Chapter 4 Sensation and Perception Flashcards
Stimuli
An energy change
Light
Part of the electromagnetic spectrum and is visible because our receptors respond to certain wavelengths
Pupil
Adjustable opening that controls amount of
light that enters the eye
Iris
Colored structure on the surface of the eye,
surrounds the pupil
Retina
Layer of visual receptors covering the back
surface of the eyebal
Cornea
Rigid, transparent
structure on the
surface of the eyeball;
focuses light on retina
Lens
Flexible structure; varies in
thickness; focuses light on
the retina; adjusts focus for
different objects at different
distance
Fovea
Greatest density of receptors
Cones only
Rods
Adapted for vision in dim light (95%)
Cones
Adapting for perceiving color and detail in bright light (cons=color)
Visual Pathway
Contains receptors, bipolar cells, and ganglion cells> optic nerve
Blind Spot
Retinal area where the optic nerve exits
Trichromatic Theory
Color vision depends on the relative responses of three types of cones
blue=sensitive to short wavelengths
green=sensitive to medium wavelengths
red=sensitive to long wavelengths
(Young-Helmholtz Theory)
Opponent-Process Theory
We perceive color in terms of paired
opposites (ex: red vs. green, yellow vs. blue, white vs. black)
• Probably due to your neurons overcorrecting
• Color vision depends on cerebral cortex, not just retina
Retinex Theory
The cerebral cortex compares the patterns of light coming from different parts of the retina and synthesizes a color perception for each area (Retina+Cortex=Retinex)
Synesthesia
A neurological phenomenon in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway (smelling a word)
Signal-Detection Theory
a theory that determines an individual’s ability to detect, discriminate, recognize, and identify stimuli based on his level of sensitivity and bias
Subliminal Perception
A stimulus that can influence behavior even when it is presented so
faintly or briefly that the observer has no conscious perception of it
Feature-Detector Approach
specialized neurons in the visual cortex that
respond to the presence of simple features, such as lines and angles
Gestalt Psychology
A field that emphasizes perception of overall patterns and gestalt is German for pattern/configuration
Top-Down Perception
applying experience and
expectations to interpret each item in context
Visual Constancy
Tendency to perceive objects as keeping their shape, size, and color
Induced Movement
When the background
really is moving
Stroboscopic Movement
The illusion of motion that occurs when a stationary object is first seen briefly in one location and, following a short interval, is seen in another location (Stop Motion)
