scholarly journals Neural activity precedes conscious awareness of being in or out of a transient hallucinatory state

2020 ◽  
Author(s):  
Kenneth Hugdahl ◽  
Alexander R. Craven ◽  
Erik Johnsen ◽  
Lars Ersland ◽  
Drozdstoy Stoyanov ◽  
...  
Keyword(s):  
Neural Activity ◽  
Button Press ◽  
Conscious Awareness ◽  
Response Button ◽  
Hearing Voices ◽  
Auditory Verbal Hallucinations ◽  
Before And After ◽  
Neurological Patients ◽  
Time Courses ◽  
The Mind

SummaryAuditory verbal hallucinations, or “hearing voices”, is a remarkable state of the mind, occurring in psychiatric and neurological patients, and in a significant minority of the general population. An unexplained characteristic of this phenomenon is that it transiently fluctuates, with coming and going of episodes with time. We monitored neural activity with BOLD-fMRI second-by-second before and after participants indicated the start and end of a transient hallucinatory episode during the scanning session by pressing a response-button. We show that a region in the ventro-medial frontal cortex is activated in advance of conscious awareness of going in or out of a transient hallucinatory state. There was an increase in activity initiated a few seconds before the button-press for onsets, and a corresponding decrease in activity initiated a few seconds before the button-press for offsets. We identified the time between onset and offset button-presses, extracted the corresponding BOLD time-courses from nominated regions-of-interest, and analyzed changes in the signal from 10 seconds before to 15 seconds after the response-button was pressed, which identified onset and offset events. We suggest that this brain region act as a switch to turn on and off a hallucinatory episode. The results may have implications for new interventions for intractable hallucinations.

Benjamin Libet’s Big Experiment

2019 ◽  
pp. 186-199
Author(s):  
Alan J. McComas
Keyword(s):  
Electrical Activity ◽  
Neural Activity ◽  
The Body ◽  
The Other ◽  
Sensory Stimulus ◽  
Conscious Awareness ◽  
Evoked Responses ◽  
Temporal Reference ◽  
The Mind ◽  
The Brain

This chapter describes Benjamin Libet’s finding that electrical activity in the brain precedes conscious awareness. Libet’s work had shown that, no matter how brief it was, a sensory stimulus evoked responses in the cortex that lasted hundreds of milliseconds. He also suggested that, just as the somatosensory cortex was able to refer sensations to a particular point on the opposite side of the body (“spatial reference”) so it could refer sensations to an earlier moment—the time when impulse activity had first been initiated in the cortex following the stimulus (“temporal reference”). These were important conclusions and inevitably became the subjects of debate following their publication. But Libet was soon to deliver a greater surprise when he discovered that a decision only entered consciousness when the underlying neural activity was already far advanced. Rather than the mind controlling the brain—thought by thought—it was the other way round and “free will,” seemingly so self-evident, was an illusion.

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 Confusions about ‘Inner’ and ‘Outer’ Voices: Conceptual Problems in the Study of Auditory Verbal Hallucinations

2021 ◽  
Author(s):  
Franz Knappik ◽  
Josef J. Bless ◽  
Frank Larøi
Keyword(s):  
Twentieth Century ◽  
Clinical Assessment ◽  
Empirical Studies ◽  
Diagnostic Value ◽  
Assessment Tools ◽  
Auditory Verbal Hallucinations ◽  
Early Twentieth Century ◽  
Conceptual Problems ◽  
The Mind

AbstractBoth in research on Auditory Verbal Hallucinations (AVHs) and in their clinical assessment, it is common to distinguish between voices that are experienced as ‘inner’ (or ‘internal’, ‘inside the head’, ‘inside the mind’, ...) and voices that are experienced as ‘outer’ (‘external’, ‘outside the head’, ‘outside the mind’, ...). This inner/outer-contrast is treated not only as an important phenomenological variable of AVHs, it is also often seen as having diagnostic value. In this article, we argue that the distinction between ‘inner’ and ‘outer’ voices is ambiguous between different readings, and that lack of disambiguation in this regard has led to flaws in assessment tools, diagnostic debates and empirical studies. Such flaws, we argue furthermore, are often linked to misreadings of inner/outer-terminology in relevant 19th and early twentieth century work on AVHs, in particular, in connection with Kandinsky’s and Jaspers’s distinction between hallucinations and pseudo-hallucinations.

Ventilatory dynamics during transient arousal from NREM sleep: implications for respiratory control stability

1996 ◽  
Vol 80 (5) ◽  
pp. 1475-1484 ◽  
Author(s):  
M. C. Khoo ◽  
S. S. Koh ◽  
J. J. Shin ◽  
P. R. Westbrook ◽  
R. B. Berry
Keyword(s):  
Respiratory Control ◽  
Upper Airway ◽  
Nrem Sleep ◽  
Before And After ◽  
Stage 2 Sleep ◽  
Repeated Administrations ◽  
Time Courses ◽  
Control Stability ◽  
Airway Dynamics ◽  
Normal Adults

The polysomnographic and ventilatory patterns of nine normal adults were measured during non-rapid-eye-movement (NREM) stage 2 sleep before and after repeated administrations of a tone (40-72 dB) lasting 5 s. The ventilatory response to arousal (VRA) was determined in data sections showing electrocortical arousal following the start of the tone. Mean inspiratory flow and tidal volume increased significantly above control levels in the first seven breaths after the start of arousal, with peak increases (64.2% > control) occurring on the second breath. Breath-to-breath occlusion pressure 100 ms after the start of inspiration showed significant increases only on the second and third postarousal breaths, whereas upper airway resistance declined immediately and remained below control for > or = 7 consecutive breaths. These results suggest that the first breath and latter portion of the VRA are determined more by upper airway dynamics than by changes in the neural drive to breathe. Computer model simulations comparing different VRA time courses show that sustained periodic apnea is more likely to occur when the fall in the postarousal increase in ventilation is more abrupt.

scholarly journals Connectome to behaviour: modelling Caenorhabditis elegans at cellular resolution

2018 ◽  
Vol 373 (1758) ◽  
pp. 20170366 ◽  
Author(s):  
Stephen D. Larson ◽  
Padraig Gleeson ◽  
André E. X. Brown
Keyword(s):  
Caenorhabditis Elegans ◽  
Neural Activity ◽  
Multiscale Simulations ◽  
Theme Issue ◽  
Wiring Diagram ◽  
C Elegans ◽  
Behaviour Modelling ◽  
Cellular Resolution ◽  
The Mind

It has been 30 years since the ‘mind of the worm’ was published in Philosophical Transactions B (White et al . 1986 Phil. Trans. R. Soc. Lond. B 314 , 1–340). Predicting Caenorhabditis elegans ' behaviour from its wiring diagram has been an enduring challenge since then. This special theme issue of Philosophical Transactions B combines research from neuroscientists, physicists, mathematicians and engineers to discuss advances in neural activity imaging, behaviour quantification and multiscale simulations, and how they are bringing the goal of whole-animal modelling at cellular resolution within reach. This article is part of a discussion meeting issue ‘Connectome to behaviour: modelling C. elegans at cellular resolution’.

scholarly journals Listening to speech and non-speech sounds activates phonological and semantic knowledge differently

2020 ◽  
Vol 73 (8) ◽  
pp. 1135-1149 ◽  
Author(s):  
James Bartolotti ◽  
Scott R Schroeder ◽  
Sayuri Hayakawa ◽  
Sirada Rochanavibhata ◽  
Peiyao Chen ◽  
...  
Keyword(s):  
Auditory Processing ◽  
Semantic Information ◽  
Semantic Knowledge ◽  
Phonological Information ◽  
Opposite Pattern ◽  
Semantic Access ◽  
Word Forms ◽  
Time Courses ◽  
The Mind ◽  
Phonological Activation

How does the mind process linguistic and non-linguistic sounds? The current study assessed the different ways that spoken words (e.g., “dog”) and characteristic sounds (e.g., <barking>) provide access to phonological information (e.g., word-form of “dog”) and semantic information (e.g., knowledge that a dog is associated with a leash). Using an eye-tracking paradigm, we found that listening to words prompted rapid phonological activation, which was then followed by semantic access. The opposite pattern emerged for sounds, with early semantic access followed by later retrieval of phonological information. Despite differences in the time courses of conceptual access, both words and sounds elicited robust activation of phonological and semantic knowledge. These findings inform models of auditory processing by revealing the pathways between speech and non-speech input and their corresponding word forms and concepts, which influence the speed, magnitude, and duration of linguistic and nonlinguistic activation.

Teaching about Near-Death Experiences: The Effectiveness of Using the Day I Died

2011 ◽  
Vol 63 (4) ◽  
pp. 373-388 ◽  
Author(s):  
Janice Miner Holden ◽  
Kathy Oden ◽  
Kelly Kozlowski ◽  
Bert Hayslip
Keyword(s):  
Repeated Measures ◽  
Future Research ◽  
Control Group ◽  
Waitlist Control ◽  
Before And After ◽  
Waitlist Control Group ◽  
Quasi Experimental ◽  
The Mind ◽  
Near Death Experiences ◽  
The Brain

In this article, we reviewed results of research on near-death experiences (NDEs) over the past 3 decades and examined the effect of viewing the hour-long 2002 BBC documentary The Day I Died: The Mind, the Brain, and Near-Death Experiences on accurate knowledge about near-death experiences among advanced undergraduates at a southwestern university. In a quasi-experimental research design, the experimental group completed a 20-item questionnaire before and after viewing the documentary ( n = 66; 45 females, 21 males), and the waitlist control group completed the questionnaire as pre- and posttest before viewing the documentary ( n = 39; 36 female, 3 male). The two groups' scores at pretest were not significantly different ( p > .05). Group by occasion repeated measures ANOVA revealed the experimental group's posttest scores moved significantly in the direction of correctness with a large effect size ( p < .001; η2= .56), whereas waitlist control group posttest scores remained similar to pretest scores. We discuss two exceptions to the effectiveness of the documentary and recommendations for educators using it as well as for future research.

"Dreams and Deeds" and other Dualities: Nielsen and the Two-Movement Sympony

2012 ◽  
Vol 5 ◽  
Author(s):  
David Fanning ◽  
Michelle Assay
Keyword(s):  
Present Article ◽  
History Of Ideas ◽  
Before And After ◽  
History Of ◽  
Yin And Yang ◽  
The Mind

It is well known that Nielsen’s two-movement Fifth Symphony is strongly dualistic in character. The composer himself commented that ‘A title such as “Dreams and Deeds” [Drøm og Daad] could maybe sum up the inner picture I had in front of my eyes when composing’. But it is by no means clear at what level that duality and others he mentioned are actually embodied in the work, or where it stands in relation to other two-movement symphonies composed before and after. Building on an essay by David Fanning in Carl Nielsen Studies 4, the present article fi rst considers these questions in the light of the model for symphonism proposed by the Russian scholar Mark Aranovsky. The Fifth Symphony and those two-movement symphonies found to contain the most fundamental and polarised dualities are then variously related to religious and philosophical traditions that stress dualism – from Zoroastrianism, through Yin and Yang, to Sufism, touching in passing on the philosophy of the mind and on Jung. The aim is to gain a richer and clearer picture of the uniqueness of Nielsen’s Fifth in relation both to symphonic tradition and to the history of ideas.

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