The visual and oculomotor systems Peter H. Schiller, year 2013

Review, the visual and oculomotor systems

1 Basic wiring of the

2 Primates

Image removed due to copyright restrictions.

Please see lecture video or Figure 3 from Schiller, Peter H., and Edward J. Tehovnik. "Visual prosthesis." Perception 37, no. 10 (2008): 1529.

3 and LGN

4 sign inverting synapse sign conserving synapse pigment epithelium

rods cones

photo- receptors

Bipolar glutamate receptors: ON = mGluR6 OFF = mGluR 1 & 2

OPL

gap junction cone horizontal H ON OFF bipolars ON glycinergic synapse

IPL AII ON OFF amacrine

ganglion cells

incoming light to CNS

5 Coronal section of monkey LGN fovea

6 5

4 periphery

3 4 2 3 1 2 1 Figure removed due to copyright restrictions.

6 layers 4 layers

Please see lecture video or Figure 4A of Schiller, Peter H., midget/parasol ratio: fovea: 8 to 1 periphery: 1 to 1 and Edward J. Tehovnik. "Visual Prosthesis." Perception 37, no. 10 (2008): 1529.

midget

parasol

fovea periphery eccentricity

6

7 MIP MEP Central Sulcus LIP STS FEF

V1

Principalis Lunate Arcuate V4

Image by MIT OpenCourseWare.

8 Cortical projections from LGN

K1

M

P K2

6 345 2 1 V1

Lamina: 3-6 = parvo 1-2 = magno interlaminar

LGN © Pion Ltd. and John Wiley & Sons, Inc.. All rights reserved. This content is excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/help/faq-fair-use/. 9 Transforms in V1

Orientation Direction Spatial Frequency Binocularity ON/OFF Convergence Midget/Parasol Convergence

10 Three models of columnar organization in V1

Original Hubel-Wiesel "Ice-Cube" Model

Cortical Midget Left Eye Right Eye Parasol Sub-cortical Radical Model

1 mm

Left Eye Right Eye Swirl Model

Image by MIT OpenCourseWare. 11 Striate Cortex Output Cell

Intracortical

Midget ON Midget ON Midget OFF Midget OFF LEFT EYE RIGHT EYE INPUT INPUT Parasol ON Parasol ON Parasol OFF Parasol OFF

luminance color orientation spatial frequency depth motion

12 Extrastriate cortex

13 V1 STS LIP MIP Lunate Image by MIT OpenCourseWare.

Central Sulcus V4 Arcuate MEP FEF Principalis Major cortical visual areas:

Occipital V1 V2 V3 V4 MT (medial temporal)

Temporal IT (inferotemporal)

Parietal LIP (lateral intraparietal) VIP (ventral intraparietal) MST (medial superior temporal)

Frontal FEF ()

15 The ON and OFF Channels

16 The receptive fields of three major classes of retinal ganglion cells

ON OFF ON/OFF inhibition inhibition inhibition

17 Action potentials discharged by an ON and an OFF retinal ganglion cell

Figure removed due to copyright restrictions.

Please see lecture video or Figure 2A of Schiller, Peter H., and Edward J. Tehovnik. "Visual Prosthesis." Perception 37, no. 10 (2008): 1529.

18 The 2-amino-4-phosphonobutyrate (APB) experiments blocking the ON channel:

1. No effect on center-surround antagonism and on orientation and direction selectivities in V1.

2. Deficit in detecting light increment but not light decrement.

19 The central conclusion:

The ON and OFF channels have emerged in the course of evolution to enable organisms to process both light incremental and light decremental information rapidly and effectively.

20 The midget and parasol channels

21 MIDGET SYSTEM PARASOL SYSTEM

Neuronal response profile

ON OFF ON OFF

time 22 Projections of the midget and parasol systems

Midget V1 Mixed V2

Parasol

w

LGN P M ? MT V4

Midget Parasol

PARIETAL LOBE TEMPORAL LOBE

23 Summary of PLGN and MLGN lesion deficit magnitudes

VISUAL CAPACITY PLGN MLGN V 4 MT color vision severe none mild none

texture perception severe none mild none

pattern perception fine severe none mild none

shape perception fine severe none mild none

coarse mild none none none

brightness perception none none none none

coarse scotopic vision none none none none

contrast sensitivity fine severe none mild mild coarse mild none none mild BASIC VISUAL FUNCTIONS stereopsis fine severe none none none

coarse pronounced none none none

motion perception none moderate none moderate

flicker perception none severe none pronounced

choice of "lesser" stimuli severesevere none severe none

visual learning not tested not tested severe none

object transformation not tested not tested pronounced not tested INTERMEDIATE INTERMEDIATE

24 Spatial Frequency H The midget system extends the range of in the spatial frequency and wavelength range.

L

L H

Midget System Parasol System Processing Capacity Temporal Frequency

H The parasol system extends the range of visual processing in the temporal frequency range.

L

L H

Image by MIT OpenCourseWare.

25 Color vision and adaptation

26 The color circle

Y

Hue

G R Saturation

B

Image by MIT OpenCourseWare.

27 Basic facts and rules of color vision

1. There are three qualities of color: hue, brightness, saturation

2. There is a clear distinction between the physical and psychological attributes of color: wavelength vs. color, luminance vs. brightness.

3. Peak sensitivity of human photoreceptors (in nanometers): S = 420, M = 530, L = 560, Rods = 500

4. Grassman's laws: 1. Every color has a complimentary which when mixed propery yields gray. 2. Mixture of non-complimentary colors yields intermediates.

5. Abney's law: The luminance of a mixture of differently colored lights is equal to the sum of the luminances of the components.

6. Metamers: stimuli producing different distributions of light energy that yield the same color sensations.

28 Response to Different Wavelength Compositions in LGN Blue ON cell Yellow ON cell 90 90

135 45 135 45 Spikes per Second

180 0 180 0 10 20 30 40 50 60 20 40 60 80 100

225 315 225 315

270 270

Green OFF cell Red ON cell 90 90

135 45 135 45

180 0 180 0 10 20 30 40 10 20 30 40 50

225 315 225 315 maintained discharge rate 270 270 29 Response of a retinal ganglion cell at various background adaptation levels

400

300 background log cd/m2 -5 -4 -2-3 -1 0

200 Discharge rate (spikes/sec) rate Discharge 100

0 -5 -4 -3 -2 -1 0 Test flash (log cd/m2)

Image by MIT OpenCourseWare.

30 Basic facts about light adaptation

1. Range of illumination is 10 log units. But reflected light yields only a 20 fold change (expressed as percent contrast).

2. The amount of light the admits into the eye varies over a range of 16 to 1. Therefore the pupil makes only a limited contribution to adaptation.

3. Most of light adaptation takes place in the photoreceptors.

4. Any increase in the rate at which quanta are delivered to the eye results in a proportional decrease in the number of pigment molecules available to absorb those quanta.

5. Retinal ganglion cells are sensitive to local contrast differences, not absolute levels of illumination.

31 Depth perception

32 Cues used for coding depth in the

Oculomotor cues Visual cues

Binocular stereopsis

Monocular motion parallax shading interposition size perspective

33 Autostereogram

Image removed due to copyright restrictions.

Please see lecture video or the autostereogram from The Magic Eye, Volume I: A New Way of Looking at the World. Andrews McMeel Publishing, 1993.

Masayuki Ito, 1970, Chris Tyler, 1990

34 MOTION PARALLAX, the eye tracks

1 a

2

b object motion a

1

The eye tracks the circle, which therefore remains stationary on the fovea

Objects nearer than the one tracked move 2 b at greater velocities on the retinal surface than objects further; the further objects actually move in the opposite direction on the retina. 35 36 37 37 38 Form perception

39 Three general theories of form perception:

1. Form perception is accomplished by neurons that respond selectively to line segments of different orientations.

2. Form perception is accomplished by spatial mapping of the visual scene onto visual cortex.

3. Form perception is accomplished by virtue of Fourier analysis.

40 Form perception with little information about orientation of line segments

Image removed due to copyright restrictions.

Please refer to lecture video.

41 Cortical layout of neurons activated by disks

disks in one hemifield

Image by MIT OpenCourseWare. 42 Cortical layout of neurons activated by disks

7 90 6 45 5 45 4 3 2 disks across 1 midline 0 0

-45 -45

-90 -90

-45

0

45 0.25 0.25 0.5 0.5 1 90 1 2 2 4 7 7 4

Image by MIT OpenCourseWare. 43 Prosthetics

44 Image removed due to copyright restrictions.

Please see lecture video or Figure 5 from Schiller, Peter H., and Edward J. Tehovnik. "Visual prosthesis." Perception 37, no. 10 (2008): 1529.

45 Image removed due to copyright restrictions.

Please see lecture video or Figure 7 from Schiller, Peter H., and Edward J. Tehovnik. "Visual prosthesis." Perception 37, no. 10 (2008): 1529.

46 Image removed due to copyright restrictions.

Please see lecture video or Figure 9 from Schiller, Peter H., and Edward J. Tehovnik. "Visual prosthesis." Perception 37, no. 10 (2008): 1529.

47 Illusions

48 The Hermann grid illusion

The most widely cited theory purported to explain the illusion:

Due to antagonistic center/surround organization, the activity of ON-center retinal ganglion cells whose receptive fields fall into the intersections of the grid produces a smaller response than those neurons whose receptive fields fall elsewhere. Image is in public domain.

49 Differently oriented vertical and horizontal lines reduce illusion

Figure removed due to copyright restrictions.

Please see lecture video or Schiller PH, Carvey CE (2005). "The Hermann Grid Illusion Revisited." Perception 34 (11): 1375–97.

50 Retinal ganglion cell layout at an eccentricity of 5 degrees

Figure removed due to copyright restrictions.

Please see lecture video or Schiller PH, Carvey CE (2005). "The Hermann Grid Illusion Revisited." Perception 34 (11): 1375–97.

51 After-effect illusions explained by the facts and rules of adaptation.

interocular experiments

52 Effects of lesions on vision

53 Summary of lesion deficit magnitudes

VISUAL CAPACITY PLGN MLGN V 4 MT color vision severe none mild none

texture perception severe none mild none

pattern perception fine severe none mild none

shape perception fine severe none mild none

coarse mild none none none

brightness perception none none none none

coarse scotopic vision none none none none

contrast sensitivity fine severe none mild mild coarse mild none none mild BASIC VISUAL FUNCTIONS stereopsis fine severe none none none

coarse pronounced none none none

motion perception none moderate none moderate

flicker perception none severe none pronounced

choice of "lesser" stimuli severesevere none severe none

visual learning not tested not tested severe none

object transformation not tested not tested pronounced not tested INTERMEDIATE INTERMEDIATE

54 Eye-movement control

55 Electrical stimulation triggering eye movements:

Figure removed due to copyright restrictions.

Please see lecture video or Figure 2 from Schiller, Peter H., and Edward J. Tehovnik. "Look and See: How the Brain Moves Your Eyes About." Progress in Brain Research 134 (2001): 127-42.

56 Electrical stimulation triggering eye movements:

Figure removed due to copyright restrictions.

Please see lecture video or Figure 3 from Schiller, Peter H., and Edward J. Tehovnik. "Look and See: How the Brain Moves Your Eyes About." Progress in Brain Research 134 (2001): 127-42.

57 Summary of the effects of the GABA agonist muscimol and the GABA antagonist bicuculline

Target selection Visual discrimination

muscimol bicuculline muscimol bicuculline

V1 INTERFERENCE INTERFERENCE V1 DEFICIT DEFICIT

FEF INTERFERENCE FACILITATION FEF MILD DEFICIT NO EFFECT

LIP NO EFFECT NO EFFECT LIP NO EFFECT NO EFFECT

SC INTERFERENCE FACILITATION Hikosaka and Wurtz

58 Figure removed due to copyright restrictions.

Please see lecture video or Figure 17 from Schiller, Peter H., and Edward J. Tehovnik. "Look and See: How the Brain Moves Your Eyes About." Progress in Brain Research 134 (2001): 127-42.

59 Midget V 1 V Auditory Mixed V2 ? system Parasol ?

w

LGN P Somatosensory M MT V system 4 ? Posterior Midget system Parasol

PARIETAL LOBE TEMPORAL LOBE Olfactory system w SC BG rate code SN BS vector code FEF MEF BS system vector code Anterior place code system

Vergence Accessory Vestibular system optic system system

60 Motion perception

61 Summary of cell types in V1 s1 D s5 D L .1 .2 .3 .4 .5 .1 .2 .3 .4 .5 .6 .7 deg DEGREES OF VISUAL ANGLE L D

s2 L D

s6 D L .1 .2 .3 .4 .5 .6 .7 .8 DEGREES OF VISUAL ANGLE

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 1.1 deg

D s3 L L

.1 .2 .3 .4 .5 .6 .7 .8 .9 deg

s7 D D L L

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 deg L D s4 L L D

.1 .2 .3 .4 .5 .6 deg CX D D L

.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 1.1 1.2 deg Image by MIT OpenCourseWare. 62 The central role of the parasol system in motion processing and in the perception of apparent motion.

63 Major Pathways of the Accessory Optic System (AOS)

Velocity response of AOS neurons = 0.1-1.0 deg/sec Number of AOS RGCs in rabbit = 7K out of 350K

Cortex 2 1 Ant 3

climbing fibers Prime axes of retinal NOT direction-selective neurons

Inferior Olive D Semicircular 1 canals

M 2,3 Vestibular L Nucleus rate code 2,3 BS Terminal BS Nuclei

vestibulo-ocular reflex 64 MIT OpenCourseWare http://ocw.mit.edu

9.04 Sensory Systems Fall 2013

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