Please enable JavaScript.
Coggle requires JavaScript to display documents.
BIOPSYCHOLOGY UNIT 4 EXAM (COLOR VISION (Young-Helmholtz (1802) The…
BIOPSYCHOLOGY UNIT 4 EXAM
COLOR VISION
Young-Helmholtz (1802)
The Trichromatic Theory
3 types of color receptors/cones
differential sensitivity to light wavelengths
red= long
green= medium
blue= short
perceived color= overall pattern of stimulation, like mixing paint
not enough to totally explain this concept
negative after-image=seeing opposite colors
Hering Opponent-Process Theory
center-surround organization (BP, RGC, LGN)
Antagonistic for color always
red-green
blue-yellow
black-white
which theory?
both correct in retina
photoreceptors: trichromatic
higher levels: opponent process
more complex at cortical level
LGN: Parallel Processing
only from 1 eye
parvocellular system (layers 3-6. small RFs, info from cones, where form and color are processed)
magnocellular system (layers 1 and 2, large RF's, info from cones, where form processed. no color processed)
VI organization
6 layers (most input in layer 4)
1st binocular receptive fields -input comes from both eyes, ocular dominance= one eye more influential to VI cells
modular organization--- blob cells (color processing, wavelength specific)
same color percieved differently
double opponent process cells
different from rgc and cgn
center
red- excitation
green= inhibition
surround
red= inhibition
green = excitation
divergence of color and form
VI= input to layer 4
color- blob cells
form -interblob cells
higher level color processing
v1-v2-v4(in medial occipital cortex)
v4 damage = disrupts color constancy,
achromatopsia = lack of color vision
unilateral = 1 visual field, brain fills in bad part
bilateral= no color perception
SCHIZOPHRENIA
Basic things
-subtypes with different types of symptoms
-disordered thoughts and bizarre behavior
-1% of population
-equal among sexes
-progressive (gets worse over time)
-can only manage symptoms, not cure
2 classes of symptoms
positive = present in people with schizophrenia that are not in normal population
negative= not present in people with schizophrenia but are in normal population
Heritability
-general population = 1%
-one parent with schizophrenia = 17%
-DZ twins = 17%
-MZ twins = 48%
STRONG GENETIC COMPONENT
ADOPTION STUDIES= risks more like biological parents
MOOD DISORDERS
HORMONES & SEX