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Gallese V, Ardizzi M, Ferroni F. Schizophrenia and the bodily self. Schizophr Res 2024; 269:152-162. [PMID: 38815468 DOI: 10.1016/j.schres.2024.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/17/2024] [Accepted: 05/21/2024] [Indexed: 06/01/2024]
Abstract
Despite the historically consolidated psychopathological perspective, on the one hand, contemporary organicistic psychiatry often highlights abnormalities in neurotransmitter systems like dysregulation of dopamine transmission, neural circuitry, and genetic factors as key contributors to schizophrenia. Neuroscience, on the other, has so far almost entirely neglected the first-person experiential dimension of this syndrome, mainly focusing on high-order cognitive functions, such as executive function, working memory, theory of mind, and the like. An alternative view posits that schizophrenia is a self-disorder characterized by anomalous self-experience and awareness. This view may not only shed new light on the psychopathological features of psychosis but also inspire empirical research targeting the bodily and neurobiological changes underpinning this disorder. Cognitive neuroscience can today address classic topics of phenomenological psychopathology by adding a new level of description, finally enabling the correlation between the first-person experiential aspects of psychiatric diseases and their neurobiological roots. Recent empirical evidence on the neurobiological basis of a minimal notion of the self, the bodily self, is presented. The relationship between the body, its motor potentialities and the notion of minimal self is illustrated. Evidence on the neural mechanisms underpinning the bodily self, its plasticity, and the blurring of self-other distinction in schizophrenic patients is introduced and discussed. It is concluded that brain-body function anomalies of multisensory integration, differential processing of self- and other-related bodily information mediating self-experience, might be at the basis of the disruption of the self disorders characterizing schizophrenia.
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Affiliation(s)
- Vittorio Gallese
- Dept. of Medicine and Surgery, Unit of Neuroscience, University of Parma, Italy; Italian Academy for Advanced Studies in America, Columbia University, New York, USA.
| | - Martina Ardizzi
- Dept. of Medicine and Surgery, Unit of Neuroscience, University of Parma, Italy
| | - Francesca Ferroni
- Dept. of Medicine and Surgery, Unit of Neuroscience, University of Parma, Italy
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2
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Harduf A, Panishev G, Harel EV, Stern Y, Salomon R. The bodily self from psychosis to psychedelics. Sci Rep 2023; 13:21209. [PMID: 38040825 PMCID: PMC10692325 DOI: 10.1038/s41598-023-47600-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 11/16/2023] [Indexed: 12/03/2023] Open
Abstract
The sense of self is a foundational element of neurotypical human consciousness. We normally experience the world as embodied agents, with the unified sensation of our selfhood being nested in our body. Critically, the sense of self can be altered in psychiatric conditions such as psychosis and altered states of consciousness induced by psychedelic compounds. The similarity of phenomenological effects across psychosis and psychedelic experiences has given rise to the "psychotomimetic" theory suggesting that psychedelics simulate psychosis-like states. Moreover, psychedelic-induced changes in the sense of self have been related to reported improvements in mental health. Here we investigated the bodily self in psychedelic, psychiatric, and control populations. Using the Moving Rubber Hand Illusion, we tested (N = 75) patients with psychosis, participants with a history of substantial psychedelic experiences, and control participants to see how psychedelic and psychiatric experience impacts the bodily self. Results revealed that psychosis patients had reduced Body Ownership and Sense of Agency during volitional action. The psychedelic group reported subjective long-lasting changes to the sense of self, but no differences between control and psychedelic participants were found. Our results suggest that while psychedelics induce both acute and enduring subjective changes in the sense of self, these are not manifested at the level of the bodily self. Furthermore, our data show that bodily self-processing, related to volitional action, is disrupted in psychosis patients. We discuss these findings in relation to anomalous self-processing across psychedelic and psychotic experiences.
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Affiliation(s)
- Amir Harduf
- The Multidisciplinary Brain Research Center, Bar-Ilan University, 5290002, Ramat-Gan, Israel
- The Faculty of Life Sciences, Bar-Ilan University, 5290002, Ramat-Gan, Israel
| | - Gabriella Panishev
- The Multidisciplinary Brain Research Center, Bar-Ilan University, 5290002, Ramat-Gan, Israel
| | - Eiran V Harel
- Beer Yaakov-Ness Ziona Mental Health Center, Beer Yaakov, Israel
| | - Yonatan Stern
- The Multidisciplinary Brain Research Center, Bar-Ilan University, 5290002, Ramat-Gan, Israel
- Department of Cognitive Sciences, University of Haifa, 3498838, Haifa, Israel
| | - Roy Salomon
- Department of Cognitive Sciences, University of Haifa, 3498838, Haifa, Israel.
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Bertoni T, Mastria G, Akulenko N, Perrin H, Zbinden B, Bassolino M, Serino A. The self and the Bayesian brain: Testing probabilistic models of body ownership through a self-localization task. Cortex 2023; 167:247-272. [PMID: 37586137 DOI: 10.1016/j.cortex.2023.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/29/2023] [Accepted: 06/19/2023] [Indexed: 08/18/2023]
Abstract
Simple multisensory manipulations can induce the illusory misattribution of external objects to one's own body, allowing to experimentally investigate body ownership. In this context, body ownership has been conceptualized as the result of the online Bayesian optimal estimation of the probability that one object belongs to the body from the congruence of multisensory inputs. This idea has been highly influential, as it provided a quantitative basis to bottom-up accounts of self-consciousness. However, empirical evidence fully supporting this view is scarce, as the optimality of the putative inference process has not been assessed rigorously. This pre-registered study aimed at filling this gap by testing a Bayesian model of hand ownership based on spatial and temporal visuo-proprioceptive congruences. Model predictions were compared to data from a virtual-reality reaching task, whereby reaching errors induced by a spatio-temporally mismatching virtual hand have been used as an implicit proxy of hand ownership. To rigorously test optimality, we compared the Bayesian model versus alternative non-Bayesian models of multisensory integration, and independently assess unisensory components and compare them to model estimates. We found that individually measured values of proprioceptive precision correlated with those fitted from our reaching task, providing compelling evidence that the underlying visuo-proprioceptive integration process approximates Bayesian optimality. Furthermore, reaching errors correlated with explicit ownership ratings at the single individual and trial level. Taken together, these results provide novel evidence that body ownership, a key component of self-consciousness, can be truly described as the bottom-up, behaviourally optimal processing of multisensory inputs.
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Affiliation(s)
- Tommaso Bertoni
- MySpace Lab, Department of Clinical Neurosciences, University Hospital of Lausanne, University of Lausanne, Lausanne, Switzerland
| | - Giulio Mastria
- MySpace Lab, Department of Clinical Neurosciences, University Hospital of Lausanne, University of Lausanne, Lausanne, Switzerland
| | - Nikita Akulenko
- MySpace Lab, Department of Clinical Neurosciences, University Hospital of Lausanne, University of Lausanne, Lausanne, Switzerland
| | - Henri Perrin
- School of Medicine, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Boris Zbinden
- MySpace Lab, Department of Clinical Neurosciences, University Hospital of Lausanne, University of Lausanne, Lausanne, Switzerland
| | | | - Andrea Serino
- MySpace Lab, Department of Clinical Neurosciences, University Hospital of Lausanne, University of Lausanne, Lausanne, Switzerland.
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Ma K, Yang L, Hommel B. The impact of interoceptive accuracy and stimulation type on the out-of-body experience. Q J Exp Psychol (Hove) 2023; 76:1940-1952. [PMID: 36113171 DOI: 10.1177/17470218221128285] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
People tend to perceive a virtual body standing in front of them as their own if it is either stroked or moving synchronously with their own real body-the out-of-body experience (OBE). We combined synchrony manipulation with two other factors of theoretical interest: the kind of stimulation, visuotactile stimuli or visuomotor correlations, being synchronised and the interoceptive accuracy (IA) of participants, assessed by means of the heartbeat counting task. Results showed that explicit measures of embodiment were systematically affected by synchrony, and this synchrony effect was more pronounced for visuomotor than for visuotactile conditions. The walking drift was affected by IA: In visuotactile conditions, the synchrony effect was pronounced in individuals with low IA, presumably reflecting a stronger impact of the visual information. In visuomotor conditions, however, the synchrony effect was stronger in individuals with high IA, presumably reflecting a stronger impact of re-afferent information generated by the participants' own movements.
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Affiliation(s)
- Ke Ma
- Key Laboratory of Personality and Cognition, Faculty of Psychological Science, Southwest University, Chongqing, China
| | - Liping Yang
- Key Laboratory of Personality and Cognition, Faculty of Psychological Science, Southwest University, Chongqing, China
| | - Bernhard Hommel
- University Neuropsychology Center and Cognitive Neurophysiology, Faculty of Medicine, TU Dresden, Dresden, Germany
- Faculty of Psychology, TU Dresden, Dresden, Germany
- Department of Psychology, Shandong Normal University, Jinan, China
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5
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Body transfer illusions in the schizophrenia spectrum: a systematic review. SCHIZOPHRENIA 2022; 8:103. [PMID: 36424451 PMCID: PMC9691625 DOI: 10.1038/s41537-022-00314-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 11/09/2022] [Indexed: 11/26/2022]
Abstract
Schizophrenia has been viewed as a disorder of the self. Accordingly, the question arises if and how senses of ownership and agency are impaired in schizophrenia. To address this question, several body transfer illusions (BTIs) have been investigated in schizophrenia patients and other schizophrenia spectrum (SCZ-S) populations. The objective of the study was to systematically review the current evidence from BTIs in the SCZ-S. A systematic literature search in PubMed and CENTRAL (search date: February 12, 2022) was conducted on BTI studies carried out in SCZ-S populations. Studies were included if they were published in English after peer review, reported original research data, related to the SCZ-S, and used a BTI as its study method. Conference papers, study protocols, and reviews were excluded. For each included BTI study, various study characteristics and outcomes were retrieved, and a risk-of-bias score was calculated based on six study quality criteria. K = 40 studies were identified, of which k = 20 studies met the eligibility criteria. For BTI paradigms using visuotactile stimulation, most studies found elevated sense of ownership ratings in SCZ-S populations compared to healthy controls (HC). Implicit illusion measures (e.g., proprioceptive drift), in turn, did not generally indicate elevated embodiment levels in SCZ-S populations. Likewise, no consistent group differences emerged between SCZ-S populations and HC with respect to BTI paradigms using visuomotor stimulation. Furthermore, BTI vividness was found to correlate significantly with core symptoms of schizophrenia and various subclinical characteristics related to the SCZ-S. In line with the self-disturbance hypothesis, SCZ-S populations appear to be affected by aberrations in bodily self-awareness. Review registration: PROSPERO (identifier: CRD42022287960).
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Abstract
Recent research suggests that embodiment sensations (sense of body ownership and sense of body agency) are altered in schizophrenia. Using a mirror box illusion setup, we tested if the anomalous embodiment experience depends on deficient processing of visuomotor synchrony, disrupted processing of movement mode, or both. The task required participants to press a lever with their index while looking at the image of the experimenter's hand moving on a similar lever. The illusion of embodiment could arise because looking toward the direction of their own hand the participant saw the reflection of the experimenter's hand visually superimposed to his own one through a mirror. During the illusion induction, we systematically varied visuomotor asynchrony (4 delays were imposed on the movement of the experimenter's hand) and the mode of movement (the participant could perform active vs. passive movements). The strength of the illusion of embodiment of the external hand was assessed with explicit judgments of ownership and agency. Patients' data showed an anomalous modulation of ownership with respect to visuomotor synchrony manipulation and an altered modulation of agency with respect to both visuomotor synchrony and movement mode manipulations. Results from the present study suggest that impairments affecting both the processing of temporal aspects of visuomotor signals and the processing of type of movement underlie anomalous embodiment sensations in schizophrenia. Hypotheses about potential deficits accounting for our results are proposed.
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Paredes R, Ferri F, Seriès P. Influence of E/I balance and pruning in peri-personal space differences in schizophrenia: A computational approach. Schizophr Res 2022; 248:368-377. [PMID: 34509334 DOI: 10.1016/j.schres.2021.06.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 05/06/2021] [Accepted: 06/22/2021] [Indexed: 11/25/2022]
Abstract
The encoding of the space close to the body, named peri-personal space (PPS), is thought to play a crucial role in the unusual experiences of the self observed in schizophrenia (SCZ). However, it is unclear why SCZ patients and high schizotypal (H-SPQ) individuals present a narrower PPS and why the boundaries of the PPS are more sharply defined in patients. We hypothesise that the unusual PPS representation observed in SCZ is caused by an imbalance of excitation and inhibition (E/I) in recurrent synapses of unisensory neurons or an impairment of bottom-up and top-down connectivity between unisensory and multisensory neurons. These hypotheses were tested computationally by manipulating the effects of E/I imbalance, feedback weights and synaptic density in the network. Using simulations we explored the effects of such impairments in the PPS representation generated by the network and fitted the model to behavioural data. We found that increased excitation of sensory neurons could account for the smaller PPS observed in SCZ and H-SPQ, whereas a decrease of synaptic density caused the sharp definition of the PPS observed in SCZ. We propose a novel conceptual model of PPS representation in the SCZ spectrum that can account for alterations in self-world demarcation, failures in tactile discrimination and symptoms observed in patients.
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Affiliation(s)
- Renato Paredes
- The University of Edinburgh, School of Informatics, 10 Crichton Street, Edinburgh, United Kingdom; Cognitive Science Group, Instituto de Investigaciones Psicológicas, Facultad de Psicología Universidad Nacional de Córdoba - CONICET, Argentina; Department of Psychology, Pontifical Catholic University of Peru, Lima, Peru
| | - Francesca Ferri
- Department of Neuroscience, Imaging and Clinical Sciences, University of Chieti-Pescara, Chieti, Italy
| | - Peggy Seriès
- The University of Edinburgh, School of Informatics, 10 Crichton Street, Edinburgh, United Kingdom.
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Favrod O, Brand A, Berdzenishvili E, Chkonia E, Akselrod M, Wagemans J, Herzog MH, Roinishvili M. Embedded figures in schizophrenia: A main deficit but no specificity. Schizophr Res Cogn 2022; 28:100227. [PMID: 34976748 PMCID: PMC8683755 DOI: 10.1016/j.scog.2021.100227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/21/2021] [Accepted: 11/21/2021] [Indexed: 11/28/2022] Open
Abstract
Visual deficits are core deficits of schizophrenia. Classically, deficits are determined with demanding psychophysical tasks requiring fine-grained spatial or temporal resolution. Less is known about holistic processing. Here, we employed the Leuven Embedded Figures Test (L-EFT) measuring classic aspects of Gestalt processing. A target shape is embedded in a context and observers have to detect as quickly as possible in which display the target is embedded. Targets vary in closure, symmetry, complexity, and good continuation. In all conditions, schizophrenia patients had longer RTs compared to controls and depressive patients and to a lesser extent compared to their siblings. There was no interaction suggesting that, once the main deficit of schizophrenia patients is discarded, there are no further deficits in Gestalt perception between the groups. This result is in line with a growing line of research showing that when schizophrenia patients are given sufficient time to accomplish the task, they perform as well as controls.
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Affiliation(s)
- Ophélie Favrod
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland
- Corresponding author.
| | - Andreas Brand
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - Eka Berdzenishvili
- Department of Psychiatry, Tbilisi State Medical University, Tbilisi, Georgia
| | - Eka Chkonia
- Department of Psychiatry, Tbilisi State Medical University, Tbilisi, Georgia
- Institute of Cognitive Neurosciences, Agricultural University of Georgia, Tbilisi, Georgia
| | - Michel Akselrod
- MySpace Laboratory, Department of Clinical Neurosciences, University Hospital (CHUV), Lausanne, Switzerland
| | - Johan Wagemans
- Laboratory of Experimental Psychology, Department of Brain and Cognition, KU Leuven (University of Leuven), Belgium
| | - Michael H. Herzog
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland
| | - Maya Roinishvili
- Institute of Cognitive Neurosciences, Agricultural University of Georgia, Tbilisi, Georgia
- Laboratory of Vision Physiology, Beritashvili Centre of Experimental Biomedicine, Tbilisi, Georgia
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Roel Lesur M, Bolt E, Saetta G, Lenggenhager B. The monologue of the double: Allocentric reduplication of the own voice alters bodily self-perception. Conscious Cogn 2021; 95:103223. [PMID: 34653785 DOI: 10.1016/j.concog.2021.103223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 08/25/2021] [Accepted: 10/07/2021] [Indexed: 10/20/2022]
Abstract
During autoscopic phenomena, people perceive a double of themselves in extrapersonal space. Such clinical allocentric self-experiences sometimes co-occur with auditory hallucinations, yet experimental setups to induce similar illusions in healthy participants have generally neglected acoustic cues. We investigated whether feeling the presence of an auditory double could be provoked experimentally by recording healthy participants' own versus another person's voice and movements using binaural headphones from an egocentric (the participants' own) and an allocentric (a dummy head located elsewhere) perspective. When hearing themselves allocentrically, participants reported feeling a self-identified presence extracorporeally, an arguably distinct quality of autoscopy. Our results suggest that participants without hallucinatory experiences localized their own voice closer to themselves compared to that of another person. Explorative findings suggest that distinct patterns for hallucinators should be further investigated. This study suggests a successful induction of the feeling of an acoustic doppelganger, bridging clinical phenomena and experimental work.
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Affiliation(s)
- Marte Roel Lesur
- Department of Psychology, University of Zurich, Zurich, Switzerland.
| | - Elena Bolt
- Department of Psychology, University of Zurich, Zurich, Switzerland
| | - Gianluca Saetta
- Department of Psychology, University of Zurich, Zurich, Switzerland
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Hara M, Kanayama N, Blanke O, Salomon R. Modulation of Bodily Self-Consciousness by Self and External Touch. IEEE TRANSACTIONS ON HAPTICS 2021; 14:615-625. [PMID: 33750715 DOI: 10.1109/toh.2021.3067651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The full body illusion (FBI) is a bodily illusion based on the application of multisensory conflicts that induce changes in bodily self-consciousness (BSC). This has been used to study cognitive brain mechanisms underlying body ownership and related aspects of self-consciousness. Typically, such paradigms employ external passive multisensory stimulation, thus neglecting the possible contributions of self-generated action and haptic cues to body ownership. In this article, the effects of both external and voluntary self-touch on BSC were examined with a robotics-based FBI paradigm. We compared the effects of classical passive visuotactile stimulation and active self-touch (in which experimental participants had a sense of agency over the tactile stimulation) on the FBI. We evaluated these effects using a questionnaire, crossmodal congruency task, and measurements of changes in self-location. The results indicated that both synchronous passive visuotactile stimulation and synchronous active self-touch induced illusory ownership over a virtual body, without significant differences in their magnitudes. However, the FBI induced by active self-touch was associated with a larger drift in self-location towards the virtual body. These results show that movement-related signals arising from self-touch impact the BSC not only for hand ownership but also for torso-centered body ownership and related aspects of BSC.
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11
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Zopf R, Boulton K, Langdon R, Rich AN. Perception of visual-tactile asynchrony, bodily perceptual aberrations, and bodily illusions in schizophrenia. Schizophr Res 2021; 228:534-540. [PMID: 33234423 DOI: 10.1016/j.schres.2020.11.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 10/12/2020] [Accepted: 11/16/2020] [Indexed: 11/26/2022]
Abstract
Body perception can be altered in individuals with schizophrenia resulting in experiences of undefined boundaries, loss of ownership, and size changes. These individuals may also be more susceptible to the rubber hand illusion (RHI: an illusion of body perception that can also be induced in neurotypical populations), but the findings are mixed. Furthermore, the perception of multisensory timing, which is thought to be fundamental for body perception, is altered in schizophrenia. We tested whether altered perception of the temporal relationship between visual and tactile signals in schizophrenia predicts self-reported perceptual aberrations and RHI susceptibility. We found that the sensitivity to detect temporal asynchronies is reduced in schizophrenia and this is a significant predictor for bodily perceptual symptoms. In contrast, we found no evidence for a direct relationship between asynchrony detection sensitivity and RHI susceptibility. Instead, our findings suggest that experiencing more bodily perceptual symptoms increases the likelihood of endorsing unusual bodily experiences, resulting in higher RHI self-ratings but not higher proprioceptive drift scores. Our findings provide new insight into factors that may underlie the report of unusual body perceptions in schizophrenia.
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Affiliation(s)
- Regine Zopf
- Department of Cognitive Science, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, Australia; Perception in Action Research Centre, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, Australia; Body Image and Ingestion Group, Macquarie University, Sydney, Australia.
| | - Kelsie Boulton
- Department of Psychology, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, Australia
| | - Robyn Langdon
- Department of Cognitive Science, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, Australia
| | - Anina N Rich
- Department of Cognitive Science, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, Australia; Perception in Action Research Centre, Faculty of Medical, Health & Human Sciences, Macquarie University, Sydney, Australia; Centre for Elite Performance, Training & Expertise, Macquarie University, Sydney, Australia
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12
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Kwok SC, Xu X, Duan W, Wang X, Tang Y, Allé MC, Berna F. Autobiographical and episodic memory deficits in schizophrenia: A narrative review and proposed agenda for research. Clin Psychol Rev 2021; 83:101956. [DOI: 10.1016/j.cpr.2020.101956] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 10/04/2020] [Accepted: 12/07/2020] [Indexed: 02/06/2023]
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13
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Lyons N, Dietrich DE, Graser J, Juckel G, Koßmann C, Krauß H, Müller B, Michalak J. Reduced Jumping to Conclusion Bias after Experimentally Induced Enhancement of Subjective Body Boundaries in Psychosis. Psychopathology 2021; 54:92-97. [PMID: 33611331 DOI: 10.1159/000513271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/20/2020] [Indexed: 11/19/2022]
Abstract
INTRODUCTION A disturbed sense of self is frequently discussed as an etiological factor for delusion symptoms in psychosis. Phenomenological approaches to psychopathology posit that lacking the sense that the self is localized within one's bodily boundaries (disembodiment) is one of the core features of the disturbed self in psychosis. The present study examines this idea by experimentally manipulating the sense of bodily boundaries. METHODS Seventy-three patients with psychosis were randomly assigned to either a 10-min, guided self-massage in the experimental group (EG) to enhance the sense of bodily boundaries or a control group (CG), which massaged a fabric ring. Effects on an implicit measure (jumping to conclusion bias; JTC) and an explicit measure (Brief State Paranoia Checklist; BSPC) of delusion processes were assessed. The JTC measures the tendency to make a decision with little evidence available, and the BSPC explicitly measures the approval of paranoid beliefs. RESULTS Patients in the EG showed a lower JTC (M = 4.11 draws before decision) than the CG (M = 2.43; Cohen's d = 0.64). No significant difference in the BSPC was observed. DISCUSSION/CONCLUSION Our results indicate that enhancing the sense of body boundaries through a self-massage can reduce an implicit bias associated with delusional ideation and correspondingly support the idea that disembodiment might be a relevant factor in the formation of psychotic symptoms.
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Affiliation(s)
- Naomi Lyons
- Department for Psychology and Psychotherapy, Witten/Herdecke University, Witten, Germany,
| | - Detlef E Dietrich
- Burghof-Klinik Rinteln, Center for Systems Neuroscience Hannover, Center for Mental Health, Hannover Medical School, Hannover, Germany
| | - Johannes Graser
- Department for Psychology and Psychotherapy, Witten/Herdecke University, Witten, Germany
| | - Georg Juckel
- Psychiatry, Psychotherapy, Psychosomatics, Ruhr-University Bochum, Bochum, Germany
| | - Christian Koßmann
- Psychiatry, Psychotherapy, Psychosomatics, Ruhr-University Bochum, Bochum, Germany
| | | | | | - Johannes Michalak
- Department for Psychology and Psychotherapy, Witten/Herdecke University, Witten, Germany
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14
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Costantini M, Salone A, Martinotti G, Fiori F, Fotia F, Di Giannantonio M, Ferri F. Body representations and basic symptoms in schizophrenia. Schizophr Res 2020; 222:267-273. [PMID: 32461087 DOI: 10.1016/j.schres.2020.05.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/24/2019] [Accepted: 05/16/2020] [Indexed: 12/25/2022]
Abstract
Patients with schizophrenia report a wide range of anomalous body experiences. According to the basic symptom model of schizophrenia, disturbances of body perception and awareness are among the most powerful predictors of the changes in the subjective experience of the self in schizophrenia. In this study we first investigated the body structural representation (BSR), a specific aspect of body awareness, and its association to basic symptoms in patients with schizophrenia. Using a finger localization task, we found that patients are significantly less accurate than healthy controls when asked to identify pairs of fingers touched by the experimenter, when the hand is hidden from view. Most importantly, patients' performance at the finger localization task was negatively associated to basic symptoms: the worse the individual accuracy, the higher the SPI-A total score. Moreover, the accuracy at the finger localization task was also negatively correlated with the malleability of the sense of body ownership: the less the individual ability to localize fingers, the stronger the rubber hand illusion. These results are in agreement with the idea that self-disorders in schizophrenia reveal a disconnectedness that can be regarded as a problem of disembodiment and traced back to abnormal body experiences.
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Affiliation(s)
- Marcello Costantini
- Department of Psychological, Health and Territorial Sciences, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy; Institute for Advanced Biomedical Technologies, ITAB, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy
| | - Anatolia Salone
- Department of Neuroscience, Imaging and Clinical Sciences, University of Chieti-Pescara, Chieti, Italy
| | - Giovanni Martinotti
- Institute for Advanced Biomedical Technologies, ITAB, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy; Department of Neuroscience, Imaging and Clinical Sciences, University of Chieti-Pescara, Chieti, Italy
| | | | - Francesca Fotia
- Department of Psychology, University of Essex, Colchester CO4 3SQ, UK
| | - Massimo Di Giannantonio
- Institute for Advanced Biomedical Technologies, ITAB, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy; Department of Neuroscience, Imaging and Clinical Sciences, University of Chieti-Pescara, Chieti, Italy
| | - Francesca Ferri
- Institute for Advanced Biomedical Technologies, ITAB, "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy; Department of Neuroscience, Imaging and Clinical Sciences, University of Chieti-Pescara, Chieti, Italy.
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15
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Ardizzi M, Ambrosecchia M, Buratta L, Ferri F, Ferroni F, Palladini B, Volpe-Gaudelli T, Peciccia M, Mazzeschi C, Gallese V. The motor roots of minimal self disorders in schizophrenia. Schizophr Res 2020; 218:302-303. [PMID: 32171636 DOI: 10.1016/j.schres.2020.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 02/27/2020] [Accepted: 03/05/2020] [Indexed: 01/17/2023]
Affiliation(s)
- Martina Ardizzi
- Department of Medicine and Surgery, Unit of Neuroscience, University of Parma, Parma, Italy.
| | - Marianna Ambrosecchia
- Department of Medicine and Surgery, Unit of Neuroscience, University of Parma, Parma, Italy
| | - Livia Buratta
- Department of Human Science and Education, University of Perugia, Perugia, Italy
| | - Francesca Ferri
- Department of Neuroscience, Imaging and Clinical Science, University G. d'Annunzio, Chieti, Italy
| | - Francesca Ferroni
- Department of Medicine and Surgery, Unit of Neuroscience, University of Parma, Parma, Italy
| | - Barbara Palladini
- Department of Medicine and Surgery, Unit of Neuroscience, University of Parma, Parma, Italy
| | - Taras Volpe-Gaudelli
- Department of Medicine and Surgery, Unit of Neuroscience, University of Parma, Parma, Italy
| | - Maurizio Peciccia
- Department of Human Science and Education, University of Perugia, Perugia, Italy
| | - Claudia Mazzeschi
- Department of Human Science and Education, University of Perugia, Perugia, Italy
| | - Vittorio Gallese
- Department of Medicine and Surgery, Unit of Neuroscience, University of Parma, Parma, Italy
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16
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Sandsten KE, Nordgaard J, Kjaer TW, Gallese V, Ardizzi M, Ferroni F, Petersen J, Parnas J. Altered self-recognition in patients with schizophrenia. Schizophr Res 2020; 218:116-123. [PMID: 32007345 DOI: 10.1016/j.schres.2020.01.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 01/12/2020] [Accepted: 01/19/2020] [Indexed: 10/25/2022]
Abstract
Self-alienation is a common characterization of various disturbing experiences in patients with schizophrenia. A vivid example comes from patient reports of not recognizing themselves when inspecting their specular image in the mirror. By applying the multisensory paradigm of the Enfacement Illusion, this study empirically addresses the specular Self-Other discrimination in patients with schizophrenia. 35 patients diagnosed with schizophrenia and 35 healthy matched controls were enrolled in the study. Results found that the group of patients with schizophrenia had a significant skewed self-other discrimination towards the other at baseline. Furthermore, the effect of visuo-tactile stimulation on self-recognition in the schizophrenia patients was significantly altered after both synchronous and asynchronous stimulation compared to baseline. This contrasted with healthy controls which in line with earlier studies only had significantly different self-recognition after synchronous stimulation. The study thus suggests that patients with schizophrenia have deviations in their specular self-recognition compared to healthy controls. Moreover, that temporal factors in multisensory integration may contribute to alterations of self-related stimuli in patients with schizophrenia.
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Affiliation(s)
- Karl Erik Sandsten
- Early Psychosis Intervention Center, Region Zealand Psychiatry, Roskilde, Denmark.
| | | | | | - Vittorio Gallese
- Department of Medicine and Surgery, University of Parma, Parma, Italy; Institute of Philosophy, School of Advanced Study, University of London, London, UK
| | - Martina Ardizzi
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Francesca Ferroni
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Janne Petersen
- Center for Clinical Research and Prevention, Frederiksberg Hospital, Copenhagen, Denmark
| | - Josef Parnas
- Center for Subjectivity Research, Copenhagen University, Denmark; Mental Health Center Glostrup, Brondby, Denmark
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17
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Roel Lesur M, Weijs ML, Simon C, Kannape OA, Lenggenhager B. Psychometrics of Disembodiment and Its Differential Modulation by Visuomotor and Visuotactile Mismatches. iScience 2020; 23:100901. [PMID: 32109678 PMCID: PMC7044746 DOI: 10.1016/j.isci.2020.100901] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/12/2019] [Accepted: 01/20/2020] [Indexed: 10/29/2022] Open
Abstract
Altered states of embodiment are fundamental to the scientific understanding of bodily self consciousness. The feeling of disembodiment during everyday activities is common to clinical conditions; however, the direct study of disembodiment in experimental setups is rare compared to the extensive investigation of illusory embodiment of an external object. Using mixed reality to modulate embodiment through temporally mismatching sensory signals from the own body, we assessed how such mismatches affect phenomenal and physiological aspects of embodiment and measured perceptual thresholds for these across multimodal signals. The results of a principal component analysis suggest that multimodal mismatches generally induce disembodiment by increasing the sense of disownership and deafference and decreasing embodiment; however, this was not generally reflected in physiological changes. Although visual delay decreased embodiment both during active movement and passive touch, the effect was stronger for the former. We discuss the relevance of these findings for understanding bodily self plasticity.
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Affiliation(s)
- Marte Roel Lesur
- Department of Psychology, Cognitive Neuropsychology with Focus on Body, Self, and Plasticity, University of Zurich, Zurich, Switzerland.
| | - Marieke Lieve Weijs
- Department of Psychology, Cognitive Neuropsychology with Focus on Body, Self, and Plasticity, University of Zurich, Zurich, Switzerland
| | - Colin Simon
- Department of Psychology, Cognitive Neuropsychology with Focus on Body, Self, and Plasticity, University of Zurich, Zurich, Switzerland
| | - Oliver Alan Kannape
- School of Psychology, University of Central Lancashire, Preston PR1 2HE, UK; Laboratory of Cognitive Neuroscience, Center for Neuroprosthetics and Brain Mind Institute, Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland
| | - Bigna Lenggenhager
- Department of Psychology, Cognitive Neuropsychology with Focus on Body, Self, and Plasticity, University of Zurich, Zurich, Switzerland.
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18
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Heartbeat-evoked cortical responses: Underlying mechanisms, functional roles, and methodological considerations. Neuroimage 2019; 197:502-511. [DOI: 10.1016/j.neuroimage.2019.04.081] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 11/24/2022] Open
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19
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Crespi B, Dinsdale N. Autism and psychosis as diametrical disorders of embodiment. Evol Med Public Health 2019; 2019:121-138. [PMID: 31402979 PMCID: PMC6682708 DOI: 10.1093/emph/eoz021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/11/2019] [Indexed: 12/12/2022] Open
Abstract
Humans have evolved an elaborate system of self-consciousness, self-identity, self-agency, and self-embodiment that is grounded in specific neurological structures including an expanded insula. Instantiation of the bodily self has been most-extensively studied via the 'rubber hand illusion', whereby parallel stimulation of a hidden true hand, and a viewed false hand, leads to the felt belief that the false hand is one's own. Autism and schizophrenia have both long been regarded as conditions centrally involving altered development of the self, but they have yet to be compared directly with regard to the self and embodiment. Here, we synthesize the embodied cognition literature for these and related conditions, and describe evidence that these two sets of disorders exhibit opposite susceptibilities from typical individuals to the rubber hand illusion: reduced on the autism spectrum and increased in schizophrenia and other psychotic-affective conditions. Moreover, the opposite illusion effects are mediated by a consilient set of associated phenomena, including empathy, interoception, anorexia risk and phenotypes, and patterns of genetic correlation. Taken together, these findings: (i) support the diametric model of autism and psychotic-affective disorders, (ii) implicate the adaptive human system of self-embodiment, and its neural bases, in neurodevelopmental disorders, and suggest new therapies and (iii) experimentally ground Bayesian predictive coding models with regard to autism compared with psychosis. Lay summary: Humans have evolved a highly developed sense of self and perception of one's own body. The 'rubber hand illusion' can be used to test individual variation in sense of self, relative to connection with others. We show that this illusion is reduced in autism spectrum disorders, and increased in psychotic and mood disorders. These findings have important implications for understanding and treatment of mental disorders.
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Affiliation(s)
- Bernard Crespi
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada
| | - Natalie Dinsdale
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada
- Department of Psychology, University of Saskatchewan, Saskatoon, SK, Canada
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20
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Poletti M, Tortorella A, Raballo A. Impaired Corollary Discharge in Psychosis and At-Risk States: Integrating Neurodevelopmental, Phenomenological, and Clinical Perspectives. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2019; 4:832-841. [PMID: 31262709 DOI: 10.1016/j.bpsc.2019.05.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/01/2019] [Accepted: 05/01/2019] [Indexed: 12/28/2022]
Abstract
The brain is increasingly viewed in contemporary neuroscience as a predictive machine; its products, such as movements and decisions, are indeed accompanied by predictions of outcomes at distinct levels of awareness. In this conceptual review, we focus on corollary discharge, a basic neurophysiological mechanism that is allegedly involved in sensory prediction and contributes to the distinction between self-generated and externally generated actions. Failures in corollary discharge have been hypothesized as potentially relevant for the progressive development of positive psychotic symptoms such as passivity delusions and auditory verbal hallucinations. We articulate this framework adopting three confocal lenses, namely, the neurodevelopmental, phenomenological, and clinical perspectives. Converging evidence from these research domains indicates a possible developmental cascade leading to increased lifetime risk of psychosis. That is, early childhood alterations of corollary discharge mechanisms, endophenotypically expressed in motor impairment, may concur with a progressive fading of the feeling of self-agency on one's own experiences. Combined with other age-dependent situational challenges occurring along development, this may progressively hamper the ontogenesis of the embodied self, thereby facilitating the emergence of anomalous subjective experiences such as self-disorders (a longitudinal index of schizophrenia spectrum vulnerability) and broadly conceived clinical high-risk states. Overall, this condition increases the risk of developing passivity symptoms, phenotypically expressed in a severity gradient ranging from intrusive thoughts to passivity delusions and auditory verbal hallucinations. Empirical and clinical implications of this framework, as well as future scenarios, are discussed.
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Affiliation(s)
- Michele Poletti
- Department of Mental Health, Azienda Unità Sanitaria Locale-IRCSS di Reggio Emilia, Reggio Emilia, Italy
| | - Alfonso Tortorella
- Department of Medicine, Division of Psychiatry, Clinical Psychology and Rehabilitation, University of Perugia, Perugia, Italy
| | - Andrea Raballo
- Department of Medicine, Division of Psychiatry, Clinical Psychology and Rehabilitation, University of Perugia, Perugia, Italy; Center for Translational, Phenomenological and Developmental Psychopathology, Perugia University Hospital, Perugia, Italy.
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21
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Serino A. Peripersonal space (PPS) as a multisensory interface between the individual and the environment, defining the space of the self. Neurosci Biobehav Rev 2019; 99:138-159. [DOI: 10.1016/j.neubiorev.2019.01.016] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 12/23/2018] [Accepted: 01/14/2019] [Indexed: 11/25/2022]
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22
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Ferroni F, Ardizzi M, Sestito M, Lucarini V, Daniel BD, Paraboschi F, Tonna M, Marchesi C, Gallese V. Shared multisensory experience affects Others' boundary: The enfacement illusion in schizophrenia. Schizophr Res 2019; 206:225-235. [PMID: 30473209 DOI: 10.1016/j.schres.2018.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/15/2018] [Accepted: 11/16/2018] [Indexed: 02/07/2023]
Abstract
Schizophrenia has been described as a psychiatric condition characterized by deficits in one's own and others' face recognition, as well as by a disturbed sense of body-ownership. To date, no study has integrated these two lines of research with the aim of investigating Enfacement Illusion (EI) proneness in schizophrenia. To accomplish this goal, the classic EI protocol was adapted to test the potential plasticity of both Self-Other and Other-Other boundaries. Results showed that EI induced the expected malleability of Self-Other boundary among both controls and patients. Interestingly, for the first time, the present study demonstrates that also the Other-Other boundary was influenced by EI. Furthermore, comparing the two groups, the malleability of the Other-Other boundary showed an opposite modulation. These results suggest that, instead of greater Self-Other boundary plasticity, a qualitative difference can be detected between schizophrenia patients and controls in the malleability of the Other-Other boundary. The present study points out a totally new aspect about body-illusions and schizophrenia disorder, demonstrating that EI is not only confined to self-sphere but it also affects the way we discriminate others, representing a potential crucial aspect in the social domain.
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Affiliation(s)
- F Ferroni
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - M Ardizzi
- Department of Medicine and Surgery, University of Parma, Parma, Italy.
| | - M Sestito
- Department of Psychology, Wright State University, Dayton, OH, United States
| | - V Lucarini
- Department of Medicine and Surgery, Psychiatry Unit, University of Parma, Parma, Italy
| | - B D Daniel
- Department of Medicine and Surgery, Psychiatry Unit, University of Parma, Parma, Italy
| | - F Paraboschi
- Department of Medicine and Surgery, Psychiatry Unit, University of Parma, Parma, Italy
| | - M Tonna
- Department of Mental Health, Local Health Service, Parma, Italy
| | - C Marchesi
- Department of Medicine and Surgery, Psychiatry Unit, University of Parma, Parma, Italy
| | - V Gallese
- Department of Medicine and Surgery, University of Parma, Parma, Italy; Institute of Philosophy, School of Advanced Study, University of London, London, UK
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23
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Shaqiri A, Roinishvili M, Grzeczkowski L, Chkonia E, Pilz K, Mohr C, Brand A, Kunchulia M, Herzog MH. Sex-related differences in vision are heterogeneous. Sci Rep 2018; 8:7521. [PMID: 29760400 PMCID: PMC5951855 DOI: 10.1038/s41598-018-25298-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 04/13/2018] [Indexed: 12/19/2022] Open
Abstract
Despite well-established sex differences for cognition, audition, and somatosensation, few studies have investigated whether there are also sex differences in visual perception. We report the results of fifteen perceptual measures (such as visual acuity, visual backward masking, contrast detection threshold or motion detection) for a cohort of over 800 participants. On six of the fifteen tests, males significantly outperformed females. On no test did females significantly outperform males. Given this heterogeneity of the sex effects, it is unlikely that the sex differences are due to any single mechanism. A practical consequence of the results is that it is important to control for sex in vision research, and that findings of sex differences for cognitive measures using visually based tasks should confirm that their results cannot be explained by baseline sex differences in visual perception.
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Affiliation(s)
- Albulena Shaqiri
- Laboratory of Psychophysics, Brain Mind Institute, EPFL, Lausanne, Switzerland.
| | - Maya Roinishvili
- Laboratory of Vision Physiology, Ivane Beritashvili Center of Experimental Biomedicine, Tbilisi, Georgia.,Institute of Cognitive Neurosciences, Free University of Tbilisi, Tbilisi, Georgia
| | | | - Eka Chkonia
- Institute of Cognitive Neurosciences, Free University of Tbilisi, Tbilisi, Georgia.,Department of Psychiatry, Tbilisi State Medical University, Tbilisi, Georgia
| | - Karin Pilz
- School of Psychology, University of Aberdeen, Aberdeen, Scotland, UK
| | - Christine Mohr
- Institute of Psychology, Faculty of Social and Political Sciences, Bâtiment Geopolis, Quartier Mouline, 1015, Lausanne, Switzerland
| | - Andreas Brand
- Institute for Psychology and Cognition Research, University of Bremen, Bremen, Germany
| | - Marina Kunchulia
- Laboratory of Vision Physiology, Ivane Beritashvili Center of Experimental Biomedicine, Tbilisi, Georgia.,Institute of Cognitive Neurosciences, Free University of Tbilisi, Tbilisi, Georgia
| | - Michael H Herzog
- Laboratory of Psychophysics, Brain Mind Institute, EPFL, Lausanne, Switzerland
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