Psychosomatic states and their correlation with letting-go: two newly evaluated core factors for investigating the therapeutic effect of spa treatment.

Spa therapy (aka crenobalneotherapy) has been the object of criticism due to insufficient evidence of its effectiveness. While further effectiveness studies are needed, others are also required to better evaluate the curative factors involved during spa therapy that may contribute to the effectiveness. The current study used specific scales to investigate two possible curative factors: the psychosomatic state and the letting-go of patients with mental disorders after 3 weeks of spa therapy. The Saujon Psychosomatic Questionnaire (SPQ) and the Quantified Assessment of Fluidity of Consciousness Questionnaire (QACF) evaluate psychosomatic state and letting-go, respectively. The Hospital Anxiety and Depression Scale (HAD) and the Insomnia Severity Index (ISI) evaluate depression and anxiety symptoms and insomnia symptoms, respectively. Sixty-five subjects (57 women (87.69%); 8 men), with a mean age of 56.9 (± 9.7) years, were included. SPQ and QAFC scores improved significantly before and after the 3 weeks of spa therapy. Improvement in HAD and ISI scores was significantly correlated with SPQ and QACF scores. These preliminary results suggest that the induced psychosomatic state and the letting-go induced by spa treatment with bubbling baths, jet showers, pool bathing and massage could help patients to become more available and more able to change their psychophysiological state.

Electroencephalogram Modifications Associated With Atypical Strict Antipsychotic Monotherapies.

BACKGROUND: Antipsychotics produce electroencephalogram (EEG) modifications and increase the risk of epileptic seizure. These modifications remain sparsely studied specifically for atypical antipsychotics. In this context, our study focuses on EEG modifications associated with atypical strict antipsychotic monotherapies. METHODS: Electroencephalogram recordings of 84 psychiatric patients treated with atypical antipsychotics in strict monotherapy (clozapine, n = 22; aripiprazole, n = 22; olanzapine, n = 17; risperidone, n = 9; quetiapine, n = 8; risperidone long-acting injection, n = 4; and paliperidone long-acting injection, n = 2) were analyzed. The modifications were ranked according to both slowing and excitability scores. RESULTS: Electroencephalogram modifications (in 51 subjects, 60.71%) were graded according to 4 stages combining general slowing and sharp slow waves and/or epileptiform activities. The presence of sharp or epileptiform activities was significantly greater for clozapine (90.9%) compared with other second-generation antipsychotics (aripiprazole, 50%; olanzapine, 58.8%; quetiapine, 37.5%; risperidone, 44.4%). Age, duration of disease progression, and diagnosis were not associated as risk factors. Electroencephalogram modifications were associated with lower doses for treatment with quetiapine but not for specific antipsychotics. Electroencephalogram modifications and severe excitability were associated with higher chlorpromazine equivalent doses. CONCLUSIONS: Atypical antipsychotics (clozapine, aripiprazole, quetiapine, olanzapine, and risperidone) induce EEG modifications, and these are significantly greater for clozapine and appear dependent on chlorpromazine equivalent dose. No encephalopathy was observed in these antipsychotic monotherapies, whatever dose.

Sensory gating deficits and impaired quality of life in patients with schizophrenia: A preliminary study.

BACKGROUND: New determinants of quality of life in schizophrenia need to be identified. As sensory gating deficit is core impairment in schizophrenia, the present study hypothesized that sensory gating deficit is a determinant of impaired quality of life in schizophrenia. This study therefore investigated the relationship between sensory gating deficit and quality of life in patients with schizophrenia after adjusting for key confounding factors. SUBJECTS AND METHODS: Sensory gating was assessed with the auditory event-related potential method by measuring P50 amplitude changes in a double-click conditioning-testing procedure, perceptual impairments related to sensory gating deficit was assessed with the SGI questionnaire and quality of life was assessed with the SQoL 18 questionnaire in 39 patients with schizophrenia. RESULTS: Patients with sensory gating deficit (n=14) had a lower subjective quality of life on the psychological well-being dimension evaluated with SQoL 18 questionnaire (p=0.008) compared to those without it (n=25). This result remained significant (B=-0.45, Wald=4.84, p=0.02) after taking into account 7 potential confounding factors (gender, age, level of education, duration of disorder, positive symptoms, depressive symptoms and anxiety symptoms). Poorer psychological well-being was related to a higher score on the SGI (rho=-0.40, p=0.01), in particular on the Distractibility dimension (rho=-0.47, p=0.001). CONCLUSIONS: These findings suggest that sensory gating deficit may be a determinant of impaired quality of life in schizophrenia. Further studies are needed to address the causal relationship between sensory gating deficit, perceptual impairments, attentional deficit and impaired quality of life in schizophrenia in order to act more efficiently on the quality of life of patients with this disorder.

Effects of clozapine on perceptual abnormalities and sensory gating: a preliminary cross-sectional study in schizophrenia.

The aim of the present study was to investigate the effect of second-generation antipsychotics (clozapine or another second-generation antipsychotic) on perceptual abnormalities related to sensory gating deficit. Although clozapine is known to improve sensory gating assessed neurophysiologically, we hypothesized that patients with schizophrenia treated with clozapine would report less perceptual abnormalities related to sensory gating deficit than patients treated with other second-generation antipsychotics do. Forty patients with a diagnosis of schizophrenia were investigated (10 patients treated with clozapine and 30 patients treated with another second-generation antipsychotic drug). Perceptual abnormalities were assessed with the Sensory Gating Inventory. Sensory gating was assessed through electroencephalogram with the auditory event-related potential method by measuring P50 amplitude changes in a dual click conditioning-testing procedure. Patients treated with clozapine present normal sensory gating and report less perceptual abnormalities related to sensory gating than patients treated with other second-generation antipsychotics do. Although the cross-sectional design of this study is limited because causal inferences cannot be clearly concluded, the present study suggests clinical and neurophysiological advantages of clozapine compared with other second-generation antipsychotics and provides a basis for future investigations on the effect of this treatment on perceptual abnormalities related to sensory gating deficit in patients with schizophrenia.

Skin conductance biofeedback training in adults with drug-resistant temporal lobe epilepsy and stress-triggered seizures: a proof-of-concept study.

The present proof-of-concept study investigated the feasibility of skin conductance biofeedback training in reducing seizures in adults with drug-resistant temporal lobe epilepsy (TLE), whose seizures are triggered by stress. Skin conductance biofeedback aims to increase levels of peripheral sympathetic arousal in order to reduce cortical excitability. This might seem somewhat counterintuitive, since such autonomic arousal may also be associated with increased stress and anxiety. Thus, this sought to verify that patients with TLE and stress-triggered seizures are not worsened in terms of stress, anxiety, and negative emotional response to this nonpharmacological treatment. Eleven patients with drug-resistant TLE with seizures triggered by stress were treated with 12 sessions of biofeedback. Patients did not worsen on cognitive evaluation of attentional biases towards negative emotional stimuli (P>.05) or on psychometric evaluation with state anxiety inventory (P = .059); in addition, a significant improvement was found in the Negative Affect Schedule (P = .014) and in the Beck Depression Inventory (P = .009). Biofeedback training significantly reduced seizure frequency with a mean reduction of -48.61% (SD = 27.79) (P = .005). There was a correlation between the mean change in skin conductance activity over the biofeedback treatment and the reduction of seizure frequency (r(11) = .62, P = .042). Thus, the skin conductance biofeedback used in the present study, which teaches patients to achieve an increased level of peripheral sympathetic arousal, was a well-tolerated nonpharmacological treatment. Further, well-controlled studies are needed to confirm the therapeutic value of this nonpharmacological treatment in reducing seizures in adults with drug-resistant TLE with seizures triggered by stress.

The covariation of independent and dependant variables in neurofeedback: a proposal framework to identify cognitive processes and brain activity variables.

This methodological article proposes a framework for analysing the relationship between cognitive processes and brain activity using variables measured by neurofeedback (NF) carried out by functional Magnetic Resonance Imagery (fMRI NF). Cognitive processes and brain activity variables can be analysed as either the dependant variable or the independent variable. Firstly, we propose two traditional approaches, defined in the article as the "neuropsychological" approach (NP) and the "psychophysiology" approach (PP), to extract dependent and independent variables in NF protocols. Secondly, we suggest that NF can be inspired by the style of inquiry used in neurophenomenology. fMRI NF allows participants to experiment with his or her own cognitive processes and their effects on brain region of interest (ROI) activations simultaneously. Thus, we suggest that fMRI NF could be improved by implementing "the elicitation interview method", which allows the investigator to gather relevant verbatim from participants' introspection on subjective experiences.

Coloring complex shapes decreases patient anxiety in three care environments: a pilot study with color analysis.

Introduction: This study was conducted to determine the effectiveness of coloring activity of circular symmetrical shape with complex patterns, so-called mandala, on anxiety associated with chronic illness in three different ambulatory medical situations (general consultation, psychiatric day hospital, and hemodialysis session). Methods: Thirty patients were included in three groups and came from three different ambulatory medical situations: a hemodialysis group (n = 10), a psychiatric day hospital group (n = 10), and a nephrology consultation group (n = 10). We asked the patients to fill STAI-S and STAI-T questionnaires before to color complex circular shape with complex patterns, then to fill the STAI-S questionnaire again and a questionnaire on the experience of the activity. Results: The results show that the STAI-S score was significantly lower after coloring for the hemodialysis (p = 0.02) and psychiatric groups (p = 0.005) but not for the general consultation group (p = 0.26). STAI-T scores did not differ between groups. The distribution of colors in the mandala was different in the three groups of patients. A positive subjective experience of the activity was found in all groups. Discussion: These results show the effectiveness of a coloring activity of a circular shape with complex patterns on anxiety associated with chronic illness in care environment. The different distribution of the colors of the mandala in the three groups raises the question of the influence of the context on the mood of the patients and the deeper meaning of the choice of colors and their placement in the mandala. Our study reinforces the multiple applications of art activities in different medical disciplines and encourages their development within healthcare settings.

Iatrogenic encephalopathies are not so rare in psychiatry: A retrospective study about 5217 EEG examinations.

OBJECTIVES: Encephalopathy is a severe pathological process induced by multiple factors, which is typically associated with electroencephalogram (EEG) abnormalities. Early diagnosis, management, and treatment improve the patient's prognosis. Psychotropic treatments are a risk for drug-induced encephalopathies. In this study, the prevalence of encephalopathies in a psychiatric hospital has been studied for 5 years (2012 to 2016) using 5217 EEG records. METHODS: EEGs were performed i) systematically on patient admission, ii) in response to inexplicable modifications of consciousness or behavior, or when metabolic anomalies occurred, and iii) to perform therapeutic monitoring in outpatient consultations. When encephalopathy was suspected, the clinical data (age, sex and concomitant treatment) and biological data (plasma levels of medications) were collected. RESULTS: Encephalopathy was suspected in 189 patients. Following EEG examination, and monitoring of clinical course, encephalopathy was subsequently determined to be highly probable for 52 patients, (giving a prevalence of 1% per year), and low suspicion of encephalopathy in the other 137 patients. The suspicion of encephalopathy was made on both clinical (n=28) and non-clinical (n=24) signs. Involved drugs were mainly valproic acid (n=14), lithium (n=11) and clozapine (n=11) in the highly probable encephalopathy group. CONCLUSIONS: Our study demonstrates the importance of EEG in the diagnosis and monitoring of encephalopathies in a psychiatric hospital. Clinical symptoms of encephalopathies are polymorphic and sometimes atypical. This diagnosis is underestimated in a context where behavior or consciousness disorders are generally not attributed to psychotropic drugs used in psychiatry.

[Neuroenhancement in healthy subject? A French case study]. / Peut-on prescrire des psychostimulants chez un étudiant sain? Exemple d'un cas clinique.

Neuroenhancement is an anglo-saxon concept concerning the use of stimulating psychotropic drugs by healthy subjects, outside any established medical indication or festive setting, to achieve an improvement of their mental functioning. In 2009, because of increasing requests for neuroenhancement in USA, the American Association of Neurology has published practical recommendations stating that "it is ethically permissible to prescribe medications for neuroenhancement" if a number of conditions is met. We present these ethical and psychopharmacological conditions ("the inverted U-Shape principle" in which cognitive performance is related to catecholamine levels and "the trade-off principle" to cognitive enhancement) through a clinical case of methylphenidate prescription in a healthy 24 years old medical student, preparing for the "examen classant national" (the French national ranking before postgraduate education). We then discuss anglo-saxon ethical context in which these recommendations have been proposed.

Categorization and timbre perception of environmental sounds in schizophrenia.

Perception of environmental sounds from impacted materials (Wood, Metal and Glass) was examined by conducting a categorization experiment. Stimuli consisted of sound continua evoking progressive transitions between material categories. Results highlighted shallower response curves in subjects with schizophrenia than healthy participants, and are discussed in the framework of Signal Detection Theory and in terms of impaired perception of specific timbre features in schizophrenia.

Sensory Gating Capacity and Attentional Function in Adults With ADHD: A Preliminary Neurophysiological and Neuropsychological Study.

Objective: The inability to filter sensory input correctly may impair higher cognitive function in ADHD. However, this relationship remains largely elusive. The objectives of the present study is to investigate the relationship between sensory input processing and cognitive function in adult patients with ADHD. Method: This study investigated the relationship between deficit in sensory gating capacity (P50 amplitude changes in a double-click conditioning-testing paradigm and perceptual abnormalities related to sensory gating deficit with the Sensory Gating Inventory [SGI]) and attentional and executive function (P300 amplitude in an oddball paradigm and attentional and executive performances with a neuropsychological test) in 24 adult patients with ADHD. Results: The lower the sensory gating capacity of the brain and the higher the distractibility related to sensory gating inability that the patients reported, the lower the P300 amplitude. Conclusion: The capacity of the brain to gate the response to irrelevant incoming sensory input may be a fundamental protective mechanism that prevents the flooding of higher brain structures with irrelevant information in adult patients with ADHD.

Elevated C-reactive protein is associated with sensory gating deficit in schizophrenia.

Sensory and cognitive impairments and inflammatory processes are contributing factors to the pathogenesis of schizophrenia. A previous study found that an elevated CRP level (≥5mg/L) was associated with higher cognitive impairments in schizophrenia. We aimed to investigate the association between an elevated CRP level and sensory impairments defined by a sensory gating deficit (abnormal P50 suppression) in 55 outpatients. Fifteen patients (27.3%) had an elevated CRP level that was associated with higher rate of sensory gating deficit (60% vs. 12.5%, p<0.001). This is the first study suggesting a relationship between sensory gating deficit and inflammatory processes in schizophrenia.

Association of metabolic syndrome with sensory gating deficits in patients with chronic schizophrenia.

Metabolic syndrome is more prevalent in schizophrenia than in the general population and is associated with an increased rate of morbidity. It has been associated with cognitive impairments in schizophrenia, which are a core deficit in patients with chronic schizophrenia. Sensory gating deficit is also a core deficit in schizophrenia. The principal objective of this study was to investigate the relationship between sensory gating deficit and metabolic syndrome in patients with schizophrenia, after adjusting for key confounding factors. We hypothesized that patients with metabolic syndrome exhibit a higher rate of sensory gating deficit compared to those without metabolic syndrome. This study investigated sensory gating with the auditory event-related potential method by measuring P50 amplitude changes in a double click conditioning-testing procedure in 51 patients with schizophrenia. Patients with metabolic syndrome (n = 14) had a higher rate of sensory gating deficit (P50 suppression <50%) (p < 0.001) compared to those without metabolic syndrome (n = 37). This result remained significant (B = 2.94, Wald = 8.32, p = 0.004) after taking into account 5 potential confounding factors (age, gender, duration of disorder, Fagerström test, presence of clozapine or olanzapine). In patients without metabolic syndrome, sensory gating deficit was linked to a poorer attentional performance (rho = -0.371, p = 0.05). In patients with metabolic syndrome, sensory gating deficit was linked to poorer memory performance (rho = -0.635, p = 0.02). These findings suggest that metabolic syndrome may be linked to sensory gating deficit in patients with schizophrenia and that the relationship between neurocognitive function and sensory gating deficit could be affected by the metabolic status of the patients. Further studies are needed to address the causal relationship between sensory gating deficit related to schizophrenia, cognitive impairments and metabolic syndrome.

Sensory gating in adult with attention-deficit/hyperactivity disorder: Event-evoked potential and perceptual experience reports comparisons with schizophrenia.

BACKGROUND: In daily life, adults with attention-deficit/hyperactivity disorder (ADHD) report abnormal perceptual experiences that can be related to sensory gating deficit. This study investigated and compared P50 suppression (a neurophysiological measure of sensory gating) and perceptual abnormalities related to sensory gating deficit in ADHD and schizophrenias patients. METHODS: Three groups were compared: 24 adults with ADHD, 24 patients with schizophrenia and 24 healthy subjects. The Sensory Gating Inventory (SGI), a validated self-report questionnaire, was used to measure perceptual abnormalities related to sensory gating deficit. P50 suppression was measured by P50 amplitude changes in a dual-click conditioning-testing auditory event-related potential procedure. RESULTS: Adults with ADHD had significantly higher scores on the SGI and significantly lower P50 suppression than healthy subjects. These deficits were similar to those found in patients with schizophrenia. A correlation was found between both the SGI and P50 suppression data in adults with ADHD and patients with schizophrenia. DISCUSSION: The findings confirm previous results found in patients with schizophrenia. Moreover, adults with ADHD, similar to patients with schizophrenia, had abnormal P50 suppression and reported being flooded with sensory stimuli. Abnormal neurophysiologic responses to repetitive stimuli gave rise to clinically abnormal perceptions.

Magnetic resonance imaging of the neuroprotective effect of xaliproden in rats.

RATIONALE AND OBJECTIVES: The neurotrophic effect of Xaliproden has been followed using sequential cerebral magnetic resonance imaging (MRI) in rats with vincristine-induced brain lesion as a model of Alzheimer disease. METHODS: Nineteen rats received an intraseptal injection of vincristine on day 0, followed by a daily gavage with either the vehicle (Tween-20 1%) (n = 10) or Xaliproden (10 mg/kg) (n = 9). Eight sham-operated controls received a daily gavage with either the vehicle (n = 4) or Xaliproden (n = 4). Brain MR imaging was performed at 4.7 T on a Biospec 47/30 MR system before surgery then 3, 7, 10, and 14 days after surgery. RESULTS: At day 3 following vincristine injection, an increase in MR signal intensity in the septum was observed on T2-weighted images. This increase was maximal at day 10, and remained stable until day 14. Daily treatment with Xaliproden delayed the appearance of hypersignals until day 7 and reduced by Ca. 50% the magnitude of the increase in signal intensity from day 10. No changes were observed in the hippocampus. CONCLUSION: Quantitative MRI objectifies noninvasively the neuroprotective effect of Xaliproden on rat brain anatomy.

Natural speech comprehension in bipolar disorders: an event-related brain potential study among manic patients.

BACKGROUND: Thought and language disturbances are crucial clinical features in Bipolar Disorders (BD), and constitute a fundamental basis for social cognition. In BD, clinical manifestations such as disorganization and formal thought disorders may play a role in communication disturbances. However, only few studies have explored language disturbances in BD at a neurophysiological level. Two main Event-Related brain Potentials (ERPs) have been used in language comprehension research: the N400 component, elicited by incongruous word with the preceding semantic context, and the Late Positive Component (LPC), associated with non-specifically semantic and more general cognitive processes. Previous studies provided contradictory results regarding N400 in mood disorders, showing either preserved N400 in depression or dysthymia, or altered N400 in BD during semantic priming paradigm. The aim of our study was to explore N400 and LPC among patients with BD in natural speech conditions. METHODS: ERPs from 19 bipolar type I patients with manic or hypomanic symptomatology and 19 healthy controls were recorded. Participants were asked to listen to congruous and incongruous complete sentences and to judge the match between the final word and the sentence context. Behavioral results and ERPs data were analyzed. RESULTS: At the behavioral level, patients with BD show worst performances than healthy participants. At the electrophysiological level, our results show preserved N400 component in BD. LPC elicited under natural speech conditions shows preserved amplitude but delayed latency in difference waves. LIMITATIONS: Small size of samples, absence of schizophrenic group and medication status. CONCLUSIONS: In contrast with the only previous N400 study in BD that uses written semantic priming, our results show a preserved N400 component in ecological and natural speech conditions among patients with BD. Possible implications in terms of clinical specificity are discussed.

Validation of the French sensory gating inventory: a confirmatory factor analysis.

The Sensory Gating Inventory (SGI) is an instrument investigating daily experiences of sensory gating deficit developed for English speaking schizophrenia patients. The purpose of this study is to design and validate a French version of the SGI. A forward-backward translation of the SGI was performed. The psychometric properties of the French SGI version were analyzed. A confirmatory factor analysis (CFA) was carried out to determine whether factor structure of the French version is similar to the original English version. In a sample of 363 healthy subjects (mean age=31.8 years, S.D.=12.2 years) the validation process revealed satisfactory psychometric properties: the internal consistency reliability was confirmed for each dimension; each item achieved the 0.40 standard threshold for item-internal consistency; each item was more highly correlated with its contributive dimension than with the other dimensions; and based on a CFA, we found a 4-factor structure for the French version of the SGI similar to the original instrument. Test-retest reliability was not determined. The French version of the SGI is a psychometrically sound self-report for measuring phenomenological sensory gating experiences.

Do schizophrenia patients with low P50-suppression report more perceptual anomalies with the sensory gating inventory?

BACKGROUND: P50 amplitude changes in dual click conditioning-testing procedure might be a neurophysiological marker of deficient sensory gating in schizophrenia. However, the relationship between abnormalities in the neurophysiological and phenomenological dimensions of sensory gating in schizophrenia remains unclear. The aim of the present study was to determine if patients with low P50-suppression (below 50%) report more perceptual anomalies. METHODS: Three groups were compared: twenty-nine schizophrenia patients with high P50-suppression (above 50% amplitude suppression), twenty-three schizophrenia patients with low P50-suppression (below 50%) and twenty-six healthy subjects. The Sensory Gating Inventory (SGI), a four-factor self-report questionnaire, was used to measure perceptual anomalies related to sensory gating. A comparison of demographic and clinical data was also carried out. RESULTS: Patients with low P50-suppression presented: i) significantly higher scores on the SGI (for the overall SGI score and for each of the 4 factors) and ii) significantly larger P50 amplitude at the second click, than both patients with high P50-suppression and healthy subjects. There were no group differences in the most of demographic and clinical data. DISCUSSION: The finding offers support for conceptual models wherein abnormal neurophysiologic responses to repetitive stimuli give rise to clinically relevant perceptions of being inundated and overwhelmed by external sensory stimuli. Further studies are needed to explore the contributions of clinical symptoms, medication and neuropsychological functions to the relationship between P50-suppression and the SGI, and the role of sensory "gating in" versus "gating out".

Parieto-temporal alpha EEG band power at baseline as a predictor of antidepressant treatment response with repetitive Transcranial Magnetic Stimulation: a preliminary study.

BACKGROUND: The aim of this preliminary study was to determine the predictive value of absolute alpha band power measured during the rest EEG eyes closed task for responses to 20 sessions of high frequency repetitive transcranial stimulation (rTMS) in the left dorsolateral prefrontal cortex in patients with pharmacoresistant major depressive episode. METHODS: 13 major depressive disorders (8 males) and 8 bipolar disorders (6 males) were included (mean age 58years). Spearman correlations between pretreatment alpha band power in height regions of analysis and absolute improvement in Beck Depression Inventory Short Form (ΔBDI-SF) were analyzed. The predictive value of alpha band power for classifying patients as responders and non-responders to rTMS was determined using Receiver Operating Characteristic (ROC) curve. RESULTS: Spearman correlation analysis revealed that ΔBDI-SF correlated significantly and negatively with alpha band power on the right (r=-.673, p=.001) and left parieto-temporal regions (r=-.638, p=.002). The area under the ROC curve for the right parieto-temporal was .815, p=.0037. The cut-off point that maximized both sensitivity and specificity was 1.49µV. Sensitivity, specificity, positive and negative predictive values were 100, 66, 80, 100% respectively. LIMITATIONS: The population was small and lacked homogeneity concerning affective disorders (unipolar and bipolar disorder). The use of a self-rating subjective scale (BDI-SF) to measure the severity of depression could be criticized. CONCLUSIONS: Pretreatment alpha band power on parieto-temporal regions could be a predictor for response to rTMS in patients with homogenous demographic/clinical features. The association between electrical activity and the perfusion under each electrode need to be examined.

Toward an exploration of feeling of strangeness in schizophrenia: perspectives on acousmatic and everyday listening.

The aim of this study was to investigate abnormal perceptual experiences in schizophrenia, in particular the feeling of strangeness, which is commonly found in patients' self-reports. The experimental design included auditory complex stimuli within 2 theoretical frameworks based on "sensory gating deficit" and "aberrant salience," inspired from conventional perceptual scales. A specific sound corpus was designed with environmental (meaningful) and abstract (meaningless) sounds. The authors compared sound evaluations on 3 perceptual dimensions (bizarre, familiar, and invasive) and 2 emotional dimensions (frightening and reassuring) between 20 patients with schizophrenia (SCZ) and 20 control participants (CTL). The perceptual judgment was rated on independent linear scales for each sound. In addition, the conditioning-testing P50 paradigm was conducted on 10 SCZ and 10 CTL. Both behavioral and electrophysiological data confirmed the authors' expectations according to the 2 previous theoretical frameworks and showed that abnormal perceptual experiences in SCZ consisted of perceiving meaningful sounds in a distorted manner and as flooding/inundating but also in perceiving meaningless sounds as things that become meaningful by assigning them some significance. In addition, the use of independent scales to each perceptual dimension highlighted an unexpected ambivalence on familiarity and bizarreness in SCZ compatible with the explanation of semantic process impairment. The authors further suggested that this ambivalence might be due to a conflicting coactivation of 2 types of listening, that is, every day and musical (or acousmatic) listening.