Is this my voice or yours? The role of emotion and acoustic quality in self-other voice discrimination in schizophrenia

Targeting the superior temporal gyrus with real-time fMRI neurofeedback: A pilot study of the indirect effects on self-referential processes in schizophrenia

BACKGROUND

Individuals with schizophrenia (SZ) and auditory hallucinations (AHs) display a distorted sense of self and self-other boundaries. Alterations of activity in midline cortical structures such as the prefrontal cortex (mPFC) and anterior cingulate cortex (ACC) during self-reference as well as in the superior temporal gyrus (STG) have been proposed as neuromarkers of SZ and AHs.

METHODS

In this randomized, participant-blinded, sham-controlled trial, 22 adults (18 males) with SZ spectrum disorders (SZ or schizoaffective disorder) and frequent medication-resistant AHs received one session of real-time fMRI neurofeedback (NFB) either from the STG (n = 11; experimental group) or motor cortex (n = 11; control group). During NFB, participants were instructed to upregulate their STG activity by attending to pre-recorded sentences spoken in their own voice and downregulate it by ignoring unfamiliar voices. Before and after NFB, participants completed a self-reference task where they evaluated if trait adjectives referred to themselves (self condition), Abraham Lincoln (other condition), or whether adjectives had a positive valence (semantic condition). FMRI activation analyses of self-reference task data tested between-group changes after NFB (self>semantic, post>pre-NFB, experimental>control). Analyses were pre-masked within a self-reference network.

RESULTS

Activation analyses revealed significantly (p < 0.001) greater activation increase in the experimental, compared to the control group, after NFB within anterior regions of the self-reference network (mPFC, ACC, superior frontal cortex).

CONCLUSIONS

STG-NFB was associated with activity increase in the mPFC, ACC, and superior frontal cortex during self-reference. Modulating the STG is associated with activation changes in other, not-directly targeted, regions subserving higher-level cognitive processes associated with self-referential processes and AHs psychopathology in SZ.

CLINICALTRIALS

GOV: Rt-fMRI Neurofeedback and AH in Schizophrenia; https://clinicaltrials.gov/study/NCT03504579.

Examining the relationships between cognition and auditory hallucinations: A systematic review

OBJECTIVE

Auditory hallucinations (hearing voices) have been associated with a range of altered cognitive functions, pertaining to signal detection, source-monitoring, memory, inhibition and language processes. Yet, empirical results are inconsistent. Despite this, several theoretical models of auditory hallucinations persist, alongside increasing emphasis on the utility of a multidimensional framework. Thus, clarification of current evidence across the broad scope of proposed mechanisms is warranted.

METHOD

A systematic search of the Web of Science, PubMed and Scopus databases was conducted. Records were screened to confirm the use of an objective behavioural cognitive task, and valid measurement of hallucinations specific to the auditory modality.

RESULTS

Auditory hallucinations were primarily associated with difficulties in perceptual decision-making (i.e. reduced sensitivity/accuracy for signal-noise discrimination; liberal responding to ambiguity), source-monitoring (i.e. self-other and temporal context confusion), working memory and language function (i.e. reduced verbal fluency). Mixed or limited support was observed for perceptual feature discrimination, imagery vividness/illusion susceptibility, source-monitoring for stimulus form and spatial context, recognition and recall memory, executive functions (e.g. attention, inhibition), emotion processing and language comprehension/hemispheric organisation.

CONCLUSIONS

Findings were considered within predictive coding and self-monitoring frameworks. Of concern was the portion of studies which - despite offering auditory-hallucination-specific aims and inferences - employed modality-general measures, and/or diagnostic-based contrasts with psychologically healthy individuals. This review highlights disparities within the literature between theoretical conceptualisations of auditory hallucinations and the body of rigorous empirical evidence supporting such inferences. Future cognitive investigations, beyond the schizophrenia-spectrum, which explicitly define and measure the timeframe and sensory modality of hallucinations, are recommended.

Attention Modulates the Role of Speakers' Voice Identity and Linguistic Information in Spoken Word Processing: Evidence From Event-Related Potentials

PURPOSE

The human voice usually contains two types of information: linguistic and identity information. However, whether and how linguistic information interacts with identity information remains controversial. This study aimed to explore the processing of identity and linguistic information during spoken word processing by considering the modulation of attention.

METHOD

We conducted two event-related potentials (ERPs) experiments in the study. Different speakers (self, friend, and unfamiliar speakers) and emotional words (positive, negative, and neutral words) were used to manipulate the identity and linguistic information. With the manipulation, Experiment 1 explored the identity and linguistic information processing with a word decision task that requires participants' explicit attention to linguistic information. Experiment 2 further investigated the issue with a passive oddball paradigm that requires rare attention to either the identity or linguistic information.

RESULTS

Experiment 1 revealed an interaction among speaker, word type, and hemisphere in N400 amplitudes but not in N100 and P200, which suggests that identity information interacted with linguistic information at the later stage of spoken word processing. The mismatch negativity results of Experiment 2 showed no significant interaction between speaker and word pair, which indicates that identity and linguistic information were processed independently.

CONCLUSIONS

The identity information would interact with linguistic information during spoken word processing. However, the interaction was modulated by the task demands on attention involvement. We propose an attention-modulated explanation to explain the mechanism underlying identity and linguistic information processing. Implications of our findings are discussed in light of the integration and independence theories.

From communication dysfunction to treatment options in serious mental illness

The Commentary covers research focused on language dysfunction in schizophrenia, and more broadly in communication dysfunction in this disorder, which I have examined with a variety of both behavioral and imaging methodologies. It briefly outlines how further progress can be achieved in pursuing the goal of a comprehensive understanding of its underlying causes. Possible therapeutic approaches are also briefly discussed.

Attention and emotion shape self-voice prioritization in speech processing

Both self-voice and emotional speech are salient signals that are prioritized in perception. Surprisingly, self-voice perception has been investigated to a lesser extent than the self-face. Therefore, it remains to be clarified whether self-voice prioritization is boosted by emotion, and whether self-relevance and emotion interact differently when attention is focused on who is speaking vs. what is being said. Thirty participants listened to 210 prerecorded words spoken in one's own or an unfamiliar voice and differing in emotional valence in two tasks, manipulating the attention focus on either speaker identity or speech emotion. Event-related potentials (ERP) of the electroencephalogram (EEG) informed on the temporal dynamics of self-relevance, emotion, and attention effects. Words spoken in one's own voice elicited a larger N1 and Late Positive Potential (LPP), but smaller N400. Identity and emotion interactively modulated the P2 (self-positivity bias) and LPP (self-negativity bias). Attention to speaker identity modulated more strongly ERP responses within 600 ms post-word onset (N1, P2, N400), whereas attention to speech emotion altered the late component (LPP). However, attention did not modulate the interaction of self-relevance and emotion. These findings suggest that the self-voice is prioritized for neural processing at early sensory stages, and that both emotion and attention shape self-voice prioritization in speech processing. They also confirm involuntary processing of salient signals (self-relevance and emotion) even in situations in which attention is deliberately directed away from those cues. These findings have important implications for a better understanding of symptoms thought to arise from aberrant self-voice monitoring such as auditory verbal hallucinations.

Hypersensitivity to passive voice hearing in hallucination proneness

Voices are a complex and rich acoustic signal processed in an extensive cortical brain network. Specialized regions within this network support voice perception and production and may be differentially affected in pathological voice processing. For example, the experience of hallucinating voices has been linked to hyperactivity in temporal and extra-temporal voice areas, possibly extending into regions associated with vocalization. Predominant self-monitoring hypotheses ascribe a primary role of voice production regions to auditory verbal hallucinations (AVH). Alternative postulations view a generalized perceptual salience bias as causal to AVH. These theories are not mutually exclusive as both ascribe the emergence and phenomenology of AVH to unbalanced top-down and bottom-up signal processing. The focus of the current study was to investigate the neurocognitive mechanisms underlying predisposition brain states for emergent hallucinations, detached from the effects of inner speech. Using the temporal voice area (TVA) localizer task, we explored putative hypersalient responses to passively presented sounds in relation to hallucination proneness (HP). Furthermore, to avoid confounds commonly found in in clinical samples, we employed the Launay-Slade Hallucination Scale (LSHS) for the quantification of HP levels in healthy people across an experiential continuum spanning the general population. We report increased activation in the right posterior superior temporal gyrus (pSTG) during the perception of voice features that positively correlates with increased HP scores. In line with prior results, we propose that this right-lateralized pSTG activation might indicate early hypersensitivity to acoustic features coding speaker identity that extends beyond own voice production to perception in healthy participants prone to experience AVH.

Can ambient odors influence the recognition of emotional words? A behavioral and event-related potentials study

Odor context can affect the recognition of facial expressions. However, there is no evidence to date that odor can regulate the processing of emotional words conveyed by visual words. An emotional word recognition task was combined with event-related potential technology. Briefly, 49 adults were randomly divided into three odor contexts (pleasant odor, unpleasant odor, and no odor) to judge the valence of emotional words (positive, negative, and neutral). Both behavioral and Electroencephalography (EEG) data were collected. Both the pleasant odor and unpleasant odor contexts shortened the response time of the subjects to emotional words. In addition, negative words induced greater amplitudes of early posterior negativity (EPN) and late positive potential (LPP) than the positive and neutral words. However, the neutral words induced a larger N400 amplitude than the positive and negative words. More importantly, the processing of emotional words was found to be modulated by external odor contexts. For example, during the earlier (P2) processing stages, pleasant and unpleasant odor contexts induced greater P2 amplitudes than the no odor context. In the unpleasant odor context, negative words with the same odor valence induced greater P2 amplitudes than the positive words. During the later (N400) stages, various regions of the brain regions exhibited different results. For example, in the left and right frontal areas of the brain, exposure to positive words in a pleasant odor context resulted in a smaller N400 amplitude than exposure to neutral words in the same context. Meanwhile, in the left and right central regions, emotional words with the same valence as pleasant or unpleasant odor contexts elicited the minimum N400 amplitude. Individuals are very sensitive to emotional information. With deeper processing, different cognitive processes are reflected and they can be modulated by external odors. In the early and late stages of word processing, both pleasant and unpleasant odor contexts exhibited an undifferentiated dominance effect and could specifically modulate affectively congruent words.

Expectancy changes the self-monitoring of voice identity

Self‐voice attribution can become difficult when voice characteristics are ambiguous, but functional magnetic resonance imaging (fMRI) investigations of such ambiguity are sparse. We utilized voice‐morphing (self‐other) to manipulate (un‐)certainty in self‐voice attribution in a button‐press paradigm. This allowed investigating how levels of self‐voice certainty alter brain activation in brain regions monitoring voice identity and unexpected changes in voice playback quality. FMRI results confirmed a self‐voice suppression effect in the right anterior superior temporal gyrus (aSTG) when self‐voice attribution was unambiguous. Although the right inferior frontal gyrus (IFG) was more active during a self‐generated compared to a passively heard voice, the putative role of this region in detecting unexpected self‐voice changes during the action was demonstrated only when hearing the voice of another speaker and not when attribution was uncertain. Further research on the link between right aSTG and IFG is required and may establish a threshold monitoring voice identity in action. The current results have implications for a better understanding of the altered experience of self‐voice feedback in auditory verbal hallucinations.

Altered Auditory Self-recognition in People with Schizophrenia

Self-recognition is of great significance to our sense of self. To date, disturbances in the processing of visual self-recognition are well studied in people with schizophrenia, whereas relatively few studies have focused on the processing of self in other domains, such as auditory. An investigation of auditory self-recognition contributes to delineate changes related to self and the potential roots of the described psychopathological aspects connoting schizophrenia. By applying unimodal task and multisensory test, this study investigated auditory self-recognition in people with schizophrenia under unimodal and bimodal circumstances. Forty-six adults diagnosed with schizophrenia and thirty-two healthy controls were involved in this study. Results suggested that people with schizophrenia seemed to have significantly lower perceptual sensitivity in detecting self-voice, and also showed stricter judgment criteria in self-voice decision. Furthermore, in the presentation of stimuli that combined the stimulation of others' faces with one's own voice, people with schizophrenia mistakenly attributed the voices of others as their own. In conclusion, altered auditory self-recognition in people with schizophrenia was found.

Real and imagined sensory feedback have comparable effects on action anticipation

The forward model monitors the success of sensory feedback to an action and links it to an efference copy originating in the motor system. The Readiness Potential (RP) of the electroencephalogram has been denoted as a neural signature of the efference copy. An open question is whether imagined sensory feedback works similarly to real sensory feedback. We investigated the RP to audible and imagined sounds in a button-press paradigm and assessed the role of sound complexity (vocal vs. non-vocal sound). Sensory feedback (both audible and imagined) in response to a voluntary action modulated the RP amplitude time-locked to the button press. The RP amplitude increase was larger for actions with expected sensory feedback (audible and imagined) than those without sensory feedback, and associated with N1 suppression for audible sounds. Further, the early RP phase was increased when actions elicited an imagined vocal (self-voice) compared to non-vocal sound. Our results support the notion that sensory feedback is anticipated before voluntary actions. This is the case for both audible and imagined sensory feedback and confirms a role of overt and covert feedback in the forward model.

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.

Reading characters in voices: Ratings of personality characteristics from voices predict proneness to auditory verbal hallucinations

People rapidly make first impressions of others, often based on very little information–minimal exposure to faces or voices is sufficient for humans to make up their mind about personality of others. While there has been considerable research on voice personality perception, much less is known about its relevance to hallucination-proneness, despite auditory hallucinations being frequently perceived as personified social agents. The present paper reports two studies investigating the relation between voice personality perception and hallucination-proneness in non-clinical samples. A voice personality perception task was created, in which participants rated short voice recordings on four personality characteristics, relating to dimensions of the voice’s perceived Valence and Dominance. Hierarchical regression was used to assess contributions of Valence and Dominance voice personality ratings to hallucination-proneness scores, controlling for paranoia-proneness and vividness of mental imagery. Results from Study 1 suggested that high ratings of voices as dominant might be related to high hallucination-proneness; however, this relation seemed to be dependent on reported levels of paranoid thinking. In Study 2, we show that hallucination-proneness was associated with high ratings of voice dominance, and this was independent of paranoia and imagery abilities scores, both of which were found to be significant predictors of hallucination-proneness. Results from Study 2 suggest an interaction between gender of participants and the gender of the voice actor, where only ratings of own gender voices on Dominance characteristics are related to hallucination-proneness scores. These results are important for understanding the perception of characterful features of voices and its significance for psychopathology.

Self-voice perception and its relationship with hallucination predisposition

Introduction: Auditory verbal hallucinations (AVH) are a core symptom of psychotic disorders such as schizophrenia but are also reported in 10-15% of the general population. Impairments in self-voice recognition are frequently reported in schizophrenia and associated with the severity of AVH, particularly when the self-voice has a negative quality. However, whether self-voice processing is also affected in nonclinical voice hearers remains to be specified. Methods: Thirty-five nonclinical participants varying in hallucination predisposition based on the Launay-Slade Hallucination Scale, listened to prerecorded words and vocalisations differing in identity (self/other) and emotional quality. In Experiment 1, participants indicated whether words were spoken in their own voice, another voice, or whether they were unsure (recognition task). They were also asked whether pairs of words/vocalisations were uttered by the same or by a different speaker (discrimination task). In Experiment 2, participants judged the emotional quality of the words/vocalisations. Results: In Experiment 1, hallucination predisposition affected voice discrimination and recognition, irrespective of stimulus valence. Hallucination predisposition did not affect the evaluation of the emotional valence of words/vocalisations (Experiment 2). Conclusions: These findings suggest that nonclinical participants with high HP experience altered voice identity processing, whereas HP does not affect the perception of vocal emotion. Specific alterations in self-voice perception in clinical and nonclinical voice hearers may establish a core feature of the psychosis continuum.

Temporal Features of Psychological and Physical Self-Representation: An ERP Study

Psychological and physical-self are two important aspects of self-concept. Although a growing number of behavioral and neuroimaging studies have investigated the cognitive mechanism and neural substrate underlying psychological and physical-self-representation, most of the existing research on psychological and physical-self-representation had been done in isolation. The present study aims to examine the electrophysiological responses to both psychological (one’s own name) and physical (one’s own voice) self-related stimuli in a uniform paradigm. Event-related potentials (ERPs) were recorded for subjects’ own and others’ names uttered by subjects’ own or others’ voice (own voice-own name, own voice-other’s name, other’s voice-own name, other’s voice-other’s name) while subjects performed an auditory passive oddball task. The results showed that one’s own name elicited smaller P2 and larger P3 amplitudes than those of other’s names, irrespective of the voice identity. However, no differences were observed between self and other’s voice during the P2 and P3 stages. Moreover, an obvious interaction effect was observed between voice content and voice identity at the N400 stage that the subject’s own voice elicited a larger parietal N400 amplitude than other’s voice in other name condition but not in own name condition. Taken together, these findings suggested that psychological (one’s own name) and physical (one’s own voice) self-representation induced distinct electrophysiological response patterns in auditory-cognitive processing.

Altered attentional processing of happy prosody in schizophrenia

BACKGROUND

Abnormalities in emotional prosody processing have been consistently reported in schizophrenia. Emotionally salient changes in vocal expressions attract attention in social interactions. However, it remains to be clarified how attention and emotion interact during voice processing in schizophrenia. The current study addressed this question by examining the P3b event-related potential (ERP) component.

METHOD

The P3b was elicited with a modified oddball task, in which frequent (p = .84) neutral stimuli were intermixed with infrequent (p = .16) task-relevant emotional (happy or angry) targets. Prosodic speech was presented in two conditions - with intelligible (semantic content condition - SCC) or unintelligible semantic content (prosody-only condition - POC). Fifteen chronic schizophrenia patients and 15 healthy controls were instructed to silently count the target vocal sounds.

RESULTS

Compared to controls, P3b amplitude was specifically reduced for happy prosodic stimuli in schizophrenia, irrespective of semantic status. Groups did not differ in the processing of neutral standards or angry targets.

DISCUSSION

The selectively reduced P3b for happy prosody in schizophrenia suggests top-down attentional resources were less strongly engaged by positive relative to negative prosody, reflecting alterations in the evaluation of the emotional salience of the voice. These results highlight the role played by higher-order processes in emotional prosody dysfunction in schizophrenia.

Voice-selective prediction alterations in nonclinical voice hearers

Auditory verbal hallucinations (AVH) are a cardinal symptom of psychosis but also occur in 6–13% of the general population. Voice perception is thought to engage an internal forward model that generates predictions, preparing the auditory cortex for upcoming sensory feedback. Impaired processing of sensory feedback in vocalization seems to underlie the experience of AVH in psychosis, but whether this is the case in nonclinical voice hearers remains unclear. The current study used electroencephalography (EEG) to investigate whether and how hallucination predisposition (HP) modulates the internal forward model in response to self-initiated tones and self-voices. Participants varying in HP (based on the Launay-Slade Hallucination Scale) listened to self-generated and externally generated tones or self-voices. HP did not affect responses to self vs. externally generated tones. However, HP altered the processing of the self-generated voice: increased HP was associated with increased pre-stimulus alpha power and increased N1 response to the self-generated voice. HP did not affect the P2 response to voices. These findings confirm that both prediction and comparison of predicted and perceived feedback to a self-generated voice are altered in individuals with AVH predisposition. Specific alterations in the processing of self-generated vocalizations may establish a core feature of the psychosis continuum.

Stimulus complexity matters when you hear your own voice: Attention effects on self-generated voice processing

The ability to discriminate self- and non-self voice cues is a fundamental aspect of self-awareness and subserves self-monitoring during verbal communication. Nonetheless, the neurofunctional underpinnings of self-voice perception and recognition are still poorly understood. Moreover, how attention and stimulus complexity influence the processing and recognition of one's own voice remains to be clarified. Using an oddball task, the current study investigated how self-relevance and stimulus type interact during selective attention to voices, and how they affect the representation of regularity during voice perception. Event-related potentials (ERPs) were recorded from 18 right-handed males. Pre-recorded self-generated (SGV) and non-self (NSV) voices, consisting of a nonverbal vocalization (vocalization condition) or disyllabic word (word condition), were presented as either standard or target stimuli in different experimental blocks. The results showed increased N2 amplitude to SGV relative to NSV stimuli. Stimulus type modulated later processing stages only: P3 amplitude was increased for SGV relative to NSV words, whereas no differences between SGV and NSV were observed in the case of vocalizations. Moreover, SGV standards elicited reduced N1 and P2 amplitude relative to NSV standards. These findings revealed that the self-voice grabs more attention when listeners are exposed to words but not vocalizations. Further, they indicate that detection of regularity in an auditory stream is facilitated for one's own voice at early processing stages. Together, they demonstrate that self-relevance affects attention to voices differently as a function of stimulus type.

Attenuation of visual evoked responses to hand and saccade-initiated flashes

Sensory attenuation refers to reduced brain responses to self-initiated sensations relative to those produced by the external world. It is a low-level process that may be linked to higher-level cognitive tasks such as reality monitoring. The phenomenon is often explained by prediction error mechanisms of universal applicability to sensory modality; however, it is most widely reported for auditory stimuli resulting from self-initiated hand movements. The present series of event-related potential (ERP) experiments explored the generalizability of sensory attenuation to the visual domain by exposing participants to flashes initiated by either their own button press or volitional saccade and comparing these conditions to identical, computer-initiated stimuli. The key results showed that the largest reduction of anterior visual N1 amplitude occurred for saccade-initiated flashes, while button press-initiated flashes evoked an intermediary response between the saccade-initiated and externally initiated conditions. This indicates that sensory attenuation occurs for visual stimuli and suggests that the degree of electrophysiological attenuation may relate to the causal likelihood of pairings between the type of motor action and the modality of its sensory response.

On "Hearing" Voices and "Seeing" Things: Probing Hallucination Predisposition in a Portuguese Nonclinical Sample with the Launay-Slade Hallucination Scale-Revised

The experience of hallucinations is a hallmark of psychotic disorders, but they are also present in other psychiatric and medical conditions, and may be reported in nonclinical individuals. Despite the increased number of studies probing the incidence of nonclinical hallucinations, the underlying phenomenological characteristics are still poorly understood. This study aimed to examine the psychometrics proprieties of the Portuguese adaptation of the 16-item Launay-Slade Hallucinations Scale (LSHS), the phenomenological characteristics of nonclinical hallucinatory experiences in a Portuguese sample, and the relationship between clinical symptoms and hallucination predisposition. Three-hundred-and-fifty-four European Portuguese college students completed the LSHS. Of those, 16 participants with high LSHS scores and 14 with low LSHS scores were further screened for clinical symptoms. A three-factor solution for the LSHS Portuguese version proved to be the most adequate. Intrusive or vivid thoughts and sleep-related hallucinations were the most common. Although, fundamentally perceived as positive experiences, all types of hallucinations were described as uncontrollable and dominating. However, the more pleasant they were perceived, the more controllable they were assessed. In addition, hallucination predisposition was associated with increased clinical symptoms. These results corroborate the lower severity of hallucinations in the general population compared to psychotic individuals. Further, they support an association between clinical symptoms and increased vulnerability to hallucinations. Specifically, increased schizotypal tendencies and negative mood (anxiety and depression) may be related to increased psychotic risk.

Emotional self-other voice processing in schizophrenia and its relationship with hallucinations: ERP evidence

Abnormalities in self-other voice processing have been observed in schizophrenia, and may underlie the experience of hallucinations. More recent studies demonstrated that these impairments are enhanced for speech stimuli with negative content. Nonetheless, few studies probed the temporal dynamics of self versus nonself speech processing in schizophrenia and, particularly, the impact of semantic valence on self-other voice discrimination. In the current study, we examined these questions, and additionally probed whether impairments in these processes are associated with the experience of hallucinations. Fifteen schizophrenia patients and 16 healthy controls listened to 420 prerecorded adjectives differing in voice identity (self-generated [SGS] versus nonself speech [NSS]) and semantic valence (neutral, positive, and negative), while EEG data were recorded. The N1, P2, and late positive potential (LPP) ERP components were analyzed. ERP results revealed group differences in the interaction between voice identity and valence in the P2 and LPP components. Specifically, LPP amplitude was reduced in patients compared with healthy subjects for SGS and NSS with negative content. Further, auditory hallucinations severity was significantly predicted by LPP amplitude: the higher the SAPS "voices conversing" score, the larger the difference in LPP amplitude between negative and positive NSS. The absence of group differences in the N1 suggests that self-other voice processing abnormalities in schizophrenia are not primarily driven by disrupted sensory processing of voice acoustic information. The association between LPP amplitude and hallucination severity suggests that auditory hallucinations are associated with enhanced sustained attention to negative cues conveyed by a nonself voice.