Subject SB

Subject SB

• Born in 1900, lost site in both eyes because of corneal infections

• Prior to 2 years of age; kept bandaged to reduce puss

• Went to a school for the blind to learn a trade; married

• Received a corneal graft in London at the age of 52

Subject SB

Quite recently he had been struck by how objects changed their shape when he walked round them. He would look at a lamp post, walk round it, stand studying it from a different aspect, and wonder why it looked different and yet the same. (Gregory, 1974, p. 111)

Subject Virgil

(Sacks, 1993)

During these first weeks [after surgery] I had no appreciation of depth or distance; street lights were luminous stains stuck to the window panes and corridors of the hospital were black holes. When I crossed the road the traffic terrified me, even when I was accompanied. I was very insecure while walking; indeed I am more afraid now than before the operation. (Virgil, May 10, 1993 from Sacks).

Subject SB

The congenitally blind person especially, has to face the prospect of a difficult struggle before reaching a stage at which his vision permits him to understand the world around him. For a period of time varying with each patient, these people experience a confusing proliferation of perceptions, and they must learn to see as a child learns to walk. Moreover, personalities and character armors bult up as a blind person have to be shed, and they often find it difficult to change their ways of living. As one of our patients put it, “I had to die as a blind person to be reborn as a seeing person. (Valvo, 1971, p. 4)

Recovered Sight

(Sacks, 1993)

During these first weeks [after surgery] I had no appreciation of depth or distance; street lights were luminous stains stuck to the window panes and corridors of the hospital were black holes. When I crossed the road the traffic terrified me, even when I was accompanied. I was very insecure while walking; indeed I am more afraid now than before the operation. (Virgil, May 10, 1993).

SB

Recovered Sight(Fine, Wade, Wandell)

• Chemical accident at 3 yrs• One eye lost; other cornea destroyed• Blind from age 3 through 46 • Stem cell replacement in right eye for both epithelium and stem cells

Corneal epithelium

cellsLimbic stem

cells

Primary visual cortex is one-fourth the normal size

Motion selective cortex is the normal size

MM

AAB

Primary Visual

Cortex And Nearby Regions Respond

Below Our Instrumental Sensitivity

Primary visual cortex is one-fourth the normal size

MM

AAB

Motion Selective Cortex

Responds Powerfully, Is Retinotopic, And Has The Same Size As

Controls

Motion selective cortex is the normal size

Ventral responses to objects and faces in Michael May and a control

OcP

LiGLiG

FuGFuG

OcP

LiGLiGFuGFuG

0 10.4 0.41

posterior

medial

MM AB

Seeing Faces Is Special(Margaret Thatcher Illusion)

•Thompson,P.(1980) Margaret Thatcher: a new illusion. Perception 9 483-4.

Seeing Faces Is Special(Margaret Thatcher Illusion)