Scientific and philosophical perspectives on hallucination: essays that draw on empirical evidence from psychology, neuroscience, and cutting-edge philosophical theory.
Reflection on the nature of ...hallucination has relevance for many traditional philosophical debates concerning the nature of the mind, perception, and our knowledge of the world. In recent years, neuroimaging techniques and scientific findings on the nature of hallucination, combined with interest in new philosophical theories of perception such as disjunctivism, have brought the topic of hallucination once more to the forefront of philosophical thinking. Scientific evidence from psychology, neuroscience, and psychiatry sheds light on the functional role and physiology of actual hallucinations; some disjunctivist theories offer a radically new and different philosophical conception of hallucination. This volume offers interdisciplinary perspectives on the nature of hallucination, offering essays by both scientists and philosophers.
Contributors first consider topics from psychology and neuroscience, including neurobiological mechanisms of hallucination and the nature and phenomenology of auditory-verbal hallucinations. Philosophical discussions follow, with contributors first considering disjunctivism and then, more generally, the relation between hallucination and the nature of experience.
Contributors
István Aranyosi, Richard P. Bentall, Paul Coates, Fabian Dorsch, Katalin Farkas, Charles Fernyhough, Dominic H. ffytche, Benj Hellie, Matthew Kennedy, Fiona Macpherson, Ksenija Maravic da Silva, Peter Naish, Simon McCarthy-Jones, Matthew Nudds, Costas Pagondiotis, Ian Phillips, Dimitris Platchias, Howard Robinson, Susanna Schellenberg, Filippo Varese
The recent renaissance of psychedelic science has reignited interest in the similarity of drug-induced experiences to those more commonly observed in psychiatric contexts such as the ...schizophrenia-spectrum. This report from a multidisciplinary working group of the International Consortium on Hallucinations Research (ICHR) addresses this issue, putting special emphasis on hallucinatory experiences. We review evidence collected at different scales of understanding, from pharmacology to brain-imaging, phenomenology and anthropology, highlighting similarities and differences between hallucinations under psychedelics and in the schizophrenia-spectrum disorders. Finally, we attempt to integrate these findings using computational approaches and conclude with recommendations for future research.
W artykule przedstawiono opis przypadku 57-letniego pacjenta od ponad 20 lat chornjacego na schizolrenie, z wyslepnjacynri ciezkiini, opornymi na leczenie omamami cenestetycznymi, ktdre sa ...zlokalizowane w okolicy narzadów plciowych. Ze wzgledn na brak alternatyw terapeutycznych przeprowadzono serie zabiegdw przezczaszkowej stymulacji prüdem stalym, ktdre byly nakierowane na kore soinalosensoryczna reprezeiilnjaca okolice narzadów plciowych. Nasilenie objawdw oceniano za poinoca Clinical Global Impression (CGI, Severity and Improvement), Positive and Negative Syndrome Scale (PANSS) oraz trzech skal wizualno-analogowych, oddzielnie dla nastepiijacych, charakterystycznych cech: „ogdlny dyskomfort", „uczucie przebijania sic jader" oraz „bdl". Po ukohezeniu 3-tygodniowej serii zabiegdw przezczaszkowej stymulacji prüdem stalym nie uzyskano zmian iniedzy poczalkowa a koiicowa ocena kliniczny.
Abstract
That trauma can play a significant role in the onset and maintenance of voice-hearing is one of the most striking and important developments in the recent study of psychosis. Yet the finding ...that trauma increases the risk for hallucination and for psychosis is quite different from the claim that trauma is necessary for either to occur. Trauma is often but not always associated with voice-hearing in populations with psychosis; voice-hearing is sometimes associated with willful training and cultivation in nonclinical populations. This article uses ethnographic data among other data to explore the possibility of multiple pathways to voice-hearing for clinical and nonclinical individuals whose voices are not due to known etiological factors such as drugs, sensory deprivation, epilepsy, and so forth. We suggest that trauma sometimes plays a major role in hallucinations, sometimes a minor role, and sometimes no role at all. Our work also finds seemingly distinct phenomenological patterns for voice-hearing, which may reflect the different salience of trauma for those who hear voices.
Auditory hallucinations can be manifested in a variety of ways, as a single voice or multiple voices that comment, communicate instructions, offend or comfort. They can do it in the first person ...(“I’m hopeless. Everyone hates me”), the second person (“Run away from here,” “Kill yourself ”) or the third person (“She is good for nothing. She should jump off the bridge”). Hallucinations vary widely in content, form and dynamics. Some researchers believe that the experience of voices in people from various clinical groups is very similar (or even identical) and is transdiagnostic. Others draw attention to significant differences regarding the characteristics of voices. Verbal auditory hallucinations are commonly associated with schizophrenia. However, different studies show that this symptom was also reported by individuals with other disorders, and by healthy people as well. This led to developing a notion of a continuum, which suggests that the experience of hearing voices has similar qualities, no matter in which context it occurs. In this paper, we present psychological theories and neurobiological mechanisms offering explanations for verbal auditory hallucinations. We also elaborate on phenomenological aspects of voice hearing in patients from different diagnostic groups, and highlight their unique features. Finally, we stress the need for further, in-depth qualitative investigation of verbal auditory hallucinations in these groups, which could help clinicians choose more appropriate treatment solutions.
Nonauditory hallucinations in psychosis have not received as much attention relative to voice-hearing experiences. The current paper aimed to document the characteristics of these hallucinations in ...affective and nonaffective psychosis. Participants were selected from a primary voice-hearing sample, who had endorsed visual, tactile, or olfactory hallucinations ( N = 55-75). A comprehensive, semistructured phenomenological interview was conducted, followed by mixed methods analysis. Visual hallucinations typically occurred daily, for a few minutes per episode, within one's direct line of sight; persons and/or animals were most commonly seen, with low controllability and mostly engendered negative affective outcomes. Tactile and olfactory hallucinations were endorsed by 46.8% and 39.0% of participants, respectively. The affective psychosis group ( n = 33) reported significantly greater awareness and lower functional impairment relative to the nonaffective psychosis group ( n = 42). Qualitative thematic analysis revealed notable themes and subthemes across each of these hallucinations modes. Further phenomenological investigations should be carried out in lesser known hallucination modalities, assisted by the development of appropriate assessment tools.
Non-motor features of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), such as auditory hallucinations (AH), contribute to disease burden but are not well understood.
Systematic review ...and random-effects meta-analyses of studies reporting AH associated with PD or DLB. Prevalence of visual hallucinations (VH) in identified studies meeting eligibility criteria were included in meta-analyses, facilitating comparison with AH. Synthesis of qualitative descriptions of AH was performed. PubMed, Web of Science and Scopus databases were searched for primary journal articles, written in English, published from 1970 to 2017. Studies reporting AH prevalence in PD or DLB were screened using PRISMA methods.
Searches identified 4542 unique studies for consideration, of which, 26 met inclusion criteria. AH pooled prevalence in PD was estimated to be 8.9% 95% confidence interval (CI) 5.3-14.5, while in DLB was estimated to be 30.8% (±23.4 to 39.3). Verbal hallucinations, perceived as originating outside the head, were the most common form of AH. Non-verbal AH were also common while musical AH were rare. VH were more prevalent, with an estimated pooled prevalence in PD of 28.2% (±19.1 to 39.5), while in DLB they were estimated to be 61.8% (±49.1 to 73.0). Meta-regression determined that the use of validated methodologies to identify hallucinations produced higher prevalence estimates.
AH and VH present in a substantial proportion of PD and DLB cases, with VH reported more frequently in both conditions. Both AH and VH are more prevalent in DLB than PD. There is a need for standardised use of validated methods to detect and monitor hallucinations.
Peduncluar hallucinosis is a rare neurological disorder characterized by visual hallucinations, often described to be vivid and dream-like. While the exact pathophysiology has yet to be elucidated, ...most cases to date have suggested an etiology stemming from lesions to the thalamus or midbrain. Here presented is a case of a 54-year-old female with peduncular hallucinosis secondary to a pontine cavernoma hemorrhage in the setting of essential hypertension. The patient's vivid visual and auditory hallucinations aligned temporally with the lesion's discovery and resolved after pharmaceutical treatment. This case represents a rare form of peduncular hallucinosis secondary to a pontine cavernoma hemorrhage leading to vasospasm in the arteries feeding the brainstem.
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