The Sense of Touch: Embodied Simulation in a Visuotactile Mirroring Mechanism for Observed Animate or Inanimate Touch

2008 ◽  
Vol 20 (9) ◽  
pp. 1611-1623 ◽  
Author(s):  
Sjoerd J. H. Ebisch ◽  
Mauro G. Perrucci ◽  
Antonio Ferretti ◽  
Cosimo Del Gratta ◽  
Gian Luca Romani ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Precentral Gyrus ◽  
Video Clips ◽  
Secondary Somatosensory Cortex ◽  
Somatosensory Cortices ◽  
Significant Difference ◽  
Human Tendency ◽  
Abstract Notion ◽  
Sense Of Touch ◽  
Healthy Participants

Previous studies have shown a shared neural circuitry in the somatosensory cortices for the experience of one's own body being touched and the sight of intentional touch. Using functional magnetic resonance imaging (fMRI), the present study aimed to elucidate whether the activation of a visuotactile mirroring mechanism during touch observation applies to the sight of any touch, that is, whether it is independent of the intentionality of observed touching agent. During fMRI scanning, healthy participants viewed video clips depicting a touch that was intentional or accidental, and occurring between animate or inanimate objects. Analyses showed equal overlapping activation for all the touch observation conditions and the experience of one's own body being touched in the bilateral secondary somatosensory cortex (SII), left inferior parietal lobule (IPL)/supramarginal gyrus, bilateral temporal-occipital junction, and left precentral gyrus. A significant difference between the sight of an intentional touch, compared to an accidental touch, was found in the left primary somatosensory cortex (SI/Brodmann's area [BA] 2). Interestingly, activation in SI/BA 2 significantly correlated with the degree of intentionality of the observed touch stimuli as rated by participants. Our findings show that activation of a visuotactile mirroring mechanism for touch observation might underpin an abstract notion of touch, whereas activation in SI might reflect a human tendency to “resonate” more with a present or assumed intentional touching agent.

Effects of looming and static sounds on somatosensory processing: A MEG study

2012 ◽  
Vol 25 (0) ◽  
pp. 94
Author(s):  
Elisa Leonardelli ◽  
Valeria Occelli ◽  
Gianpaolo Demarchi ◽  
Massimo Grassi ◽  
Christoph Braun ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Time Window ◽  
The Body ◽  
Head Model ◽  
Somatosensory Processing ◽  
Global Field Power ◽  
Secondary Somatosensory Cortex ◽  
Head Space ◽  
Extrapersonal Space ◽  
Significant Difference

The present study aims to assess the mechanisms involved in the processing of potentially threatening stimuli presented within the peri-head space of humans. Magnetic fields evoked by air-puffs presented at the peri-oral area of fifteen participants were recorded by using magnetoencephalography (MEG). Crucially, each air puff was preceded by a sound, which could be either perceived as looming, stationary and close to the body (i.e., within the peri-head space) or stationary and far from the body (i.e., extrapersonal space). The comparison of the time courses of the global field power (GFP) indicated a significant difference in the time window ranging from 70 to 170 ms between the conditions. When the air puff was preceded by a stationary sound located far from the head stronger somatosensory activity was evoked as compared to the conditions where the sounds were located close to the head. No difference could be shown for the looming and the stationary prime stimulus close to the head. Source localization was performed assuming a pair of symmetric dipoles in a spherical head model that was fitted to the MRI images of the individual participants. Results showed sources in primary and secondary somatosensory cortex. Source activities in secondary somatosensory cortex differed between the three conditions, with larger effects evoked by the looming sounds and smaller effects evoked by the far stationary sounds, and the close stationary sounds evoking intermediate effects. Overall, these findings suggest the existence of a system involved in the detection of approaching objects and protecting the body from collisions in humans.

scholarly journals Ipsilateral stimulus encoding in primary and secondary somatosensory cortex of awake mice

2021 ◽  
Author(s):  
Aurélie Pala ◽  
Garrett B Stanley
Keyword(s):  
Somatosensory Cortex ◽  
The Body ◽  
Mammalian Brain ◽  
Equal Proportion ◽  
Somatosensory Processing ◽  
Secondary Somatosensory Cortex ◽  
Tactile Stimuli ◽  
Somatosensory Cortices ◽  
Stimulus Responsive ◽  
Layer 4

Lateralization is a hallmark of somatosensory processing in the mammalian brain. However, in addition to their contralateral representation, unilateral tactile stimuli also modulate neuronal activity in somatosensory cortices of the ipsilateral hemisphere. The cellular organization and functional role of these ipsilateral stimulus responses in awake somatosensory cortices, especially regarding stimulus coding, are unknown. Here, we targeted silicon probe recordings to the vibrissa region of primary (S1) and secondary (S2) somatosensory cortex of awake head-fixed male and female mice while delivering ipsilateral and contralateral whisker stimuli. Ipsilateral stimuli drove larger and more reliable responses in S2 than in S1, and activated a larger fraction of stimulus-responsive neurons. Ipsilateral stimulus-responsive neurons were rare in layer 4 of S1, but were located in equal proportion across all layers in S2. Linear classifier analyses further revealed that decoding of the ipsilateral stimulus was more accurate in S2 than S1, while S1 decoded contralateral stimuli most accurately. These results reveal substantial encoding of ipsilateral stimuli in S1 and especially S2, consistent with the hypothesis that higher cortical areas may integrate tactile inputs across larger portions of space, spanning both sides of the body.

Somatotopy in Human Primary Somatosensory Cortex in Pain System

2005 ◽  
Vol 103 (4) ◽  
pp. 821-827 ◽  
Author(s):  
Yuichi Ogino ◽  
Hidenori Nemoto ◽  
Fumio Goto
Keyword(s):  
Somatosensory Cortex ◽  
Pain Perception ◽  
Primary Somatosensory Cortex ◽  
Supporting Evidence ◽  
Nociceptive Neurons ◽  
Secondary Somatosensory Cortex ◽  
Significant Difference ◽  
Postcentral Gyrus ◽  
Somatotopical Organization ◽  
Tactile System

Background Compared with somatotopical organization (somatotopy) in the postcentral gyrus in the tactile system, somatotopy in the pain system is not well understood. The aim of this study is to elucidate whether there is somatotopy in the human pain system. Methods To elucidate the somatotopy of nociceptive neurons in the postcentral gyrus, the authors recorded pain-evoked cortical responses to noxious intraepidermal electrical stimulation applied to the left hand and left foot in 11 male subjects, using magnetoencephalography. Results Brief painful stimuli evoked sustained cortical activity in the primary somatosensory cortex (SI) in the hemisphere contralateral to the stimulated side and in the secondary somatosensory cortex in both hemispheres. In SI, representations of the hand and foot were distinctly separated, with a more medial and posterior location for the foot, whereas no significant difference was found in the locations for the secondary somatosensory cortex dipole. The SI arrangement along the central sulcus was compatible with the homunculus revealed by Penfield using direct cortical stimulation during surgery. Conclusions The human pain system contains a somatotopical representation in SI but with less somatotopical organization in the secondary somatosensory cortex. The current results provide supporting evidence of SI involvement in human pain perception and suggest that human SI subserves the localization of the stimulated site in nociceptive processing.

scholarly journals Dispositional empathy predicts primary somatosensory cortex activity while receiving touch by a hand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael Schaefer ◽  
Anja Kühnel ◽  
Franziska Rumpel ◽  
Matti Gärtner
Keyword(s):  
Somatosensory Cortex ◽  
Anterior Cingulate ◽  
Primary Somatosensory Cortex ◽  
Rubber Hand ◽  
Somatosensory Cortices ◽  
Touch Perception ◽  
Trait Empathy ◽  
Human Perceptions ◽  
Dispositional Empathy

AbstractPrevious research revealed an active network of brain areas such as insula and anterior cingulate cortex when witnessing somebody else in pain and feeling empathy. But numerous studies also suggested a role of the somatosensory cortices for state and trait empathy. While recent studies highlight the role of the observer’s primary somatosensory cortex when seeing painful or nonpainful touch, the interaction of somatosensory cortex activity with empathy when receiving touch on the own body is unknown. The current study examines the relationship of touch related somatosensory cortex activity with dispositional empathy by employing an fMRI approach. Participants were touched on the palm of the hand either by the hand of an experimenter or by a rubber hand. We found that the BOLD responses in the primary somatosensory cortex were associated with empathy personality traits personal distress and perspective taking. This relationship was observed when participants were touched both with the experimenter’s real hand or a rubber hand. What is the reason for this link between touch perception and trait empathy? We argue that more empathic individuals may express stronger attention both to other’s human perceptions as well as to the own sensations. In this way, higher dispositional empathy levels might enhance tactile processing by top-down processes. We discuss possible implications of these findings.

scholarly journals The morality of abusing a robot

2020 ◽  
Vol 11 (1) ◽  
pp. 271-283
Author(s):  
Christoph Bartneck ◽  
Merel Keijsers
Keyword(s):  
Mediation Analysis ◽  
Aggressive Behaviour ◽  
Video Clips ◽  
Significant Difference ◽  
Abusive Behaviour ◽  
Different Levels ◽  
Identical Behaviour

AbstractIt is not uncommon for humans to exhibit abusive behaviour towards robots. This study compares how abusive behaviour towards a human is perceived differently in comparison with identical behaviour towards a robot. We showed participants 16 video clips of unparalleled quality that depicted different levels of violence and abuse. For each video, we asked participants to rate the moral acceptability of the action, the violence depicted, the intention to harm, and how abusive the action was. The results indicate no significant difference in the perceived morality of the actions shown in the videos across the two victim agents. When the agents started to fight back, their reactive aggressive behaviour was rated differently. Humans fighting back were seen as less immoral compared with robots fighting back. A mediation analysis showed that this was predominately due to participants perceiving the robot’s response as more abusive than the human’s response.

scholarly journals Effects of Wrist Posture and Fingertip Force on Median Nerve Blood Flow Velocity

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Katherine E. Wilson ◽  
Jimmy Tat ◽  
Peter J. Keir
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Median Nerve ◽  
Blood Flow Velocity ◽  
Nerve Blood Flow ◽  
Occupational Risk Factors ◽  
Early Evaluation ◽  
Fingertip Force ◽  
Significant Difference ◽  
Healthy Participants

Purpose. The purpose of this study was to assess nerve hypervascularization using high resolution ultrasonography to determine the effects of wrist posture and fingertip force on median nerve blood flow at the wrist in healthy participants and those experiencing carpal tunnel syndrome (CTS) symptoms. Methods. The median nerves of nine healthy participants and nine participants experiencing symptoms of CTS were evaluated using optimized ultrasonography in five wrist postures with and without a middle digit fingertip press (0, 6 N). Results. Both wrist posture and fingertip force had significant main effects on mean peak blood flow velocity. Blood flow velocity with a neutral wrist (2.87 cm/s) was significantly lower than flexed 30° (3.37 cm/s), flexed 15° (3.27 cm/s), and extended 30° (3.29 cm/s). Similarly, median nerve blood flow velocity was lower without force (2.81 cm/s) than with force (3.56 cm/s). A significant difference was not found between groups. Discussion. Vascular changes associated with CTS may be acutely induced by nonneutral wrist postures and fingertip force. This study represents an early evaluation of intraneural blood flow as a measure of nerve hypervascularization in response to occupational risk factors and advances our understanding of the vascular phenomena associated with peripheral nerve compression.

scholarly journals Influence of virtual reality visual feedback on the illusion of movement induced by tendon vibration of wrist in healthy participants

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242416
Author(s):  
Salomé Le Franc ◽  
Mathis Fleury ◽  
Mélanie Cogne ◽  
Simon Butet ◽  
Christian Barillot ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Visual Feedback ◽  
Visual Cues ◽  
Static Condition ◽  
Likert Scale ◽  
Tendon Vibration ◽  
Virtual Hand ◽  
Significant Difference ◽  
Illusory Movement ◽  
Healthy Participants

Introduction Illusion of movement induced by tendon vibration is an effective approach for motor and sensory rehabilitation in case of neurological impairments. The aim of our study was to investigate which modality of visual feedback in Virtual Reality (VR) associated with tendon vibration of the wrist could induce the best illusion of movement. Methods We included 30 healthy participants in the experiment. Tendon vibration inducing illusion of movement (wrist extension, 100Hz) was applied on their wrist during 3 VR visual conditions (10 times each): a moving virtual hand corresponding to the movement that the participants could feel during the tendon vibration (Moving condition), a static virtual hand (Static condition), or no virtual hand at all (Hidden condition). After each trial, the participants had to quantify the intensity of the illusory movement on a Likert scale, the subjective degree of extension of their wrist and afterwards they answered a questionnaire. Results There was a significant difference between the 3 visual feedback conditions concerning the Likert scale ranking and the degree of wrist’s extension (p<0.001). The Moving condition induced a higher intensity of illusion of movement and a higher sensation of wrist’s extension than the Hidden condition (p<0.001 and p<0.001 respectively) than that of the Static condition (p<0.001 and p<0.001 respectively). The Hidden condition also induced a higher intensity of illusion of movement and a higher sensation of wrist’s extension than the Static condition (p<0.01 and p<0.01 respectively). The preferred condition to facilitate movement’s illusion was the Moving condition (63.3%). Conclusions This study demonstrated the importance of carefully selecting a visual feedback to improve the illusion of movement induced by tendon vibration, and the increase of illusion by adding VR visual cues congruent to the illusion of movement. Further work will consist in testing the same hypothesis with stroke patients.

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