1
|
Frumento S, Preatoni G, Chee L, Gemignani A, Ciotti F, Menicucci D, Raspopovic S. Unconscious multisensory integration: behavioral and neural evidence from subliminal stimuli. Front Psychol 2024; 15:1396946. [PMID: 39091706 PMCID: PMC11291458 DOI: 10.3389/fpsyg.2024.1396946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 07/04/2024] [Indexed: 08/04/2024] Open
Abstract
Introduction The prevailing theories of consciousness consider the integration of different sensory stimuli as a key component for this phenomenon to rise on the brain level. Despite many theories and models have been proposed for multisensory integration between supraliminal stimuli (e.g., the optimal integration model), we do not know if multisensory integration occurs also for subliminal stimuli and what psychophysical mechanisms it follows. Methods To investigate this, subjects were exposed to visual (Virtual Reality) and/or haptic stimuli (Electro-Cutaneous Stimulation) above or below their perceptual threshold. They had to discriminate, in a two-Alternative Forced Choice Task, the intensity of unimodal and/or bimodal stimuli. They were then asked to discriminate the sensory modality while recording their EEG responses. Results We found evidence of multisensory integration for supraliminal condition, following the classical optimal model. Importantly, even for subliminal trials participant's performances in the bimodal condition were significantly more accurate when discriminating the intensity of the stimulation. Moreover, significant differences emerged between unimodal and bimodal activity templates in parieto-temporal areas known for their integrative role. Discussion These converging evidences - even if preliminary and needing confirmation from the collection of further data - suggest that subliminal multimodal stimuli can be integrated, thus filling a meaningful gap in the debate about the relationship between consciousness and multisensory integration.
Collapse
Affiliation(s)
- Sergio Frumento
- Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy
| | - Greta Preatoni
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zürich, Zürich, Switzerland
| | - Lauren Chee
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zürich, Zürich, Switzerland
| | - Angelo Gemignani
- Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy
- Clinical Psychology Branch, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
| | - Federico Ciotti
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zürich, Zürich, Switzerland
| | - Danilo Menicucci
- Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Pisa, Italy
| | - Stanisa Raspopovic
- Laboratory for Neuroengineering, Department of Health Sciences and Technology, Institute of Robotics and Intelligent Systems, ETH Zürich, Zürich, Switzerland
| |
Collapse
|
2
|
Fossataro C, Noel JP, Bruno V. Editorial: The bodily self in the multisensory world. Front Hum Neurosci 2024; 18:1418014. [PMID: 38779447 PMCID: PMC11109373 DOI: 10.3389/fnhum.2024.1418014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 04/26/2024] [Indexed: 05/25/2024] Open
Affiliation(s)
| | - Jean-Paul Noel
- Center for Neural Science, New York University, New York, NY, United States
| | - Valentina Bruno
- Manibus Lab, Psychology Department, University of Turin, Turin, Italy
| |
Collapse
|
3
|
Kraus J, Čavojská N, Harvanová S, Hajdúk M. Interpersonal distance in schizophrenia: A systematic review. Schizophr Res 2024; 266:1-11. [PMID: 38359513 DOI: 10.1016/j.schres.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 01/24/2024] [Accepted: 02/10/2024] [Indexed: 02/17/2024]
Abstract
BACKGROUND AND HYPOTHESIS Schizophrenia is often associated with severe difficulties in social functioning, resulting in increased isolation and subsequent loneliness. Interpersonal distance - the amount of space around an individual's body during social interaction - can signal such difficulties. However, little is known about how individuals with schizophrenia regulate their interpersonal distance during social encounters. Summarizing the current empirical findings of interpersonal distance regulation in schizophrenia can bring novel perspectives for understanding interpersonal difficulties observed in this clinical population. STUDY DESIGN This systematic review examined empirical studies indexed in Web of Science and PubMed based on a-priori-defined criteria. 1164 studies were screened with the final review consisting of 14 studies. They together included 1145 adult participants, of whom 668 were diagnosed with schizophrenia or psychotic disorder. STUDY RESULTS The studies clearly showed that patients maintain greater interpersonal distances than do controls. Furthermore, a larger distance was linked to more severe positive and negative symptoms. More specifically, the link to symptoms was more pronounced when patients were being approached by someone else during interactions. On a neurobiological level, the increased activity and functional connectivity of the dorsal inferior parietal sulcus and increased subjective state-dependent stress are further indicated as being potentially related to increase interpersonal distancing in schizophrenia. CONCLUSIONS We provided information about the aberrant modulation of interpersonal distance in schizophrenia. Studies showed substantial heterogeneity in tasks used to measure interpersonal distance. Future studies should look at links to social functioning, underlying neurobiology, and neuroendocrinal regulation of interpersonal space in schizophrenia.
Collapse
Affiliation(s)
- Jakub Kraus
- Department of Psychology, Faculty of Arts, Comenius University in Bratislava, Slovakia; Centre for Psychiatric Disorders Research, Science Park, Comenius University in Bratislava, Slovakia.
| | - Natália Čavojská
- Centre for Psychiatric Disorders Research, Science Park, Comenius University in Bratislava, Slovakia; Department of Psychiatry, Faculty of Medicine, Comenius University in Bratislava, Slovakia
| | - Silvia Harvanová
- Department of Psychology, Faculty of Arts, Comenius University in Bratislava, Slovakia
| | - Michal Hajdúk
- Department of Psychology, Faculty of Arts, Comenius University in Bratislava, Slovakia; Centre for Psychiatric Disorders Research, Science Park, Comenius University in Bratislava, Slovakia; Department of Psychiatry, Faculty of Medicine, Comenius University in Bratislava, Slovakia
| |
Collapse
|
4
|
Fossataro C, Galigani M, Rossi Sebastiano A, Bruno V, Ronga I, Garbarini F. Spatial proximity to others induces plastic changes in the neural representation of the peripersonal space. iScience 2022; 26:105879. [PMID: 36654859 PMCID: PMC9840938 DOI: 10.1016/j.isci.2022.105879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 11/21/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
Peripersonal space (PPS) is a highly plastic "invisible bubble" surrounding the body whose boundaries are mapped through multisensory integration. Yet, it is unclear how the spatial proximity to others alters PPS boundaries. Across five experiments (N = 80), by recording behavioral and electrophysiological responses to visuo-tactile stimuli, we demonstrate that the proximity to others induces plastic changes in the neural PPS representation. The spatial proximity to someone else's hand shrinks the portion of space within which multisensory responses occur, thus reducing the PPS boundaries. This suggests that PPS representation, built from bodily and multisensory signals, plastically adapts to the presence of conspecifics to define the self-other boundaries, so that what is usually coded as "my space" is recoded as "your space". When the space is shared with conspecifics, it seems adaptive to move the other-space away from the self-space to discriminate whether external events pertain to the self-body or to other-bodies.
Collapse
Affiliation(s)
- Carlotta Fossataro
- MANIBUS Lab, Psychology Department, University of Turin, Turin 10123, Italy
| | - Mattia Galigani
- MANIBUS Lab, Psychology Department, University of Turin, Turin 10123, Italy
| | | | - Valentina Bruno
- MANIBUS Lab, Psychology Department, University of Turin, Turin 10123, Italy
| | - Irene Ronga
- MANIBUS Lab, Psychology Department, University of Turin, Turin 10123, Italy
| | - Francesca Garbarini
- MANIBUS Lab, Psychology Department, University of Turin, Turin 10123, Italy,Neuroscience Institute of Turin (NIT), Turin 10123, Italy,Corresponding author
| |
Collapse
|
5
|
Multisensory-driven facilitation within the peripersonal space is modulated by the expectations about stimulus location on the body. Sci Rep 2022; 12:20061. [PMID: 36414633 PMCID: PMC9681840 DOI: 10.1038/s41598-022-21469-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/27/2022] [Indexed: 11/24/2022] Open
Abstract
Compelling evidence from human and non-human studies suggests that responses to multisensory events are fastened when stimuli occur within the space surrounding the bodily self (i.e., peripersonal space; PPS). However, some human studies did not find such effect. We propose that these dissonant voices might actually uncover a specific mechanism, modulating PPS boundaries according to sensory regularities. We exploited a visuo-tactile paradigm, wherein participants provided speeded responses to tactile stimuli and rated their perceived intensity while ignoring simultaneous visual stimuli, appearing near the stimulated hand (VTNear) or far from it (VTFar; near the non-stimulated hand). Tactile stimuli could be delivered only to one hand (unilateral task) or to both hands randomly (bilateral task). Results revealed that a space-dependent multisensory enhancement (i.e., faster responses and higher perceived intensity in VTNear than VTFar) was present when highly predictable tactile stimulation induced PPS to be circumscribed around the stimulated hand (unilateral task). Conversely, when stimulus location was unpredictable (bilateral task), participants showed a comparable multisensory enhancement in both bimodal conditions, suggesting a PPS widening to include both hands. We propose that the detection of environmental regularities actively shapes PPS boundaries, thus optimizing the detection and reaction to incoming sensory stimuli.
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
Noel JP, Paredes R, Terrebonne E, Feldman JI, Woynaroski T, Cascio CJ, Seriès P, Wallace MT. Inflexible Updating of the Self-Other Divide During a Social Context in Autism: Psychophysical, Electrophysiological, and Neural Network Modeling Evidence. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2022; 7:756-764. [PMID: 33845169 PMCID: PMC8521572 DOI: 10.1016/j.bpsc.2021.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/08/2021] [Accepted: 03/29/2021] [Indexed: 01/21/2023]
Abstract
BACKGROUND Autism spectrum disorder (ASD) affects many aspects of life, from social interactions to (multi)sensory processing. Similarly, the condition expresses at a variety of levels of description, from genetics to neural circuits and interpersonal behavior. We attempt to bridge between domains and levels of description by detailing the behavioral, electrophysiological, and putative neural network basis of peripersonal space (PPS) updating in ASD during a social context, given that the encoding of this space relies on appropriate multisensory integration, is malleable by social context, and is thought to delineate the boundary between the self and others. METHODS Fifty (20 male/30 female) young adults, either diagnosed with ASD or age- and sex-matched individuals, took part in a visuotactile reaction time task indexing PPS, while high-density electroencephalography was continuously recorded. Neural network modeling was performed in silico. RESULTS Multisensory psychophysics demonstrates that while PPS in neurotypical individuals shrinks in the presence of others-as to "give space"-this does not occur in ASD. Likewise, electroencephalography recordings suggest that multisensory integration is altered by social context in neurotypical individuals but not in individuals with ASD. Finally, a biologically plausible neural network model shows, as a proof of principle, that PPS updating may be inflexible in ASD owing to the altered excitatory/inhibitory balance that characterizes neural circuits in animal models of ASD. CONCLUSIONS Findings are conceptually in line with recent statistical inference accounts, suggesting diminished flexibility in ASD, and further these observations by suggesting within an example relevant for social cognition that such inflexibility may be due to excitatory/inhibitory imbalances.
Collapse
Affiliation(s)
- Jean-Paul Noel
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee; Center for Neural Science, New York University, New York, New York.
| | - Renato Paredes
- Institute for Adaptive and Neural Computation, University of Edinburgh, Edinburgh, United Kingdom
| | - Emily Terrebonne
- Undergraduate Neuroscience Program, Vanderbilt University, Nashville, Tennessee; School of Medicine and Health Sciences, George Washington University, Washington, District of Columbia
| | - Jacob I Feldman
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee; Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Tiffany Woynaroski
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee; Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Carissa J Cascio
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee; Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Peggy Seriès
- Institute for Adaptive and Neural Computation, University of Edinburgh, Edinburgh, United Kingdom
| | - Mark T Wallace
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, Tennessee; Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, Tennessee; Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, Tennessee
| |
Collapse
|
8
|
Ronga I, Galigani M, Bruno V, Castellani N, Rossi Sebastiano A, Valentini E, Fossataro C, Neppi-Modona M, Garbarini F. Seeming confines: Electrophysiological evidence of peripersonal space remapping following tool-use in humans. Cortex 2021; 144:133-150. [PMID: 34666298 DOI: 10.1016/j.cortex.2021.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 02/05/2021] [Accepted: 08/07/2021] [Indexed: 11/29/2022]
Abstract
The peripersonal space (PPS) is a special portion of space immediately surrounding the body, where the integration between tactile stimuli delivered on the body and auditory or visual events emanating from the environment occurs. Interestingly, PPS can widen if a tool is employed to interact with objects in the far space. However, electrophysiological evidence of such tool-use dependent plasticity in the human brain is scarce. Here, in a series of three experiments, participants were asked to respond to tactile stimuli, delivered to their right hand, either in isolation (unimodal condition) or combined with auditory stimulation, which could occur near (bimodal-near) or far from the stimulated hand (bimodal-far). According to multisensory integration spatial rule, when bimodal stimuli are presented at the same location, we expected a response enhancement (response time - RT - facilitation and event-related potential - ERP - super-additivity). In Experiment 1, we verified that RT facilitation was driven by bimodal input spatial congruency, independently from auditory stimulus intensity. In Experiment 2, we showed that our bimodal task was effective in eliciting the magnification of ERPs in bimodal conditions, with significantly larger responses in the near as compared to far condition. In Experiment 3 (main experiment), we explored tool-use driven PPS plasticity. Our audio-tactile task was performed either following tool-use (a 20-min reaching task, performed using a 145 cm-long rake) or after a control cognitive training (a 20-min visual discrimination task) performed in the far space. Following the control training, faster RTs and greater super-additive ERPs were found in bimodal-near as compared to bimodal-far condition (replicating Experiment 2 results). Crucially, this far-near differential response was significantly reduced after tool-use. Altogether our results indicate a selective effect of tool-use remapping in extending the boundaries of PPS. The present finding might be considered as an electrophysiological evidence of tool-use dependent plasticity in the human brain.
Collapse
Affiliation(s)
- Irene Ronga
- MANIBUS Research Group, Department of Psychology, University of Turin, Italy
| | - Mattia Galigani
- MANIBUS Research Group, Department of Psychology, University of Turin, Italy
| | - Valentina Bruno
- MANIBUS Research Group, Department of Psychology, University of Turin, Italy
| | - Nicolò Castellani
- MANIBUS Research Group, Department of Psychology, University of Turin, Italy; Molecular Mind Lab, IMT School for Advanced Studies, Lucca, Italy
| | | | - Elia Valentini
- Department of Psychology and Centre for Brain Science, University of Essex, UK
| | - Carlotta Fossataro
- MANIBUS Research Group, Department of Psychology, University of Turin, Italy
| | - Marco Neppi-Modona
- MANIBUS Research Group, Department of Psychology, University of Turin, Italy
| | - Francesca Garbarini
- MANIBUS Research Group, Department of Psychology, University of Turin, Italy.
| |
Collapse
|
9
|
Heine L, Corneyllie A, Gobert F, Luauté J, Lavandier M, Perrin F. Virtually spatialized sounds enhance auditory processing in healthy participants and patients with a disorder of consciousness. Sci Rep 2021; 11:13702. [PMID: 34211035 PMCID: PMC8249625 DOI: 10.1038/s41598-021-93151-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 06/22/2021] [Indexed: 11/14/2022] Open
Abstract
Neuroscientific and clinical studies on auditory perception often use headphones to limit sound interference. In these conditions, sounds are perceived as internalized because they lack the sound-attributes that normally occur with a sound produced from a point in space around the listener. Without the spatial attention mechanisms that occur with localized sounds, auditory functional assessments could thus be underestimated. We hypothesize that adding virtually externalization and localization cues to sounds through headphones enhance sound discrimination in both healthy participants and patients with a disorder of consciousness (DOC). Hd-EEG was analyzed in 14 healthy participants and 18 patients while they listened to self-relevant and irrelevant stimuli in two forms: diotic (classic sound presentation with an "internalized" feeling) and convolved with a binaural room impulse response (to create an "externalized" feeling). Convolution enhanced the brains' discriminative response as well as the processing of irrelevant sounds itself, in both healthy participants and DOC patients. For the healthy participants, these effects could be associated with enhanced activation of both the dorsal (where/how) and ventral (what) auditory streams, suggesting that spatial attributes support speech discrimination. Thus, virtually spatialized sounds might "call attention to the outside world" and improve the sensitivity of assessment of brain function in DOC patients.
Collapse
Affiliation(s)
- Lizette Heine
- Audition Cognition and Psychoacoustics Team, Lyon Neuroscience Research Center, UCBL, INSERM U1028, CNRS UMR5292, Centre Hospitalier Le Vinatier, Bâtiment 462, Neurocampus Michel Jouvet, 95 Boulevard Pinel, Bron Cedex, 69675, Lyon, France
- Laboratoire de Tribologie et Dynamique des Systèmes UMR 5513, ENTPE, University of Lyon, Rue Maurice Audin, 69518, Vaulx-en-Velin Cedex, France
| | - Alexandra Corneyllie
- Audition Cognition and Psychoacoustics Team, Lyon Neuroscience Research Center, UCBL, INSERM U1028, CNRS UMR5292, Centre Hospitalier Le Vinatier, Bâtiment 462, Neurocampus Michel Jouvet, 95 Boulevard Pinel, Bron Cedex, 69675, Lyon, France
| | - Florent Gobert
- Audition Cognition and Psychoacoustics Team, Lyon Neuroscience Research Center, UCBL, INSERM U1028, CNRS UMR5292, Centre Hospitalier Le Vinatier, Bâtiment 462, Neurocampus Michel Jouvet, 95 Boulevard Pinel, Bron Cedex, 69675, Lyon, France
- Trajectoires Team, Lyon Neuroscience Research Center, UCBL, INSERM U1028, CNRS UMR5292, Centre Hospitalier Le Vinatier, Lyon, France
| | - Jacques Luauté
- Service de Médecine Physique et de Réadaptation, Rééducation Neurologique, Hôpital Henry-Gabrielle, CHU de Lyon, 69230, Saint-Genis-Laval, France
- Trajectoires Team, Lyon Neuroscience Research Center, UCBL, INSERM U1028, CNRS UMR5292, Centre Hospitalier Le Vinatier, Lyon, France
| | - Mathieu Lavandier
- Laboratoire de Tribologie et Dynamique des Systèmes UMR 5513, ENTPE, University of Lyon, Rue Maurice Audin, 69518, Vaulx-en-Velin Cedex, France
| | - Fabien Perrin
- Audition Cognition and Psychoacoustics Team, Lyon Neuroscience Research Center, UCBL, INSERM U1028, CNRS UMR5292, Centre Hospitalier Le Vinatier, Bâtiment 462, Neurocampus Michel Jouvet, 95 Boulevard Pinel, Bron Cedex, 69675, Lyon, France.
| |
Collapse
|
10
|
Garipelli G, Rossy T, Perez-Marcos D, Jöhr J, Diserens K. Movement-Related Cortical Potentials in Embodied Virtual Mirror Visual Feedback. Front Neurol 2021; 12:646886. [PMID: 34211428 PMCID: PMC8239222 DOI: 10.3389/fneur.2021.646886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 05/14/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Mirror therapy is thought to drive interhemispheric communication, resulting in a balanced activation. We hypothesized that embodied virtual mirror visual feedback (VR-MVF) presented on a computer screen may produce a similar activation. In this proof-of-concept study, we investigated differences in movement-related cortical potentials (MRCPs) in the electroencephalogram (EEG) from different visual feedback of user movements in 1 stroke patient and 13 age-matched adults. Methods: A 60-year-old right-handed (Edinburgh score >95) male ischemic stroke [left paramedian pontine, National Institutes of Health Stroke Scale (NIHSS) = 6] patient and 13 age-matched right-handed (Edinburgh score >80) healthy adults (58 ± 9 years; six female) participated in the study. We recorded 16-electrode electroencephalogram (EEG), while participants performed planar center-out movements in two embodied visual feedback conditions: (i) direct (movements translated to the avatar's ipsilateral side) and (ii) mirror (movements translated to the avatar's contralateral side) with left (direct left/mirror left) or right (direct right/mirror right) arms. Results: As hypothesized, we observed more balanced MRCP hemispheric negativity in the mirror right compared to the direct right condition [statistically significant at the FC4 electrode; 99.9% CI, (0.81, 13)]. MRCPs in the stroke participant showed reduced lateralized negativity in the direct left (non-paretic) situation compared to healthy participants. Interestingly, the potentials were stronger in the mirror left (non-paretic) compared to direct left case, with significantly more bilateral negativity at FC3 [95% CI (0.758 13.2)] and C2 [95% CI (0.04 9.52)]. Conclusions: Embodied mirror visual feedback is likely to influence bilateral sensorimotor cortical subthreshold activity during movement preparation and execution observed in MRCPs in both healthy participants and a stroke patient.
Collapse
Affiliation(s)
| | - Tamara Rossy
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | - Jane Jöhr
- Acute Neurorehabilitation Unit, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Karin Diserens
- Acute Neurorehabilitation Unit, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| |
Collapse
|
11
|
Aloi D, della Rocchetta AI, Ditchfield A, Coulborn S, Fernández-Espejo D. Therapeutic Use of Transcranial Direct Current Stimulation in the Rehabilitation of Prolonged Disorders of Consciousness. Front Neurol 2021; 12:632572. [PMID: 33897592 PMCID: PMC8058460 DOI: 10.3389/fneur.2021.632572] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 03/09/2021] [Indexed: 12/20/2022] Open
Abstract
Patients with Prolonged Disorders of Consciousness (PDOC) have catastrophic disabilities and very complex needs for care. Therapeutic options are very limited, and patients often show little functional improvement over time. Neuroimaging studies have demonstrated that a significant number of PDOC patients retain a high level of cognitive functioning, and in some cases even awareness, and are simply unable to show this with their external behavior - a condition known as cognitive-motor dissociation (CMD). Despite vast implications for diagnosis, the discovery of covert cognition in PDOC patients is not typically associated with a more favorable prognosis, and the majority of patients will remain in a permanent state of low responsiveness. Recently, transcranial direct current stimulation (tDCS) has attracted attention as a potential therapeutic tool in PDOC. Research to date suggests that tDCS can lead to clinical improvements in patients with a minimally conscious state (MCS), especially when administered over multiple sessions. While promising, the outcomes of these studies have been highly inconsistent, partially due to small sample sizes, heterogeneous methodologies (in terms of both tDCS parameters and outcome measures), and limitations related to electrode placement and heterogeneity of brain damage inherent to PDOC. In addition, we argue that neuroimaging and electrophysiological assessments may serve as more sensitive biomarkers to identify changes after tDCS that are not yet apparent behaviorally. Finally, given the evidence that concurrent brain stimulation and physical therapy can enhance motor rehabilitation, we argue that future studies should focus on the integration of tDCS with conventional rehabilitation programmes from the subacute phase of care onwards, to ascertain whether any synergies exist.
Collapse
Affiliation(s)
- Davide Aloi
- School of Psychology, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
| | | | - Alice Ditchfield
- School of Psychology, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
| | - Sean Coulborn
- School of Psychology, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
| | - Davinia Fernández-Espejo
- School of Psychology, University of Birmingham, Birmingham, United Kingdom
- Centre for Human Brain Health, University of Birmingham, Birmingham, United Kingdom
| |
Collapse
|
12
|
Masson C, van der Westhuizen D, Noel JP, Prevost A, van Honk J, Fotopoulou A, Solms M, Serino A. Testosterone administration in women increases the size of their peripersonal space. Exp Brain Res 2021; 239:1639-1649. [PMID: 33770219 DOI: 10.1007/s00221-021-06080-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 03/08/2021] [Indexed: 01/08/2023]
Abstract
Peripersonal space (PPS) is the space immediately surrounding the body, conceptualised as a sensory-motor interface between body and environment. PPS size differs between individuals and contexts, with intrapersonal traits and states, as well as social factors having a determining role on the size of PPS. Testosterone plays an important role in regulating social-motivational behaviour and is known to enhance dominance motivation in an implicit and unconscious manner. We investigated whether the dominance-enhancing effects of testosterone reflect as changes in the representation of PPS in a within-subjects testosterone administration study in women (N = 19). Participants performed a visuo-tactile integration task in a mixed-reality setup. Results indicated that the administration of testosterone caused a significant enlargement of participants' PPS, suggesting that testosterone caused participants to implicitly appropriate a larger space as their own. These findings suggest that the dominance-enhancing effects of testosterone reflect at the level of sensory-motor processing in PPS.
Collapse
Affiliation(s)
| | | | - Jean-Paul Noel
- Center for Neural Science, New York University, New York, USA
| | | | - Jack van Honk
- University of Cape Town, Cape Town, South Africa.,Utrecht University, Utrecht, The Netherlands
| | | | - Mark Solms
- University of Cape Town, Cape Town, South Africa
| | - Andrea Serino
- MySpace Lab, Department of Clinical Neuroscience, Center Hospitalier Universitaire Vaudois (CHUV), University of Lausanne, Lausanne, Switzerland
| |
Collapse
|
13
|
Spatial tuning of electrophysiological responses to multisensory stimuli reveals a primitive coding of the body boundaries in newborns. Proc Natl Acad Sci U S A 2021; 118:2024548118. [PMID: 33798099 PMCID: PMC8000027 DOI: 10.1073/pnas.2024548118] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The ability to identify our own body and its boundaries is crucial for survival. Ideally, the sooner we learn to discriminate external stimuli occurring close to our body from those occurring far from it, the better (and safer) we may interact with the sensory environment. However, when this mechanism emerges within ontogeny is unknown. Is it something acquired throughout infancy, or is it already present soon after birth? The presence of a spatial modulation of multisensory integration (MSI) is considered a hallmark of a functioning representation of the body position in space. Here, we investigated whether MSI is present and spatially organized in 18- to 92-h-old newborns. We compared electrophysiological responses to tactile stimulation when concurrent auditory events were delivered close to, as opposed to far from, the body in healthy newborns and in a control group of adult participants. In accordance with previous studies, adult controls showed a clear spatial modulation of MSI, with greater superadditive responses for multisensory stimuli close to the body. In newborns, we demonstrated the presence of a genuine electrophysiological pattern of MSI, with older newborns showing a larger MSI effect. Importantly, as for adults, multisensory superadditive responses were modulated by the proximity to the body. This finding may represent the electrophysiological mechanism responsible for a primitive coding of bodily self boundaries, thus suggesting that even just a few hours after birth, human newborns identify their own body as a distinct entity from the environment.
Collapse
|
14
|
Pincherle A, Rossi F, Jöhr J, Dunet V, Ryvlin P, Oddo M, Schiff N, Diserens K. Early discrimination of cognitive motor dissociation from disorders of consciousness: pitfalls and clues. J Neurol 2021; 268:178-188. [PMID: 32754829 PMCID: PMC7815538 DOI: 10.1007/s00415-020-10125-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 07/22/2020] [Accepted: 07/27/2020] [Indexed: 01/02/2023]
Abstract
Bedside assessment of consciousness and awareness after a severe brain injury might be hampered by confounding clinical factors (i.e., pitfalls) interfering with the production of behavioral or motor responses to external stimuli. Despite the use of validated clinical scales, a high misdiagnosis rate is indeed observed. We retrospectively analyzed a cohort of 49 patients with severe brain injury admitted to an acute neuro-rehabilitation program. Patients' behavior was assessed using the Motor Behavior Tool and Coma Recovery Scale Revised. All patients underwent systematic assessment for pitfalls including polyneuropathy and/or myopathy and/or myelopathy, major cranial nerve palsies, non-convulsive status epilepticus, aphasia (expressive or comprehensive), cortical blindness, thalamic involvement and frontal akinetic syndrome. A high prevalence (75%) of pitfalls potentially interfering with sensory afference (polyneuropathy, myopathy, myelopathy, and sensory aphasia), motor efference (polyneuropathy, myopathy, motor aphasia, and frontal akinetic syndrome), and intrinsic brain activity (thalamic involvement and epilepsy) was found. Nonetheless, the motor behavior tool identified residual cognition (i.e. a cognitive motor dissociation condition) regardless of the presence of these pitfalls in 70% of the patients diagnosed as unresponsive using the Coma Recovery Scale Revised. On one hand, pitfalls might contribute to misdiagnosis. On the other, it could be argued that they are clues for diagnosing cognitive motor dissociation rather than true disorders of consciousness given their prominent effect on the sensory-motor input-output balance.
Collapse
Affiliation(s)
- Alessandro Pincherle
- Acute Neuro-rehabilitation Unit, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Bâtiment Champ de l'Air, Rue du Bugnon 21, 1011, Lausanne, Switzerland.
- Neurology Unit, Department of Medicine, Hopitaux Robert Schuman, Luxembourg, Luxembourg.
| | - Frederic Rossi
- Acute Neuro-rehabilitation Unit, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Bâtiment Champ de l'Air, Rue du Bugnon 21, 1011, Lausanne, Switzerland
| | - Jane Jöhr
- Acute Neuro-rehabilitation Unit, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Bâtiment Champ de l'Air, Rue du Bugnon 21, 1011, Lausanne, Switzerland
| | - Vincent Dunet
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Philippe Ryvlin
- Acute Neuro-rehabilitation Unit, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Bâtiment Champ de l'Air, Rue du Bugnon 21, 1011, Lausanne, Switzerland
| | - Mauro Oddo
- Intensive Care Unit, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Nicolas Schiff
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
| | - Karin Diserens
- Acute Neuro-rehabilitation Unit, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Bâtiment Champ de l'Air, Rue du Bugnon 21, 1011, Lausanne, Switzerland
| |
Collapse
|
15
|
Rabellino D, Frewen PA, McKinnon MC, Lanius RA. Peripersonal Space and Bodily Self-Consciousness: Implications for Psychological Trauma-Related Disorders. Front Neurosci 2020; 14:586605. [PMID: 33362457 PMCID: PMC7758430 DOI: 10.3389/fnins.2020.586605] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 11/10/2020] [Indexed: 11/24/2022] Open
Abstract
Peripersonal space (PPS) is defined as the space surrounding the body where we can reach or be reached by external entities, including objects or other individuals. PPS is an essential component of bodily self-consciousness that allows us to perform actions in the world (e.g., grasping and manipulating objects) and protect our body while interacting with the surrounding environment. Multisensory processing plays a critical role in PPS representation, facilitating not only to situate ourselves in space but also assisting in the localization of external entities at a close distance from our bodies. Such abilities appear especially crucial when an external entity (a sound, an object, or a person) is approaching us, thereby allowing the assessment of the salience of a potential incoming threat. Accordingly, PPS represents a key aspect of social cognitive processes operational when we interact with other people (for example, in a dynamic dyad). The underpinnings of PPS have been investigated largely in human models and in animals and include the operation of dedicated multimodal neurons (neurons that respond specifically to co-occurring stimuli from different perceptive modalities, e.g., auditory and tactile stimuli) within brain regions involved in sensorimotor processing (ventral intraparietal sulcus, ventral premotor cortex), interoception (insula), and visual recognition (lateral occipital cortex). Although the defensive role of the PPS has been observed in psychopathology (e.g., in phobias) the relation between PPS and altered states of bodily consciousness remains largely unexplored. Specifically, PPS representation in trauma-related disorders, where altered states of consciousness can involve dissociation from the body and its surroundings, have not been investigated. Accordingly, we review here: (1) the behavioral and neurobiological literature surrounding trauma-related disorders and its relevance to PPS; and (2) outline future research directions aimed at examining altered states of bodily self-consciousness in trauma related-disorders.
Collapse
Affiliation(s)
- Daniela Rabellino
- Department of Psychiatry, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| | - Paul A. Frewen
- Department of Psychiatry, Western University, London, ON, Canada
- Department of Psychology, Western University, London, ON, Canada
| | - Margaret C. McKinnon
- Mood Disorders Program, St. Joseph’s Healthcare, Hamilton, ON, Canada
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
- Homewood Research Institute, Guelph, ON, Canada
| | - Ruth A. Lanius
- Department of Psychiatry, Western University, London, ON, Canada
- Imaging Division, Lawson Health Research Institute, London, ON, Canada
| |
Collapse
|
16
|
Noel JP, Bertoni T, Terrebonne E, Pellencin E, Herbelin B, Cascio C, Blanke O, Magosso E, Wallace MT, Serino A. Rapid Recalibration of Peri-Personal Space: Psychophysical, Electrophysiological, and Neural Network Modeling Evidence. Cereb Cortex 2020; 30:5088-5106. [PMID: 32377673 PMCID: PMC7391419 DOI: 10.1093/cercor/bhaa103] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 12/20/2022] Open
Abstract
Interactions between individuals and the environment occur within the peri-personal space (PPS). The encoding of this space plastically adapts to bodily constraints and stimuli features. However, these remapping effects have not been demonstrated on an adaptive time-scale, trial-to-trial. Here, we test this idea first via a visuo-tactile reaction time (RT) paradigm in augmented reality where participants are asked to respond as fast as possible to touch, as visual objects approach them. Results demonstrate that RTs to touch are facilitated as a function of visual proximity, and the sigmoidal function describing this facilitation shifts closer to the body if the immediately precedent trial had indexed a smaller visuo-tactile disparity. Next, we derive the electroencephalographic correlates of PPS and demonstrate that this multisensory measure is equally shaped by recent sensory history. Finally, we demonstrate that a validated neural network model of PPS is able to account for the present results via a simple Hebbian plasticity rule. The present findings suggest that PPS encoding remaps on a very rapid time-scale and, more generally, that it is sensitive to sensory history, a key feature for any process contextualizing subsequent incoming sensory information (e.g., a Bayesian prior).
Collapse
Affiliation(s)
- Jean-Paul Noel
- Neuroscience Graduate Program, Vanderbilt Brain Institute, Vanderbilt University Medical School, Vanderbilt University, Nashville, TN 37235, USA
- Vanderbilt Brain Institute, Vanderbilt University Medical School, Vanderbilt University, Nashville, TN 37235, USA
- Center for Neural Science, New York University, New York City, NY 10003, USA
| | - Tommaso Bertoni
- MySpace Lab, Department of Clinical Neurosciences, University Hospital of Lausanne, University of Lausanne, Lausanne CH-1011, Switzerland
| | - Emily Terrebonne
- Vanderbilt Brain Institute, Vanderbilt University Medical School, Vanderbilt University, Nashville, TN 37235, USA
| | - Elisa Pellencin
- Department of Psychology and Cognitive Science, University of Trento, Rovereto, Trento 38068, Italy
| | - Bruno Herbelin
- Laboratory of Cognitive Neuroscience, Brain Mind Institute, Ecole Polytechnique Federale de Lausanne, Lausanne CH-1015, Switzerland
- Center for Neuroprosthetics, Campus BioTech, Geneva CH-1202, Switzerland
| | - Carissa Cascio
- Vanderbilt Brain Institute, Vanderbilt University Medical School, Vanderbilt University, Nashville, TN 37235, USA
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medial Center, Nashville, TN 37235, USA
| | - Olaf Blanke
- Laboratory of Cognitive Neuroscience, Brain Mind Institute, Ecole Polytechnique Federale de Lausanne, Lausanne CH-1015, Switzerland
- Center for Neuroprosthetics, Campus BioTech, Geneva CH-1202, Switzerland
| | - Elisa Magosso
- Department of Electrical, Electronic, and Information Engineering ``Guglielmo Marconi'', University of Bologna, Cesena 40126, Italy
| | - Mark T Wallace
- Vanderbilt Brain Institute, Vanderbilt University Medical School, Vanderbilt University, Nashville, TN 37235, USA
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medial Center, Nashville, TN 37235, USA
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN 37235, USA
- Department of Psychology, Vanderbilt University, Nashville, TN 37235, USA
| | - Andrea Serino
- MySpace Lab, Department of Clinical Neurosciences, University Hospital of Lausanne, University of Lausanne, Lausanne CH-1011, Switzerland
| |
Collapse
|
17
|
Møller MLH, Højlund A, Jensen M, Gansonre C, Shtyrov Y. Applied potential of task-free event-related paradigms for assessing neurocognitive functions in disorders of consciousness. Brain Commun 2020; 2:fcaa087. [PMID: 33134912 PMCID: PMC7585695 DOI: 10.1093/braincomms/fcaa087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 04/21/2020] [Accepted: 04/29/2020] [Indexed: 12/17/2022] Open
Abstract
Diagnosing patients with disorders of consciousness is immensely difficult and often results in misdiagnoses, which can have fatal consequences. Despite the severity of this well-known issue, a reliable assessment tool has not yet been developed and implemented in the clinic. The main aim of this focused review is to evaluate the various event-related potential paradigms, recorded using EEG, which may be used to improve the assessment of patients with disorders of consciousness; we also provide a brief comparison of these paradigms with other measures. Notably, most event-related potential studies on the topic have focused on testing a small set of components, or even just a single component. However, to be of practical use, we argue that an assessment should probe a range of cognitive and linguistic functions at once. We suggest a novel approach that combines a set of well-tested auditory event-related potential components: N100, mismatch negativity, P3a, N400, early left anterior negativity and lexical response enhancement. Combining these components in a single, task-free design will provide a multidimensional assessment of cognitive and linguistic processes, which may help physicians make a more precise diagnosis.
Collapse
Affiliation(s)
- Marie Louise Holm Møller
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Andreas Højlund
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Mads Jensen
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Christelle Gansonre
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Yury Shtyrov
- Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
18
|
Immersive virtual reality reveals that visuo-proprioceptive discrepancy enlarges the hand-centred peripersonal space. Neuropsychologia 2020; 146:107540. [PMID: 32593721 DOI: 10.1016/j.neuropsychologia.2020.107540] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/11/2020] [Accepted: 06/19/2020] [Indexed: 12/23/2022]
Abstract
Vision and proprioception, informing the system about the body position in space, seem crucial in defining the boundary of the peripersonal space (PPS). What happens to the PPS representation when a conflict between vision and proprioception arises? We capitalize on the Immersive Virtual Reality to dissociate vision and proprioception by presenting the participants' 3D hand image in congruent/incongruent positions with respect to the participants' real hand. To measure the hand-centred PPS, we exploit multisensory integration occurring when visual stimuli are delivered simultaneously with tactile stimuli applied to a body district; i.e., visual enhancement of touch (VET). Participants are instructed to respond to tactile stimuli while ignoring visual stimuli (red LED), which can appear either near to or far from the hand receiving tactile (electrical) stimuli. The results show that, when vision and proprioception are congruent (i.e., real and virtual hand coincide), a space-dependent modulation of the VET effect occurs (with faster responses when visual stimuli are near to than far from the stimulated hand). Contrarily, when vision and proprioception are incongruent (i.e., a discrepancy between real and virtual hand is present), a comparable VET effect is observed when visual stimuli occur near to the real hand and when they occur far from it, but close to the virtual hand. These findings, also confirmed by the independent estimate of a Bayesian Causal Inference model, suggest that, when the visuo-proprioceptive discrepancy makes the coding of the hand position less precise, the hand-centred PPS is enlarged, likely to optimize reactions to external events.
Collapse
|
19
|
Calabrò RS, Chillura A, Billeri L, Cannavò A, Buda A, Molonia F, Manuli A, Bramanti P, Naro A. Peri-Personal Space Tracing by Hand-Blink Reflex Modulation in Patients with Chronic Disorders of Consciousness. Sci Rep 2020; 10:1712. [PMID: 32015445 PMCID: PMC6997168 DOI: 10.1038/s41598-020-58625-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 01/17/2020] [Indexed: 12/14/2022] Open
Abstract
The assessment of awareness in patients with chronic Disorders of Consciousness (DoC), including Unresponsive Wakefulness Syndrome (UWS) and Minimally Conscious State (MCS), is challenging. The level of awareness impairment may depend on the degree of deterioration of the large-scale cortical-thalamo-cortical networks induced by brain injury. Electrophysiological approaches may shed light on awareness presence in patients with DoC by estimating cortical functions related to the cortical-thalamo-cortical networks including, for example, the cortico-subcortical processes generating motor responses to the perturbation of the peri-personal space (PPS). We measured the amplitude, latency, and duration of the hand-blink reflex (HBR) responses by recording electromyography (EMG) signals from both the orbicularis oculi muscles while electrically stimulating the median nerve at the wrist. Such a BR is thought to be mediated by a neural circuit at the brainstem level. Despite its defensive-response nature, HBR can be modulated by the distance between the stimulated hand and the face. This suggests a functional top-down control of HBR as reflected by HBR features changes (latency, amplitude, and magnitude). We therefore estimated HBR responses in a sample of patients with DoC (8 MCS and 12 UWS, compared to 15 healthy controls -HC) while performing a motor task targeting the PPS. This consisted of passive movements in which the hand of the subject was positioned at different distances from the participant's face. We aimed at demonstrating a residual top-down modulation of HBR properties, which could be useful to differentiate patients with DoC and, potentially, demonstrate awareness preservation. We found a decrease in latency, and an increase in duration and magnitude of HBR responses, which were all inversely related to the hand-to-face distance in HC and patients with MCS, but not in individuals with UWS. Our data suggest that only patients with MCS have preserved, residual, top-down modulation of the processes related to the PPS from higher-order cortical areas to sensory-motor integration network. Although the sample size was relatively small, being thus our data preliminary, HBR assessment seems a rapid, easy, and first-level tool to differentiate patients with MCS from those with UWS. We may also hypothesize that such a HBR modulation suggests awareness preservation.
Collapse
Affiliation(s)
| | | | - Luana Billeri
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | | | - Antonio Buda
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | | | | | | | - Antonino Naro
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| |
Collapse
|