Perception Flashcards
Color Perception
Determined by the wavelength of light reflected from or emitted by an object. Wavelengths of light are physical, but the perception of color is purely psychological.
Spectral Colors
Comprised of a single wavelength (ROYGBIV)
Non-Spectral Colors
Comprised of more than one wavelength.
Additive Mixing
Combination that increases amount of light reflected (ex: computer monitor)
Subtractive Mixing
Combination that reduces amount of light reflected (ex: paint)
Hue
Variations described by names such as red, purple, blue, orange, etc.
Saturation
Apparent purity, vividness, or richness.
Lightness
Dark to light, measured in luminosity, perceived as “brightness”.
Color Circle
Isaac Newton. Describes hue and saturation. Hue (around). Saturation (in).
Trichromatic Theory
Human color vision is trichromatic. Any hue matched with combination of 3 primary colors. Proposes there are 3 types of receptors: blue, green, red.
Cones
- Short wavelength (blue) receptors, cyanolabe
- Medium wavelength (green) receptors, chlorolabe
- Long wavelength (red) receptors, erythrolabe
Color Blind
1 in every 12 men have some form of color-blindness.
Dichromatic Vision
Missing one photo pigment.
Protanopia
Long wavelength (red) cones don’t contain erythrolabe.
Deutanopia
Medium wavelength (green) cones don’t contain chlorolabe.
Opponent Process Theory
Color perception is controlled by two opponent systems: blue-yellow & red-green. Only one color signaled at a time.
Visual Acuity
Represents the clearness/sharpness of vision. Snellen Eye Chart.
Contrast Sensitivity
Ability of the visual system to distinguish bright and dim components of a static image. Important in night time vision. A function of both contrast and spatial frequency.
Figure/Ground
Figure: front
Ground: background
Proximity
Elements close together are perceived as a group.
Similarity
Similar elements (in terms of color, form, or orientation) are perceived together.
Continuity
Points connected in straight or smoothly curving lines are perceived together.
Closure
Open curves are perceived as complete forms.
Common Fate
Elements moving in the same direction at the same speed are perceived as together.
Common Region
An explicit boundary for grouping.
Connectedness
Explicit lines for grouping.
Proprioception
Ability to feel what your muscles are doing and where your limbs are positioned.
Accommodation
Automatic adjustments of the lens that maintain a focused image on the retina.
Vergence
Degree to which the eyes are turned inward to maintain fixation on an object.
Interposition (Monocular Depth Cues)
Nearer objects will block the view of more distant objects if they are in the same line of vision.
Size (MDC)
Bigness of an object.
Perspective (MDC)
Angles such as when you know something is rectangular but its appears trapezoidal.
Binocular Disparity (BDC)
Each eye receives a slightly different image of the world because of the eye’s location. Depth information and 3D.
Object Motion
External object is moving.
Induced Motion
A stationary background causes movement to be attributed to the wrong part of a scene.
Apparent Motion
Discrete jumps of retinal images can produce the appearance of smooth motion. (Flip through cards quickly).
Sone
Scale for measuring loudness.
Proximity
Sounds close together are perceived as together.
Similarity
Similar sounds are perceived as together.
Sound Localization
The ability to locate sounds in space.
Vestibular System
Located in inner ear. Allows us to feel the movement of our bodies. Balance, posture.
Somesthetic System
Touch, pressure,vibration, temperature, pain.
Passive Touch
Skin is stationary and an external pressure stimulus is applied to it.
Active Touch
Person contacts the stimulus by moving the skin (reading brail).
