Seeing With the Tongue

1
Seeing With the Tongue

• Rewiring the Senses
• Allison Shankel

2
The Visual Pathway

• Normal Conditions
• Eyes
• Optic Nerve
• Thalamus
• Visual Cortex
• In Blind People
• This pathway is disrupted

3
Sensory Manipulation

• Electrotactile Stimulation
• Coded electrode signals that represent sensory
  information
• Used for
• Sensory substitution
• Sensory augmentation

• Sensory Pathways
• Similar mechanisms
• Travel to the brain via nerves as a pattern of
  impulses
• Pathway Substitution
• Encode signals for the visual pathway
• Transmit to the brain via tactile pathways

4
Why the Tongue?

• More sensitive
• Nerve fibers closer to the surface
• No outer layer of dead skin
• Less Voltage required
• Saliva

5
Encoding Visual Information

• Light patterns are picked up using a camera
• An image representing light patterns is created

6
Transmission of Information

• Light Patterns are converted to electrical
  impulses
• 49-point electrode array
• Controlled, painless current
• To Parietal Lobe

7
New Pathway

• Electrode Array
• Tongue
• Sensory Receptors
• Brainstem
• Parietal Lobe
• Visual Cortex

8
Plasticity of the Brain

• Eventually
• The brain can interpret the information from the
  tongue as if it were coming from the eyes
• Substitution of Pathways

Parietal lobe
?
Occipital Lobe
(tongue)
9
BrainPort

• Paul Bach-y-Rita
• Tactile Vision
• Camera records visual data
• Optical Data ?pixels ?Computer ? spatial signal?
  electrical impulses

10
Results of Blind Subjects

• Can perceive depth, perspective, size, and shape
• Can discern numbers and letters
• PET Scans
• Visual Centers light up

11
Vestibular Correction

• Restoring Balance
• Impaired Vestibular System
• Retrains the brain to receive balance input from
  the tongue instead of the inner ear

12
Other Applications

• Sensory-motor training for stroke patients
• Overcoming nerve damage (tactile)
• Improving interpretation and integration of
  sensory information in Autism
• Navigation in dark murky water (Navy)

13
The Potential of the Brain

• The plasticity of the brain is being studied and
  explored
• Will be able to do things never thought possible
  before
• Reworking of pathways through stimulation and
  learning
• Endless applications

14
References

• "Can You See With Your Tongue?" DISCOVER
  Magazine Mind Brain. 1 June 2003
  lthttp//discovermagazine.com/2003/jun/feattonguegt.
  
• Bach-y-Rita, Paul et al. "Form perception with a
  49-point electrotactile stimulus array on the
  tongue A technical note." Journal of
  Rehabilitation Research and Development 35
  (1998) 427-30.
•  
• Bach-y-Rita, Paul et al. "Vision Substitution by
  Tactile Image Projection." Nature 221 (1969)
  963-4.
•  
• Bach-y-Rita, Paul and Kercel, Stephen W. Sensory
  substitution and the human-machine interface.
  TRENDS in Cognitive Sciences 712 (2003) 541-6.
• Bach-y-Rita, Paul. Tactile Sensory Substitution
  Studies. Annals of the New York Academy of
  Sciences 1013 (2006) 83-91.