sang wook hong. neural pathway of color processing color appearance: local and global processing...
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Sang Wook Hong
Neural Pathway of Color Processing
Color Appearance: local and global processing
Color Binding
Neural Pathway of Color Processing
Color Appearance: local and global processing
Color Binding
Parallel Processing Hypothesis: Livingstone & Hubel (1987)
Retinal ganglion cells
LGN
Parvocellular color selective low temporal resolution low contrast sensitivity high spatial resolution
Magnocellular color blind high temporal resolution high contrast sensitivity low spatial resolution
1
2 & 3
4A
4B
4C
56
form form
color colorcolor
movement
Primary visual cortex
color
color
form
form
form
form
Depth
Depth
Depth
Visual area 2
MT
V4 color
Landisman & TS’O (1999)
Conway (2001)
Moutoussis & Zeki (2002)
Zeki & Marini (1998)
Neural Pathway of Color Processing
Color Appearance: local and global processing
Color Binding
• Chromatic contrast: The color of the light appears to change in a direction away from the color of the surrounding light;
• Chromatic assimilation: The color of the light appears to change in a direction toward the color of the surrounding light;
• Color appearance of a light can be altered in the presence of a surrounding light. This phenomenon is referred to as chromatic induction.
Monnier & Shevell (2003, 2004)
Monnier & Shevell (2003, 2004)
BACKGROUND CONDITION
+S
-S
+S-S
+S
-S
RE
LA
TIV
E R
ES
PO
NS
E
0.0
-0.2
-0.4
-0.6
0.2
0.4
0.6
+S-S
+S-S
“Hourglass” Structure
5.5 5.5 1.9
Comparison Square
11 min
Test Surround 15cd/m2Comparison Surround 15cd/m2
Test Square
20cd/m2
Test Surround 15cd/m2
5.5 5.5 1.9
Comparison Surround 15cd/m2
Inducing Bars
20cd/m2
Obs. S.X.
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0.62 0.64 0.66 0.68 0.7
s =
S/(
L+
M)
l = L/(L+M)
Isomeric Matches
Surround chromaticities
Test-square chromaticities
Isomeric Matches
Surround chromaticities
Test on a -s stripe alone
Test&6bars on -s stripes
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0.62 0.64 0.66 0.68 0.7
s =
S/(
L+
M)
l = L/(L+M)
Obs. R.S.
Isomeric Matches
Surround chromaticities
Test on a -s stripe alone
Test&6bars on -s stripes
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0.62 0.64 0.66 0.68 0.7
s =
S/(
L+
M)
l = L/(L+M)
Obs. R.S.
Test on a -s stripe with6 bars on +s stripes
Neural Pathway of Color Processing
Color Appearance: local and global processing
Color Binding
Is binding necessary?
Retinal ganglion cells
LGN
Parvocellular color selective low temporal resolution low contrast sensitivity high spatial resolution
Magnocellular color blind high temporal resolution high contrast sensitivity low spatial resolution
Livingstone & Hubel (1987)
Retinal ganglion cells
LGN
Parvocellular color selective low temporal resolution low contrast sensitivity high spatial resolution
Magnocellular color blind high temporal resolution high contrast sensitivity low spatial resolution
1
2 & 3
4A
4B
4C
56
form form
color colorcolor
movement
Primary visual cortex
color
color
form
form
form
form
Depth
Depth
Depth
Visual area 2
MT
V4 colorLivingstone & Hubel (1987)
Physiological support for ‘Specific Color Pathway’
- A large concentration of color opponent cells in the CO blobs in V1
Livingstone & Hubel (1984)
- A concentration of color opponent cells in thin CO-bands in V2
Hubel & Livingstone (1987), Ts’o, Roe & Gilbert (2001)
- Cerebral achromatopsia
Zeki (2003)
Multi-selective cells
- The same concentration of color opponent cells in all CO-bands in V2
Gegenfurtner, Kiper & Fenstemaker (1996)
- Color selective cells are tuned also to orientation
Kiper, Fenstemaker & Gegenfurtner(1997)
- Most color-luminance cells in V1 are tuned also to orientation
Johnson, Hawken & Shapley (2001)
- Orientation selective cells in V1 are also sensitive to chromatic variation
Friedman, Zhou & von der Heydt (2003)
If the response is 5 spikes/sec, then
Illusory Conjunction (Treisman & Schmidt, 1982)
Primary task: odd or even?
Secondary task: what you saw between the numbers?
letter intrusion:
color intrusion:
illusory conjunction: