Please enable JavaScript.
Coggle requires JavaScript to display documents.
Perception and decision making & Color (Color (colors & wavelength…
Perception and decision making & Color
Signal detection
Detection
method of limits
ascending/descending series of stimuli
descending gives lower thresholds
focus on absolute threshold
adaptive testing
stimuli hover around absolute treshold
method of constant stimuli
set of stimuli; participant indicated if noticed
works for all sensory systems: takes time
arbitrary threshold
Signal detection theory
mathematical
deduces individual sensitivity
testing
2 types
signal present
signal absent
possible outcomes
Hit
False alarm
correct negative
miss
probability distribution
X: sensory activity level
Y: likelihood of occurrences
ß-criterion used to make decisions
activity over ß: yes
below: no
Sensitivity
measured in d
can be calculated by overlap between hit/miss distributions
Discrimination
difference threshold
derived from interval of uncertainty
Threshold = just noticeable difference
Webers law
sensitivity can be calculated using weber constant
large = poor
difference threshold larger for larger standards
roughly linear
Color
colors & wavelength
500-575nm green
575-590nm yellow
450-490nm blue
590-620nm orange
400-450nm violet
620-700nm red
colors show different reflectance on objects
selective reflection
Trichromatic theory of color vision
3 types of receptors to detect color
each responsive best to low middle or high nm
mix of three receptors can create any color
by young & helmholtz
cone pigments
made from opsin & retinal
different structures in opsin for diff. spectra
metamerism
multiple combinations create the same color
Opponent-Process Theory of color vision
receptors are exited & inhibited by different wavelengths
3 mechanisms
Black(-) White (+)
Red(+) Green(-)
Blue(-) Yellow (+)
Opponent neurons found in retina & lateral geniculate nucleus
cause for afterimages
Trichromatic theory first, then opponent theory
perception of color depends on
wavelength to which the receptor fires most
arrangement ob inhibiting and exiting neurons
color deficiency
Dichromatism
one detector malfunctioning
Types
deuteranopia
tritianopia
protanopia
anomalous trichromat
different mixing of wavelenghts
Monochromatism
no color vision
unilateral diochromats
only affecting one eye
about the concept map
Sources
Blake, R., & Sekuler, R. (2005). Perception (5th ed.). Boston, MA: McGraw-Hill. (20%)
Coren, S., Ward, L.M., & Enns, J.T. (1999). Sensation and perception (5th ed.). New York, NY: Harcourt Brace. (50%)
3.Goldstein, E.B. (2010). Sensation and perception (8th ed.). New York, NY: Wadsworth. (30%)
