Intact prioritisation of unconscious face processing in schizophrenia

Self-monitoring in schizophrenia: Weighting exteroceptive visual signals against self-generated vestibular cues

Disturbances in self-monitoring are core symptoms of schizophrenia. Some research suggests an over-reliance on exteroceptive cues and a reduced weighting of self-generated interoceptive signals to guide perception. The vestibular sense provides important self-generated information about the body in space. Alterations of vestibular function are reported in schizophrenia, but it is unknown whether internally generated vestibular information is discounted in favour of exteroceptive input. In this study, we test for evidence of an over-reliance on exteroceptive visual cues and a reduced weighting of vestibular signals in guiding perception. In a group of individuals with schizophrenia and healthy controls, we used a well-studied visual illusion - the Tilt Illusion - to probe the respective weight given to visual and vestibular cues in judging line orientation. The Tilt Illusion reveals that perceived orientation of a vertical grating is biased by the orientation in its surround. This illusion increases when the head is tilted, due to the reduced reliability of vestibular information that would otherwise provide an internally generated reference for vertical. We predicted that an over-reliance on exteroceptive cues in schizophrenia would lead to a reduced susceptibility to the effects of head position on Tilt Illusion strength. We find no difference between patients and controls. Both groups show comparable Tilt Illusion magnitudes that increase when the head is tilted. Thus, our findings suggest that chronic patients with schizophrenia adequately combine self-generated vestibular cues and exteroceptive visual input to judge line verticality. A stronger reliance on exteroceptive information over internally generated signals in guiding perception is not evident in our data. Deficits in self-monitoring might therefore be modality specific or state dependant.

Characteristics of Facial Muscle Activity Intensity in Patients With Schizophrenia and Its Relationship to Negative Symptoms

INTRODUCTION

Previous studies have shown that in addition to having impairments in facial emotion recognition, patients with schizophrenia also show a lack of facial expression. Although negative symptoms such as decreased facial activity are common symptoms of schizophrenia, the related factors remain inconclusive. Therefore, this study compared healthy controls to explore the characteristics of facial muscle activity intensity in patients with schizophrenia and its relationship with negative symptoms.

METHODS

This observational and cross-sectional study conducted in a psychiatric hospital in China included a total of 135 patients with schizophrenia and 134 healthy controls. The negative symptoms of schizophrenia were evaluated using the Brief Negative Symptom Scale. The intensity of facial muscle activity under positive, neutral, and negative emotional stimuli conditions was automatically collected by a computer, including 17 values (F01-F17) that represent different facial muscle activities. Statistical tests were performed to analyze facial muscle activity indexes, to explore an objective and quantitative method to evaluate the negative symptoms of schizophrenia.

RESULTS

The facial muscle activity intensity of the schizophrenia group at F02 (outer eyebrow), F04 (upper eyelid), F07 (nose), F10 (dimple), F12 (lower jaw 1), F14 (lip 2), and F17 (blink) was lower than that of the healthy controls (p < 0.05). Under positive, neutral, and negative emotional stimuli conditions, the facial muscle activity intensity of F16 (lower jaw 2) was positively correlated with negative symptoms (p < 0.05).

CONCLUSION

Our study indicated that patients with schizophrenia show defects in facial muscle activity and that is associated with negative symptoms.

Objects that induce face pareidolia are prioritized by the visual system

The human visual system has evolved specialized neural mechanisms to rapidly detect faces. Its broad tuning for facial features is thought to underlie the illusory perception of faces in inanimate objects, a phenomenon called face pareidolia. Recent studies on face pareidolia suggest that the mechanisms underlying face processing, at least at the early stages of visual encoding, may treat objects that resemble faces as real faces; prioritizing their detection. In our study, we used breaking continuous flash suppression (b-CFS) to examine whether the human visual system prioritizes the detection of objects that induce face pareidolia over stimuli matched for object content. Similar to previous b-CFS results using real face stimuli, we found that participants detected the objects with pareidolia faces faster than object-matched control stimuli. Given that face pareidolia has been more frequently reported amongst individuals prone to hallucinations, we also explored whether this rapid prioritization is intact in individuals with schizophrenia, and found evidence suggesting that it was. Our findings suggest that face pareidolia engages a broadly tuned mechanism that facilitates rapid face detection. This may involve the proposed fast subcortical pathway that operates outside of visual awareness.

Overlapping and specific neural correlates for empathizing, affective mentalizing, and cognitive mentalizing: A coordinate-based meta-analytic study

While the discussion on the foundations of social understanding mainly revolves around the notions of empathy, affective mentalizing, and cognitive mentalizing, their degree of overlap versus specificity is still unclear. We took a meta-analytic approach to unveil the neural bases of cognitive mentalizing, affective mentalizing, and empathy, both in healthy individuals and pathological conditions characterized by social deficits such as schizophrenia and autism. We observed partially overlapping networks for cognitive and affective mentalizing in the medial prefrontal, posterior cingulate, and lateral temporal cortex, while empathy mainly engaged fronto-insular, somatosensory, and anterior cingulate cortex. Adjacent process-specific regions in the posterior lateral temporal, ventrolateral, and dorsomedial prefrontal cortex might underpin a transition from abstract representations of cognitive mental states detached from sensory facets to emotionally-charged representations of affective mental states. Altered mentalizing-related activity involved distinct sectors of the posterior lateral temporal cortex in schizophrenia and autism, while only the latter group displayed abnormal empathy related activity in the amygdala. These data might inform the design of rehabilitative treatments for social cognitive deficits.

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

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

Bottom-up processing of fearful and angry facial expressions is intact in schizophrenia

INTRODUCTION

Judgments of emotion from faces are reportedly impaired in schizophrenia. However, it is unclear whether this is due to a top-down cognitive deficit in evaluating sensory information or a fundamental bottom-up perturbation in the early stages of face encoding. This study examined whether deficits in emotion processing reflect imprecision in the initial preconscious registration of emotional face expressions within the visual system.

METHODS

Using continuous flash suppression (CFS), we presented participants (18 patients with schizophrenia, 8M/10F; 20 healthy controls, 13M/7F) with fearful and angry faces. Previous CFS research on healthy participants reveals that fearful facial expressions gain privileged access to awareness over angry faces-demonstrating the visual system's ability to discriminate these emotions at a preconscious level. We used this same approach to probe the integrity of early emotion encoding whilst minimising the potential contribution of any top-down cognitive biases on perceptual judgments.

RESULTS

In both groups, fearful faces were perceived faster than angry faces, with no differences observed between patients and controls.

CONCLUSIONS

Emotion processing difficulties in schizophrenia are unlikely to reflect an early sensory deficit, but rather a deficit in social cognition that has a top-down impact on the conscious evaluation of facial expressions.

Gaze direction biases emotion categorisation in schizophrenia

The successful integration of eye gaze direction and emotion cues from faces is important not only for co-ordinated interactions, but also for the detection of social signals alerting us to threat posed by a conspecific, or elsewhere in our immediate environment. It is now well-established that people with schizophrenia experience aberrant eye gaze and facial emotion processing. These social-cognitive differences might contribute to the maintenance of socially-themed delusions which are characterised by the hyper-attribution of threatening intentions to others. However, no study has directly examined whether the mechanisms which govern the integration of eye gaze and emotion information diverge in schizophrenia, and more importantly, whether this reflects a fundamental 'bottom-up' perceptual deficit or a 'top-down' cognitive bias. Fifteen outpatients diagnosed with schizophrenia and 21 healthy age- and IQ-matched controls performed an emotion categorisation task (anger/fear) on morphed facial expressions of anger or fear, displaying either direct or averted gaze. Results in both controls and patients replicated the previous finding that combinations of anger with direct gaze, and fear with averted gaze - which signal a relevant threat to the observer - benefited from more accurate emotion recognition than alternate gaze-emotion combinations. Bayesian model selection revealed that for patients this effect was mediated by a shift in decision bias towards emotions which signal self-relevant threat, rather than a change in sensitivity as observed in controls. These results critically highlight a different cognitive mechanism governing gaze and face-cued emotion integration in schizophrenia, which has a top-down influence on the evaluation of perceptual input.

Alterations of social attention in mental disorders: Phenomenology, scope, and future directions for research

Mental disorders often involve changes in the way subjects attend to other people. However, the nature of these modifications and how they unfold in different pathologies are not sufficiently clear. This article addresses these issues from the perspective of phenomenological psychopathology. The primary goal of the article is to suggest a new way of assessing and distinguishing the alterations of social attention in subjects with mental disorders. The first part of the article characterizes the essential properties of a capacity for social attention based on multidisciplinary evidence. This model is then used to examine anomalies in social attention in autism, schizophrenia, borderline personality disorder, and social anxiety disorder. The analysis of alterations in the way subjects with different types of pathologies attend to and with others is followed by a threefold typology, which clarifies the phenomenal nature of impairments of social attention in mental disorders.