Transcript
Page 1: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

contrast sensitivity

[email protected]

Page 2: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Receptive field�The region of retina over �

which a stimulus affects the� electrical activity of a neuron

-- -

--

---

-+ ++ +

--

-

bipolar cellin vivo

+ ++ +

-- -

--

---

-+ ++ +

--

-

ganglion cellin vivo

receptorin vitro

Page 3: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Receptive field of a ganglion cell

1°-10° Light stimulus Light in

RF centre

RF periphery Centre and periphery On-centre neuron

Off-centre neuron 1s

RF centre

RF periphery Centre and periphery

Page 4: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Orientation tuning

Page 5: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

A cortical binocular cell

Page 6: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Ocular dominance

Page 7: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Ocular dominance columns

Page 8: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Orientation columns

Page 9: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 10: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

A sinusoidal grating

Page 11: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

contrast

Page 12: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Spatial frequency

Page 13: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

A neuron as a spatial filter

Page 14: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Filtering along the pathway

Page 15: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

A spatial analysis

Page 16: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Contrast responses

1.0

0.5

Contrast %0.1 0.3 1.0

Sens

itivi

ty

P-cells

threshold saturation

Page 17: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Contrast vs spatial frequency

SPATIAL FREQUENCY (cycles/degree)

CON

TRA

ST S

ENSI

TIV

ITY

Page 18: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Window of visibility

SPATIAL FREQUENCY (cycles/degree)

CON

TRA

ST S

ENSI

TIV

ITY

Page 19: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Spatially-tuned channels

SPATIAL FREQUENCY (cycles/degree)

CON

TRA

ST S

ENSI

TIV

ITY

Page 20: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 21: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Temporal response of a neuron

1.0

0.5

Temporal Frequency (hz)1 10 100

Sens

itivi

ty

Page 22: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Human temporal sensitivity

Page 23: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Peripheral sensitivity

Page 24: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Types of retinal ganglion cell

Page 25: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Magno & parvo layers

Page 26: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

An isoluminant grating

Page 27: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Colour vs luminance CSF

Page 28: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Robert F Hess

Amblyopia: a new view

McGill Vision Research Unit Dept. of Ophthalmology, McGill University, Canada

Page 29: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 30: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 31: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 32: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 33: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 34: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 35: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

The Stimuli

Page 36: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 37: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 38: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 39: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial
Page 40: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Visual Development

Eileen Birch

Page 41: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Days of recovery

G

ratin

g ac

uity

(c/d

egre

e)

Page 42: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Gaussian size (sd min)

Alig

nmen

t acc

urac

y (m

in)

Monocular deprived cats

Page 43: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Strabismic cats

Gaussian size (sd min) Alig

nmen

t acc

urac

y (m

in)

Page 44: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Unrelated to visibility loss

Positional loss

Acu

ity lo

ss

Cont

rast

sens

itivi

ty lo

ss

Page 45: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Stimuli: positional sensitivity

Page 46: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Amblyopes

Page 47: contrast sensitivity - McGill Universitymvr.mcgill.ca/Residents/Fall_11_Lecture_PPTs/Contrast_Sensitivity.pdf · contrast sensitivity Robert.Hess@McGill.CA. ... Contrast vs spatial

Contrast sensitivity ratio (dB)

Alig

nmen

t acc

urac

y ra

tio


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