Presentation is loading. Please wait.

Presentation is loading. Please wait.

Sang Wook Hong. Neural Pathway of Color Processing Color Appearance: local and global processing Color Binding.

Similar presentations


Presentation on theme: "Sang Wook Hong. Neural Pathway of Color Processing Color Appearance: local and global processing Color Binding."— Presentation transcript:

1 Sang Wook Hong

2 Neural Pathway of Color Processing Color Appearance: local and global processing Color Binding

3 Neural Pathway of Color Processing Color Appearance: local and global processing Color Binding

4

5 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 5 6 form color movement Primary visual cortex color form Depth Visual area 2 MT V4 color

6

7

8 Landisman & TS ’ O (1999)

9 Conway (2001)

10 Moutoussis & Zeki (2002)

11 Zeki & Marini (1998)

12 Neural Pathway of Color Processing Color Appearance: local and global processing Color Binding

13 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.

14

15

16

17 Monnier & Shevell (2003, 2004)

18

19 BACKGROUND CONDITION +S -S +S -S +S -S RELATIVE RESPONSE S -S +S -S

20

21

22 “Hourglass” Structure

23 5.5  1.9  Comparison Square 11 min Test Surround 15cd/m 2 Comparison Surround 15cd/m 2 Test Square 20cd/m 2

24 Test Surround 15cd/m  1.9  Comparison Surround 15cd/m 2 Inducing Bars 20cd/m 2

25 Obs. S.X s = S/(L+M) l = L/(L+M) Isomeric Matches Surround chromaticities Test-square chromaticities

26 Isomeric Matches Surround chromaticities Test on a -s stripe alone Test&6bars on -s stripes s = S/(L+M) l = L/(L+M) Obs. R.S.

27 Isomeric Matches Surround chromaticities Test on a -s stripe alone Test&6bars on -s stripes s = S/(L+M) l = L/(L+M) Obs. R.S. Test on a -s stripe with 6 bars on +s stripes

28 Neural Pathway of Color Processing Color Appearance: local and global processing Color Binding

29 Is binding necessary?

30 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)

31 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 5 6 form color movement Primary visual cortex color form Depth Visual area 2 MT V4 color Livingstone & Hubel (1987)

32 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)

33 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)

34 If the response is 5 spikes/sec, then

35 Illusory Conjunction (Treisman & Schmidt, 1982) Primary task: odd or even? Secondary task: what you saw between the numbers? letter intrusion: color intrusion: illusory conjunction:


Download ppt "Sang Wook Hong. Neural Pathway of Color Processing Color Appearance: local and global processing Color Binding."

Similar presentations


Ads by Google