PERCEPTIONPERCEPTION

is the process of organizing and interpreting is the process of organizing and interpreting sensory information.sensory information.

A 

BIRD  

IN THE 

THE HAND

Selective AttentionSelective Attention

The focusing of conscious awareness on a The focusing of conscious awareness on a particular stimulus.particular stimulus.

For example: For example:

1. “the cocktail party effect”1. “the cocktail party effect”

2. in a restaurant when you listen to other 2. in a restaurant when you listen to other people have a conversation. people have a conversation.

3. What other examples can you think of?3. What other examples can you think of?

PERCEPTUAL ILLUSIONSPERCEPTUAL ILLUSIONS

Muller-Lyer IllusionMuller-Lyer Illusion

Which line is bigger?Which line is bigger?

The Ames RoomThe Ames Room

Visual Capture: Visual Capture: vision dominates the other senses.vision dominates the other senses.

Example: 3D movie, roller coaster rideExample: 3D movie, roller coaster ride

PERCEPTUAL ORGANIZATIONPERCEPTUAL ORGANIZATION

FORM PERCEPTIONFORM PERCEPTIONFigure and GroundFigure and Ground-the -the

organization of the visual organization of the visual into objects (the figures) into objects (the figures) that stand out from their that stand out from their surroundings. (the ground surroundings. (the ground is the background in is the background in which the individual which the individual stands)stands)

-The following slides are -The following slides are examples of figure & examples of figure & groundground

FORM PERCEPTIONFORM PERCEPTION

Can you see Can you see the old the old

woman? woman? Can you see Can you see

the young the young woman?woman?

Do you see a vase? Or two faces?Do you see a vase? Or two faces?

What do you see in this image?

Is this a bunny or is this a duck?Is this a bunny or is this a duck?

Examples of GroupingExamples of Grouping

Grouping-we organize the figure into a Grouping-we organize the figure into a meaningful form so that people can make meaningful form so that people can make sense of what they see.sense of what they see.

Figure & GroundFigure & Ground

(previous slides are examples of- the vase (previous slides are examples of- the vase or 2 faces, and the dog)or 2 faces, and the dog)

ProximityProximity-group nearby figures together. -group nearby figures together.

SimilaritySimilarity-we group together figures similar to -we group together figures similar to one another.one another.

ContinuityContinuity-we perceive smooth continuous -we perceive smooth continuous patterns rather than discontinuous ones.patterns rather than discontinuous ones.

Form PerceptionForm Perception

ConnectednessConnectedness-when they are uniform and -when they are uniform and linked, we perceive spots, lines or areas as a linked, we perceive spots, lines or areas as a single unit.single unit.

Form PerceptionForm Perception

ClosureClosure--we fill in we fill in the gaps to create the gaps to create a complete, whole a complete, whole object.object.

Depth PerceptionDepth Perception

Is the ability to see objects in 3 dimensions.Is the ability to see objects in 3 dimensions.

Binocular cues-Binocular cues-depth cues, that depend on the depth cues, that depend on the use of two eyes.use of two eyes.

Examples:Examples: 1. Retinal Disparity1. Retinal Disparity-by comparing 2 images from the -by comparing 2 images from the

eyeballs, the brain computes distance-the greater the eyeballs, the brain computes distance-the greater the disparity (difference) between the 2 images, the closer disparity (difference) between the 2 images, the closer the object.the object.

-Try the floating finger sausage-Try the floating finger sausage..

Visual Cliff-a laboratory device for testing Visual Cliff-a laboratory device for testing depth perception in infants.depth perception in infants.

Monocular cuesMonocular cues-distance cues available to -distance cues available to either eye aloneeither eye alone

Examples:Examples:1.1. Relative size-if we assume that 2 objects Relative size-if we assume that 2 objects

are similar in size, we perceive the one are similar in size, we perceive the one that casts the smaller image to be further that casts the smaller image to be further away.away.

2.2. Interposition-if one object blocks the view Interposition-if one object blocks the view of another, we perceive it to be closer.of another, we perceive it to be closer.

3.3. Relative Clarity-because light from Relative Clarity-because light from distant objects passes through more distant objects passes through more atmosphere, we perceive hazy objects atmosphere, we perceive hazy objects as farther away than sharp, clear objects.as farther away than sharp, clear objects.

4.4. Texture gradient-a gradual change from Texture gradient-a gradual change from a coarse, distinct texture signals a coarse, distinct texture signals increasing distance. Objects further increasing distance. Objects further away appear smaller and more densely away appear smaller and more densely packed.packed.

5.5. Relative Height-we perceive objects higher in Relative Height-we perceive objects higher in our field of vision as farther awayour field of vision as farther away

6.6. Relative Motion-as we move, objects that are Relative Motion-as we move, objects that are stable may appear to move.stable may appear to move.

For exampleFor example: if while riding in a train you fix your : if while riding in a train you fix your gaze on an object-house-the objects closer to gaze on an object-house-the objects closer to the house appear to move backward. The the house appear to move backward. The nearer an object is, the faster it seems to nearer an object is, the faster it seems to move.move.

7.7. Linear Perspective-parallel lines such as Linear Perspective-parallel lines such as railroads appear to converge with railroads appear to converge with distance. The more the lines converge, distance. The more the lines converge, the greater their perceived distance.the greater their perceived distance.

8.8. Light and shadow-nearby objects reflect Light and shadow-nearby objects reflect more light to our eyes. Thus given 2 more light to our eyes. Thus given 2 identical objects, the dimmer one seems identical objects, the dimmer one seems farther away.farther away.

MOTION PERCEPTIONMOTION PERCEPTION

Stroboscopic movement is when the brain Stroboscopic movement is when the brain interprets a rapid series of slightly varying interprets a rapid series of slightly varying images. By flashing 24 still pictures each images. By flashing 24 still pictures each second, a motion picture creates second, a motion picture creates perceived movement. (a flip book)perceived movement. (a flip book)

The PHI PHENOMENONThe PHI PHENOMENON

is created when 2 or more is created when 2 or more adjacent lights blink on and off in adjacent lights blink on and off in succession, creating the illusion succession, creating the illusion of movement.of movement.

PERCEPTUAL CONSTANCYPERCEPTUAL CONSTANCY

Perceiving objects as unchanging, in size, Perceiving objects as unchanging, in size, color, shape, brightness, location and light.color, shape, brightness, location and light.

Is the ability to recognize than object Is the ability to recognize than object remains the same even when it produces remains the same even when it produces different images on the retina.different images on the retina.

PERCEPTUAL INTERPRETATIONPERCEPTUAL INTERPRETATIONSensory Deprivation-Infancy is a critical period Sensory Deprivation-Infancy is a critical period during which experience must activate the during which experience must activate the brain’s innate visual mechanisms.brain’s innate visual mechanisms.

Perceptual Adaptation-Human vision is Perceptual Adaptation-Human vision is adaptable. Given glasses that shift the world to adaptable. Given glasses that shift the world to the left or right or upside down, humans can the left or right or upside down, humans can adapt and see with ease.adapt and see with ease.

PERCEPTUAL SETPERCEPTUAL SETPerceptual Set Perceptual Set is the readiness to see objects is the readiness to see objects in a particular way based on expectations, in a particular way based on expectations, experiences, emotions & assumptions. experiences, emotions & assumptions. Perceptual set influences our everyday Perceptual set influences our everyday perceptions.perceptions.

Human Factors Psychology Human Factors Psychology (p255)(p255)

A branch of psychology that explores how A branch of psychology that explores how people and machines interact and how people and machines interact and how machines & physical environments can be machines & physical environments can be adapted to human behaviors.adapted to human behaviors.

Perceptions vary and may not be what a Perceptions vary and may not be what a designer assumes so human factors designer assumes so human factors studies how machines & physical studies how machines & physical environments can be improved i.e. safetyenvironments can be improved i.e. safety

EXTRASENSORY PERCEPTIONEXTRASENSORY PERCEPTIONThe claim that perception can occur apart from The claim that perception can occur apart from sensory input.sensory input.

Parapsychology Parapsychology is the study of paranormal is the study of paranormal

phenomena, including ESP (astrology, psychic phenomena, including ESP (astrology, psychic healing, communication with the dead, out of body healing, communication with the dead, out of body experiences.experiences.

Types:Types:

telepathy-mind to mind communicationtelepathy-mind to mind communication

clairvoyance-perceiving remote eventsclairvoyance-perceiving remote events

precognition-perceiving future eventsprecognition-perceiving future events

psychokinesis-mind over matterpsychokinesis-mind over matter

The Ganzfeld ProcedureThe Ganzfeld Procedure

Is the use of sensory deprivation to minimize Is the use of sensory deprivation to minimize distractions, hoping to detect faint distractions, hoping to detect faint telepathy signals.telepathy signals.