Overview
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.
Eligibility
Inclusion Criteria:
- 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 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
Exclusion Criteria:
- 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
- Have metal tattoos close to the head
- Have permanent make-up