The day C/O L O/R … d raine d a wa y … v i s ual + I ntelligence Chapter 5 …

The Case of “Jonathan I ” Received concussion through minor car accident Lost color vision and only saw Grays. Science previously assumed color vision represented inherent properties of the external world, not a mental construction. Inferior occipital lobe, lingual fusiform gyri V 4 : DisCovered to Pro Cess CO/ L /OR When lingual fusiform gyri is magnetically stimulated, see colored R-I-n-g-s or HALOS. L ight is not required for This. Damage LEFT HEMISPHERE (lingual and fusiform gyri)  LOSE color in RIGHT visual field

Visual Examples The Neon Worm: The Blue on the Black lines makes the blue appear to glow like a neon sign. A photometer cannot detect this It is our mental construction

Red and Black Star: When the red star is made part of the black star, a disk seems to appear. Why is it such?

49 Colored Squares: identical inks can appear as different colors depending on their visual proximity to other colors. Different inks can appear as the same color, depending on the lighting. Colored squares hit by lights opposite in color (R,G,B,Y) will appear as a single color

These illusions support the idea that color construction is not an “isolated” event. “When you construct color you do not just construct color. Instead you construct several visual properties at once, and try to make them all mutually consistent: you organize your visual world into objects, you endow those objects with three-dimensional shapes, place light sources that illuminate those objects, and assign color to both the light sources and the objects.” (Hoffman, p )

“ I don ’ t remember doing any of that! It must all be … UNCONSCIOUS ?! ” -Joseph Shmofenheimer

RULE 21: We interpret GRADUAL Changes of hue, saturation and brightness in images as … CHANGES in ILLUMINATION. »Example: a shirt that looks a slightly different color indoors than outdoors RULE 22: We interpret ABRUPT Changes of hue, saturation and brightness in images as … CHANGES in SURFACES. »Examples: corners, object boundaries, and color changes like ink on paper

RULE 23: We construct as few light sources as possible to minimize complexity. RULE 24: We habitually place light sources as emanating from overhead. Muffin Pan: demonstrates the influence of light sources and shading on perception.

Rules Regarding Perceived Brightness “…you use the relative luminance’s of regions both within and between groups to create the grays you see.” (Hoffman, p. 119) Figure devised by Michael White, PhD

Ted Adelson’s “corrugated Mondrian” Notice how A looks darker than B Alan Gilchrist, PhD: we group each surface with those that lie in the same 3D plane

Surface colors and grays are not constructed in isolation. Colors and grays are constructed in the context of a mutually consistent coordinated construction of surface shapes, surface colors, light sources and transparent filters in as simple a manner as possible.

Why do we utilize these rules for constructing what we See? We are Cognitive Misers “ Budget ” metaphor for the consistency: each solution has a different ‘ cost ’ associated with it. “ Set crew ” metaphor for the consistency: relative distribution of labor results in different associated costs. Four markers of different subprocesses that synergize to construct the most specific and cognitively “ cheapest ” image possible.

Transparent Filters Ted Adelson ’ s argyle pattern Left Diamond looks brighter than Right Diamond because of dark filter Compensate for filters by calibrating inferred brightness

Rules for Constructing Filters RULE 25: Filters don ’ t invert lightness. Since B is darker than A, D must be darker than C to logically create a C/D filter RULE 26: Filters decrease lightness differences. Difference between C & D must be smaller than difference between A & B to construct a filter

Spatial Relations and Filters Minima Rule and Part Boundaries: Affect our construction of transparency o Where cusps meet implies a BOUNDARY, unlike the previous rectangular example, because the cusps meet at the color barrier.

In Summary: For Grays and Colors, we use: –Light –Luminescence at focal point and the global image –Filters –image shape

RULE 27: We choose a fair pick that’s most stable. Fair Pick: a combination of shape, color, light, etc. Changing any one factor can change perception of an image. oChoosing the fair pick that changes image least reduces number of possible interpretations and makes deciphering images less ambiguous.

RULE 28: Determine the highest luminescence in the visual field as white, fluorescent or self-luminous. oWe tend not to Construct BLACK, but rather simply process it as lacking color. What Anchoring Rules are used?

COLOR Color Aperture Displays: show all of the colors that can be made, including ones we don ’ t generally see in the real world. Color Terms: oHUE: color like red, green, blue, etc oS-a-t-u-r-a-t-i-o-n: purity of Hue; no black or grays oBrightness: visibility goes from barely there to dazzling Photometer ’ s are more sensitive than humans re: color apertures. We see vague color BOUNDARIES, where it sees c o n t i n u o u s c h a n g e oBut here too, like us, photometers “ CONSTRUCT ” light properties, not merely report upon them. oLight has no properties unto itself until an Observer looks at it!

Color Solids

Young-Helmholtz Trichromatic Theory

Color Blindness Provides further evidence that we C-O-N-S-T-R-U-C-T color, not merely report it. Defective gene coding for chemicals in cones creates inability to distinguish Red from Green Since these genes are on X-chromosome, if men carry a defective one their prognosis is not so good. Since women have two sets of X- chromosomes, they are likely to still possess one “ good ” set. Further proof we construct color, rather than merely report on it as it actually ‘ is ’. This relates to Supervenience, in which a change in material biology creates a change in phenomenal perception. Implies a physicalist perspective, but how does it relate to the IDEALIST perspective? What are some implications for our collective reality if we can materially modify the functioning of our brains? How would our world phenomenally “ appear ” on the macrophysical level?

Defective Genes Protanopia: lacking L-pigment –Serine & Alanine versions of L- pigment Deutranopia: lacking M-pigment Tritanopia: lacking S-pigment

Opponent Process Theory Opponent Color Scales –Red vs. Green and Blue vs. Yellow –Combinations of these create all of our color perceptions –It is still unknown why color opponency is responsible for our color senses –Why not green vs. blue, and yellow vs. red? –If light has no properties until an observer constructs it, why do these rules apply?

Approximate Color Constancy: colors change slightly when different light shines on them, but then your eyes adjust and the colors return to their previous color Linear Models: linear calculations of color changes under different lighting regiments. –Possibility of creating something that hardly changes under different lights. Color Transparencies –Rule of Generic Views at work –Obscuring T-junctions with circles impairs transparency and creates a non-generic view –Hearing analogy: When listening to a tone that gets interrupted by a hiss, if there is a pause between the two sounds, they don ’ t appear to overlap.

Constructing the Square

Stereo Vision Revisited Transparencies appear as 3D. Slight changes to the edges of transparencies produce very different 3D images. (Harkening to supervenience again!)

Binocular Disparity

May we ALL come to SEE the “apparent” …for what IT TRULY IS.

Food For Thought: