Stable and Independent Communication Brain-computer Interfaces

Stable and Independent Non-invasive Communication Brain-computer Interfaces Based on Error-adaptive Decoding Algorithms

People with locked-in syndrome cannot move their limbs or talk because of a motor impairment, but remain conscious and intellectually awake. Restoring the ability to communicate to people with locked-in syndrome will have a positive effect on their quality of life, will enable them to reintegrate into society and increase their capacity to lead productive and fulfilling lives. This study sims to develop a new assisted communication device based on a brain-computer interface, a system that allows the user to control a computer with his brain activity. The investigators will develop this brain-computer system for long-term stability and independent use by using adaptive decoders. The investigators will test the long-term stability and independence of this system with healthy volunteers, people with tetraplegia and people with locked-in syndrome over time periods of several months.

Inclusion criteria for healthy persons:

• Older than 18
• Fluent in French, English, German or Italian
• Good visual acuity

Inclusion criteria for people with tetraplegia:

• Older than 18
• Fluent in French, English, German or Italian
• Good visual acuity
• Diagnosed with spinal cord injury, brainstem stroke, spinal stroke, muscular dystrophy or other non-degenerative motor neuron disorders
• Limited or no ability to use both hands - less than grade 4 muscle strength in elbow extension and wrist extension and less than grade 2 strength in finger flexor and abduction on both sides

Inclusion criteria for people with locked-in syndrome:

• Were fluent in French, English, German or Italian before losing the ability to speak
• Enough visual capability to see large letters from a distance of around 50cm according to caretaker's or guardian's opinion

Exclusion criteria for healthy persons:

• Smokers
• Substance or alcohol abuse
• Neurological or psychiatric illness
• History of cranio-facial surgery
• Metallic implants that would prohibit the subject from having a MRI scan
• Medications that may retard motor coordination and cognitive ability (such as sedatives)
• Seizure disorders
• Treated with anti-epileptic medications

Exclusion criteria for people with tetraplegia and locked-in syndrome:

• Disabling neurological illness other than tetraplegia or locked-in syndrome
• Disabling psychiatric illness
• History of cranio-facial surgery