Sensations vs. Perceptions
Transcript of Sensations vs. Perceptions
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Chapter 5Chapter 5
PERCEPTIONPERCEPTION
Sensations vs. PerceptionsSensations vs. Perceptions
Perception Our interpretations of the real world
How do Sensations Become Perceptions A perception begins with some stimulus
which activates sense receptors Once activated, a sense organ transforms
energy into electrical signals or impulsesthat travel to the brain
Sensations vs. Perceptions (continued)Sensations vs. Perceptions (continued)
Parts of the Brain transform electrical signalsinto basic sensationsSensations are your first experiences ofoutside stimuli They consist of meaningless bits of sensory
information
Each of us has a unique set of experiencesthat may automatically add meanings,feelings, or memories to our perceptions
Sensations vs. Perceptions (continued)Sensations vs. Perceptions (continued)
The brain automatically assemblesmany thousands of individual sensationsinto a meaningful pattern or imagewhich is called perception Personalized interpretations rather than
true copies of things in the real world
Enduring Issues in PerceptionEnduring Issues in Perception
Role of Learning Newborns’ senses are all functional and
some degree of perceptual ability isprobably innate
Enduring Issues in Perception (Enduring Issues in Perception (concon’’tt))
Parts vs. the Whole Feature Analysis
The theory that weperceive a form onthe basis of arelatively smallcollection of features,which can becombined, rotatedand expanded(Structuralism)
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Enduring Issues in Perception (Enduring Issues in Perception (concon’’tt))
Gestalt School Psychologists who
believe that ameaningful overallpattern (Gestalt) isperceived before itsparts are recognized
“The whole is morethan the sum of itsparts”
Enduring Issues in Perception (Enduring Issues in Perception (concon’’tt))
Perceptual Illusions Used to determine how people process
perceptual informationBottom-Up vs. Top-Down Processing Bottom-Up: sensory receptors to brain Top-Down: perceiver’s expectations &
context play a role from the beginning Perceptual Sets:
learned expectations that are based on ourpersonal social or cultural experiences. Theseexpectations change or bias what we see.
Functions of PerceptionFunctions of Perception
Where is it? – Location Attention
Automatic – distinguishing object frombackground
Deliberate – allocation of attention
Depth Perception Ability to experience depth in visual perception
(relative & absolute distances)
Functions of Perception:Functions of Perception:Depth Perception Depth Perception (continued)(continued)
Binocular Depth Cues – depend uponthe movement of both eyes Convergence – based on signals sent from
the muscles that turn the eyes Binocular (Retinal) Disparity – depends on
the distance between the eyes Stereopsis 3-D Glasses
Functions of Perception:Functions of Perception:Depth Perception Depth Perception (continued)(continued)
Monocular Depth Cues Depend upon the signals sent from one
eye Determined by how objects are arranged in
the environment
Functions of Perception:Functions of Perception:Depth Perception Depth Perception (continued)(continued)
Motion ParallaxRelative SizeConstancyLinear PerspectiveTexture GradientAerial PerspectiveOcclusion (Interposition)
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Functions of Perception (continued)Functions of Perception (continued)
Illusions of Depth Muller-Lyer, Ponzo, Ames Room, Vista
Paradox (pg. 146) If our perceptual cues are changed, our
otherwise reliable perceptual processes canbe deceived
Functions of Perception (continued)Functions of Perception (continued)
Auditory Localization Differences in how and when a sound
reaches the two ears enable the brain tocompute the location of its source
Functions of Perception (continued)Functions of Perception (continued)
Is it Moving? – Movement Motion Perception
We distinguish between changes inenvironment that are caused by movements inthe environment and changes that are causedby our own movements
Functions of Perception (continued)Functions of Perception (continued)
Illusions of Motion Apparent Motion (Phi Phenomenon) Induced Motion (moon appears to move
through clouds) Motion Aftereffect (train stops and objects
outside appear to move backwards)
Functions of Perception (continued)Functions of Perception (continued)
What is It? – Form Feature Analysis
Involves the recognition of features (lines,intersections & corners) as well as location,orientation, contrast, and fuzziness.
Features are grouped into clusters
Functions of Perception (continued)Functions of Perception (continued)
Gestalt View (Principles) Figure-Ground Distinction
In organizing stimuli, we tend to automaticallydistinguish between a figure and a ground
The figure with more detail, stands out againstthe background, which has less detail
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Functions of Perception (continued)Functions of Perception (continued)
Gestalt View (continued)Grouping Similarity Proximity Continuity Simplicity Closure
Subliminal PerceptionSubliminal Perception
Subliminal Messages Brief auditory or visual messages that are
presented below the absolute threshold, whichmeans that there is a <50% chance that they willbe perceived
Although subliminal messages may be ineffectivein changing behavior, there is evidence thatemotions may unknowingly or subliminallyinfluence perception
Cultural Diversity:Cultural Diversity:Changing PerceptionsChanging Perceptions
Besides affecting social and personalvalues, cultural influences can alsoaffect our perception of color depth,constancy, and motion
ESP: Extrasensory Perception
A group of psychic experiences thatinvolve perceiving or sendinginformation outside normal sensoryprocesses or channels Includes 4 general abilities
Telepathy Precognition Clairvoyance Psychokinesis
ESP: Extrasensory Perception (con’t)
Most academic psychologists do not yetaccept the existence of psychic powersor extrasensory perception, which arecollectively called psi phenomena Trickery Questionable methodology (unreliable
scientific procedures)
Application: Creating PerceptionsApplication: Creating Perceptions
Creating Reality Virtual Reality
A perceptual experience of being inside anobject, moving through an environment, orcarrying out some action – that is entirelysimulated by a computer
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Application: Creating PerceptionsApplication: Creating Perceptions(continued)(continued)
Creating Impressions Social psychologists have concluded that
facial features have a significant affect onour first impressions of people
First impressions are also influenced byracial stereotypes, both positive andnegative, based on physical features suchas skin and hair color
Life-Span Changes in PerceptionLife-Span Changes in Perception
Sensory World of Infant A newborn’s distance senses (sight &
hearing) are not as developed as the senseof touch, smell & taste
Sight is probably the least developed sense They have poor depth perception and are
unable to see the full color spectrum
By the age of 7 months, babies’ vision &hearing are acute
Life-Span Changes in PerceptionLife-Span Changes in Perception
The Aging Senses Sensory systems begin aging during the
40s and may become severe by the 70sand 80s
Life in a noisy environment may contributeto hearing loss
Medication may reduce taste sensitivity