Sensation and Sensation and PerceptionPerception

Worksheet SolutionsWorksheet Solutions

Learning GoalsLearning Goals

�� What is the difference between sensation What is the difference between sensation and perception?and perception?

�� Sensation is the process of receiving Sensation is the process of receiving information from the environment.information from the environment.

�� Perception is the process of organizing this Perception is the process of organizing this information and making it meaningful.information and making it meaningful.

�� SensationSensation�� Refers to how our sense receptors and nervous Refers to how our sense receptors and nervous

system physically represent our external system physically represent our external environment (bottomenvironment (bottom--up).up).

�� PerceptionPerception�� How we mentally organize and interpret this How we mentally organize and interpret this

information (topinformation (top--down).down).

Learning GoalsLearning Goals

�� What is meant by the term What is meant by the term adaptationadaptation? ? �� Adaption refers to the process of ignoring Adaption refers to the process of ignoring

unimportant sensory information. unimportant sensory information. �� It allows us to deal with environments containing It allows us to deal with environments containing

large amounts of sensory inputs, such as different large amounts of sensory inputs, such as different background noises, while still focusing on background noises, while still focusing on significant ones.significant ones.

�� The gradual loss of attention to unneeded or The gradual loss of attention to unneeded or unwanted sensory informationunwanted sensory information

�� Examples?Examples?

Learning GoalsLearning Goals

�� What is white light?What is white light?�� White light is light as it originates from the sun or White light is light as it originates from the sun or

a light bulb*.a light bulb*.

�� What is color?What is color?�� White light bounces off at different speeds which White light bounces off at different speeds which

results in the perception of color.results in the perception of color.

�� What do we call light outside the visible What do we call light outside the visible spectrum?spectrum?�� Ultraviolet or infraredUltraviolet or infrared

VisionVision

�� Dominant senseDominant sense�� LightLight

�� Light originates from the sun or a light source as Light originates from the sun or a light source as white lightwhite light

�� What we interpret as color is simply different light What we interpret as color is simply different light wavelengthswavelengths

�� We only see a small slice of the whole spectrum of We only see a small slice of the whole spectrum of electromagnetic rayselectromagnetic rays

�� Wavelength determines color (or hue)Wavelength determines color (or hue)�� Intensity determines brightness of a colorIntensity determines brightness of a color

VisionVision

VisionVision

VisionVision

�� Cornea Cornea �� The clear outer The clear outer covering of the eyecovering of the eye, behind which , behind which

there is fluidthere is fluid

�� IrisIris�� Colored circular muscleColored circular muscle that opens and closesthat opens and closes�� Forms larger and smaller circles to Forms larger and smaller circles to control the control the

amount of light getting into the eyeamount of light getting into the eye�� Have you ever walked out of a dark theater? Have you ever walked out of a dark theater?

VisionVision

�� LensLens�� FocusesFocuses the objects you see on to the back of the the objects you see on to the back of the

eye, where there are receptorseye, where there are receptors�� If the lens isnIf the lens isn’’t shaped correctly, objects will blurt shaped correctly, objects will blur�� Eyeglasses change the angle as which the light hits Eyeglasses change the angle as which the light hits

the lens, so they land properly on the receptors the lens, so they land properly on the receptors

VisionVision

�� PupilPupil�� An An openingopening that changes size as the iris muscles that changes size as the iris muscles

movemove to cover and uncover the lensto cover and uncover the lens�� Controlled by psychological factorsControlled by psychological factors

•• Gets smaller if weGets smaller if we’’re disgustedre disgusted•• Gets larger if we see something we really like, or if Gets larger if we see something we really like, or if

there is strong emotional arousal of any kindthere is strong emotional arousal of any kind

VisionVision

�� RetinaRetina�� When light entering the When light entering the

eye hits the eye hits the back of the back of the eyeballeyeball, it hits the retina, it hits the retina

�� Contains millions of Contains millions of receptors for lightreceptors for light

�� Blind spotBlind spot-- where the where the optic nerve connects to optic nerve connects to the eye. (no receptors the eye. (no receptors are located there)are located there)

VisionVision

�� What is the difference between Rods and Cones?What is the difference between Rods and Cones?�� The retina is made of two types of receptorsThe retina is made of two types of receptors

•• RodRod-- shaped like a rod shaped like a rod �� sensitive to violetsensitive to violet--purple range of wavelengthspurple range of wavelengths, but we , but we

only only ““seesee”” black and white with themblack and white with them�� We use these for We use these for night visionnight vision

•• ConeCone-- shaped like a coneshaped like a cone�� Used for Used for color and daylight visioncolor and daylight vision�� Shut off at nightShut off at night�� Respond best to wavelengths in the red rangeRespond best to wavelengths in the red range�� Located towards the center of a retina Located towards the center of a retina

VisionVision

�� When light is dim, why is it best to look When light is dim, why is it best to look slightly away from an object?slightly away from an object?�� At night we rely on the rods in our eyes.At night we rely on the rods in our eyes.�� These are These are located on the sides of the retinalocated on the sides of the retina..

�� What are the three colors that make up What are the three colors that make up vision?vision?�� Red, Blue, GreenRed, Blue, Green

VisionVision

�� Color VisionColor Vision�� All colors we see are red, blue, and green, or a All colors we see are red, blue, and green, or a

mixture of the three.mixture of the three.

�� Color BlindnessColor Blindness�� The inability to perceive certain colors, such as red The inability to perceive certain colors, such as red

or green.or green.

ColorColor

�� What does it mean to be completely color blind?What does it mean to be completely color blind?�� You respond to light only with the rods in your eyes.You respond to light only with the rods in your eyes.

�� How is this different from the form of color How is this different from the form of color blindness that is most common?blindness that is most common?�� Most color blind people see only the yellowMost color blind people see only the yellow--blue blue

range.range.�� They cannot see red or greenThey cannot see red or green�� Most color blind people are men, but there are color Most color blind people are men, but there are color

blind women also.blind women also.

AfterimagesAfterimages

�� When we stare at something, chemicals in When we stare at something, chemicals in the cones are used.the cones are used.

�� When we look away, unused chemicals When we look away, unused chemicals are released in order to balance the are released in order to balance the system.system.

�� This causes us to This causes us to ““seesee”” an after image.an after image.

HearingHearing�� Another name for hearing is Another name for hearing is ““auditionaudition””..�� We hear sound waves, much like we see light We hear sound waves, much like we see light

waves.waves.�� Sounds vary in Sounds vary in pitchpitch, , how high or low a sound ishow high or low a sound is�� Timbre Timbre refers to the refers to the complexity of a tonecomplexity of a tone�� Sounds vary in Sounds vary in intensityintensity, it is , it is the loudness of a the loudness of a

soundsound (how loud they are)(how loud they are)�� DecibelsDecibels is a unit of measurement.is a unit of measurement.

•• The intensity of a sound (its loudness) is measured in The intensity of a sound (its loudness) is measured in decibels.decibels.

HearingHearing

�� Intensity is measured in Intensity is measured in decibelsdecibels

HearingHearing

�� EardrumEardrum�� Piece of skin stretched tightly over the entrance to Piece of skin stretched tightly over the entrance to

the rest of the ear.the rest of the ear.�� It vibrates and causes a small bone in the ear to It vibrates and causes a small bone in the ear to

vibratevibrate..

�� CochleaCochlea�� SnailSnail--shapedshaped part of the earpart of the ear filled with fluid and filled with fluid and

small hairs that vibrate to incoming sound.small hairs that vibrate to incoming sound.

HearingHearing

�� Hair cells (cilia)Hair cells (cilia)�� Contain hair like extensions called Contain hair like extensions called ciliacilia that are that are

tuned to tuned to receive different frequenciesreceive different frequencies..

�� Auditory NerveAuditory Nerve�� Carries the information about sound to the brain.Carries the information about sound to the brain.�� Which part of the brain?Which part of the brain?

TouchTouch

�� Our skin contains three types of Our skin contains three types of cutaneouscutaneous, or , or touch, receptorstouch, receptors�� PressurePressure�� Changes in Changes in temperaturetemperature�� InjuryInjury or poison or poison

SmellSmell

�� Smell is also called Smell is also called olfactionolfaction�� CiliaCilia are hairs that collect odor moleculesare hairs that collect odor molecules�� Olfactory bulbsOlfactory bulbs communicate information communicate information

about odor molecules to the brain.about odor molecules to the brain.

PheromonesPheromones

�� Animals use smell to communicate sexual Animals use smell to communicate sexual interest.interest.

�� They send out odor chemicals called They send out odor chemicals called PheromonesPheromones

�� Perfume and cologne companies try to Perfume and cologne companies try to imitate this effect in humans.imitate this effect in humans.

�� AxeAxe AnarchyAnarchy

TasteTaste

�� We have four types of taste receptorsWe have four types of taste receptors�� Salty, sour, sweet, bitterSalty, sour, sweet, bitter�� Babies do not crave saltBabies do not crave salt�� The craving for salt increases gradually with The craving for salt increases gradually with

age then tapers off.age then tapers off.

Perceptual ConstantsPerceptual Constants

�� SizeSize�� objects are perceived as remaining the same objects are perceived as remaining the same

size regardless of distance.size regardless of distance.�� Color and BrightnessColor and Brightness

�� Objects are perceived as remaining the same Objects are perceived as remaining the same color and brightness regardless of lightingcolor and brightness regardless of lighting

�� SpaceSpace�� The ability to keep objects in the environment The ability to keep objects in the environment

steadysteady

SizeSize

Color and BrightnessColor and Brightness

SpaceSpace

Visual cliffVisual cliff

�� Humans have depth perceptionHumans have depth perception�� It occurs very early in life (before your first It occurs very early in life (before your first

birthday)birthday)�� EXPERIMENTEXPERIMENT

Retinal Disparity & Visual TextureRetinal Disparity & Visual Texture

�� How do they help in depth perception?How do they help in depth perception?�� Each eye sends a slightly different Each eye sends a slightly different

message to the brainmessage to the brain�� This This disparitydisparity helps us perceive depthhelps us perceive depth�� Rough objects will seems nearRough objects will seems near�� Smooth object will seem farther awaySmooth object will seem farther away

Gestalt PsychologyGestalt Psychology

�� Tend to perceive the world in wholesTend to perceive the world in wholes�� Gestalt means whole, shape, or form.Gestalt means whole, shape, or form.�� SimilaritySimilarity

�� We group like thingsWe group like things�� One of these things is not like the otherOne of these things is not like the other

�� ClosureClosure�� We have fill in the details to complete a pictureWe have fill in the details to complete a picture�� I donI don’’t have a problem with closuret have a problem with closure……

�� ProximityProximity�� We group things that are nearWe group things that are near�� How many times do the players wearing WHITE pass How many times do the players wearing WHITE pass

the ball?the ball?

What is an illusion?What is an illusion?

�� Caused by an inaccurate perceptionCaused by an inaccurate perception�� MullerMuller--LyerLyer illusionillusion

�� One line is perceived as being farther away One line is perceived as being farther away so we so we mentallymentally stretch it. This make it stretch it. This make it appearappearlonger.longer.

Reversible FigureReversible Figure�� One object is interpreted in an alternate One object is interpreted in an alternate

mannermanner

Subliminal PerceptionSubliminal Perception

�� Occurs below mental awarenessOccurs below mental awareness

What is your Psychological IQ?What is your Psychological IQ?

�� 1. The words sensation and perception mean the 1. The words sensation and perception mean the same thing.same thing.�� FALSE FALSE –– gathering and processing informationgathering and processing information

�� 2. Only men are color blind.2. Only men are color blind.�� FALSE FALSE –– men do men do outnumberoutnumber womenwomen

�� 3. Generally speaking, people are able to block 3. Generally speaking, people are able to block out background noise, focusing on only those out background noise, focusing on only those sounds that are important to them.sounds that are important to them.�� TRUE TRUE –– this is adaptationthis is adaptation

What is your Psychological IQ?What is your Psychological IQ?

�� 4. Scientists have been able to prove the 4. Scientists have been able to prove the existence of mental telepathy by conducting existence of mental telepathy by conducting carefully controlled experiments.carefully controlled experiments.�� FALSEFALSE

�� 5. People who have sight in only one eye have no 5. People who have sight in only one eye have no depth perception.depth perception.�� FALSE FALSE –– there are other clues that compensatethere are other clues that compensate

�� 6. To a large extent, what we see is influenced by 6. To a large extent, what we see is influenced by what we expect to see.what we expect to see.�� TRUE TRUE –– optical illusionsoptical illusions

What is your Psychological IQ?What is your Psychological IQ?�� 7. People7. People’’s pupils frequently enlarge when they see s pupils frequently enlarge when they see

something that pleases them.something that pleases them.�� TRUETRUE

�� 8. Children do not have depth perception until about 8. Children do not have depth perception until about the age of three or four.the age of three or four.�� FALSE FALSE –– visual cliff experimentvisual cliff experiment

�� 9. Our tongues have only four different types of taste 9. Our tongues have only four different types of taste buds.buds.�� TRUE TRUE –– sweet, sour, salt, bittersweet, sour, salt, bitter

�� 10. The sense of touch is our most animal10. The sense of touch is our most animal--like sense.like sense.�� FALSE FALSE –– it is the sense of smellit is the sense of smell

EYEEYE

B= irisC= pupilD= corneaE= lensF= retinaG= optic nerve

EAREAR

A= bones (hammer, anvil, stirrup)B= semicircular canalsC= auditory nerveD= cochleaE= eustachian tubeF= eardrumG= auditory canal