scholarly journals Do interoception and attending to the upper limbs affect body ownership and body representation in the grasp illusion?

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259988
Author(s):  
Annie A. Butler ◽  
Lucy S. Robertson ◽  
Audrey P. Wang ◽  
Simon C. Gandevia ◽  
Martin E. Héroux
Keyword(s):  
Index Finger ◽  
Body Representation ◽  
Left Index Finger ◽  
Body Ownership ◽  
Upper Limbs ◽  
Verbal Cues ◽  
Counting Task ◽  
Tactile Cues ◽  
Perceived Ownership ◽  
Interoceptive Accuracy

Passively grasping an unseen artificial finger induces ownership over this finger and an illusory coming together of one’s index fingers: a grasp illusion. Here we determine how interoceptive ability and attending to the upper limbs influence this illusion. Participants passively grasped an unseen artificial finger with their left index finger and thumb for 3 min while their right index finger, located 12 cm below, was lightly clamped. Experiment 1 (n = 30) investigated whether the strength of the grasp illusion (perceived index finger spacing and perceived ownership) is related to a person’s level of interoceptive accuracy (modified heartbeat counting task) and sensibility (Noticing subscale of the Multidimensional Assessment of Interoceptive Awareness). Experiment 2 (n = 30) investigated the effect of providing verbal or tactile cues to guide participants’ attention to their upper limbs. On their own, neither interoceptive accuracy and sensibility or verbal and tactile cueing had an effect on the grasp illusion. However, verbal cueing increased the strength of the grasp illusion in individuals with lower interoceptive ability. Across the observed range of interoceptive accuracy and sensibility, verbal cueing decreased perceived index spacing by 5.6 cm [1.91 to 9.38] (mean [95%CI]), and perceived ownership by ∼3 points on a 7-point Likert scale (slope -0.93 [-1.72 to -0.15]). Thus, attending to the upper limbs via verbal cues increases the strength of the grasp illusion in a way that is inversely proportional to a person’s level of interoceptive accuracy and sensibility.

scholarly journals Generic Inhibition of the Selected Movement and Constrained Inhibition of Nonselected Movements during Response Preparation

2014 ◽  
Vol 26 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Ludovica Labruna ◽  
Florent Lebon ◽  
Julie Duque ◽  
Pierre-Alexandre Klein ◽  
Christian Cazares ◽  
...  
Keyword(s):  
Impulse Control ◽  
Index Finger ◽  
Response Competition ◽  
Action Selection ◽  
Left Index Finger ◽  
Response Alternative ◽  
Upper Limbs ◽  
Response Preparation ◽  
Inhibitory Mechanisms ◽  
Response Alternatives

Previous studies have identified two inhibitory mechanisms that operate during action selection and preparation. One mechanism, competition resolution, is manifest in the inhibition of the nonselected response and attributed to competition between candidate actions. The second mechanism, impulse control, is manifest in the inhibition of the selected response and is presumably invoked to prevent premature response. To identify constraints on the operation of these two inhibitory mechanisms, we manipulated the effectors used for the response alternatives, measuring changes in corticospinal excitability with motor-evoked potentials to TMS. Inhibition of the selected response (impulse control) was independent of the task context, consistent with a model in which this form of inhibition is automatically triggered as part of response preparation. In contrast, inhibition of the nonselected response (competition resolution) was context-dependent. Inhibition of the nonselected response was observed when the response alternatives involved movements of the upper limbs but was absent when one response alternative involved an upper limb and the other involved a lower limb. Interestingly, competition resolution for pairs of upper limbs did not require homologous effectors, observed when a left index finger response was pitted with either a nonhomologous right index finger movement or a right arm movement. These results argue against models in which competition resolution is viewed as a generic or fully flexible process, as well as models based on strong anatomical constraints. Rather, they are consistent with models in which inhibition for action selection is constrained by the similarity between the potential responses, perhaps reflecting an experience-dependent mechanism sensitive to the past history of competitive interactions.

scholarly journals Response preparation involves a release of intracortical inhibition in task-irrelevant muscles

2020 ◽  
Author(s):  
Isaac N. Gomez ◽  
Kara Ormiston ◽  
Ian Greenhouse
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Index Finger ◽  
Intracortical Inhibition ◽  
Left Index Finger ◽  
Task Condition ◽  
Response Preparation ◽  
Action Preparation ◽  
The Right ◽  
Task Irrelevant

AbstractAction preparation involves widespread modulation of motor system excitability, but the precise mechanisms are unknown. In this study, we investigated whether intracortical inhibition changes in task-irrelevant muscle representations during action preparation. We used transcranial magnetic stimulation (TMS) combined with electromyography in healthy human adults to measure motor evoked potentials (MEPs) and cortical silent periods (CSPs) in task-irrelevant muscles during the preparatory period of simple delayed response tasks. In Experiment 1, participants responded with the left-index finger in one task condition and the right-index finger in another task condition, while MEPs and CSPs were measured from the contralateral non-responding and tonically contracted index finger. During Experiment 2, participants responded with the right pinky finger while MEPs and CSPs were measured from the tonically contracted left-index finger. In both experiments, MEPs and CSPs were compared between the task preparatory period and a resting intertrial baseline. The CSP duration during response preparation decreased from baseline in every case. A laterality difference was also observed in Experiment 1, with a greater CSP reduction during the preparation of left finger responses compared to right finger responses. MEP amplitudes showed no modulation during movement preparation in any of the three response conditions. These findings indicate cortical inhibition associated with task-irrelevant muscles is transiently released during action preparation and implicate a novel mechanism for the controlled and coordinated release of motor cortex inhibition.New & NoteworthyIn this study we observed the first evidence of a release of intracortical inhibition in task-irrelevant muscle representations during response preparation. We applied transcranial magnetic stimulation to elicit cortical silent periods in task-irrelevant muscles during response preparation and observed a consistent decrease in the silent period duration relative to a resting baseline. These findings address the question of whether cortical mechanisms underlie widespread modulation in motor excitability during response preparation.

scholarly journals A case report of a severe neonatal systemic vasculitis on the first day of life

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Stephanie Wong ◽  
Erkan Demirkaya ◽  
Roberta Berard
Keyword(s):  
Lupus Erythematosus ◽  
Reactive Arthritis ◽  
Index Finger ◽  
Systemic Vasculitis ◽  
Clinical Signs ◽  
The Body ◽  
Oral Steroid ◽  
Left Index Finger ◽  
High Dose ◽  
New Onset

Abstract Background Neonatal systemic vasculitis syndromes have been reported in infants born to mothers with systemic lupus erythematosus, Sjögren’s syndrome, Behҫet’s disease, cutaneous polyarteritis nodosa and anti-neutrophil cytoplasmic antibody-associated vasculitides. Here we report a novel association of a case of new-onset maternal seronegative inflammatory arthritis associated with a transient systemic vasculitis in a neonate. Case presentation In the first 24 h of life, a preterm Caucasian baby boy was noted to have blue discoloration to all four extremities. Despite antibiotics, fresh frozen plasma and anticoagulation, the discoloration remained, particularly in the left index finger. This was associated with fever and a maximum C-reactive protein (CRP) of 148 mg/L. Intravenous immunoglobulin (IVIG) was given with short-term improvement. Initial echocardiogram showed enlarged coronary arteries with normalization on repeat 1 week later. Clinical signs and symptoms responded to high dose oral steroid administration. MRI angiography (MRA) of the body and heart showed tortuosity of arteries in the upper and lower extremities with gadolinium uptake, suggestive of vasculitis. Autoantibody profile negative. Genetic panel for hereditary autoinflammatory diseases was negative as was whole exome sequencing performed on the trio. The baby was weaned off steroids by 5 months of age. A small distal autoamputation of the left index finger occurred. He was born to a 28-year-old woman who developed new onset severe symmetrical polyarthritis at 8 weeks gestation. This was presumed a reactive arthritis secondary to a dental infection. Infectious work up and autoantibodies were negative. She was treated with high dose prednisone for the remainder of her pregnancy. The mother was weaned off prednisone, treated with hydroxychloroquine for 8 months post-partum and remains in remission. A repeat MRA done at 1 year old showed mild residual tortuosities of the arteries in the forearms. The remainder of the medium and large vessels were within normal limits with no gadolinium enhancement to suggest active disease. The child is now 4 years old with normal growth and development. Conclusion This is a unique case of new-onset seronegative presumed reactive arthritis in a mother with the rare development of a successfully treated medium vessel vasculitis in an infant.

scholarly journals Changing Body Representation Through Full Body Ownership Illusions Might Foster Motor Rehabilitation Outcome in Patients With Stroke

2020 ◽  
Vol 11 ◽  
Author(s):  
Marta Matamala-Gomez ◽  
Clelia Malighetti ◽  
Pietro Cipresso ◽  
Elisa Pedroli ◽  
Olivia Realdon ◽  
...  
Keyword(s):  
Body Representation ◽  
Body Ownership ◽  
Motor Rehabilitation ◽  
Rehabilitation Outcome ◽  
Full Body

scholarly journals Photo Quiz: A 53-Year-Old Thai Man with Progressive Swelling of the Left Index Finger

2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Piyaporn Chokevittaya ◽  
Anucha Apisarnthanarak ◽  
Siriththin Chansirikarnjana ◽  
Chinnakart Boonyasirikool ◽  
Jutatip Kintarak ◽  
...  
Keyword(s):  
Index Finger ◽  
Left Index Finger

Interoceptive accuracy scores from the heartbeat counting task are problematic: Evidence from simple bivariate correlations

2018 ◽  
Vol 137 ◽  
pp. 12-17 ◽  
Author(s):  
Giorgia Zamariola ◽  
Pierre Maurage ◽  
Olivier Luminet ◽  
Olivier Corneille
Keyword(s):  
Counting Task ◽  
Interoceptive Accuracy

scholarly journals PROSTHETIC REHABILITATION OF EXTRA-ORAL DEFECTS WITH SILICONE PROSTHESIS

2012 ◽  
Vol 02 (04) ◽  
pp. 12-15
Author(s):  
Harshitha Alva ◽  
Krishna Prasad D. ◽  
Manoj Shetty
Keyword(s):  
Index Finger ◽  
Left Index Finger ◽  
Body Parts ◽  
Prosthetic Rehabilitation ◽  
Silicone Prosthesis ◽  
Normal Life ◽  
Facial Defects ◽  
Custom Made ◽  
The Ideal

AbstractMan's need for artificial replacements to supply missing or lost body parts has probably existed as long as man himself. Body abnormalities or defects compromise appearance, function and render an individual incapable of leading a relatively normal life. Extraoral defects involving ear, eye, nose, finger and few others are commonly encountered. Prosthetic restoration of these facial defects is an ancient art, in which success has always been limited due to the unavailability of adequate materials or because the available materials do not fulfil the ideal requirements. The most accepted materials today are the silicones because of their better esthetics.This paper presents prosthetic rehabilitation of the distal phalynx of left index finger with custom-made silicone prosthesis.

Assessment of Radiation Protection in Hand-Shielding Products With Mini C-Arm Fluoroscopy

Hand ◽  
2019 ◽  
pp. 155894471986593 ◽  
Author(s):  
Matthew B. Cantlon ◽  
Asif M. Ilyas
Keyword(s):  
Radiation Exposure ◽  
Index Finger ◽  
Proximal Phalanx ◽  
Left Index Finger ◽  
Surgical Glove ◽  
Thermoluminescent Dosimeters ◽  
Intraoperative Fluoroscopy ◽  
The Mean ◽  
The Right ◽  
Free Metal

Background: Previous studies have highlighted the particular risk of radiation exposure to the surgeon’s hands with intraoperative fluoroscopy. Although evidence exists that shielding equipment for the hands reduces exposure, the extent of protection is not well understood. Therefore, we set out to determine the degree to which radiation exposure to the surgeon’s hands is decreased with hand-shielding products. Methods: An anthropomorphic model was positioned to simulate a surgeon sitting at a hand table. Thermoluminescent dosimeters were placed on the proximal phalanx of each index finger. The right index finger dosimeter was covered with a standard polyisoprene surgical glove (control arm), whereas the left index finger dosimeter was covered with commercially available hand-shielding products (study arm): lead-free metal-oxide gloves, leaded gloves, and radiation-attenuating cream. Mini fluoroscope position, configuration, and settings were standardized. The model was scanned for 15 continuous minutes in each test run, and each comparative arm was run 3 times. Results: The mean radiation dose absorbed by the control and variable dosimeters across all tests was 44.8 mrem (range, 30-54) and 18.6 mrem (range, 14-26), respectively. Each hand-shielding product resulted in statistically lower radiation exposure than a single polyisoprene surgical glove. Conclusions: The mean radiation exposure to the hands was significantly decreased when protected by radiation-attenuating options. Each product individually resulted in a statistically significant decrease in hand exposure compared with the control. We recommend that in addition to efforts to decrease radiation exposure, surgeons consider routine use of hand-shielding products when using mini c-arm fluoroscopy.

Music Affects Learning of a Braille-Like Task by Sighted Subjects

1989 ◽  
Vol 69 (3-1) ◽  
pp. 923-929
Author(s):  
Robert F. Kennison ◽  
Richard A. Mcfarland
Keyword(s):  
College Students ◽  
Sensory Input ◽  
Index Finger ◽  
Practical Importance ◽  
Left Index Finger ◽  
Interhemispheric Competition ◽  
Male College ◽  
The Right ◽  
The Brain ◽  
Male College Students

24 consistently right-handed male college students felt sets of four Braille symbols with either the right or the left index finger and identified by touch alone which two of the four symbols in each set were identical. During the task music was played to either the right ear, the left ear, both ears, or neither ear. Significantly fewer errors were made when the music was in the ear contralateral to whichever hand performed the task. The ipsilateral, binaural, and no-music groups did not differ significantly from each other. It is suggested that monaural music to the ear contralateral to the engaged hand led to reduced interhemispheric competition acting on the hemisphere controlling the hand. Such a facilitating effect may be of practical importance in tasks during which one hemisphere receives the bulk of the task-related sensory input and/or processes the final order from the brain to the task-related muscles.

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