N170 component, while present in relatives and control subjects, was reduced in patients, not only for faces, but also for face-word differences, suggesting a deficit in structural processing of stimuli. Control subjects showed N170 modulation according to the valence of facial stimuli. However, this discrimination effect was found to be reduced both in patients and relatives. This is the first report showing N170 valence deficits in relatives. Our results suggest a generalized deficit affecting the structural encoding of faces in patients, as well as the emotion discrimination both in patients and relatives. Finally, these findings lend support to the notion that cortical markers of facial discrimination can be validly considered as vulnerability markers.     

Sustained attention in the context of emotional processing in patients with schizophrenia

Patients with schizophrenia show dysfunction in sustained attention and facial emotion processing. We investigated the interplay between sustained attention and emotion by presenting emotional faces as background during AX-CPT in patients with schizophrenia. Nineteen schizophrenia patients and 21 healthy control subjects participated. We presented AX-CPT number stimuli superimposed on the nose of background facial expressions (happy, neutral or sad) over three experimental blocks for each emotion. Signal detection sensitivity (A') and reaction time were measured. Patients showed a steeper sensitivity decline when happy faces (compared with sad faces) were presented as background stimuli. By contrast, controls' sensitivity was not affected by the background facial emotion stimuli. Across the emotion conditions, the decline of sensitivity over time was evident in patients, but not in controls. To our knowledge, the present study is the first to explore a change in sustained attention accompanied by simultaneous processing of emotional faces in schizophrenia patients. Our findings suggest that mechanisms underlying continuous performance test (CPT) performance decline over time and facial emotion deficit may interact with each other in patients with schizophrenia.     

Reconnaissance de l’émotion faciale et schizophrénie

A broad range of deficits in interpersonal skills characterizes schizophrenia. A natural way to tackle these deficits is to explore the ability of schizophrenic patients to process stimuli that have a well-established psychosocial content: faces, for instance. Schizophrenia deficits in facial recognition and discrimination have been studied extensively and most investigators have pointed out that patients with schizophrenia perform less well than non-patients and psychiatric controls in numerous facial paradigms, including facial identity, emotion and age recognition tests. The extent of the schizophrenic deficit suggests the alteration of a processing mechanism common to all kinds of facial information and the configural information extraction process has then been regarded as a probable candidate. Nevertheless, only a few studies directly tested the hypothesis. In what follows, we draw a general schema of the schizophrenia deficit in facial processing, next we present a series of studies investigating the putative implication of configural information in the abnormal processing of facial emotion in the disease.     

Impaired recognition of facial expressions of emotion in Alzheimer's disease

Recognizing facial emotions is an important aspect of interpersonal communication that may be impaired in Alzheimer's disease (AD). The authors examined facial emotion matching, facial emotion labeling, and same--different emotion differentiation in AD patients, healthy elderly volunteers, and elderly, nondemented psychiatric outpatients. Compared with both control groups, AD patients were significantly impaired on all three measures. AD patients were also impaired on a facial identity matching task. Using facial identity matching scores as a covariate provided evidence suggesting the facial emotion processing deficit may be independent of impairment in nonemotional face processing. AD patients also had selective impairment in labeling facial expressions of sadness. The authors conclude that patients with AD have deficits in recognizing facial emotions, which may be independent of their impairment in recognizing nonemotional features of faces.     

Enhanced recognition of disgust in bipolar illness.

BACKGROUND: Bipolar disorder is associated with functional and structural abnormalities in the brain circuits involved in processing emotional stimuli. Although impairments of cognitive function have been found to persist in bipolar patients during periods of euthymic mood, it is not known whether abnormalities in emotional processing also occur during these periods of recovery. METHODS: The present investigation assessed the ability of euthymic patients with bipolar disorder to recognize different facial expressions of emotion, compared with matched controls. A nonemotional facial categorization task was used to control for possible nonspecific differences in perception or attention. RESULTS: In contrast to the small impairments seen in the nonemotional categorization task, patients with bipolar disorder showed a robust facilitation in the discrimination of disgusted facial expressions. The recognition of other basic negative and positive emotions was unchanged. CONCLUSIONS: The present results suggest a selective facilitation of the processes involved in recognizing facial expressions of disgust in patients with bipolar disorder. This difference in perception may be relevant to the decreased self-esteem and social functioning that have been associated with the euthymic phase of this disorder.     

Facial emotion discrimination: III. Behavioral findings in schizophrenia.

Emotional discrimination was studied in patients with schizophrenia (n = 20) and matched controls. Performance of the emotion-discrimination tasks in the schizophrenic patients was impaired, relative to their performance of an age-discrimination task. Performance patterns in the patient group could also be reliably distinguished from those of normal controls. The impairment was associated with the severity of both emotional and nonemotional symptoms specific to schizophrenia, but not with the severity of nonspecific symptoms. The deficit associated with schizophrenia is more marked than that reported for depression (Gur et al., 1992), particularly for the emotion-discrimination tasks, and showed no difference between "happy" discrimination and "sad" discrimination. The main difficulty in patients with schizophrenia is the assignment of emotional valence to neutral faces. The magnitude of the deficit underscores the salience of emotional impairment in schizophrenia, and its relation to cognitive dysfunction in this disorder merits further scrutiny.     

Evidence of schizophrenia patients' reduced perceptual biases in response to emotion chimera

The goal of the study was to determine whether dextral individuals with schizophrenia display atypical perceptual biases in response to faces in general, or whether they display atypical perceptual biases in response to emotional facial cues. To this end, we assessed perceptual processing in schizophrenia patients with four types of free-vision chimeric stimuli. Perceptual biases were evaluated in 45 schizophrenia patients and in 46 controls using two face (emotion, gender) tasks and two nonface (dots, gradients) tasks. In response to the emotion chimera, the patients with schizophrenia displayed a reduced left perceptual bias. The two groups did not differ significantly in their response to the gender chimera or to the two nonface chimera. These findings are consistent with the assertion that schizophrenia patients have impaired emotional perception. In the discussion we consider possible reasons for schizophrenia patients' difficulty comprehending emotional facial stimuli. We suggest that schizophrenia patients' reduced perceptual bias in response to the emotion chimera reflects a hypothesized affective information-processing deficit.     

The role of configural information in facial emotion recognition in schizophrenia

The schizophrenia deficit in facial emotion recognition could be accounted for by a deficit in processing the configural information of the face. The present experiment was designed to further test this hypothesis by studying the face-inversion effect in a facial emotion recognition task. The ability of 26 schizophrenic patients and 26 control participants to recognize facial emotions on upright and upside-down faces was assessed. Participants were told to state whether faces expressed one of six possible emotions (happiness, anger, disgust, fear, sadness, neutrality) in two sessions, one with upright faces and the other with upside-down faces. Discriminability and the decision criterion were computed. The results indicated that the schizophrenic patients were impaired in upright facial emotion discrimination by comparison with the controls. They also exhibited an inversion effect similar to the controls. However, whereas controls tended to adopt a more conservative criterion for all emotions and a liberal criterion for neutrality when the faces were upside-down, schizophrenic patients presented a decision criterion pattern that was similar for the two orientations and similar to controls in upside-down emotion recognition. The lack of a decision criterion shift was associated with positive symptoms such as delusions, hallucinations, and bizarre behavior. Moreover, positive and negative symptoms were associated with inversion effect on discriminability; the more severe the symptoms, the weaker the inversion effect. We conclude that individuals with schizophrenia do process the configural information of the face. However, further investigations are needed to assert whether this information is of good quality in schizophrenia.     

Implicit emotion perception in schizophrenia

Explicit but not implicit facial emotion perception has been shown to be impaired in schizophrenia. In this study, we used newly developed technology in social neuroscience to examine implicit emotion processing. It has been shown that when people look at faces, they automatically infer social traits, and these trait judgments rely heavily on facial features and subtle emotion expressions even with neutral faces. Eighty-one individuals with schizophrenia or schizoaffective disorder and 62 control subjects completed a computer task with 30 well-characterized neutral faces. They rated each face on 10 trait judgments: attractive, mean, trustworthy, intelligent, dominant, fun, sociable, aggressive, emotionally stable and weird. The degree to which trait ratings were predicted by objectively-measured subtle emotion expressions served as a measure of implicit emotion processing. Explicit emotion recognition was also examined. Trait ratings were significantly predicted by subtle facial emotional expressions in controls and patients. However, impairment in the implicit emotion perception of fear, happiness, anger and surprise was found in patients. Moreover, these deficits were associated with poorer everyday problem-solving skills and were relatively independent of explicit emotion recognition. Implicit emotion processing is impaired in patients with schizophrenia or schizoaffective disorder. Deficits in implicit and explicit emotion perception independently contribute to the patients' poor daily life skills. More research is needed to fully understand the role of implicit and explicit processes in the functional deficits of patients, in order to develop targeted and useful remediation interventions.     

Facial emotion recognition in schizophrenia: when and why does it go awry?

OBJECTIVE: Schizophrenia patients demonstrate impaired emotional processing that may be due, in part, to impaired facial emotion recognition. This study examined event-related potential (ERP) responses to emotional faces in schizophrenia patients and controls to determine when, in the temporal processing stream, patient abnormalities occur. METHOD: 16 patients and 16 healthy control participants performed a facial emotion recognition task. Very sad, somewhat sad, neutral, somewhat happy, and very happy faces were each presented for 100 ms. Subjects indicated whether each face was "Happy", "Neutral", or "Sad". Evoked potential data were obtained using a 32-channel EEG system. RESULTS: Controls performed better than patients in recognizing facial emotions. In patients, better recognition of happy faces correlated with less severe negative symptoms. Four ERP components corresponding to the P100, N170, N250, and P300 were identified. Group differences were noted for the N170 "face processing" component that underlies the structural encoding of facial features, but not for the subsequent N250 "affect modulation" component. Higher amplitude of the N170 response to sad faces was correlated with less severe delusional symptoms. Although P300 abnormalities were found, the variance of this component was explained by the earlier N170 response. CONCLUSION: Patients with schizophrenia demonstrate abnormalities in early visual encoding of facial features that precedes the ERP response typically associated with facial affect recognition. This suggests that affect recognition deficits, at least for happy and sad discrimination, are secondary to faulty structural encoding of faces. The association of abnormal face encoding with delusions may denote the physiological basis for clinical misidentification syndromes.     

The effect of gender on emotion perception in schizophrenia and bipolar disorder

OBJECTIVE: Impaired emotion perception is documented for schizophrenia, but findings have been mixed for bipolar disorder. In healthy samples females perform better than males. This study compared emotion perception in schizophrenia and bipolar disorder and investigated the effects of gender. METHOD: Visual (facial pictures) and auditory (sentences) emotional stimuli were presented for identification and discrimination in groups of participants with schizophrenia, bipolar disorder and healthy controls. RESULTS: Visual emotion perception was unimpaired in both clinical groups, but the schizophrenia sample showed reduced auditory emotion perception. Healthy males and male schizophrenia subjects performed worse than their female counterparts, whereas there were no gender differences within the bipolar group. CONCLUSION: A disease-specific auditory emotion processing deficit was confirmed in schizophrenia, especially for males. Participants with bipolar disorder performed unimpaired.     

Differential amygdala response during facial recognition in patients with schizophrenia: an fMRI study

Human lesion or neuroimaging studies suggest that amygdala is involved in facial emotion recognition. Although impairments in recognition of facial and/or emotional expression have been reported in schizophrenia, there are few neuroimaging studies that have examined differential brain activation during facial recognition between patients with schizophrenia and normal controls. To investigate amygdala responses during facial recognition in schizophrenia, we conducted a functional magnetic resonance imaging (fMRI) study with 12 right-handed medicated patients with schizophrenia and 12 age- and sex-matched healthy controls. The experiment task was a type of emotional intensity judgment task. During the task period, subjects were asked to view happy (or angry/disgusting/sad) and neutral faces simultaneously presented every 3 s and to judge which face was more emotional (positive or negative face discrimination). Imaging data were investigated in voxel-by-voxel basis for single-group analysis and for between-group analysis according to the random effect model using Statistical Parametric Mapping (SPM). No significant difference in task accuracy was found between the schizophrenic and control groups. Positive face discrimination activated the bilateral amygdalae of both controls and schizophrenics, with more prominent activation of the right amygdala shown in the schizophrenic group. Negative face discrimination activated the bilateral amygdalae in the schizophrenic group whereas the right amygdala alone in the control group, although no significant group difference was found. Exaggerated amygdala activation during emotional intensity judgment found in the schizophrenic patients may reflect impaired gating of sensory input containing emotion.     

Perceptual bias of patients with schizophrenia in morphed facial expression

Limited research has specifically examined the nature of the dysfunction in emotion categorization representation in schizophrenia. The current study aimed to investigate the perception bias of morphed facial expression in subjects with schizophrenia and healthy controls in the emotion continua. Twenty-eight patients with schizophrenia and thirty-one healthy controls took part in this study. They were administered a standardized set of morphed photographs of facial expressions with varying emotional intensities between 0% and 100% of the emotion, in 10% increments to provide a range of intensities from pleasant to unpleasant and approach to withdraw. Shift points, indicating the time point that the subjects’ emotion identification begins to change, and response slopes, indicating how rapidly these changes have happened at the shift points in the emotion continuum, were measured. Patients exhibited a significantly greater response slope (i.e., patients’ perception changed more rapidly) and greater shift point (i.e., patients still perceived mild expressions of anger as happy faces) with increasing emotion signal compared with healthy controls when the facial expression morphed from happy to angry. Furthermore, patients with schizophrenia still perceived mild expressions of fear as angry faces(a greater shift point) and were less discriminative from angry to fearful emotion(a flatter response slope). They were sensitive to sadness (a smaller shift point) and the perception changed rapidly (a sharper response slope) as compared with healthy controls in the emotion continuum of happy to sad. In conclusion, patients with schizophrenia demonstrated impaired categorical perception of facial expressions, with generally ‘rapid’ but ‘late’ discrimination towards social threat-related stimuli such as angry facial expression. Compared with healthy controls, these patients have a sharper discrimination perception pattern in the emotion continua from positive valence to negative valence.     

Perception of happy and sad facial expressions in chronic schizophrenia: evidence for two evaluative systems

BACKGROUND: Persons suffering from schizophrenia have impaired perception of emotional expressions, but it is not clear whether this is part of a generalized deficit in cognitive function. AIM: To test for existence of emotion-specific deficits by studying the effects of valence on recognition of facial emotional expressions. METHODS: 24 male subjects suffering from chronic schizophrenia were examined with two tests of perception of emotion: the Penn Emotion Acuity Test (PEAT 40) and the Emotion Differentiation Task (EMODIFF). Clinical state was assessed with the Scale for the Assessment of Negative Symptoms (SANS) and Scale for the Assessment of Positive Symptoms (SAPS), visual memory with the Benton Visual Retention Test (BVRT) and motor function with the finger tapping test. RESULTS: Identification of happy facial expressions showed significant negative correlation with age, cumulated time in hospital and length of current hospitalization; positive correlations were found with visual retention and finger tapping scores. Identification of sad facial expressions showed significant correlation only with cumulated time in hospital while identification of neutral facial expressions showed no significant correlations. Discrimination between degrees of happy but not sad facial expression showed a positive correlation with negative symptoms. CONCLUSION: Perception of happy and sad emotion relates differently to significant illness parameters. This differentiability supports the existence of an emotion-specific deficit in perception of emotions in schizophrenia and of separate channels for processing positive and negative emotions.     

Emotional face processing deficit in schizophrenia: A replication study in a South African Xhosa population

Schizophrenia is associated with a deficit in the recognition of negative emotions from facial expressions. The present study examined the universality of this finding by studying facial expression recognition in African Xhosa population. Forty-four Xhosa patients with schizophrenia and forty healthy controls were tested with a computerized task requiring rapid perceptual discrimination of matched positive (i.e. happy), negative (i.e. angry), and neutral faces. Patients were equally accurate as controls in recognizing happy faces but showed a marked impairment in recognition of angry faces. The impairment was particularly pronounced for high-intensity (open-mouth) angry faces. Patients also exhibited more false happy and angry responses to neutral faces than controls. No correlation between level of education or illness duration and emotion recognition was found but the deficit in the recognition of negative emotions was more pronounced in familial compared to non-familial cases of schizophrenia. These findings suggest that the deficit in the recognition of negative facial expressions may constitute a universal neurocognitive marker of schizophrenia.     

Are there differential deficits in facial emotion recognition between paranoid and non-paranoid schizophrenia? A signal detection analysis

This study assessed facial emotion recognition abilities in subjects with paranoid and non-paranoid schizophrenia (NPS) using signal detection theory. We explore the differential deficits in facial emotion recognition in 44 paranoid patients with schizophrenia (PS) and 30 non-paranoid patients with schizophrenia (NPS), compared to 80 healthy controls. We used morphed faces with different intensities of emotion and computed the sensitivity index (d′) of each emotion. The results showed that performance differed between the schizophrenia and healthy controls groups in the recognition of both negative and positive affects. The PS group performed worse than the healthy controls group but better than the NPS group in overall performance. Performance differed between the NPS and healthy controls groups in the recognition of all basic emotions and neutral faces; between the PS and healthy controls groups in the recognition of angry faces; and between the PS and NPS groups in the recognition of happiness, anger, sadness, disgust, and neutral affects. The facial emotion recognition impairment in schizophrenia may reflect a generalized deficit rather than a negative-emotion specific deficit. The PS group performed worse than the control group, but better than the NPS group in facial expression recognition, with differential deficits between PS and NPS patients.