Sensation and Perception

Process by which sensory organs obtain information about the environment and transmit it to the brain 

The organization of sensations into interpretation

Translation of physical energy into electrical signals 

Starts with raw sensory data that gets communicated to the brain 

Starts with observer's expectations and knowledge 

Minimal amount of stimulation that can be detected half of the time 

the smallest difference between 2 stimuli that a person can detect 

States that for 2 stimuli to be perceived as different in intensity, the second must differ from the first by a constant proportion

Decreasing response of sensory receptors to unchanging stimuli. It is an evolutionary mechanism because constant sensory input provides no new information 

suggests that perception results from both sensory information and making a judgment.

A persons readiness to report detecting a stimulus

Correctly detecting a present stimulus 

Failing to detect a present stimulus

Incorrectly detecting a stimulus that isn’t present 

Correctly identifying that no stimulus is present 

Expectations, motivation and history of signal detection errors may affect future response bias 

if you expect a stimulus you are more likely to detect it 

if you are highly motivated you are likely to report detecting a stimulus 

States that we perceive objects as whole structures rather than the sum of individual parts

The ability ability to distinguish between objects and its background 

Proximity, Similarity, Continuity and Closure 

We tend to group together objects objects that are close to one another

We tend to group together objects that are similar to one another 

Brain organizes stimuli into continuous lines or patterns 

We tend to perceive incomplete figures as complete 

Use both eye for depth perception

Use one eye to perceive depth, especially for far away objects

Images produce different image on each retina

Turning inward of yes toward nearby object

Smaller objects appear farther away than larger ones 

Objects that appear clearer are perceived as closer, while hazy objects seem farther away

Parallel lines appear to converge as they recede into the distance

Color constancy, lightness constancy, shape constancy, and size constancy 

Consistent perception of color of objects although the amount of light changes 

Consistent perception of shade of objects although the amount of light changes 

Perception that object’s shape remains constant despite changing shape of retinal image 

Perception that the size of objects remains constant despite different sizes of images on retina