Visuo-Tactile Integration and Body Ownership in the Human Brain

The present project exploits brain imaging and neuroscience robotics to investigate the role of quantifiable visual input on the relationship between visuo-tactile integration and body ownership (the feeling that "this" body belongs to "me").

Study Overview

• Status: Completed
• Conditions: Behavior and Behavior Mechanisms; Body Representation
• Intervention / Treatment: Behavioral: Visuo-tactile stimulations of the right hand

Detailed Description

Observational study, fundamental research, multicentric, national. The analysis of questionnaires, self-reports, and brain imaging associated with the RHI is used to understand the influence of visual input on body ownership. To this aim, participants lay down in the magnetic resonance (MR) scanner (Figure 1B), are presented with visual stimuli (videos of the virtual rubber hand - visual stroking) simultaneously in real time with tactile stimuli (robotic stroking of the participant's hand - tactile stroking), and in combination or not with the measurement of autonomic arousal (GSR) associated with the observation of a video showing the virtual rubber hand in a threatening situation (e.g. a knife approaching the virtual hand - unconscious RHI effects). By means of structured questionnaires and semi-structured self-reports, participants (i) evaluate eventual sensations felt during the visuo-tactile stimulation and (ii) report the personal feelings and impressions about body ownership for the virtual rubber hand (conscious RHI effects).

• Study Type: Interventional
• Enrollment (Actual): 45
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Zurich, Switzerland, 8008
    • ETH Zurich, Rehabilitation Engeineering Laboratory

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• general health
• personal interest
• age between 18 and 55 years old
• fulfil standard guidelines for fMRI studies

Exclusion Criteria:

• history of seizures, epilepsy
• specific medications or treatment
• concomitant diseases (e.g. cardiopathy)
• pregnancy
• unexplained loss of consciousness
• chronic headaches
• neurological illnesses
• head concussion,
• presence of metal in the neck or head
• implanted medical devices
• drug abuse
• inability to give consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: MR imaging; The experiment is aimed to induce a virtual rubber hand illusion, in which the individuals can potentially experience an embodiment illusion

Behavioral: Visuo-tactile stimulations of the right hand; Participants lay down in the magnetic resonance (MR) scanner are presented with visual stimuli (videos of the virtual rubber hand - visual stroking) simultaneously in real time with tactile stimuli (robotic stroking of the participant's hand - tactile stroking). An MR-compatible robot systematically provides the tactile stroking on the participant's hand. MR-compatible goggles show the visual stroking. Patterns of long and short robotic movements will be provided.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neuro-behavioral changes associated with vision-dependent alterations of body ownership, measured via brain activity (fMRI)	Analysis of objective measures of the RHI	Through study completion, an average of 2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subjective Experience via VAS scale	To understand the variations of the body ownership, Visual Analogic Scale, values 0 to 7, 0 = no illusory body ownership, 7 = strong illusory body ownership	Through study completion, an average of 2 years
Automatic response (skin conductance)	Measure of the skin conductance response (SCR, measured in siemens) during experiment runs, which is an indirect measure of sympathetic activity. Compare the blocks in which a pre-recorded visual threat (a video in which a hand is being pricked by a syringe needle) with baseline blocks and expect a higher SCR signal during "visual threat" blocks compared to the baseline. The SCR will be measured through a device connected to a dedicated laptop and electrodes that will be attached to the left index and middle fingers from participants. The SCR will be saved in log files and estimated a posteriori for each block using a general linear model and the weight regressors will be compared. There are no risks to the participants (since it is a passive measurement) the electrodes are compatible to the magnetic resonance environment.	Through study completion, an average of 2 years

Collaborators and Investigators

• Sponsor: Swiss Federal Institute of Technology
• Collaborators: Psychiatric University Hospital, Zurich; Eye Hospital Jules Gonin
• Investigators: Principal Investigator: Silvio Ionta, Professor, Fondation Asile des Aveugles, 1002, Lausanne

Study record dates

Study Major Dates

• Study Start (Actual): January 10, 2022
• Primary Completion (Actual): September 1, 2023
• Study Completion (Actual): September 12, 2023

Study Registration Dates

• First Submitted: October 29, 2021
• First Submitted That Met QC Criteria: December 6, 2021
• First Posted (Actual): December 21, 2021

Study Record Updates

• Last Update Posted (Actual): September 13, 2023
• Last Update Submitted That Met QC Criteria: September 12, 2023
• Last Verified: September 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: 2021-0111

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No