Altered Effective Brain Connectivity During Habituation in First Episode Schizophrenia With Auditory Verbal Hallucinations: A Dichotic Listening EEG Study

Background: Habituation is considered to have protective and filtering mechanisms. The present study is aim to find the casual relationship and mechanisms of excitatory–inhibitory (E/I) dysfunctions in schizophrenia (SCZ) via habituation.Methods: A dichotic listening paradigm was performed with simultaneous EEG recording on 22 schizophrenia patients and 22 gender- and age-matched healthy controls. Source reconstruction and dynamic causal modeling (DCM) analysis were performed to estimate the effective connectivity and casual relationship between frontal and temporal regions before and after habituation.Results: The schizophrenia patients expressed later habituation onset (p < 0.01) and hyper-activity in both lateral frontal–temporal cortices than controls (p = 0.001). The patients also showed decreased top-down and bottom-up connectivity in bilateral frontal–temporal regions (p < 0.01). The contralateral frontal–frontal and temporal–temporal connectivity showed a left to right decreasing (p < 0.01) and right to left strengthening (p < 0.01).Conclusions: The results give causal evidence for E/I imbalance in schizophrenia during dichotic auditory processing. The altered effective connectivity in frontal–temporal circuit could represent the trait bio-marker of schizophrenia with auditory hallucinations.

Speech processing in voice-hearers: Bridging the gap between empirical research and clinical implications

Individuals who hear voices (i.e. auditory verbal hallucinations) have been reported to exhibit a range of difficulties when listening to and processing the speech of other people. These speech processing challenges are observed even in the absence of hearing voices; however, some appear to be exacerbated during periods of acute symptomology. In this advisory piece, key findings from pertinent empirical research into external speech processing in voice-hearers are presented with the intention of informing healthcare professionals. It is the view that through a better understanding of the speech processing deficits faced by individuals who hear voices, more effective communication with such patients can be had.

The “common” experience of voice-hearing and its relationship with shame and guilt: a systematic review

Background Despite Auditory Verbal Hallucinations (AVHs) have been long associated with mental illness, they represent a common experience also in the non-clinical population, yet do not exhibit distress or need for care. Objectives This paper aims to provide a systematic review of studies that investigated the relationship between auditory hallucinations, shame, and guilt in people without relevant signs of psychiatric issues. Methods We searched studies reporting information about voices characteristics, the relationship between voices and hearers, hearer's reactions, and beliefs (1946-2021) and those that explored the differences between “patients” and “non-patients”, paying peculiar attention to shame and guilt issues. Included papers were evaluated for risk of bias. Results Eleven studies that explored the relationship between AVHs, shame and guilt, were extracted. Phenomenological, pragmatic, as well as neuropsychological features of hearing voices in non-clinical populations, allowed us to note a dynamic relationship and the constellation of subjective experiences that can occur. The role of guilt was characterized by few studies and mixed results, while shame was mainly common. Conclusions Due to the high heterogeneity detected and the scarce sources available, further studies should focus on both the aetiology and the bidirectional relationship between hearing voices, shame, and guilt in non-clinical people. This might favour the development and implication of different treatments considering emotion regulation, distress tolerance and interpersonal sensitivity on the other people.

A review of functional and structural neuroimaging studies to investigate the inner speech model of auditory verbal hallucinations in schizophrenia

Although the pathophysiology of auditory verbal hallucinations remains uncertain, the inner speech model remains a prominent theory. A systematic review and meta-analyses of both functional and structural neuroimaging studies were performed to investigate the inner speech model. Of the 417 papers retrieved, 26 met the inclusion criteria. Meta-analyses found the left insula to be significantly active during auditory verbal hallucinations and to have a significantly reduced grey matter volume in hallucinators. Dysfunction of the left insula may contribute to the misattribution of inner speech due to its suggested roles in both inner speech production and the salience network. No significant activity was found at Broca’s area or Heschl’s gyrus during auditory verbal hallucinations. Furthermore, no structural abnormalities were found at these sites or in the arcuate fasciculi. Overall, evidence was found to both support and oppose the inner speech model. Further research should particularly include a systematic review of task-based trait studies with a focus on inner speech production and self-referential processing, and analyses of additional language-related white matter tracts.

Complex auditory musical hallucinations with ambivalent feelings

A 78-year-old woman with hypertension, diabetes mellitus type 2 and bilateral sensorineural hearing loss was referenced to geriatric psychiatry consultation. She presented cognitive dysfunction, erotomanic delusion and complex musical hallucinations (MH), described as hearing her neighbour singing a familiar church song along with bells in the background, making comments and talking to her. A computed tomography (CT) of the brain detected small right nucleocapsular and bilateral external capsules hypodensities of presumed vascular aetiology during hospitalisation. MH are a rare phenomenon with heterogeneous aetiology. Most frequently, the cause is hearing impairment; other causes include social isolation, cognitive dysfunction, vascular risk factors and medication. Studies suggest that some brain areas related to musical memory circuitry might be related and not fully mapped. Auditory verbal hallucinations with a voice that either comments, talks or sings to the patient have never been described in the literature, making this clinical case attractive.

A Brain Listening to Itself

The ubiquitous presence of ambiguous voices in Beckett’s work remains an enduring mystery. The narrative work is no exception, to the point that Beckett’s fiction after Murphy (1938) can be read as, to quote The Unnamable (1953), “entirely a matter of voices; no other metaphor is appropriate” (319). Given the alien qualities of these voices, their intrusive independent agency, and their sometimes tormenting phenomenology, two frameworks of interpretation have so far prevailed. On the one hand, there are narratologists such as Brian Richardson (2006) who have proposed an “unnatural” reading of these voices, by arguing that these alien, multiple, sourceless voices cannot be traced back or ascribed to any actual experience within the human domain; that they cannot be “naturalized” (Culler 1975; 2018; see also Fludernik 1996) by the reader. On the other hand, there is a long-standing “pathological” framework, which sees voices in Beckett’s work as a fictional rendering of a wide range of experiences associated with mental illnesses, mostly of auditory-verbal hallucinations (AVHs) typical of schizophrenia. This chapter suggests that an alternative, natural, and non-pathological experience is the target of Beckett’s fictional cognitive models having voices as core modeling elements. By drawing on contemporary cognitive research on inner speech (roughly speaking, the activity of silently talking to, with and within oneself), it is advocated that voices in Beckett’s models target the working of inner speech, only defamiliarized or, as we shall see, “detuned” as a modeling alteration to explore its functioning within human cognition.

Monitoring Processes and Their Neuronal Correlates as the Basis of Auditory Verbal Hallucinations in a Non-clinical Sample

Auditory verbal hallucinations (AVH) are a characteristic symptom of psychosis. An influential cognitive model accounting for the mechanisms in the generation of AVHs describes a defective monitoring of inner speech, leading to the misidentification of internally generated thoughts as externally generated events. In this study, we utilized an inner speech paradigm during a simultaneous measurement with functional near-infrared spectroscopy (fNIRS) and functional magnetic resonance imaging (fMRI), in order to replicate the findings of neural correlates of inner speech and auditory verbal imagery (AVI) in healthy subjects, reported in earlier studies, and to provide the first validation of the paradigm for fNIRS measurements. To this end, 20 healthy subjects were required to generate and silently recite first and second person sentences in their own voice (inner speech) and imagine the same sentences in a different, alien voice (AVI). Furthermore, questionnaires were deployed to assess the predisposition to acoustic hallucinations and schizotypal traits to investigate their connection to activation patterns associated with inner speech and monitoring processes. The results showed that both methods, fNIRS and fMRI, exhibited congruent activations in key brain areas, claimed to be associated with monitoring processes, indicating that the paradigm seems to be applicable using fNIRS alone. Furthermore, the results showed similar brain areas activated during inner speech and monitoring processes to those from earlier studies. However, our results indicate that the activations were dependent more on the sentence form and less on the imaging condition, showing more active brain areas associated with second person sentences. Integration of the sentence construction into the model of inner speech and deficient monitoring processes as the basis for the formation of AVHs should be considered in further studies. Furthermore, negative correlations between questionnaires' scores and activations in precentral gyrus and premotor cortex indicate a relationship of schizotypal characteristics and a deficient activation pattern.

Auditory hallucinations activate language and verbal short-term memory, but not auditory, brain regions

Auditory verbal hallucinations (AVH, ‘hearing voices’) are an important symptom of schizophrenia but their biological basis is not well understood. One longstanding approach proposes that they are perceptual in nature, specifically that they reflect spontaneous abnormal neuronal activity in the auditory cortex, perhaps with additional ‘top down’ cognitive influences. Functional imaging studies employing the symptom capture technique—where activity when patients experience AVH is compared to times when they do not—have had mixed findings as to whether the auditory cortex is activated. Here, using a novel variant of the symptom capture technique, we show that the experience of AVH does not induce auditory cortex activation, even while real speech does, something that effectively rules out all theories that propose a perceptual component to AVH. Instead, we find that the experience of AVH activates language regions and/or regions that are engaged during verbal short-term memory.

Measuring Voluntary Control Over Hallucinations: The Yale Control Over Perceptual Experiences (COPE) Scales

Auditory verbal hallucinations (AVH) frequently cause significant distress and dysfunction, and may be unresponsive to conventional treatments. Some voice-hearers report an ability to fully control the onset and offset of their AVH, making them significantly less disruptive. Measuring and understanding these abilities may lead to novel interventions to enhance control over AVH.52 voice-hearers participated in the pilot study. 318 participants with frequent AVH participated in the validation study. A pool of 59 items was developed by a diverse team including voice-hearers and clinicians. After the pilot study, 35 items were retained. Factorial structure was assessed with exploratory (EFA, n = 148) and confirmatory (CFA, n = 170) factor analyses. Reliability and convergent validity were assessed using a comprehensive battery of validated phenomenological and clinical scales. CFA supported two factors for a Methods of Control Scale (5 items each, average ω = .87), and one factor for a Degree of Control Scale (8 items, average ω = .95). Correlation with clinical measures supported convergent validity. Degree of control was associated with positive clinical outcomes in voice-hearers both with and without a psychosis-spectrum diagnosis. Degree of control also varied with quality of life independently of symptom severity and AVH content.The Yale COPE Scales are the first measure of voice-hearers’ control over AVH and exhibit sound psychometric properties. Results demonstrate that the capacity to voluntarily control AVH is independently associated with positive clinical outcomes. Reliable measurement of control over AVH will enable future development of interventions meant to bolster that control.