=====================================

10A -L1 The Retina

=====================================

Human Brain Overall View

Fig 1(a): The Human Brain: overall view

Fig 1(b)

Visual Field

Monocular Visual Field: each eye $160^\circ$ (h)

Binocular Visual Field: $120^\circ$ (h)

Total Visual Field: $200^\circ$ (h)x$135^\circ$ (v)

Fig 2(a)

Fig 2(b)

Fig 2(c): Hemifield Neglect

The Human Eye

Fig 3(a)

What your doc sees

Fig 3(b)

Blind Spot

Fig 4(a)

Fig 4(b)

Inverted Retina

Fig 5(a)

Fig 5(b)

Rods and Cones

Fig 6(a)

Rods:

• 120 million rods in the retina
• 1000X more light sensitive than cones
• Discriminate between brightness levels, in low illumination
• Short-wavelength sensitive

Cones:

• 6-7 million cones in the retina
• Responsible for high-resolution vision
• Discriminate $\color{red}{c}\color{maroon}{o}\color{blue}{l}\color{green}{o}\color{pink}{r}\color{yellow}{s}$
• There are three types of color sensors: $64\%\,\color{red}{\text{ red, }}32\%\color{green}{\text{ green, }}2\%\color{blue}{\text{ blue}}$
• Sensitive to any combination of the three

Fig 6(b)

Photoreceptors

Fig 7(a)

Fig 7(b)

Fig 7(c)

Receptor responses

Fig 7(d)

Retina

Fig 8(a)

Fig 8(b)

Fig 8(c): Microspic view of the retina

Dynamic Range

Fig 9(a)

Image capture

• Huge dynamic range
  • Overall: $10^{-6}$-$10^{+8}$ cd/$m^{2}$ (candelas)
  • Static: at least 100:1 probably more
  • A given scene in the real world: 100,000:1
• Everyone knows about the pupil, but it's actually the retina's ganglion cells that make this works

Fig 9(b): Dynamic Range

Fig 9(c)

Ganglion Processing

Fig 10(a)

Center-surround Receptive Field

Fig 10(b)

Cell Recording

Fig 11(a)

Recording from a Neuron

Fig 11(b)

ON and OFF cells in retinal ganglia

Fig 11(c)

Fig 11(d)

Contrast Sensitivity Function

Fig 11(e)

=====================================

10B -L1 Vision in the Brain

=====================================

Fig 12

Thalamus and Cortex

Fig 13(a)

Superior colliculus

Fig 13(b)

Cerebral cortex: Functional areas

Fig 13(b)

Visual Proecessing Areas

Fig 14(a)

Mapping from Retina to V1

Fig 14(b) Tootell, Switkes, Silverman, and Hamilton. Functional Anatomy of Macaque Striate Cortex. II: Retinotopic Organization The Journal of Neuroscience, May 1988

"Log-Polar" Retinatopic mapping

Fig 14(c)

V1

Physiological Recording

Fig 15(a)

Recording from a Neuron

Fig 15(b)

V1: Orientation Selectivity

Fig 15(c)

V1: Direction selectivity

Fig 15(d)

Orientation Map, Optical Recording

Fig 15(e)

V2 and IT

Hunting for features in V2

Fig 16(a) Temporal Dynamics of Shape Analysis in Macaque Visual Area V2 Hedge and Van Essen; J Neurophysiology 2004

Increasing complexity

Inferotemporal cortex Features

K. Tanka, Neuronal Mechanisms of object Recognition Science, 1993

Fig 16(b)

'Hand neuron' in area IT

Desimone, Albright, Gross and Bruce

Stimulus-selective properties of inferior temporal neurons in the macaque J Neurosci. 1984

Fig 16(c)

Some images look somewhat similar but represent different things

These fire similar cells in V1 but different cells in IT

Fig 16(d)

Other images look very different but are the same thing. These fire very different cells in V1 but the same cells in inferior temporal cortex

Fig 16(d)

fMRI and Facial Response

fMRI Magnet

Fig 17(a)

fMRI Activation

Fig 17(b)

fMRI Activation Slice

Fig 17(c)

FFA

Fig 17(d) Kalanit Grill-Spector, Nicholas Knouf & Nancy Kanwisher: The fusiform face area subserves face perception, not generic within-category udentification. Nature Neuroscience 7, 555-562 (2004)

Faces are special: Early preference for faces?

Fig 17(e): Neonates and infants prefer faces from the first minutes of life

Face-selective Responses

Fig 17(f): Cell responses to 96 images, 16 of them faces

All cells in this small area respond to faces

Fig 17(g)

And more object specific areas

Fig 17(h)

More Pathways

Fig 18(a)

Fig 18(b) The two visual streams

MT motion blindness

Fig 18(c)

Gisela Leibold -- Unable to see motion, feels anxious as she rides down an escalator in Munich

She could not cross a street, because the motion of cars was invisible to her: a car was up the streen and then upon here, without ever seeming to occupy the intervening space.

Fig 18(d)