Altered lateralisation of emotional prosody processing in schizophrenia

Changes in speech prosody perception during Parkinson's disease: A comprehensive analysis

INTRODUCTION

Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects approximately 1%-2% of individuals aged 60 and above. Communication disorders in PD can significantly impact the overall quality of life. As prosody plays a vital role in verbal communication, the present study examines Persian prosody perception in PD, focusing on linguistic and emotional aspects of prosody.

METHODS

This cross-sectional study aimed to compare the perception of linguistic and emotional prosody in three groups: middle-aged adults (n = 22; mean age = 50.40 years), healthy older adults (n = 22; mean age = 68.31 years), and individuals with Parkinson's disease (n = 22; mean age = 65years). All individuals with PD were classified in stages 1; 1.5; 2; 2.5, and 3 of the disease using the Hoehn and Yahr scale. All participants had an MMSE score of 24 or above. The Florida Affect Battery (FAB) was used to evaluate prosody perception. This Battery was validated in the Persian language and its reliability and validity were reported as 94 % and 100 % respectively.

RESULTS

Participants with PD presented significantly lower scores than the older adults in all subtests of the FAB (p < 0.05), while healthy older adults were significantly different only in linguistic discrimination (β = -2.14; -3.68 to -0.61), and linguistic naming of prosody (β = 1.25; 0.17 to 2.33) compared to middle-aged adults.

CONCLUSIONS

The present study sheds light on the influence of PD on Persian prosody perception. Given the crucial role of prosody in verbal communication, these findings enhance our understanding of communication disorders in PD and could bring attention to consider prosody perception, among other aspects, when assessing individuals affected by PD.

A Parabrachial-to-Amygdala Circuit That Determines Hemispheric Lateralization of Somatosensory Processing

BACKGROUND

The central amygdala (CeA) is a bilateral hub of pain and emotional processing with well-established functional lateralization. We reported that optogenetic manipulation of neural activity in the left and right CeA has opposing effects on bladder pain.

METHODS

To determine the influence of calcitonin gene-related peptide (CGRP) signaling from the parabrachial nucleus on this diametrically opposed lateralization, we administered CGRP and evaluated the activity of CeA neurons in acute brain slices as well as the behavioral signs of bladder pain in the mouse.

RESULTS

We found that CGRP increased firing in both the right and left CeA neurons. Furthermore, we found that CGRP administration in the right CeA increased behavioral signs of bladder pain and decreased bladder pain-like behavior when administered in the left CeA.

CONCLUSIONS

These studies reveal a parabrachial-to-amygdala circuit driven by opposing actions of CGRP that determines hemispheric lateralization of visceral pain.

Auditory emotion recognition deficits in schizophrenia: A systematic review and meta-analysis

BACKGROUND

Auditory emotion recognition (AER) deficits refer to the abnormal identification and interpretation of tonal or prosodic features that transmit emotional information in sounds or speech. Evidence suggests that AER deficits are related to the pathology of schizophrenia. However, the effect size of the deficit in specific emotional category recognition in schizophrenia and its association with psychotic symptoms have never been evaluated through a meta-analysis.

METHODS

A systematic search for literature published in English or Chinese until November 30, 2020 was conducted in PubMed, Embase, Web of Science, PsychINFO, and China National Knowledge Infrastructure (CNKI), WanFang and Weip Databases. AER differences between patients and healthy controls (HCs) were assessed by the standardized mean differences (SMDs). Subgroup analyses were conducted for the type of emotional stimuli and the diagnosis of schizophrenia or schizoaffective disorders (Sch/SchA). Meta-regression analyses were performed to assess the influence of patients' age, sex, illness duration, antipsychotic dose, positive and negative symptoms on the study SMDs.

RESULTS

Eighteen studies containing 615 psychosis (Sch/SchA) and 488 HCs were included in the meta-analysis. Patients exhibited moderate deficits in recognizing the neutral, happy, sad, angry, fear, disgust, and surprising emotion. Neither the semantic information in the auditory stimuli nor the diagnosis subtype affected AER deficits in schizophrenia. Sadness, anger, and disgust AER deficits were each positively associated with negative symptoms in schizophrenia.

CONCLUSIONS

Patients with schizophrenia have moderate AER deficits, which were associated with negative symptoms. Rehabilitation focusing on improving AER abilities may help improve negative symptoms and the long-term prognosis of schizophrenia.

Emotional Prosody Processing in Schizophrenic Patients: A Selective Review and Meta-Analysis

Emotional prosody (EP) has been increasingly recognized as an important area of schizophrenic patients’ dysfunctions in their language use and social communication. The present review aims to provide an updated synopsis on emotional prosody processing (EPP) in schizophrenic disorders, with a specific focus on performance characteristics, the influential factors and underlying neural mechanisms. A literature search up to 2018 was conducted with online databases, and final selections were limited to empirical studies which investigated the prosodic processing of at least one of the six basic emotions in patients with a clear diagnosis of schizophrenia without co-morbid diseases. A narrative synthesis was performed, covering the range of research topics, task paradigms, stimulus presentation, study populations and statistical power with a quantitative meta-analytic approach in Comprehensive Meta-Analysis Version 2.0. Study outcomes indicated that schizophrenic patients’ EPP deficits were consistently observed across studies (d = −0.92, 95% CI = −1.06 < δ < −0.78), with identification tasks (d = −0.95, 95% CI = −1.11 < δ < −0.80) being more difficult to process than discrimination tasks (d = −0.74, 95% CI = −1.03 < δ < −0.44) and emotional stimuli being more difficult than neutral stimuli. Patients’ performance was influenced by both participant- and experiment-related factors. Their social cognitive deficits in EP could be further explained by right-lateralized impairments and abnormalities in primary auditory cortex, medial prefrontal cortex and auditory-insula connectivity. The data pointed to impaired pre-attentive and attentive processes, both of which played important roles in the abnormal EPP in the schizophrenic population. The current selective review and meta-analysis support the clinical advocacy of including EP in early diagnosis and rehabilitation in the general framework of social cognition and neurocognition deficits in schizophrenic disorders. Future cross-sectional and longitudinal studies are further suggested to investigate schizophrenic patients’ perception and production of EP in different languages and cultures, modality forms and neuro-cognitive domains.

Functional brain lateralization in schizophrenia based on the variability of resting-state fMRI signal

Abnormal brain lateralization has been implicated in schizophrenia but few studies have focused on the variability of resting-state fMRI signal and its lateralization in schizophrenia. Here we utilized standard deviations (SD) to quantify the variability of resting-state fMRI signal and measured the lateralization index (LI), on the basis of SD of the resting-state fMRI signal in order to assess the difference of brain signal variability across the hemispheres. We recruited 180 patients with schizophrenia and 358 age- and sex-matched healthy volunteers. Between-group comparison revealed that in comparison to healthy volunteers, schizophrenia patients have significantly higher SD of resting-state fMRI activity in left inferior temporal, left fusiform, and right superior medial frontal cortex, and lower SD in right precuneus, posterior cingulum on both sides, right lingual, and left calcarine in the occipital region. Using region of interest approach, most brain regions showed increased leftward lateralization in patients with schizophrenia, as compared with healthy controls. SD and LI were also found to be correlated to age of onset or duration of illness. These results provide further evidence that abnormal variability and lateralization exist in schizophrenia patients, and abnormality in fusiform, lingual and inferior temporal could have potential help to identify the dysfunctional brain lateralization in schizophrenia.

Systems Neuroscience of Psychosis: Mapping Schizophrenia Symptoms onto Brain Systems

Schizophrenia research has been in a deadlock for many decades. Despite important advances in clinical treatment, there are still major concerns regarding long-term psychosocial reintegration and disease management, biological heterogeneity, unsatisfactory predictors of individual course and treatment strategies, and a confusing variety of controversial theories about its etiology and pathophysiological mechanisms. In the present perspective on schizophrenia research, we first discuss a methodological pitfall in contemporary schizophrenia research inherent in the attempt to link mental phenomena with the brain: we claim that the time-honored phenomenological method of defining mental symptoms should not be contaminated with the naturalistic approach of modern neuroscience. We then describe our Systems Neuroscience of Psychosis (SyNoPsis) project, which aims to overcome this intrinsic problem of psychiatric research. Considering schizophrenia primarily as a disorder of interindividual communication, we developed a neurobiologically informed semiotics of psychotic disorders, as well as an operational clinical rating scale. The novel psychopathology allows disentangling the clinical manifestations of schizophrenia into behavioral domains matching the functions of three well-described higher-order corticobasal brain systems involved in interindividual human communication, namely, the limbic, associative, and motor loops, including their corticocortical sensorimotor connections. The results of several empirical studies support the hypothesis that the proposed three-dimensional symptom structure, segregated into the affective, the language, and the motor domain, can be specifically mapped onto structural and functional abnormalities of the respective brain systems. New pathophysiological hypotheses derived from this brain system-oriented approach have helped to develop and improve novel treatment strategies with noninvasive brain stimulation and practicable clinical parameters. In clinical practice, the novel psychopathology allows confining the communication deficits of the individual patient, shifting attention from the symptoms to the intact resources. We have studied this approach and observed important advantages for therapeutic alliances, personalized treatment, and de-escalation strategies. Future studies will further conjoin clinical definitions of psychotic symptoms with brain structures and functions, and disentangle structural and functional deficit patterns within these systems to identify neurobiologically distinct subsyndromes. Neurobiologically homogeneous patient groups may provide new momentum for treatment research. Finally, lessons learned from schizophrenia research may contribute to developing a comprehensive perspective on human experience and behavior that integrates methodologically distinct, but internally consistent, insights from humanities and neuroscience.

How high level of anxiety in Panic Disorder can interfere in working memory? A computer simulation and electrophysiological investigation

Panic disorder (PD) is characterized by repeated and unexpected attacks of intense anxiety, which are not restricted to a determined situation or circumstance. The coherence function has been used to investigate the communication among brain structures through the quantitative EEG (qEEG). The objective of this study is to analyze if there is a difference in frontoparietal gamma coherence (GC) between panic disorder patients (PDP) and healthy controls (HC) during the Visual oddball paradigm; and verify if high levels of anxiety (produced by a computer simulation) affect PDP's working memory. Nine PDP (9 female with average age of 48.8, SD: 11.16) and ten HC (1 male and 9 female with average age of 38.2, SD: 13.69) were enrolled in this study. The subjects performed the visual oddball paradigm simultaneously to the EEG record before and after the presentation of computer simulation (CS). A two-way ANOVA was applied to analyze the factors Group and the Moment for each pair of electrodes separately, and another one to analyze the reaction time variable. We verified a F3-P3 GC increased after the CS movie, demonstrating the left hemisphere participation during the anxiety processing. The greater GC in HC observed in the frontal and parietal areas (P3-Pz, F4-F8 and Fp2-F4) points to the participation of these areas with the expected behavior. The greater GC in PDP for F7-F3 and F4-P4 pairs of electrodes assumes that it produces a prejudicial "noise" during information processing, and can be associated to interference on the communication between frontal and parietal areas. This "noise" during information processing is related to PD symptoms, which should be better known in order to develop effective treatment strategies.

Neurocircuitry of impaired affective sound processing: A clinical disorders perspective

Decoding affective meaning from sensory information is central to accurate and adaptive behavior in many natural and social contexts. Human vocalizations (speech and non-speech), environmental sounds (e.g. thunder, noise, or animal sounds) and human-produced sounds (e.g. technical sounds or music) can carry a wealth of important aversive, threatening, appealing, or pleasurable affective information that sometimes implicitly influences and guides our behavior. A deficit in processing such affective information is detrimental to adaptive environmental behavior, psychological well-being, and social interactive abilities. These deficits can originate from a diversity of psychiatric and neurological disorders, and are associated with neural dysfunctions across largely distributed brain networks. Recent neuroimaging studies in psychiatric and neurological patients outline the cortical and subcortical neurocircuitry of the complimentary and differential functional roles for affective sound processing. This points to and confirms a recently proposed distributed network rather than a single brain region underlying affective sound processing, and highlights the notion of a multi-functional process that can be differentially impaired in clinical disorders.

Functional deficit of the medial prefrontal cortex during emotional sentence attribution in schizophrenia

BACKGROUND

Functional brain imaging research has already demonstrated that patients with schizophrenia had difficulties with emotion processing, namely in facial emotion perception and emotional prosody. However, the moderating effect of social context and the boundary of perceptual categories of emotion attribution remain unclear. This study investigated the neural bases of emotional sentence attribution in schizophrenia.

METHODS

Twenty-one schizophrenia patients and 25 healthy subjects underwent an event-related functional magnetic resonance imaging paradigm including two tasks: one to classify sentences according to their emotional content, and the other to classify neutral sentences according to their grammatical person.

RESULTS

First, patients showed longer response times as compared to controls only during the emotion attribution task. Second, patients with schizophrenia showed reduction of activation in bilateral auditory areas irrespective of the presence of emotions. Lastly, during emotional sentences attribution, patients displayed less activation than controls in the medial prefrontal cortex (mPFC).

CONCLUSIONS

We suggest that the functional abnormality observed in the mPFC during the emotion attribution task could provide a biological basis for social cognition deficits in patients with schizophrenia.

A Cognitive Neuroscience View of Voice-Processing Abnormalities in Schizophrenia: A Window into Auditory Verbal Hallucinations?

Auditory verbal hallucinations (AVH) are a core symptom of schizophrenia. Like "real" voices, AVH carry a rich amount of linguistic and paralinguistic cues that convey not only speech, but also affect and identity, information. Disturbed processing of voice identity, affective, and speech information has been reported in patients with schizophrenia. More recent evidence has suggested a link between voice-processing abnormalities and specific clinical symptoms of schizophrenia, especially AVH. It is still not well understood, however, to what extent these dimensions are impaired and how abnormalities in these processes might contribute to AVH. In this review, we consider behavioral, neuroimaging, and electrophysiological data to investigate the speech, identity, and affective dimensions of voice processing in schizophrenia, and we discuss how abnormalities in these processes might help to elucidate the mechanisms underlying specific phenomenological features of AVH. Schizophrenia patients exhibit behavioral and neural disturbances in the three dimensions of voice processing. Evidence suggesting a role of dysfunctional voice processing in AVH seems to be stronger for the identity and speech dimensions than for the affective domain.

Amusia and protolanguage impairments in schizophrenia

BACKGROUND

Both language and music are thought to have evolved from a musical protolanguage that communicated social information, including emotion. Individuals with perceptual music disorders (amusia) show deficits in auditory emotion recognition (AER). Although auditory perceptual deficits have been studied in schizophrenia, their relationship with musical/protolinguistic competence has not previously been assessed.

METHOD

Musical ability was assessed in 31 schizophrenia/schizo-affective patients and 44 healthy controls using the Montreal Battery for Evaluation of Amusia (MBEA). AER was assessed using a novel battery in which actors provided portrayals of five separate emotions. The Disorganization factor of the Positive and Negative Syndrome Scale (PANSS) was used as a proxy for language/thought disorder and the MATRICS Consensus Cognitive Battery (MCCB) was used to assess cognition.

RESULTS

Highly significant deficits were seen between patients and controls across auditory tasks (p < 0.001). Moreover, significant differences were seen in AER between the amusia and intact music-perceiving groups, which remained significant after controlling for group status and education. Correlations with AER were specific to the melody domain, and correlations between protolanguage (melody domain) and language were independent of overall cognition.

DISCUSSION

This is the first study to document a specific relationship between amusia, AER and thought disorder, suggesting a shared linguistic/protolinguistic impairment. Once amusia was considered, other cognitive factors were no longer significant predictors of AER, suggesting that musical ability in general and melodic discrimination ability in particular may be crucial targets for treatment development and cognitive remediation in schizophrenia.

Social cognition in schizophrenic patients: the effect of semantic content and emotional prosody in the comprehension of emotional discourse

BACKGROUND

The recognition of the emotion expressed during conversation relies on the integration of both semantic processing and decoding of emotional prosody. The integration of both types of elements is necessary for social interaction. No study has investigated how these processes are impaired in patients with schizophrenia during the comprehension of an emotional speech. Since patients with schizophrenia have difficulty in daily interactions, it would be of great interest to investigate how these processes are impaired. We tested the hypothesis that patients present lesser performances regarding both semantic and emotional prosodic processes during emotional speech comprehension compared with healthy participants.

METHODS

The paradigm is based on sentences built with emotional (anger, happiness, or sadness) semantic content uttered with or without congruent emotional prosody. The study participants had to decide with which of the emotional categories each sentence corresponded.

RESULTS

Patients performed significantly worse than their matched controls, even in the presence of emotional prosody, showing that their ability to understand emotional semantic content was impaired. Although prosody improved performances in both groups, it benefited the patients more than the controls.

CONCLUSION

Patients exhibited both impaired semantic and emotional prosodic comprehensions. However, they took greater advantage of emotional prosody adjunction than healthy participants. Consequently, focusing on emotional prosody during carrying may improve social communication.

Cerebral responses to vocal attractiveness and auditory hallucinations in schizophrenia: a functional MRI study

Impaired self-monitoring and abnormalities of cognitive bias have been implicated as cognitive mechanisms of hallucination; regions fundamental to these processes including inferior frontal gyrus (IFG) and superior temporal gyrus (STG) are abnormally activated in individuals that hallucinate. A recent study showed activation in IFG-STG to be modulated by auditory attractiveness, but no study has investigated whether these IFG-STG activations are impaired in schizophrenia. We aimed to clarify the cerebral function underlying the perception of auditory attractiveness in schizophrenia patients. Cerebral activation was examined in 18 schizophrenia patients and 18 controls when performing Favorability Judgment Task (FJT) and Gender Differentiation Task (GDT) for pairs of greetings using event-related functional MRI. A full-factorial analysis revealed that the main effect of task was associated with activation of left IFG and STG. The main effect of Group revealed less activation of left STG in schizophrenia compared with controls, whereas significantly greater activation in schizophrenia than in controls was revealed at the left middle frontal gyrus (MFG), right temporo-parietal junction (TPJ), right occipital lobe, and right amygdala (p < 0.05, FDR-corrected). A significant positive correlation was observed at the right TPJ and right MFG between cerebral activation under FJT minus GDT contrast and the score of hallucinatory behavior on the Positive and Negative Symptom Scale. Findings of hypo-activation in the left STG could designate brain dysfunction in accessing vocal attractiveness in schizophrenia, whereas hyper-activation in the right TPJ and MFG may reflect the process of mentalizing other person's behavior by auditory hallucination by abnormality of cognitive bias.

Emotional prosody modulates attention in schizophrenia patients with hallucinations

Recent findings have demonstrated that emotional prosody (EP) attracts attention involuntarily (Grandjean et al., 2008). The automat shift of attention toward emotionally salient stimuli can be overcome by attentional control (Hahn et al., 2010). Attentional control is impaired in schizophrenia, especially in schizophrenic patients with hallucinations because the "voices" capture attention increasing the processing load and competing for top-down resources. The present study investigates how involuntary attention is driven by implicit EP in schizophrenia with auditory verbal hallucinations (AVH) and without (NAVH). Fifteen AVH patients, 12 NAVH patients and 16 healthy controls (HC) completed a dual-task dichotic listening paradigm, in which an emotional vocal outburst was paired with a neutral vocalization spoken in male and female voices. Participants were asked to report the speaker's gender while attending to either the left or right ear. NAVH patients and HC revealed shorter response times for stimuli presented to the attended left ear than the attended right ear. This laterality effect was not present in AVH patients. In addition, NAVH patients and HC showed faster responses when the EP stimulus was presented to the unattended ear, probably because of less interference between the attention-controlled gender voice identification task and involuntary EP processing. AVH patients did not benefit from presenting emotional stimuli to the unattended ear. The findings suggest that similar to HC, NAVH patients show a right hemispheric bias for EP processing. AVH patients seem to be less lateralized for EP and therefore might be more susceptible to interfering involuntary EP processing; regardless which ear/hemisphere receives the bottom up input.

Prosody recognition and audiovisual emotion matching in schizophrenia: the contribution of cognition and psychopathology

This study aimed to evaluate the ability to decode emotion in the auditory and audiovisual modality in a group of patients with schizophrenia, and to explore the role of cognition and psychopathology in affecting these emotion recognition abilities. Ninety-four outpatients in a stable phase and 51 healthy subjects were recruited. Patients were assessed through a psychiatric evaluation and a wide neuropsychological battery. All subjects completed the comprehensive affect testing system (CATS), a group of computerized tests designed to evaluate emotion perception abilities. With respect to the controls, patients were not impaired in the CATS tasks involving discrimination of nonemotional prosody, naming of emotional stimuli expressed by voice and judging the emotional content of a sentence, whereas they showed a specific impairment in decoding emotion in a conflicting auditory condition and in the multichannel modality. Prosody impairment was affected by executive functions, attention and negative symptoms, while deficit in multisensory emotion recognition was affected by executive functions and negative symptoms. These emotion recognition deficits, rather than being associated purely with emotion perception disturbances in schizophrenia, are affected by core symptoms of the illness.

Modulation of affective face processing deficits in Schizophrenia by congruent emotional sounds

Schizophrenia is a psychiatric disorder resulting in prominent impairments in social functioning. Thus, clinical research has focused on underlying deficits of emotion processing and their linkage to specific symptoms and neurobiological dysfunctions. Although there is substantial research investigating impairments in unimodal affect recognition, studies in schizophrenia exploring crossmodal emotion processing are rare. Therefore, event-related potentials were measured in 15 patients with schizophrenia and 15 healthy controls while rating the expression of happy, fearful and neutral faces and concurrently being distracted by emotional or neutral sounds. Compared with controls, patients with schizophrenia revealed significantly decreased P1 and increased P2 amplitudes in response to all faces, independent of emotion or concurrent sound. Analyzing these effects with regard to audiovisual (in)congruence revealed that P1 amplitudes in patients were only reduced in response to emotionally incongruent stimulus pairs, whereas similar amplitudes between groups could be observed for congruent conditions. Correlation analyses revealed a significant negative correlation between general symptom severity (Brief Psychiatric Rating Scale-V4) and P1 amplitudes in response to congruent audiovisual stimulus pairs. These results indicate that early visual processing deficits in schizophrenia are apparent during emotion processing but, depending on symptom severity, these deficits can be restored by presenting concurrent emotionally congruent sounds.

Hemispheric asymmetries and prosodic emotion recognition deficits in Parkinson's disease

While Parkinson's disease (PD) has traditionally been described as a movement disorder, there is growing evidence of cognitive and social deficits associated with the disease. However, few studies have looked at multi-modal social cognitive deficits in patients with PD. We studied lateralization of both prosodic and facial emotion recognition (the ability to recognize emotional valence from either tone of voice or from facial expressions) in PD. The Comprehensive Affect Testing System (CATS) is a well-validated test of human emotion processing that has been used to study emotion recognition in several major clinical populations, but never before in PD. We administered an abbreviated version of CATS (CATS-A) to 24 medicated PD participants and 12 age-matched controls. PD participants were divided into two groups, based on side of symptom onset and unilateral motor symptom severity: left-affected (N = 12) or right-affected PD participants (N = 12). CATS-A is a computer-based button press task with eight subtests relevant to prosodic and facial emotion recognition. Left-affected PD participants with inferred predominant right-hemisphere pathology were expected to have difficulty with prosodic emotion recognition since there is evidence that the processing of prosodic information is right-hemisphere dominant. We found that facial emotion recognition was preserved in the PD group, however, left-affected PD participants had specific impairment in prosodic emotion recognition, especially for sadness. Selective deficits in prosodic emotion recognition suggests that (1) hemispheric effects in emotion recognition may contribute to the impairment of emotional communication in a subset of people with PD and (2) the coordination of neural networks needed to decipher temporally complex social cues may be specifically disrupted in PD.

Contributions of emotional prosody comprehension deficits to the formation of auditory verbal hallucinations in schizophrenia

Deficits in emotional processing have been widely described in schizophrenia. Associations of positive symptoms with poor emotional prosody comprehension (EPC) have been reported at the phenomenological, behavioral, and neural levels. This review focuses on the relation between emotional processing deficits and auditory verbal hallucinations (AVH). We explore the possibility that the relation between AVH and EPC in schizophrenia might be mediated by the disruption of a common mechanism intrinsic to auditory processing, and that, moreover, prosodic feature processing deficits play a pivotal role in the formation of AVH. The review concludes with proposing a mechanism by which AVH are constituted and showing how different aspects of our neuropsychological model can explain the constellation of subjective experiences which occur in relation to AVH.

Not pitch perfect: sensory contributions to affective communication impairment in schizophrenia

BACKGROUND

Schizophrenia patients have vocal affect (prosody) deficits that are treatment resistant and associated with negative symptoms and poor outcome. The neural correlates of this dysfunction are unclear. Prior study has suggested that schizophrenia vocal affect perception deficits stem from an inability to use acoustic cues, notably pitch, in decoding emotion.

METHODS

Functional magnetic resonance imaging was performed in 24 schizophrenia patients and 28 healthy control subjects, during the performance of a four-choice (happiness, fear, anger, neutral) vocal affect identification task in which items for each emotion varied parametrically in affective salient acoustic cue levels.

RESULTS

We observed that parametric increases in cue levels in schizophrenia failed to produce the same identification rate increases as in control subjects. These deficits correlated with diminished reciprocal activation changes in superior temporal and inferior frontal gyri and reduced temporo-frontal connectivity. Task activation also correlated with independent measures of pitch perception and negative symptom severity.

CONCLUSIONS

These findings illustrate the interplay between sensory and higher-order cognitive dysfunction in schizophrenia. Sensory contributions to vocal affect deficits also suggest that this neurobehavioral marker could be targeted by pharmacological or behavioral remediation of acoustic feature discrimination.

Reduced language lateralization in first-episode medication-naive schizophrenia

Diminished functional lateralization in language-related areas is found in chronic schizophrenia. It is not clear at what stage of illness these abnormalities in lateralization arise, or whether they are affected by medication. In addition, it is hypothesized that reduced language lateralization is related to positive symptoms of schizophrenia, but studies addressing this issue have yielded contradictory results. In this study we used functional MRI to measure language lateralization in 35 first-episode medication-naive schizophrenia patients and 43 matched healthy controls. Subjects performed three language tasks: a paced verb generation task, an antonym generation task, and a semantic decision task. Lateralization Index (LI) was calculated, using a relative threshold technique, in seven Regions of Interest (ROIs), including the main language-related areas and their contralateral homologues. In addition, we investigated whether language lateralization was correlated with psychotic symptoms. Across all ROIs, LI was significantly reduced in patients (p<0.001) compared to controls. Post-hoc tests revealed that this reduction was most prominent in the inferior frontal gyrus (part of Broca's area) (p=0.003) and the superior temporal gyrus (part of Wernicke's area) (p<0.001). LI was not correlated with the positive subscale of the PANSS, nor with hallucinations or disorganization. This is the first study to report reduced LI at the onset of schizophrenia, before medical treatment is initiated.

Factors in sensory processing of prosody in schizotypal personality disorder: an fMRI experiment

INTRODUCTION

Persons diagnosed with schizophrenia demonstrate deficits in prosody recognition. To examine prosody along the schizophrenia spectrum, antipsychotic-naïve schizotypal personality disorder (SPD) subjects and healthy control subjects were compared. It was hypothesized that SPD subjects would perform more poorly; with cognitive and demographic factors contributing to the poor performance. The superior temporal gyrus (STG) was selected as the region-of-interest (ROI) given its known abnormalities in SPD and its important role in the processing of prosody.

METHODS

SPD and healthy comparison (HC) subjects were matched on age, IQ, and parental social-economic status (PSES). Cognitive measures included the Speech Sound Perception Test (SSPT) to examine phonological processing (SPD=68, HC=74) and the Verbal Fluency task to examine executive functioning (SPD=129, HC=138). The main experiment was a novel fMRI task of prosody identification using semantically neutral sentences spoken with emotional prosody (SPD=16, HC=13). Finally, volumetric measurement of the superior temporal sulcus (STS), a key region for processing prosody, and partially overlapping with the STG, was performed (SPD=30, HC=30).

RESULTS

Phonological processing and executive functioning were both impaired in SPD subjects compared with HC subjects. Contrary to the prediction, SPD subjects, as a group, were similar to HC subjects in terms of correctly indentifying the emotion conveyed and reaction time. Within the SPD group, prosody identification accuracy was influenced by executive functioning, IQ and perhaps PSES, relationships not found with HC subjects. Phonological perception aided prosody identification in both diagnostic groups. As expected, both groups activated the STG while performing the prosody identification task. However, SPD subjects may have been less "efficient" in their recruitment of STG neurons. Finally, SPD subjects demonstrated a trend toward smaller STS volumes on the left, particularly the lower bank.

CONCLUSIONS

These data suggest that subtle differences between SPD and controls in phonological processing, executive functioning, IQ, and possibly PSES, contributed to difficulty in processing prosody for some SPD subjects.

Exploring the role of face processing in facial emotion recognition in schizophrenia

OBJECTIVE

Impairment in emotion perception represents a fundamental feature of schizophrenia with important consequences in social functioning. A fundamental unresolved issue is the relationship between emotion perception and face perception. The aim of the present study was to examine whether facial identity recognition (Identity Discrimination) is a factor predicting facial emotion recognition in the context of the other factors, known as contributing to emotion perception, such as cognitive functions and symptoms.

METHODS

We enrolled 58 stable schizophrenic out-patients and 47 healthy subjects. Facial identity recognition and emotion perception were assessed with the Comprehensive Affect Testing System. Different multiple regression models with backward elimination were performed in order to discover the relation of each significant variable with emotion perception.

RESULTS

In a regression including the six significant variables (age, positive symptomatology, Identity Discrimination, attentive functions, verbal memory-learning, executive functions) versus emotion processing, only attentive functions (standardised β = 0.264, p = 0.038) and Identity Discrimination (standardised β = 0.279, p = 0.029) reached a significant level. Two partial regressions were performed including five variables, one excluding attentive functions and the other excluding Identity Discrimination. When we excluded attentive functions, the only significant variable was Identity Discrimination (standardised β = 0.278, p = 0.032). When we excluded Identity Discrimination, both verbal memory-learning (standardised β = 0.261, p = 0.042) and executive functions (standardised β = 0.253, p = 0.048) were significant.

CONCLUSIONS

Our results emphasised the role of face perception and attentional abilities on affect perception in schizophrenia. We additionally found a role of verbal memory-learning and executive functions on emotion perception. The relationship between those above-mentioned variables and emotion processing could have implications for cognitive rehabilitation.