Chapter Four Flashcards
Sensation vs perception
- sensation: the detection of physical stimuli and the sending of information to your brain
- perception: the brain’s further processing of sensory information
What is transduction
The sensory receptors change the stimulus input to neural signals that the brain can understand
What is the cornea and what does it do
Clear outer covering of the eye, focuses the incoming light which enters the lens
What is the retina
The thin inner surface of the back of the eyeball
What do sensory receptors do
They transduce light into neural signals
What are the types of sensory receptors and what do they do
Rods: low levels of illumination
Cones: high levels of illumination
What is the optic nerve
A collection of axons that carry visual information and connect the eye with the brain
What is the blind spot
The point where the optic nerve exits the retina, (no sensory receptors)
What are the two theories of color perception
Trichromatic theory and opponent process theory
What are the physical qualities of light
Amplitude: brightness
Wavelength: color
Purity: saturation of color
What is subtractive vs additive color mixing
- subtractive: (red, yellow, blue) removes some wavelengths of light
- additive: (red, green, blue) superimposes light
What is trichromatic theory and what is it related to
Human has three types of cone receptors
- S: blue
- M: green
- L: red
- color blindness
What is opponent process theory and what is it related to
Afterimage— a visual image that persists after stimulus is removed
What are the gestalt principles
Figure and ground and grouping
What is figure and ground
Figure: the thing you look at
Ground: the background against which it stands
What are the types of grouping: proximity, similarity, closure, continuity, common fate
Closeness, similar, simple ways, supplying missing elements, continuation, same direction
What is top down processing
Perception based on knowledge or past experiences affecting the interpretation of sensory info
What is informed perception
Previous knowledge influence information processing
What is perceptual set
A tendency to notice some aspects of sensory data and ignore others
What are contextual cues
The context guides our perceptual hypotheses
What are binocular depth cues
Clues about distance based on the differing views of the two eyes
What is binocular disparity
Because of the disparity between eyes, each eye receives a slightly different image
What are monocular depth cues
Clues about distance based on the image in either eye alone
What is linear perspective
Seemingly parallel lines appear to converge in the distance
What is texture gradient
As a uniformly textured surface recedes, its texture continuously becomes denser
What is interposition
A near object blocks a further object
What is relative size
Further images project a smaller retinal image than closer objects
What is height in plane
Objects that are lower in the visual field are seen as nearer than higher objects
What is perceptual constancy
A tendency to experience a stable perception in the face of continually changing sensory input
