Revisiting alpha resting state dynamics underlying hallucinatory vulnerability: Insights from Hidden semi-Markov Modeling

BACKGROUND

Resting state (RS) brain activity is inherently non-stationary. Hidden semi-Markov Models (HsMM) can characterize continuous RS data as a sequence of recurring and distinct brain states along with their spatio-temporal dynamics.

NEW METHOD

Recent explorations suggest that HsMM state dynamics in the alpha frequency band link to auditory hallucination proneness (HP) in non-clinical individuals. The present study aimed to replicate these findings to elucidate robust neural correlates of hallucinatory vulnerability. Specifically, we aimed to investigate the reproducibility of HsMM states across different data sets and within-data set variants as well as the replicability of the association between alpha brain state dynamics and HP.

RESULTS

We found that most brain states are reproducible in different data sets, confirming that the HsMM characterized robust and generalizable EEG RS dynamics on a sub-second timescale. Brain state topographies and temporal dynamics of different within-data set variants showed substantial similarities and were robust against reduced data length and number of electrodes. However, the association with HP was not directly reproducible across data sets.

COMPARISON WITH EXISTING METHODS

The HsMM optimally leverages the high temporal resolution of EEG data and overcomes time-domain restrictions of other state allocation methods.

CONCLUSION

The results indicate that the sensitivity of brain state dynamics to capture individual variability in HP may depend on the data recording characteristics and individual variability in RS cognition, such as mind wandering. Future studies should consider that the order in which eyes-open and eyes-closed RS data are acquired directly influences an individual's attentional state and generation of spontaneous thoughts, and thereby might mediate the link to hallucinatory vulnerability.

Inhibiting orofacial mimicry affects authenticity perception in vocal emotions

Although emotional mimicry is ubiquitous in social interactions, its mechanisms and roles remain disputed. A prevalent view is that imitating others' expressions facilitates emotional understanding, but the evidence is mixed and almost entirely based on facial emotions. In a preregistered study, we asked whether inhibiting orofacial mimicry affects authenticity perception in vocal emotions. Participants listened to authentic and posed laughs and cries, while holding a pen between the teeth and lips to inhibit orofacial responses (n = 75), or while responding freely without a pen (n = 75). They made authenticity judgments and rated how much they felt the conveyed emotions (emotional contagion). Mimicry inhibition decreased the accuracy of authenticity perception in laughter and crying, and in posed and authentic vocalizations. It did not affect contagion ratings, however, nor performance in a cognitive control task, ruling out the effort of holding the pen as an explanation for the decrements in authenticity perception. Laughter was more contagious than crying, and authentic vocalizations were more contagious than posed ones, regardless of whether mimicry was inhibited or not. These findings confirm the role of mimicry in emotional understanding and extend it to auditory emotions. They also imply that perceived emotional contagion can be unrelated to mimicry. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Blindness influences emotional authenticity perception in voices: Behavioral and ERP evidence

The ability to distinguish spontaneous from volitional emotional expressions is an important social skill. How do blind individuals perceive emotional authenticity? Unlike sighted individuals, they cannot rely on facial and body language cues, relying instead on vocal cues alone. Here, we combined behavioral and ERP measures to investigate authenticity perception in laughter and crying in individuals with early- or late-blindness onset. Early-blind, late-blind, and sighted control participants (n = 17 per group, N = 51) completed authenticity and emotion discrimination tasks while EEG data were recorded. The stimuli consisted of laughs and cries that were either spontaneous or volitional. The ERP analysis focused on the N1, P2, and late positive potential (LPP). Behaviorally, early-blind participants showed intact authenticity perception, but late-blind participants performed worse than controls. There were no group differences in the emotion discrimination task. In brain responses, all groups were sensitive to laughter authenticity at the P2 stage, and to crying authenticity at the early LPP stage. Nevertheless, only early-blind participants were sensitive to crying authenticity at the N1 and middle LPP stages, and to laughter authenticity at the early LPP stage. Furthermore, early-blind and sighted participants were more sensitive than late-blind ones to crying authenticity at the P2 and late LPP stages. Altogether, these findings suggest that early blindness relates to facilitated brain processing of authenticity in voices, both at early sensory and late cognitive-evaluative stages. Late-onset blindness, in contrast, relates to decreased sensitivity to authenticity at behavioral and brain levels.

Stimuli in 3 Acts: A normative study on action-statements, action videos and object photos

The study of action observation and imagery, separately and combined, is expanding in diverse research areas (e.g., sports psychology, neurosciences), making clear the need for action-related stimuli (i.e., action statements, videos, and pictures). Although several databases of object and action pictures are available, norms on action videos are scarce. In this study, we validated a set of 60 object-related everyday actions in three different formats: action-statements, and corresponding dynamic (action videos) and static (object photos) stimuli. In Study 1, ratings of imageability, image agreement, action familiarity, action frequency, and action valence were collected from 161 participants. In Study 2, a different sample of 115 participants rated object familiarity, object valence, and object-action prototypicality. Most actions were rated as easy to imagine, familiar, and neutral or positive in valence. However, there was variation in the frequency with which participants perform these actions on a daily basis. High agreement between participants' mental image and action videos was also found, showing that the videos depict a conventional way of performing the actions. Objects were considered familiar and positive in valence. High ratings on object-action prototypicality indicate that the actions correspond to prototypical actions for most objects. 3ActStimuli is a comprehensive set of stimuli that can be useful in several research areas, allowing the combined study of action observation and imagery.

Examining the effects of emotional valence and arousal on source memory: A meta-analysis of behavioral evidence

The current meta-analysis examined the effects of valence and arousal on source memory accuracy, including the identification of variables that moderate the magnitude and direction of those effects. Fifty-three studies, comprising 85 individual experiments (N = 3,040 participants), were selected. Three separate analyses focusing on valence effects (valence-based: negative-neutral; positive-neutral; negative-positive) and other three focusing exclusively on arousal (arousal-based: high-low; medium-low; high-medium) were considered. Effect sizes varied from very small to medium. For the valence-based analyses, source memory accuracy was impaired for emotional compared with neutral stimuli (dunb = -.14 for negative-neutral; dunb = -.11 for positive-neutral), with a similar performance found for the negative-positive comparison (dunb = -.04). In the case of arousal-based analyses, source memory was improved for stimuli with high and medium arousal versus low arousal (dunb = .27, dunb = .49, respectively), with no statistically significant difference between high and medium arousal stimuli (dunb = -.12). Emotion effects on source memory were modulated by methodological factors. These factors may account for the variety findings typically found in emotion-related source memory research and could be systematically addressed in future studies. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Individual differences in musical ability among adults with no music training

Good musical abilities are typically considered to be a consequence of music training, such that they are studied in samples of formally trained individuals. Here, we asked what predicts musical abilities in the absence of music training. Participants with no formal music training (N = 190) completed the Goldsmiths Musical Sophistication Index, measures of personality and cognitive ability, and the Musical Ear Test (MET). The MET is an objective test of musical abilities that provides a Total score and separate scores for its two subtests (Melody and Rhythm), which require listeners to determine whether standard and comparison auditory sequences are identical. MET scores had no associations with personality traits. They correlated positively, however, with informal musical experience and cognitive abilities. Informal musical experience was a better predictor of Melody than of Rhythm scores. Some participants (12%) had Total scores higher than the mean from a sample of musically trained individuals (⩾6 years of formal training), tested previously by Correia et al. Untrained participants with particularly good musical abilities (top 25%, n = 51) scored higher than trained participants on the Rhythm subtest and similarly on the Melody subtest. High-ability untrained participants were also similar to trained ones in cognitive ability, but lower in the personality trait openness-to-experience. These results imply that formal music training is not required to achieve musician-like performance on tests of musical and cognitive abilities. They also suggest that informal music practice and music-related predispositions should be considered in studies of musical expertise.

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.

Enhanced salience of musical sounds in singers and instrumentalists

Music training has been linked to facilitated processing of emotional sounds. However, most studies have focused on speech, and less is known about musicians' brain responses to other emotional sounds and in relation to instrument-specific experience. The current study combined behavioral and EEG methods to address two novel questions related to the perception of auditory emotional cues: whether and how long-term music training relates to a distinct emotional processing of nonverbal vocalizations and music; and whether distinct training profiles (vocal vs. instrumental) modulate brain responses to emotional sounds from early to late processing stages. Fifty-eight participants completed an EEG implicit emotional processing task, in which musical and vocal sounds differing in valence were presented as nontarget stimuli. After this task, participants explicitly evaluated the same sounds regarding the emotion being expressed, their valence, and arousal. Compared with nonmusicians, musicians displayed enhanced salience detection (P2), attention orienting (P3), and elaborative processing (Late Positive Potential) of musical (vs. vocal) sounds in event-related potential (ERP) data. The explicit evaluation of musical sounds also was distinct in musicians: accuracy in the emotional recognition of musical sounds was similar across valence types in musicians, who also judged musical sounds to be more pleasant and more arousing than nonmusicians. Specific profiles of music training (singers vs. instrumentalists) did not relate to differences in the processing of vocal vs. musical sounds. Together, these findings reveal that music has a privileged status in the auditory system of long-term musically trained listeners, irrespective of their instrument-specific experience.

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 musical ability be tested online?

We sought to determine whether an objective test of musical ability could be successfully administered online. A sample of 754 participants was tested with an online version of the Musical Ear Test (MET), which had Melody and Rhythm subtests. Both subtests had 52 trials, each of which required participants to determine whether standard and comparison auditory sequences were identical. The testing session also included the Goldsmiths Musical Sophistication Index (Gold-MSI), a test of general cognitive ability, and self-report questionnaires that measured basic demographics (age, education, gender), mind-wandering, and personality. Approximately 20% of the participants were excluded for incomplete responding or failing to finish the testing session. For the final sample (N = 608), findings were similar to those from in-person testing in many respects: (1) the internal reliability of the MET was maintained, (2) construct validity was confirmed by strong associations with Gold-MSI scores, (3) correlations with other measures (e.g., openness to experience, cognitive ability, mind-wandering) were as predicted, (4) mean levels of performance were similar for individuals with no music training, and (5) musical sophistication was a better predictor of performance on the Melody than on the Rhythm subtest. In sum, online administration of the MET proved to be a reliable and valid way to measure musical ability.

The perceived salience of vocal emotions is dampened in non-clinical auditory verbal hallucinations

Introduction: Auditory verbal hallucinations (AVH) are a cardinal symptom of schizophrenia but are also reported in the general population without need for psychiatric care. Previous evidence suggests that AVH may reflect an imbalance of prior expectation and sensory information, and that altered salience processing is characteristic of both psychotic and non-clinical voice hearers. However, it remains to be shown how such an imbalance affects the categorisation of vocal emotions in perceptual ambiguity.Methods: Neutral and emotional nonverbal vocalisations were morphed along two continua differing in valence (anger; pleasure), each including 11 morphing steps at intervals of 10%. College students (N = 234) differing in AVH proneness (measured with the Launay-Slade Hallucination Scale) evaluated the emotional quality of the vocalisations.Results: Increased AVH proneness was associated with more frequent categorisation of ambiguous vocalisations as 'neutral', irrespective of valence. Similarly, the perceptual boundary for emotional classification was shifted by AVH proneness: participants needed more emotional information to categorise a voice as emotional.Conclusions: These findings suggest that emotional salience in vocalisations is dampened as a function of increased AVH proneness. This could be related to changes in the acoustic representations of emotions or reflect top-down expectations of less salient information in the social environment.

From Sound Perception to Automatic Detection of Schizophrenia: An EEG-Based Deep Learning Approach

Deep learning techniques have been applied to electroencephalogram (EEG) signals, with promising applications in the field of psychiatry. Schizophrenia is one of the most disabling neuropsychiatric disorders, often characterized by the presence of auditory hallucinations. Auditory processing impairments have been studied using EEG-derived event-related potentials and have been associated with clinical symptoms and cognitive dysfunction in schizophrenia. Due to consistent changes in the amplitude of ERP components, such as the auditory N100, some have been proposed as biomarkers of schizophrenia. In this paper, we examine altered patterns in electrical brain activity during auditory processing and their potential to discriminate schizophrenia and healthy subjects. Using deep convolutional neural networks, we propose an architecture to perform the classification based on multi-channels auditory-related EEG single-trials, recorded during a passive listening task. We analyzed the effect of the number of electrodes used, as well as the laterality and distribution of the electrical activity over the scalp. Results show that the proposed model is able to classify schizophrenia and healthy subjects with an average accuracy of 78% using only 5 midline channels (Fz, FCz, Cz, CPz, and Pz). The present study shows the potential of deep learning methods in the study of impaired auditory processing in schizophrenia with implications for diagnosis. The proposed design can provide a base model for future developments in schizophrenia research.

Emotional authenticity modulates affective and social trait inferences from voices

The human voice is a primary tool for verbal and nonverbal communication. Studies on laughter emphasize a distinction between spontaneous laughter, which reflects a genuinely felt emotion, and volitional laughter, associated with more intentional communicative acts. Listeners can reliably differentiate the two. It remains unclear, however, if they can detect authenticity in other vocalizations, and whether authenticity determines the affective and social impressions that we form about others. Here, 137 participants listened to laughs and cries that could be spontaneous or volitional and rated them on authenticity, valence, arousal, trustworthiness and dominance. Bayesian mixed models indicated that listeners detect authenticity similarly well in laughter and crying. Speakers were also perceived to be more trustworthy, and in a higher arousal state, when their laughs and cries were spontaneous. Moreover, spontaneous laughs were evaluated as more positive than volitional ones, and we found that the same acoustic features predicted perceived authenticity and trustworthiness in laughter: high pitch, spectral variability and less voicing. For crying, associations between acoustic features and ratings were less reliable. These findings indicate that emotional authenticity shapes affective and social trait inferences from voices, and that the ability to detect authenticity in vocalizations is not limited to laughter. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.

Attention to voices is increased in non-clinical auditory verbal hallucinations irrespective of salience

Alterations in the processing of vocal emotions have been associated with both clinical and non-clinical auditory verbal hallucinations (AVH), suggesting that changes in the mechanisms underpinning voice perception contribute to AVH. These alterations seem to be more pronounced in psychotic patients with AVH when attention demands increase. However, it remains to be clarified how attention modulates the processing of vocal emotions in individuals without clinical diagnoses who report hearing voices but no related distress. Using an active auditory oddball task, the current study clarified how emotion and attention interact during voice processing as a function of AVH proneness, and examined the contributions of stimulus valence and intensity. Participants with vs. without non-clinical AVH were presented with target vocalizations differing in valence (neutral; positive; negative) and intensity (55 decibels (dB); 75 dB). The P3b amplitude was larger in response to louder (vs. softer) vocal targets irrespective of valence, and in response to negative (vs. neutral) vocal targets irrespective of intensity. Of note, the P3b amplitude was globally increased in response to vocal targets in participants reporting AVH, and failed to be modulated by valence and intensity in these participants. These findings suggest enhanced voluntary attention to changes in vocal expressions but reduced discrimination of salient and non-salient cues. A decreased sensitivity to salience cues of vocalizations could contribute to increased cognitive control demands, setting the stage for an AVH.

Does Music Training Improve Emotion Recognition Abilities? A Critical Review

There is widespread interest in the possibility that music training enhances nonmusical abilities. This possibility has been examined primarily for speech perception and domain-general abilities such as IQ. Although social and emotional processes are central to many musical activities, transfer from music training to socioemotional skills remains underexplored. Here we synthesize results from studies examining associations between music training and emotion recognition in voices and faces. Enhancements are typically observed for vocal emotions but not for faces, although most evidence is cross-sectional. These findings are discussed considering the design features of the studies. Future research could explore further the neurocognitive mechanisms underlying musician-related differences in emotion recognition, the role of predispositions, and the implications for broader aspects of socioemotional functioning.

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.

Advanced EEG-based learning approaches to predict schizophrenia: Promises and pitfalls

The complexity and heterogeneity of schizophrenia symptoms challenge an objective diagnosis, which is typically based on behavioral and clinical manifestations. Moreover, the boundaries of schizophrenia are not precisely demarcated from other nosologic categories, such as bipolar disorder. The early detection of schizophrenia can lead to a more effective treatment, improving patients' quality of life. Over the last decades, hundreds of studies aimed at specifying the neurobiological mechanisms that underpin clinical manifestations of schizophrenia, using techniques such as electroencephalography (EEG). Changes in event-related potentials of the EEG have been associated with sensory and cognitive deficits and proposed as biomarkers of schizophrenia. Besides contributing to a more effective diagnosis, biomarkers can be crucial to schizophrenia onset prediction and prognosis. However, any proposed biomarker requires substantial clinical research to prove its validity and cost-effectiveness. Fueled by developments in computational neuroscience, automatic classification of schizophrenia at different stages (prodromal, first episode, chronic) has been attempted, using brain imaging pattern recognition methods to capture differences in functional brain activity. Advanced learning techniques have been studied for this purpose, with promising results. This review provides an overview of recent machine learning-based methods for schizophrenia classification using EEG data, discussing their potentialities and limitations. This review is intended to serve as a starting point for future developments of effective EEG-based models that might predict the onset of schizophrenia, identify subjects at high-risk of psychosis conversion or differentiate schizophrenia from other disorders, promoting more effective early interventions.

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.

Do Isolamento Social ao Crescimento Pessoal: Reflexões Sobre o Impacto Psicossocial da Pandemia

INTRODUÇÃO: Esta é uma reflexão que combina o olhar integrado da Psiquiatria, da Psicologia Clínica e da Neuropsicologia sobre o impacto psicossocial da pandemia por COVID-19. As secções seguintes abordam algumas das dimensões da existência humana mais afetadas pela pandemia, através de um diálogo entre duas perspetivas: o existencialismo e a ciência. [...]

Changes in motor preparation affect the sensory consequences of voice production in voice hearers

BACKGROUND

Auditory verbal hallucinations (AVH) are a cardinal symptom of psychosis but are also present in 6-13% of the general population. Alterations in sensory feedback processing are a likely cause of AVH, indicative of changes in the forward model. However, it is unknown whether such alterations are related to anomalies in forming an efference copy during action preparation, selective for voices, and similar along the psychosis continuum. By directly comparing psychotic and nonclinical voice hearers (NCVH), the current study specifies whether and how AVH proneness modulates both the efference copy (Readiness Potential) and sensory feedback processing for voices and tones (N1, P2) with event-related brain potentials (ERPs).

METHODS

Controls with low AVH proneness (n = 15), NCVH (n = 16) and first-episode psychotic patients with AVH (n = 16) engaged in a button-press task with two types of stimuli: self-initiated and externally generated self-voices or tones during EEG recordings.

RESULTS

Groups differed in sensory feedback processing of expected and actual feedback: NCVH displayed an atypically enhanced N1 to self-initiated voices, while N1 suppression was reduced in psychotic patients. P2 suppression for voices and tones was strongest in NCVH, but absent for voices in patients. Motor activity preceding the button press was reduced in NCVH and patients, specifically for sensory feedback to self-voice in NCVH.

CONCLUSIONS

These findings suggest that selective changes in sensory feedback to voice are core to AVH. These changes already show in preparatory motor activity, potentially reflecting changes in forming an efference copy. The results provide partial support for continuum models of psychosis.

Is internal source memory recognition modulated by emotional encoding contexts?

The influence of emotion on memory has been mainly examined by manipulating the emotional valence and/or arousal of critical items. Few studies probed how emotional information presented during the encoding of critical neutral items modulates memory recognition, particularly when considering source memory features. In this study, we specified the role of emotional encoding contexts in internal source memory performance (discrimination between encoding tasks) using a mixed (Experiment 1) and a blocked design (Experiment 2). During the study phase, participants were required to evaluate a set of neutral words, using either a self-referential or a semantic (common judgment) encoding strategy. Prior and concomitantly with each word, negative, neutral or positive pictures were presented in the background. The beneficial effect of self-referential encoding was observed for both item and internal source memory in both experiments. Remarkably, item and internal source memory recognition was not modulated by emotion, even though a secondary analysis indicated that the consistent exposure to negative (vs. positive) information led to worse source memory performance. These findings suggest that internal source memory of neutral items is not always affected by changing or repetitive emotional encoding contexts.

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.

Differential Effects of Valence and Encoding Strategy on Internal Source Memory and Judgments of Source: Exploring the Production and the Self-Reference Effect

Item memory studies show that emotional stimuli are associated with improved memory performance compared to neutral ones. However, emotion-related effects on source memory are less consistent. The current study probed how emotional valence and specific encoding conditions influence internal source memory performance and judgments of source (JOSs). In two independent experiments, participants were required to read silently/aloud (Experiment 1) or to perform self-reference/common judgments (Experiment 2) on a list of negative/neutral/positive words. They also performed immediate JOSs ratings for each word. The study phase was followed by a test phase in which participants performed old-new judgments. In Experiment 1, the production effect was replicated for item memory, but the effects of valence on item and source memory were not significant. In Experiment 2, self-referential processing effects on item and source memory differed as a function of valence. In both experiments, JOSs ratings were sensitive to valence and encoding conditions, although they were not predictive of objective memory performance. These findings demonstrate that the effects of valence on internal source memory and JOSs are modulated by encoding strategy. Thus, the way information is encoded can shed light on how emotion might enhance, impair or exert no influence on source memory.

The role of the cerebellum in adaptation: ALE meta-analyses on sensory feedback error

It is widely accepted that unexpected sensory consequences of self‐action engage the cerebellum. However, we currently lack consensus on where in the cerebellum, we find fine‐grained differentiation to unexpected sensory feedback. This may result from methodological diversity in task‐based human neuroimaging studies that experimentally alter the quality of self‐generated sensory feedback. We gathered existing studies that manipulated sensory feedback using a variety of methodological approaches and performed activation likelihood estimation (ALE) meta‐analyses. Only half of these studies reported cerebellar activation with considerable variation in spatial location. Consequently, ALE analyses did not reveal significantly increased likelihood of activation in the cerebellum despite the broad scientific consensus of the cerebellum's involvement. In light of the high degree of methodological variability in published studies, we tested for statistical dependence between methodological factors that varied across the published studies. Experiments that elicited an adaptive response to continuously altered sensory feedback more frequently reported activation in the cerebellum than those experiments that did not induce adaptation. These findings may explain the surprisingly low rate of significant cerebellar activation across brain imaging studies investigating unexpected sensory feedback. Furthermore, limitations of functional magnetic resonance imaging to probe the cerebellum could play a role as climbing fiber activity associated with feedback error processing may not be captured by it. We provide methodological recommendations that may guide future studies.

Spatial location and emotion modulate voice perception

How do we perceive voices coming from different spatial locations, and how is this affected by emotion? The current study probed the interplay between space and emotion during voice perception. Thirty participants listened to nonverbal vocalizations coming from different locations around the head (left vs. right; front vs. back), and differing in valence (neutral, positive [amusement] or negative [anger]). They were instructed to identify the location of the vocalizations (Experiment 1) and to evaluate their emotional qualities (Experiment 2). Emotion-space interactions were observed, but only in Experiment 1: emotional vocalizations were better localised than neutral ones when they were presented from the back and the right side. In Experiment 2, emotion recognition accuracy was increased for positive vs. negative and neutral vocalizations, and perceived arousal was increased for emotional vs. neutral vocalizations, but this was independent of spatial location. These findings indicate that emotional salience affects how we perceive the spatial location of voices. They additionally suggest that the interaction between spatial ("where") and emotional ("what") properties of the voice differs as a function of task.

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.

Is the sunny side up and the dark side down? Effects of stimulus type and valence on a spatial detection task

In verbal communication, affective information is commonly conveyed to others through spatial terms (e.g. in "I am feeling down", negative affect is associated with a lower spatial location). This study used a target location discrimination task with neutral, positive and negative stimuli (words, facial expressions, and vocalizations) to test the automaticity of the emotion-space association, both in the vertical and horizontal spatial axes. The effects of stimulus type on emotion-space representations were also probed. A congruency effect (reflected in reaction times) was observed in the vertical axis: detection of upper targets preceded by positive stimuli was faster. This effect occurred for all stimulus types, indicating that the emotion-space association is not dependent on sensory modality and on the verbal content of affective stimuli.

Laughter catches attention!

In social interactions, emotionally salient and sudden changes in vocal expressions attract attention. However, only a few studies examined how emotion and attention interact in voice processing. We investigated neutral, happy (laughs) and angry (growls) vocalizations in a modified oddball task. Participants silently counted the targets in each block and rated the valence and arousal of the vocalizations. A combined event-related potential and time-frequency analysis focused on the P3 and pre-stimulus alpha power to capture attention effects in response to unexpected events. Whereas an early differentiation between emotionally salient and neutral vocalizations was reflected in the P3a response, the P3b was selectively enhanced for happy voices. The P3b modulation was predicted by pre-stimulus frontal alpha desynchronization, and by the perceived pleasantness of the targets. These findings indicate that vocal emotions may be differently processed based on task relevance and valence. Increased anticipation and attention to positive vocal cues (laughter) may reflect their high social relevance.

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.

Does emotion change auditory prediction and deviance detection?

In the last decades, a growing number of studies provided compelling evidence supporting the interplay of cognitive and affective processes. However, it remains to be clarified whether and how an emotional context affects the prediction and detection of change in unattended sensory events. In an event-related potential (ERP) study, we probed the modulatory role of pleasant, unpleasant and neutral visual contexts on the brain response to automatic detection of change in spectral (intensity) vs. temporal (duration) sound features. Twenty participants performed a passive auditory oddball task. Additionally, we tested the relationship between ERPs and self-reported mood. Participants reported more negative mood after the negative block. The P2 amplitude elicited by standards was increased in a positive context. Mismatch Negativity (MMN) amplitude was decreased in the negative relative to the neutral and positive contexts, and was associated with self-reported mood. These findings suggest that the detection of regularities in the auditory stream was facilitated in a positive context, whereas a negative visual context interfered with prediction error elicitation, through associated mood changes. Both ERP and behavioral effects highlight the intricate links between emotion, perception and cognitive processes.

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.

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

INTRODUCTION

Impairments in self-other voice discrimination have been consistently reported in schizophrenia, and associated with the severity of auditory verbal hallucinations (AVHs). This study probed the interactions between voice identity, voice acoustic quality, and semantic valence in a self-other voice discrimination task in schizophrenia patients compared with healthy subjects. The relationship between voice identity discrimination and AVH severity was also explored.

METHODS

Seventeen chronic schizophrenia patients and 19 healthy controls were asked to read aloud a list of adjectives characterised by emotional or neutral content. Participants' voice was recorded in the first session. In the behavioural task, 840 spoken words differing in identity (self/non-self), acoustic quality (undistorted/distorted), and semantic valence (negative/positive/neutral) were presented. Participants indicated if the words were spoken in their own voice, another person's voice, or were unsure.

RESULTS

Patients were less accurate than controls in the recognition of self-generated speech with negative content only. Impaired recognition of negative self-generated speech was associated with AVH severity ("voices conversing").

CONCLUSIONS

These results suggest that abnormalities in higher order processes (evaluation of the salience of a speech stimulus) modulate impaired self-other voice discrimination in schizophrenia. Abnormal processing of negative self-generated speech may play a role in the experience of AVH.

Did you or I say pretty, rude or brief? An ERP study of the effects of speaker's identity on emotional word processing

During speech comprehension, multiple cues need to be integrated at a millisecond speed, including semantic information, as well as voice identity and affect cues. A processing advantage has been demonstrated for self-related stimuli when compared with non-self stimuli, and for emotional relative to neutral stimuli. However, very few studies investigated self-other speech discrimination and, in particular, how emotional valence and voice identity interactively modulate speech processing. In the present study we probed how the processing of words' semantic valence is modulated by speaker's identity (self vs. non-self voice). Sixteen healthy subjects listened to 420 prerecorded adjectives differing in voice identity (self vs. non-self) and semantic valence (neutral, positive and negative), while electroencephalographic data were recorded. Participants were instructed to decide whether the speech they heard was their own (self-speech condition), someone else's (non-self speech), or if they were unsure. The ERP results demonstrated interactive effects of speaker's identity and emotional valence on both early (N1, P2) and late (Late Positive Potential - LPP) processing stages: compared with non-self speech, self-speech with neutral valence elicited more negative N1 amplitude, self-speech with positive valence elicited more positive P2 amplitude, and self-speech with both positive and negative valence elicited more positive LPP. ERP differences between self and non-self speech occurred in spite of similar accuracy in the recognition of both types of stimuli. Together, these findings suggest that emotion and speaker's identity interact during speech processing, in line with observations of partially dependent processing of speech and speaker information.

Simultaneous face and voice processing in schizophrenia

While several studies have consistently demonstrated abnormalities in the unisensory processing of face and voice in schizophrenia (SZ), the extent of abnormalities in the simultaneous processing of both types of information remains unclear. To address this issue, we used event-related potentials (ERP) methodology to probe the multisensory integration of face and non-semantic sounds in schizophrenia. EEG was recorded from 18 schizophrenia patients and 19 healthy control (HC) subjects in three conditions: neutral faces (visual condition-VIS); neutral non-semantic sounds (auditory condition-AUD); neutral faces presented simultaneously with neutral non-semantic sounds (audiovisual condition-AUDVIS). When compared with HC, the schizophrenia group showed less negative N170 to both face and face-voice stimuli; later P270 peak latency in the multimodal condition of face-voice relative to unimodal condition of face (the reverse was true in HC); reduced P400 amplitude and earlier P400 peak latency in the face but not in the voice-face condition. Thus, the analysis of ERP components suggests that deficits in the encoding of facial information extend to multimodal face-voice stimuli and that delays exist in feature extraction from multimodal face-voice stimuli in schizophrenia. In contrast, categorization processes seem to benefit from the presentation of simultaneous face-voice information. Timepoint by timepoint tests of multimodal integration did not suggest impairment in the initial stages of processing in schizophrenia.

Salience in a social landscape: electrophysiological effects of task-irrelevant and infrequent vocal change

In a dynamically changing social environment, humans have to face the challenge of prioritizing stimuli that compete for attention. In the context of social communication, the voice is the most important sound category. However, the existing studies do not directly address whether and how the salience of an unexpected vocal change in an auditory sequence influences the orientation of attention. In this study, frequent tones were interspersed with task-relevant infrequent tones and task-irrelevant infrequent vocal sounds (neutral, happy and angry vocalizations). Eighteen healthy college students were asked to count infrequent tones. A combined event-related potential (ERP) and EEG time-frequency approach was used, with the focus on the P3 component and on the early auditory evoked gamma band response, respectively. A spatial-temporal principal component analysis was used to disentangle potentially overlapping ERP components. Although no condition differences were observed in the 210-310 ms window, larger positive responses were observed for emotional than neutral vocalizations in the 310-410 ms window. Furthermore, the phase synchronization of the early auditory evoked gamma oscillation was enhanced for happy vocalizations. These findings support the idea that the brain prioritizes the processing of emotional stimuli, by devoting more attentional resources to salient social signals even when they are not task-relevant.

Paying attention to my voice or yours: An ERP study with words

Self-related stimuli-such as one's own face or name-seem to be processed differently from non-self stimuli and to involve greater attentional resources, as indexed by larger amplitude of the P3 event-related potential (ERP) component. Nonetheless, the differential processing of self-related vs. non-self information using voice stimuli is still poorly understood. The present study investigated the electrophysiological correlates of processing self-generated vs. non-self voice stimuli, when they are in the focus of attention. ERP data were recorded from twenty right-handed healthy males during an oddball task comprising pre-recorded self-generated (SGV) and non-self (NSV) voice stimuli. Both voices were used as standard and deviant stimuli in distinct experimental blocks. SGV was found to elicit more negative N2 and more positive P3 in comparison with NSV. No association was found between ERP data and voice acoustic properties. These findings demonstrated an earlier and later attentional bias to self-generated relative to non-self voice stimuli. They suggest that one's own voice representation may have a greater affective salience than an unfamiliar voice, confirming the modulatory role of salience on P3.

Abnormal interactions between context, memory structure, and mood in schizophrenia: an ERP investigation

This study used event-related potentials to examine interactions between mood, sentence context, and semantic memory structure in schizophrenia. Seventeen male chronic schizophrenia and 15 healthy control subjects read sentence pairs after positive, negative, or neutral mood induction. Sentences ended with expected words (EW), within-category violations (WCV), or between-category violations (BCV). Across all moods, patients showed sensitivity to context indexed by reduced N400 to EW relative to both WCV and BCV. However, they did not show sensitivity to the semantic memory structure. N400 abnormalities were particularly enhanced under a negative mood in schizophrenia. These findings suggest abnormal interactions between mood, context processing, and connections within semantic memory in schizophrenia, and a specific role of negative mood in modulating semantic processes in this disease.

The music of language: an ERP investigation of the effects of musical training on emotional prosody processing

Recent studies have demonstrated the positive effects of musical training on the perception of vocally expressed emotion. This study investigated the effects of musical training on event-related potential (ERP) correlates of emotional prosody processing. Fourteen musicians and fourteen control subjects listened to 228 sentences with neutral semantic content, differing in prosody (one third with neutral, one third with happy and one third with angry intonation), with intelligible semantic content (semantic content condition--SCC) and unintelligible semantic content (pure prosody condition--PPC). Reduced P50 amplitude was found in musicians. A difference between SCC and PPC conditions was found in P50 and N100 amplitude in non-musicians only, and in P200 amplitude in musicians only. Furthermore, musicians were more accurate in recognizing angry prosody in PPC sentences. These findings suggest that auditory expertise characterizing extensive musical training may impact different stages of vocal emotional processing.

Abnormalities in the processing of emotional prosody from single words in schizophrenia

BACKGROUND

Abnormalities in emotional prosody processing have been consistently reported in schizophrenia and are related to poor social outcomes. However, the role of stimulus complexity in abnormal emotional prosody processing is still unclear.

METHOD

We recorded event-related potentials in 16 patients with chronic schizophrenia and 16 healthy controls to investigate: 1) the temporal course of emotional prosody processing; and 2) the relative contribution of prosodic and semantic cues in emotional prosody processing. Stimuli were prosodic single words presented in two conditions: with intelligible (semantic content condition-SCC) and unintelligible semantic content (pure prosody condition-PPC).

RESULTS

Relative to healthy controls, schizophrenia patients showed reduced P50 for happy PPC words, and reduced N100 for both neutral and emotional SCC words and for neutral PPC stimuli. Also, increased P200 was observed in schizophrenia for happy prosody in SCC only. Behavioral results revealed higher error rates in schizophrenia for angry prosody in SCC and for happy prosody in PPC.

CONCLUSIONS

Together, these data further demonstrate the interactions between abnormal sensory processes and higher-order processes in bringing about emotional prosody processing dysfunction in schizophrenia. They further suggest that impaired emotional prosody processing is dependent on stimulus complexity.

Sensory-based and higher-order operations contribute to abnormal emotional prosody processing in schizophrenia: an electrophysiological investigation

BACKGROUND

Schizophrenia is characterized by deficits in emotional prosody (EP) perception. However, it is not clear which stages of processing prosody are abnormal and whether the presence of semantic content contributes to the abnormality. This study aimed to examine event-related potential (ERP) correlates of EP processing in 15 chronic schizophrenia individuals and 15 healthy controls.

METHOD

A total of 114 sentences with neutral semantic content [sentences with semantic content (SSC) condition] were generated by a female speaker (38 with happy, 38 with angry, and 38 with neutral intonation). The same sentences were synthesized and presented in the 'pure prosody' sentences (PPS) condition where semantic content was unintelligible.

RESULTS

Group differences were observed for N100 and P200 amplitude: patients were characterized by more negative N100 for SSC, and more positive P200 for angry and happy SSC and happy PPS. Correlations were found between delusions and P200 amplitude for happy SSC and PPS. Higher error rates in the recognition of EP were also observed in schizophrenia: higher error rates in neutral SSC were associated with reduced N100, and higher error rates in angry SSC were associated with reduced P200.

CONCLUSIONS

These results indicate that abnormalities in prosody processing occur at the three stages of EP processing, and are enhanced in SSC. Correlations between P200 amplitude for happy prosody and delusions suggest a role that abnormalities in the processing of emotionally salient acoustic cues may play in schizophrenia symptomatology. Correlations between ERP and behavioral data point to a relationship between early sensory abnormalities and prosody recognition in schizophrenia.

The interplay of phonology and orthography in visual cognate word recognition: an ERP study

This study examined the role of phonological and orthographic overlap in the recognition of cognate words by recording electrophysiological and behavioral data. One hundred and ninety-two words were selected: 96 cognate words listed according to their phonological and orthographic overlap vs. 96 noncognate words. Twenty-four proficient European Portuguese-English bilinguals performed a silent reading task with a masked priming paradigm. The results showed that phonology interacts with semantic activation at N400 modulations. Phonological priming effects were dependent on the orthographic overlap of cognate words. Thus, the distinctive processing of cognate words seems to be due to their cross-linguistic similarity, which is consistent with a localist connectionist account on cognate representation and processing.

Interactions between mood and the structure of semantic memory: event-related potentials evidence

Recent evidence suggests that affect acts as modulator of cognitive processes and in particular that induced mood has an effect on the way semantic memory is used on-line. We used event-related potentials (ERPs) to examine affective modulation of semantic information processing under three different moods: neutral, positive and negative. Fifteen subjects read 324 pairs of sentences, after mood induction procedure with 30 pictures of neutral, 30 pictures of positive and 30 pictures of neutral valence: 108 sentences were read in each mood induction condition. Sentences ended with three word types: expected words, within-category violations, and between-category violations. N400 amplitude was measured to the three word types under each mood induction condition. Under neutral mood, a congruency (more negative N400 amplitude for unexpected relative to expected endings) and a category effect (more negative N400 amplitude for between- than to within-category violations) were observed. Also, results showed differences in N400 amplitude for both within- and between-category violations as a function of mood: while positive mood tended to facilitate the integration of unexpected but related items, negative mood made their integration as difficult as unexpected and unrelated items. These findings suggest the differential impact of mood on access to long-term semantic memory during sentence comprehension.