Chapter 6
Sensation and Perception
Sensation vs. Perception
Sensation
Process of detecting physical energy (stimulus) from the environment and converting it to neural signals
Perception
Process of selecting, organizing, and interpreting our sensations
Button --Up Processing Analysis that begins with the sensory receptors and works up to the brain's integration of sensory information
Top-Down Processing
Information process guided by higher level mental processes, as when we construct perceptions drawing on our experience and expectations
Sensory Adaptation
Diminished sensitivity as a result of constant stimulation o Clothes o Band-Aid
Perceptual Organization
> How do we form meaningful perceptions from sensory information?
oWe organize it. Gestalt psychologists showed that a figure formed a "whole" different from its surroundings
Form Perception: Figure/Ground
Organization of the visual field into objects (figures) that stand out from their surroundings (ground)
Grouping
After distinguishing the figure from the ground, our perception needs to organize the figure into a meaningful form using grouping rules
Depth Perception
Depth perception enables us to judge distances Gibson and Walk (1960) suggested that depth perception is partly innate, as their studies demonstrated human infants have depth perception
Monocular Cues
Relative Size
If two objects are similar in size, we perceive the one that casts a smaller retinal image to be farther away
Interposition
Objects that block other objects tend to be perceived as closer
Relative Height
We perceive objects that are higher in our field of vision to be farther away than those that are lower
Linear Perspective
Parallel lines, such as railroad tracks, appear to converge in the distance. The sharper the angle of convergence, the greater the perceived distance
Light and Shadow
Nearby objects reflect more light into our eyes than more distant objects. Given two identical objects, the dimmer one appears to be farther away
Perceptual Constancy
Perceiving objects as unchanging even as illumination and retinal images change
Color Constancy
Perceiving familiar objects as having consistent color even when changing illumination filters the light reflected by the object Size-Distance Relationship Lightness Consta