scholarly journals Reconciling competing mechanisms posited to underlie auditory verbal hallucinations

2020 ◽  
Vol 376 (1817) ◽  
pp. 20190702 ◽  
Author(s):  
Katharine N. Thakkar ◽  
Daniel H. Mathalon ◽  
Judith M. Ford
Keyword(s):  
Sensory Stimulation ◽  
Mental Illnesses ◽  
Sense Of Agency ◽  
Predictive Processing ◽  
Action Perception ◽  
External Stimulation ◽  
Hearing Voices ◽  
Auditory Verbal Hallucinations ◽  
Sensory Data ◽  
Past Experiences

Perception is not the passive registration of incoming sensory data. Rather, it involves some analysis by synthesis, based on past experiences and context. One adaptive consequence of this arrangement is imagination—the ability to richly simulate sensory experiences, interrogate and manipulate those simulations, in service of action and decision making. In this paper, we will discuss one possible cost of this adaptation, namely hallucinations—perceptions without sensory stimulation, which characterize serious mental illnesses like schizophrenia, but which also occur in neurological illnesses, and—crucially for the present piece—are common also in the non-treatment-seeking population. We will draw upon a framework for imagination that distinguishes voluntary from non-voluntary experiences and explore the extent to which the varieties and features of hallucinations map onto this distinction, with a focus on auditory-verbal hallucinations (AVHs)—colloquially, hearing voices. We will propose that sense of agency for the act of imagining is key to meaningfully dissecting different forms and features of AVHs, and we will outline the neural, cognitive and phenomenological sequelae of this sense. We will conclude that a compelling unifying framework for action, perception and belief—predictive processing—can incorporate observations regarding sense of agency, imagination and hallucination. This article is part of the theme issue ‘Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation’.

scholarly journals M52. VOICES IN THE HEAD: AUDITORY VERBAL HALLUCINATIONS (AVH) IN HEALTHY INDIVIDUALS

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S153-S154
Author(s):  
Lisa Goller ◽  
Michael Schwartze ◽  
Ana Pinheiro ◽  
Sonja Kotz
Keyword(s):  
Disease Onset ◽  
Clinical Aspects ◽  
Button Press ◽  
Healthy Individuals ◽  
Model Concept ◽  
External Stimulation ◽  
Hearing Voices ◽  
Auditory Verbal Hallucinations ◽  
Psychosis Continuum ◽  
Suppression Effects

Abstract Background Auditory verbal hallucinations (AVH) are conscious sensory experiences occurring in the absence of external stimulation. AVH are experienced by 75% of individuals diagnosed with schizophrenia and can manifest in other neuropsychiatric disorders. However, AVH are also reported amongst healthy individuals. This implies that hearing voices is not necessarily linked to psychopathology. Amongst voice hearers, the likelihood of AVH seems to reflect individual differences in hallucination proneness (HP). The HP construct allows placing individuals on a psychosis continuum ranging from non-clinical to clinical experiences. Clinical voice hearers tend to misattribute internal events to external sources (externalization bias). Specifically, they seem to experience altered sensory feedback in response to self-initiated stimuli: Although more predictable, clinical voice hearers show similar, neurophysiological responses in reaction to self-initiated vs. externally presented stimuli. EEG studies suggest that this aberrance of prediction is associated with diminished N1-suppression effects that are observed in healthy individuals in response to self-initiated stimuli. Accordingly, clinical voice hearers may have problems differentiating between self-initiated and externally generated speech, potentially leading to externalization of their own speech. In line with this proposal, the current study focusses on non-clinical aspects of the psychosis continuum in healthy voice hearers and controls. This approach avoids confounding factors (medication, disease onset/duration etc.) that typically impede comparisons of clinical and non-clinical voice hearers. By utilizing insights on prediction from the forward model concept within the auditory-sensory domain, we want to investigate how N1-amplitudes in reaction to one’s own or someone else’s voice are modulated as a function of HP. Next to ascertaining the mechanism behind AVH, this research could give direction to identifying risk factors that potentiate the emergence of first-incidence psychosis. Methods HP was assessed by means of the Launay-Slade Hallucination Scale. Each participant’s voice was recorded prior to EEG data acquisition (monosyllabic utterances, “ah” & “oh”, duration = 500 ms). Voice stimuli were morphed with an anchor voice, so that voice identity could be alternated from self- to other-voice (0%, 40%, 50%, 60%, 100%). To contrast neurophysiological responses between self- vs. externally generated voice stimuli, a well-established motor-to-auditory paradigm was used: In a motor-to-auditory condition (MAC) participants were prompted to press a button, thereby eliciting a voice stimulus (self-initiation). In an auditory-only condition (AOC), participants were prompted to passively listen to the voice stimulus (external generation). The motor-only condition (MOC), in which participants executed the button press only, served as a control condition to correct for motor activity in MAC. Results Data from 38 participants replicate the classical N1-suppression effects for self-initiated vs. externally generated self-voice stimuli. This pattern of suppression is also visible for other-voice stimuli. Furthermore, current findings seem to replicate reversed N1-suppression for self-voice in individuals with high HP. Discussion Preliminary findings suggest that HP modulates voice identity processing. More specifically, HP determines how voice stimuli are processed within the internal and external domain. Particularly, individuals with high HP show a reversal of N1-suppression for self-voice stimuli, which corroborates the external biasing hypothesis.

scholarly journals Susceptibility to auditory hallucinations is associated with spontaneous but not directed modulation of top-down expectations for speech.

2021 ◽  
Author(s):  
Ben Alderson-Day ◽  
Jamie A. Moffatt ◽  
Cesar Lima ◽  
Saloni Krishnan ◽  
Charles Fernyhough ◽  
...  
Keyword(s):  
Prior Knowledge ◽  
Sine Wave ◽  
Predictive Processing ◽  
Future Research ◽  
Top Down ◽  
Hearing Voices ◽  
Auditory Verbal Hallucinations ◽  
Speech Stimuli ◽  
Original Language ◽  
Before And After

Auditory verbal hallucinations (AVH) – or hearing voices – occur in clinical and non-clinical populations, but their mechanisms remain unclear. Predictive processing models of psychosis have proposed that hallucinations arise from an over-weighting of prior expectations in perception. It is unknown, however, whether this reflects i) a sensitivity to explicit modulation of prior knowledge, or ii) a pre-existing tendency to spontaneously use such knowledge more in ambiguous contexts. Four experiments were conducted to examine this question in healthy participants listening to ambiguous speech stimuli. In experiments 1 (n = 60) and 2 (n = 60), participants discriminated intelligible and unintelligible sine-wave speech (SWS) before and after exposure to the original language templates (i.e., a modulation of expectation). No relationship was observed between top-down modulation and two common measures of hallucination-proneness. Experiment 3 (n = 99) confirmed this pattern with a different stimulus – sine-vocoded speech (SVS) – that was designed to minimise ceiling effects in discrimination and more closely model previous top-down effects reported in psychosis. In Experiment 4 (n = 135), participants were exposed to SVS without prior knowledge that it contained speech (i.e., naïve listening). AVH-proneness significantly predicted spontaneous pre-exposure identification of speech, but was unrelated to performance on a subsequent discrimination task, post-exposure. Altogether, these findings support a pre-existing tendency to spontaneously draw upon prior knowledge in healthy people prone to AVH, rather than a sensitivity to temporary modulations of expectation. We propose a model of clinical and non-clinical hallucinations, across auditory and visual modalities, with testable predictions for future research.

scholarly journals Brain signatures of surprise in EEG and MEG data

2020 ◽  
Author(s):  
Zahra Mousavi ◽  
Mohammad Mahdi Kiani ◽  
Hamid Aghajan
Keyword(s):  
Sensory Modality ◽  
Ideal Observer ◽  
Neural Signals ◽  
Sensory Data ◽  
Temporal Features ◽  
Recorded Data ◽  
Recent Trends ◽  
Temporal Sample ◽  
Past Experiences ◽  
The Brain

AbstractThe brain is constantly anticipating the future of sensory inputs based on past experiences. When new sensory data is different from predictions shaped by recent trends, neural signals are generated to report this surprise. Existing models for quantifying surprise are based on an ideal observer assumption operating under one of the three definitions of surprise set forth as the Shannon, Bayesian, and Confidence-corrected surprise. In this paper, we analyze both visual and auditory EEG and auditory MEG signals recorded during oddball tasks to examine which temporal components in these signals are sufficient to decode the brain’s surprise based on each of these three definitions. We found that for both recording systems the Shannon surprise is always significantly better decoded than the Bayesian surprise regardless of the sensory modality and the selected temporal features used for decoding.Author summaryA regression model is proposed for decoding the level of the brain’s surprise in response to sensory sequences using selected temporal components of recorded EEG and MEG data. Three surprise quantification definitions (Shannon, Bayesian, and Confidence-corrected surprise) are compared in offering decoding power. Four different regimes for selecting temporal samples of EEG and MEG data are used to evaluate which part of the recorded data may contain signatures that represent the brain’s surprise in terms of offering a high decoding power. We found that both the middle and late components of the EEG response offer strong decoding power for surprise while the early components are significantly weaker in decoding surprise. In the MEG response, we found that the middle components have the highest decoding power while the late components offer moderate decoding powers. When using a single temporal sample for decoding surprise, samples of the middle segment possess the highest decoding power. Shannon surprise is always better decoded than the other definitions of surprise for all the four temporal feature selection regimes. Similar superiority for Shannon surprise is observed for the EEG and MEG data across the entire range of temporal sample regimes used in our analysis.

Interactively human: Sharing time, constructing materiality

2013 ◽  
Vol 36 (3) ◽  
pp. 224-225 ◽  
Author(s):  
Andreas Roepstorff
Keyword(s):  
Predictive Processing ◽  
Action Perception ◽  
Sharing Time

AbstractPredictive processing models of cognition are promising an elegant way to unite action, perception, and learning. However, in the current formulations, they are species-unspecific and have very little particularly human about them. I propose to examine how, in this framework, humans can be able to massively interact and to build shared worlds that are both material and symbolic.

scholarly journals “But What About Real Mental Illnesses?” Alternatives to the Disease Model Approach to “Schizophrenia”

2017 ◽  
Vol 58 (1) ◽  
pp. 47-71 ◽  
Author(s):  
Anne Cooke ◽  
Peter Kinderman
Keyword(s):  
Psychiatric Diagnosis ◽  
Disease Model ◽  
Mental Illnesses ◽  
Anxiety And Depression ◽  
Hearing Voices ◽  
The United Kingdom ◽  
British Psychological Society ◽  
Significant Attention ◽  
Consensus Report ◽  
Model Approach

The old dichotomy between “neurosis” and “psychosis” appears to be alive and well in the debate about psychiatric diagnosis. It is often suggested that while diagnostic alternatives may be appropriate for the relatively common forms of distress with which we can all identify such as anxiety and depression, psychiatric diagnoses remain vital for experiences such as hearing voices, holding beliefs that others find strange, or appearing out of touch with reality—experiences that are traditionally thought of as symptoms of psychosis. Such experiences are often assumed to be symptoms of underlying brain pathology or “real mental illnesses” that need to be diagnosed or “excluded” (in the medical sense of ruling out particular explanations of problems) before deciding on the appropriate intervention. This article argues that this belief is misguided, and that far from being essential, psychiatric diagnosis has the potential to be particularly damaging when applied to such experiences. It describes an alternative perspective outlined in a recent consensus report by the British Psychological Society Division of Clinical Psychology ( Understanding Psychosis and Schizophrenia), which has attracted significant attention in the United Kingdom and internationally. The report argues that even the most severe distress and the most puzzling behavior can often be understood psychologically, and that psychological approaches to helping can be very effective. It exhorts professionals not to insist that people accept any one particular framework of understanding, for example, that their experiences are symptoms of an illness. This article outlines that report’s main findings, together with their implications for how professionals can best help.

scholarly journals Too much or too little? Disorders of agency on a spectrum

2020 ◽  
Vol 16 (2) ◽  
pp. 79-99
Author(s):  
Valentina Petrolini
Keyword(s):  
Mental Disorders ◽  
Mind Wandering ◽  
Sense Of Agency ◽  
False Confessions ◽  
Sense Of Control ◽  
Thought Insertion ◽  
Auditory Verbal Hallucinations ◽  
In Virtue Of ◽  
Frequency Intensity

Disorders of agency could be described as cases where people encounter difficulties in assessing their own degree of responsibility or involvement with respect to a relevant action or event. These disturbances in one’s sense of agency appear to be meaningfully connected with some mental disorders and with some symptoms in particular—i.e. auditory verbal hallucinations, thought insertion, pathological guilt. A deeper understanding of these experiences may thus contribute to better identification and possibly treatment of people affected by such disorders. In this paper I explore disorders of agency to flesh out their phenomenology in more detail as well as to introduce some theoretical distinctions between them. Specifically, I argue that we may better understand disorders of agency by characterizing them as dimensional. In §1 I explore the cases of Auditory Verbal Hallucinations (AVH) and pathological guilt and I show that they lie at opposite ends of the agency spectrum (i.e. hypoagency versus hyperagency). In §2 I focus on two intermediate cases of hypo- and hyper- agency. These are situations that, despite being very similar to pathological ones, may be successfully distinguished from them in virtue of quantitative factors (e.g. duration, frequency, intensity). I first explore the phenomenon of mind wandering as an example of hypoagency, and I then discuss the phenomenon of false confessions as an example of hyperagency. While cases of hypoagency exemplify situations where people experience their own thoughts, bodies, or actions as something beyond their control, experiences of hyperagency provide an illusory sense of control over actions or events.

Neurobiology of Auditory Hallucinations

2019 ◽  
Author(s):  
Judith M. Ford ◽  
Holly K. Hamilton ◽  
Alison Boos
Keyword(s):  
Help Seeking ◽  
Treatment Approach ◽  
Neural Mechanisms ◽  
Hearing Voices ◽  
Auditory Verbal Hallucinations ◽  
Self And Other ◽  
Neurological Conditions ◽  
Language Areas ◽  
The Voice ◽  
The Brain

Auditory verbal hallucinations (AVH), also referred to as “hearing voices,” are vivid perceptions of speech that occur in the absence of any corresponding external stimulus but seem very real to the voice hearer. They are experienced by the majority of people with schizophrenia, less frequently in other psychiatric and neurological conditions, and are relatively rare in the general population. Because antipsychotic medications are not always successful in reducing the severity or frequency of AVH, a better understanding is needed of their neurobiological basis, which may ultimately lead to more precise treatment targets. What voices say and how the voices sound, or their phenomenology, varies widely within and across groups of people who hear them. In help-seeking populations, such as people with schizophrenia, the voices tend to be threatening and menacing, typically spoken in a non-self-voice, often commenting and sometimes commanding the voice hearers to do things they would not otherwise do. In psychotic populations, voices differ from normal inner speech by being unbidden and unintended, co-opting the voice hearer’s attention. In healthy voice-hearing populations, voices are not typically distressing nor disabling, and are sometimes comforting and reassuring. Regardless of content and valence, voices tend to activate some speech and language areas of the brain. Efforts to silence these brain areas with neurostimulation have had mixed success in reducing the frequency and salience of voices. Progress with this treatment approach would likely benefit from more precise anatomical targets and more precisely dosed neurostimulation. Neural mechanisms that may underpin the experience of voices are being actively investigated and include mechanisms enabling context-based predictions and distinctions between experiences coming from self and other. Both these mechanisms can be studied in non-human animal “models” and both can provide new anatomical targets for neurostimulation.

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