Blindness
Conditions
Keywords
Blindness, Visual cortex, Sensory substitution, Assistive technology, Magnetic resonance imaging, Brain, Sound, Touch
Brief summary
The goal of this clinical investigation is to learn how the brain responds when visual information is converted into patterns of sound or touch in blind and sighted participants. The main questions it aims to answer are: * Does converting visual information into sound or touch patterns change visual performance in the blind or blindfolded? * How does the brain adapt to different kinds of sensory information? Researchers will use brain imaging and simple performance tasks to see how people process and learn from this type of converted sensory input. The investigators will compare how individuals with and without long-term vision loss respond to these signals. Participants will: * Learn to use technologies to assist in visual information conversion into sound or touch patterns every day for 5 weeks; * Visit the brain imaging center 3 times for brain scans and behavioral tests.
Interventions
DEVICEElectrotactile display (BrainPort)
The BrainPort is a non-surgical assistive device that translates digital information from a video camera to gentle electrotactile stimulation patterns on the surface of the tongue.
DEVICEVision-to-sound converter (AI Sight)
The AI Sight is an auditory technology software that can convert visual information into sound patterns, which can be delivered through regular headphones.
DEVICESham
Participants will wear the assistive technology system, but there will be no active sensory signals applied.
Sponsors
Stanford University
National Eye Institute (NEI)
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
A parallel model will be used, in which participants are assigned to one of the two sensory substitution devices for the duration of the study.
Eligibility
Sex/Gender
ALL
Age
8 Years to 85 Years
Healthy volunteers
Yes
Inclusion criteria
1. 8-85 years old for blind individuals; or 18-85 years old for sighted controls. 2. (a) Blind due to ocular impairment (documented visual acuity of light perception or worse) in both eyes, or (b) sighted healthy adult controls with corrected visual acuity of 20/40 or better and with no known vision disorders. 3. Able to hear the Informed Consent Form being read out to him or her, to understand it, and sign the Informed Consent Form. 4. Able to undergo functional neuroimaging tests. 5. Able to walk and stand independently. 6. Able to understand and remember the training protocols involved in the research study. 7. Willing and able to use the provided sensory substitution system to solve simple visual tasks. 8. Willing and able to complete simple tactile or auditory tasks. 9. Able to communicate by telephone and/or computer with research staff.
Exclusion criteria
1. Prior use with the sensory substitution device under investigation. This applies to both the auditory and tactile stimulators. 2. Presence of any foreign metal in the body, except for dental fillings (will need to be pre-screened by a radiologist prior to signing the informed consent and enrollment). 3. Pregnant or breastfeeding by self-report or urine test. 4. Is a prisoner or has any required movements legally restricted. 5. Unwilling or unable to adhere to all study requirements, including completion of the training period and any evaluation tests. 6. Implanted electrical medical devices such as pacemakers. 7. Claustrophobia that would prevent functional neuroimaging. 8. Obesity preventing placement in the MRI scanner. 9. No known neurological disorders or any medical condition that can possibly lead to emergency medical care (e.g., history of seizures, family history of epilepsy, stroke, severe headaches, use of medication for neurological or psychiatric conditions). 10. Documented or suspected brain damage resulting in significant cognitive or sensory impairment (e.g., traumatic brain injury).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of correct responses to visual performance tasks | 5 weeks | Measuring the change in the number of correct responses to visual performance tasks from baseline to week 5. |
| Reaction time to visual performance tasks | 5 weeks | Measuring the change in reaction time to visual performance tasks from baseline to week 5. |
| Metabolic brain profile | 5 weeks | Measuring the change in neurometabolic markers by magnetic resonance spectroscopy from baseline to week 5. |
| Blood-oxygenation-level-dependent functional brain activity level | 5 weeks | Measuring the change in blood-oxygenation-level-dependent brain activity level by T2\*-weighted functional magnetic resonance imaging from baseline to week 5. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Gray matter density | 5 weeks | The change in gray matter density signals from T1-weighted magnetic resonance imaging through 5 weeks |
| White matter directional diffusivity | 5 weeks | The change in directional diffusivity in the white matter microstructures measured from advanced diffusion magnetic resonance imaging through 5 weeks |
Countries
United States
Contacts
CONTACTStudy Team
CONTACTMariana Nunez, CCRP
PRINCIPAL_INVESTIGATORKevin C. Chan, PhD
Stanford University
Outcome results
None listed