Publications by Hyeongdong Park

Breathing affects self-other voice discrimination in a bodily state associated with somatic passivity

Olaf Blanke, Nathan Quentin Faivre, Pavo Orepic, Hyeongdong Park, Giulio Rognini

A growing number of studies have focused on identifying cognitive processes that are modulated by interoceptive signals, particularly in relation to the respiratory or cardiac cycle. Considering the fundamental role of interoception in bodily self-consciousness, we here investigated whether interoceptive signals also impact self-voice perception. We applied an interactive, robotic paradigm associated with somatic passivity (a bodily state characterized by illusory misattribution of self-generated touches to someone else) to investigate whether somatic passivity impacts self-voice perception as a function of concurrent interoceptive signals. Participants' breathing and heartbeat signals were recorded while they performed two self-voice tasks (self-other voice discrimination and loudness perception) and while simultaneously experiencing two robotic conditions (somatic passivity condition; control condition). Our data reveal that respiration, but not cardiac activity, affects self-voice perception: participants were better at discriminating self-voice from another person's voice during the inspiration phase of the respiration cycle. Moreover, breathing effects were prominent in participants experiencing somatic passivity and a different task with the same stimuli (i.e., judging the loudness and not identity of the voices) was unaffected by breathing. Combining interoception and voice perception with self-monitoring framework, these data extend findings on breathing-dependent changes in perception and cognition to self-related processing.

WILEY2022

Breathing is coupled with voluntary initiation of mental imagery

Olaf Blanke, Oliver Alan Kannape, Hyeongdong Park

Previous research has suggested that bodily signals from internal organs are associated with diverse cortical and subcortical processes involved in sensory-motor functions, beyond homeostatic reflexes. For instance, a recent study demonstrated that the preparation and execution of voluntary actions, as well as its underlying neural activity, are coupled with the breathing cycle. In the current study, we investigated whether such breathing-action coupling is limited to voluntary motor action or whether it is also present for mental actions not involving any overt bodily movement. To answer this question, we recorded electroencephalography (EEG), electromyography (EMG), and respiratory signals while participants were conducting a voluntary action paradigm including self-initiated motor execution (ME), motor imagery (MI), and visual imagery (VI) tasks. We observed that the voluntary initiation of ME, MI, and VI are similarly coupled with the respiration phase. In addition, EEG analysis revealed the existence of readiness potential (RP) waveforms in all three tasks (i.e., ME, MI, VI), as well as a coupling between the RP amplitude and the respiratory phase. Our findings show that the voluntary initiation of both imagined and overt action is coupled with respiration, and further suggest that the breathing system is involved in preparatory processes of voluntary action by contributing to the temporal decision of when to initiate the action plan, regardless of whether this culminates in overt movements.

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Sense of self impacts spatial navigation and hexadirectional coding in human entorhinal cortex

Olaf Blanke, Nathan Quentin Faivre, Baptiste Gauthier, Hyukjun Moon, Hyeongdong Park

Grid cells in entorhinal cortex (EC) encode an individual’s location in space and rely on environmental cues and self-motion cues derived from the individual’s body. Body-derived signals are also primary signals for the sense of self and based on integrated sensorimotor signals (proprioceptive, tactile, visual, motor) that have been shown to enhance self-centered processing. However, it is currently unknown whether such sensorimotor signals that modulate self-centered processing impact grid cells and spatial navigation. Integrating the online manipulation of bodily signals, to modulate self-centered processing, with a spatial navigation task and an fMRI measure to detect grid cell-like representation (GCLR) in humans, we report improved performance in spatial navigation and decreased GCLR in EC. This decrease in entorhinal GCLR was associated with an increase in retrosplenial cortex activity, which was correlated with participants’ navigation performance. These data link self-centered processes during spatial navigation to entorhinal and retrosplenial activity and highlight the role of different bodily factors at play when navigating in VR.

2022

The perspectives of mapping and monitoring of the sense of self in neurosurgical patients

Sixto Luis Alcoba Banqueri, Sophie Jacqueline Andrée Betka, Olaf Blanke, Bruno Herbelin, Giannina Rita Iannotti, Pavo Orepic, Hyeongdong Park

Surgical treatment of tumors, epileptic foci or of vascular origin, requires a detailed individual pre-surgical workup and intra-operative surveillance of brain functions to minimize the risk of post-surgical neurological deficits and decline of quality of life. Most attention is attributed to language, motor functions, and perception. However, higher cognitive functions such as social cognition, personality, and the sense of self may be affected by brain surgery. To date, the precise localization and the network patterns of brain regions involved in such functions are not yet fully understood, making the assessment of risks of related post-surgical deficits difficult. It is in the interest of neurosurgeons to understand with which neural systems related to selfhood and personality they are interfering during surgery. Recent neuroscience research using virtual reality and clinical observations suggest that the insular cortex, medial prefrontal cortex, and temporo-parietal junction are important components of a neural system dedicated to self-consciousness based on multisensory bodily processing, including exteroceptive and interoceptive cues (bodily self-consciousness (BSC)). Here, we argue that combined extra- and intra-operative approaches using targeted cognitive testing, functional imaging and EEG, virtual reality, combined with multisensory stimulations, may contribute to the assessment of the BSC and related cognitive aspects. Although the usefulness of particular biomarkers, such as cardiac and respiratory signals linked to virtual reality, and of heartbeat evoked potentials as a surrogate marker for intactness of multisensory integration for intra-operative monitoring has to be proved, systemic and automatized testing of BSC in neurosurgical patients will improve future surgical outcome.

SPRINGER WIEN2021

Behavioral and neurophysiological evidence for altered interoceptive bodily processing in chronic pain

Fosco Bernasconi, Olaf Blanke, Hyeongdong Park, Marco Solcà

Whereas impaired multisensory processing of bodily stimuli and distorted body representation are well-established in various chronic pain disorders, such research has focused on exteroceptive bodily cues and neglected bodily signals from the inside of the body (or interoceptive signals). Extending existing basic and clinical research, we investigated for the first time interoception and its neurophysiological correlates in patients with complex regional pain syndrome (CRPS). In three different experiments, including a total of 36 patients with CRPS and 42 aged-gender matched healthy controls, we measured interoceptive sensitivity (heart beat counting task, HBC) and neural responses to heartbeats (heartbeat evoked potentials, HEP). As hypothesized, we observed reduced sensitivity in perceiving interoceptive bodily stimuli, i.e. their heartbeat, in two independent samples of CRPS patients (studies 1 and 2). Moreover, the cortical processing of their heartbeat, i.e. the HEP, was reduced compared to controls (study 3) and reduced interoceptive sensitivity and HEPs were related to CRPS patients’ motor impairment and pain duration. By providing consistent evidence for impaired processing of interoceptive bodily cues in CRPS, this study shows that the perceptual changes occurring in chronic pain include signals originating from the visceral organs, suggesting changes in the neural body representation, that includes next to exteroceptive, also interoceptive bodily signals. By showing that impaired interoceptive processing is associated with clinical symptoms, our findings also encourage the use of interoceptive-related information in future rehabilitation for chronic pain.

2020

Breathing affect self-other voice discrimination in a bodily state with increased otherness

Olaf Blanke, Nathan Quentin Faivre, Pavo Orepic, Hyeongdong Park, Giulio Rognini

A growing number of studies have focused on identifying cognitive processes that are modulated by interoceptive signals. Here we investigated whether interoception affects self-processing, by assessing changes in self-voice perception as a function of respiratory and cardiac cycles. Considering the fundamental role interoception plays in bodily self-consciousness, we additionally applied conflicting sensorimotor stimulation inducing a state characterized by a loss of self and increased otherness, and investigated its effects in self-other voice perception. Our data reveal that breathing, but not heartbeat, affects self-voice perception, by showing that participants (N = 30) discriminated self-voice from other voices better during inspiration, while being in the state of increased otherness and especially when hearing voices of other people. Loudness judgement of equivalent self-related stimuli was unaffected by breathing. Combining interoception and voice perception with self-monitoring framework, these data extend recent findings on breathing-dependent cognition to self-processing.

2020

Breathing is coupled with voluntary action and the cortical readiness potential

Coline Barnoud, Olaf Blanke, Oliver Alan Kannape, Hyeongdong Park, Henri Dan Trang

Voluntary action is a fundamental element of self-consciousness. The readiness potential (RP), a slow drift of neural activity preceding self-initiated movement, has been suggested to reflect neural processes underlying the preparation of voluntary action; yet more than fifty years after its introduction, interpretation of the RP remains controversial. Based on previous research showing that internal bodily signals affect sensory processing and ongoing neural activity, we here investigated the potential role of interoceptive signals in voluntary action and the RP. We report that (1) participants initiate voluntary actions more frequently during expiration, (2) this respiration-action coupling is absent during externally triggered actions, and (3) the RP amplitude is modulated depending on the respiratory phase. Our findings demonstrate that voluntary action is coupled with the respiratory system and further suggest that the RP is associated with fluctuations of ongoing neural activity that are driven by the involuntary and cyclic motor act of breathing.

2020

Coupling Inner and Outer Body for Self-Consciousness

Olaf Blanke, Hyeongdong Park

Although recent studies on self-consciousness emphasized the importance of bodily processing and multisensory integration, such research has focused solely on bodily signals originating from the outside of the body (i.e., exteroceptive bodily signals) or internal bodily signals from visceral organs (i.e., interoceptive bodily signals) and how each system contributes to self-consciousness, without much interaction between the two approaches. Reviewing the latest evidence on interoceptive bodily processing and the combination of exteroceptive and interoceptive bodily signals for self-consciousness, we propose an integrated neural system reconciling these two largely separated views and delineate how it accounts for fundamental aspects of self-consciousness such as self-identification and self-location, as well as its experienced global unity and temporal continuity.

2019

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The heart continuously and cyclically communicates with the brain. Beyond homeostatic regulation and sensing, recent neuroscience research has started to shed light on brain-heart interactions in diverse cognitive and emotional processes. In particular, neural responses to heartbeats, as measured with the so-called heartbeat-evoked potential, have been shown to be useful for investigating cortical activity processing cardiac signals. In this review, we first overview and discuss the basic properties of the HEP such as underlying physiological pathways, brain regions, and neural mechanisms. We then provide a systematic review of the mental processes associated with cortical HEP activations, notably heartbeat perception, emotional feelings, perceptual awareness, and self-consciousness, in healthy subjects and clinical populations. Finally, we discuss methodological issues regarding the experimental design and data analyses for separating genuine HEP components from physiological artifacts (e.g., cardiac field artifact, pulse artifact) or other neural activities that are not specifically associated with the heartbeat. Findings from this review suggest that when intrinsic limitations (e.g., artifacts) are carefully controlled, the HEP could provide a reliable neural measure for investigating the brain-viscera interactions in diverse mental processes.

2019

Increased heartbeat-evoked potential during REM sleep in nightmare disorder

Olaf Blanke, Hyeongdong Park

2019