Sensation/Perception Flashcards
Signal Detection Theory
1) Sensitivity - how well a subject can sense a stimulus
2) Response bias - subjects respond in a particular way due to nonsensory factors
Feature Detection Theory
Certain cells are sensitive to certain features of stimuli Measured from single-cell recordings 1. Simple - orientation 2. Complex - movement 3. Hypercomplex - shape
Illumination vs. Brightness
Illumination: objective measurement - amount of light falling on a surface
Brightness: subjective measurement - impression of the intensity of the light of a stimulus
Brightness Factors
- Adaptation - dark and light - dark: bleaching of rhodopsin into retinal and opsin
- Simultaneous brightness contrast - target appears brighter if surrounded by darker stimuli (lateral inhibition)
Lateral Inhibition
Adjacent retinal cells inhibit each other to sharpen and highlight borders between light and dark areas
Subtractive and Additive Color Mixing
Subtractive: pigments
Additive: light
Trichromatic Theory
Three types of color receptors - red, green, blue
Opponent Process Theory of Color Vision
Three opponent pairs - red/green, blue/yellow, black/white
Afterimage
Opposite color of the intense stimulus you just saw. Provides evidence for the opponent process theory.
Depth Perception: Overlap
Object A covers object B, partially hidden image seems further away
Depth Perception: Relative Size
Object gets farther away and image on retina gets smaller
Depth Perception: Linear Perspective
Parallel lines converge in the distance, you know they don’t converge, so they must be in the distance
Depth Perception: Texture Gradients
Variations in perceived surface texture can indicate distance from observer, a change in the shape, direction
Motion Parallax
Variation in speed and motion of objects that are moving rather than you. Ex-car, train
Kinetic depth effect
Binocular Disparity/Stereopsis
Binocular depth cue
Distance between the eyes provides slightly different views of the world - combining of these views