NCT05199896

Brief Summary

The use of tools is ubiquitous in our lives and allows us to expand the sensorimotor capacities of our body. Much research has been done on the subject in sighted people over the past decades. This work has mainly focused on the motor aspect of using the tool, neglecting the sensory aspect. However, any action involving a tool carries sensory information, for example in the use of the white cane by blind people. 26% (\> 200,000) of blind people in France use a white cane to get around. By sweeping the cane on the ground, they use it as a sensorimotor extension of their body to extract information from the environment in order to locate a pedestrian crossing or possible obstacles. While it is well established that the tools increase the user's motor skills, we have only just begun to clarify how they also function as sensory extensions of the user's body and how this phenomenon is potentially dependent on constant use of the tool to compensate for a missing sense, as is the case with blind people using a cane. The aim of this study is to fill this important gap in our knowledge.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
300

participants targeted

Target at P75+ for not_applicable

Timeline
30mo left

Started Apr 2022

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress63%
Apr 2022Oct 2028

First Submitted

Initial submission to the registry

January 4, 2022

Completed
16 days until next milestone

First Posted

Study publicly available on registry

January 20, 2022

Completed
3 months until next milestone

Study Start

First participant enrolled

April 20, 2022

Completed
6.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

October 1, 2028

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

October 1, 2028

Last Updated

March 24, 2026

Status Verified

March 1, 2026

Enrollment Period

6.5 years

First QC Date

January 4, 2022

Last Update Submit

March 20, 2026

Conditions

Keywords

Blind/Non-sightedHealthy subjectfMRIEEG

Outcome Measures

Primary Outcomes (1)

  • Perceived location

    Tactile stimulus will be applied on a tool (a rod). Subject should determine the exact spatial location of the stimulus. This will be measure at each stimulation.

    90 minutes

Secondary Outcomes (2)

  • Brain activity

    6 hours

  • Brain activity

    3 hours

Study Arms (3)

All protocols (behavioral and EEG and fMRI)

EXPERIMENTAL

If participants accepts (non-sighted participants and Healthy volunteers), they will carry out the behavioral protocol and the EEG protocol and fMRI protocol.

Behavioral: Behavioral protocolDevice: EEG protocolDevice: fMRI protocol

Behavioral protocol and EEG protocol

EXPERIMENTAL

Participants who agree to participate in only one of the experiments (EEG or MRI) will be assigned to either the EEG or fMRI type of study in each subgroup. All participants (non-sighted participants and Healthy volunteers) will do the behavioral session and at least one EEG or MRI session.

Behavioral: Behavioral protocolDevice: EEG protocol

Behavioral protocol and fMRI protocol

EXPERIMENTAL

Participants who agree to participate in only one of the experiments (EEG or MRI) will be assigned to either the EEG or fMRI type of study in each subgroup. All participants (non-sighted participants and Healthy volunteers) will do the behavioral session and at least one EEG or MRI session.

Behavioral: Behavioral protocolDevice: fMRI protocol

Interventions

A touch sensitive computer screen either displaying a downscaled (45cm long) image of the rod (for the sighted), or supporting a same sized wooden rod (for the blind), will be placed on the table in front of the participant to record their localization performance. They will be instructed to use their left index fingertip to indicate on the image of the screen (for sighted) or on the wooden rod (for the blind) the position where they have felt the touch provided to the 90 cm long they held in their right dominant hand. Participants will wear a headset playing white noise to prevent any auditory localization cues when the long rod will be touched. The rod will be touched by a computer controlled solenoid. Thus, participants will respond with a hand gesture on the image or rod and will be asked to validate the position by pressing a foot-pedal with their left foot.

All protocols (behavioral and EEG and fMRI)Behavioral protocol and EEG protocolBehavioral protocol and fMRI protocol

The EEG protocol will be similar as the behavioral one described above, with the distinction of taking place in two separate sessions: one where the rod are touched, and one where their hand is touched. The participant will hold a rod in each hand and he will have to indicate on which rod he felt the touch. Additionally electrophysiological responses will be continuously recorded using a 65 channel ActiCap system (Brain Products).

All protocols (behavioral and EEG and fMRI)Behavioral protocol and EEG protocol

The same behavioral task and procedures of the behavioral protocol described above will be applied, adapted to take into account the constraints posed by the magnetic environment of the MR scanner. The participant will be placed on the scanner bed and provided with earphones that will both protect against the noise of the machine (80dB) and ensure a continuous communication with the participant. During the fMRI sessions, the participant will solve the same rod localization behavioral task while we will record brain activations by measuring the brain oxygen level dependent signal via Echo Planar Imaging sequences. We will use an MRI compatible tactile stimulator to touch the hand-held rod and participants location judgement will be recorded by using an MRI-compatible tablet, positioned on their abdomen, where the participant will have to indicate the judged position.

All protocols (behavioral and EEG and fMRI)Behavioral protocol and fMRI protocol

Eligibility Criteria

Age18 Years - 60 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Man or woman, aged 18 to 60 years old
  • Give an informed consent by signature
  • Be part of the national health security system (registered to the Securité Sociale)
  • do not confuse his right and his left
  • Specific of the non-sighted participants:
  • Loss of vision happened at birth or 3-to 5 years later minimum in life
  • Must have a visual acuity inferior or equal to 4/10
  • Be with a close relation for read information letter and sign the consent form if needed

You may not qualify if:

  • A person presenting an history of neurological, psychiatric or linguistic problems cannot be admitted
  • Assumption of psychotropic drugs
  • Pregnancy or breast-feeding woman
  • A person under legal tutoring
  • A person under care in other medical structure for reasons different from those of this research
  • A person under administrative or judiciary contention
  • A person who is not eligible to a MRI-exam according to the following criteria cannot be admitted to the experiments including MR acquisitions :
  • Have a neurological, cardiac (battery) or defibrillator pacemaker
  • Have a cardiac prosthesis (valve, stent...) or vascular prosthesis
  • Have intracranial clips or clamps
  • Carry a bypass of the cerebrospinal fluid
  • Having metallic splinters in the eyes
  • Wear metal prostheses (teeth, knees)
  • Wear an infusion pump or system
  • Be claustrophobic or have respiratory problems
  • +2 more criteria

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Equipe IMPACT du CRNL, Bâtiment INSERM

Bron, 69676, France

RECRUITING

MeSH Terms

Conditions

Vision Disorders

Condition Hierarchy (Ancestors)

Sensation DisordersNeurologic ManifestationsNervous System DiseasesEye DiseasesSigns and SymptomsPathological Conditions, Signs and Symptoms

Central Study Contacts

Alessandro FARNE, Dr

CONTACT

Cécile FABIO

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

January 4, 2022

First Posted

January 20, 2022

Study Start

April 20, 2022

Primary Completion (Estimated)

October 1, 2028

Study Completion (Estimated)

October 1, 2028

Last Updated

March 24, 2026

Record last verified: 2026-03

Data Sharing

IPD Sharing
Will not share

Locations