sensory perception 2012_

Akiyoshi KITAOKA, Professor

What do you see?Visual Illusions

• Mermaid but not a mermaid• http://www.youtube.com/watch?

v=h7kyEarMqUo&list=UU0W6lFhlMFdbK8dGTTTfEqw&index=23&feature=plcp

• http://www.youtube.com/user/hachiyakazuhiko#p/u/12/KJFozypEMd4

Saccade?

• http://www.junji.org/saccade/index.htm

Sensation• Process of receiving information from the

environment.• What kind of Info?

1.Light2.Sound3.Chemicals: taste, smell4.Pressure, Temp, Pain5.Orientati on, Balance

If you had to lose one of your senses which one would you choose to lose? Why?

1.Light2.Sound3.Chemicals: taste, smell4.Pressure, Temp, Pain5.Orientati on, Balance

PerceptionProcess of organizing sensory information to make it meaningful.

ExperimentWhich is heavier?

Absolute Threshold

• The Level of sensory stimulation you need in order to sense something 50% of the time

Vision Absolute Threshold Vision Absolute Threshold

Candle flame seen from _______ kilometers away at night

30

Hearing Absolute Threshold

Watch ticking under quiet conditions from ___ meters away

• 20 change to meters

6 meters

Touch Absolute Threshold

• A bee’s wing falling on your cheek from ____ centimeters above

1

Smell Absolute Threshold

• In how many rooms can 1 drop of perfume be sensed?

3

Taste: Absolute Threshold1 teaspoon of sugar in how many

liters of water?

• 7.5 liters of water

Sense of Taste

• Taste Receptors– Five kinds of Taste Receptors

• Sweet• Sour• Salt• Bitter• New one? Umami

Umami Examples

• Japanese: dashi with kombu seaweed and dried bonito flakes

• Chinese: add Chinese leek and cabbage with chicken soup, as in the similar Scottish dish of cock-a-leekie soup

• Italians: combine Parmesan cheese on tomato sauce with mushrooms.

Taste Buds on Tongue

Taste Receptors• Taste Buds

TONGUE SURFACETASTE BUD

How do your taste needs develop?

• Baby salt needs? Teen salt needs? Adult salt needs?

• Baby sugar needs? Teen sugar needs? Adult sugar needs?

Salt Needs

Older people

Need for salt returns!

Later adulthood

Needs for salt tapers offFew months old baby to adulthood

want salt

Newborn

does not need salt

Sugar Needs

• Built-in• Body needs sugar for energy• Too little sugar makes you tremble

Bitterness detectors: why do we need them?

• Play an important role detecting poison.• Food gone bad has a sour taste

Taste Experiment

• 1. Blindfold yourself.• 2. Open your mouth wide, say “Ah”• 3. Wait for the food to touch your tongue

(Partner you will place item on tongue)• 5. Taste the food.• 6. Identify the food• 7. Taste in total five different items.• 8. Switch with your partner

Critical Thinking

• You have to deliver a brief speech to your class on salt and sugar needs. What do you say?

ARE YOU A SUPERTASTER?

Use blue food coloring and a plastic reinforcement ring for a three-hole binder (paper reinforcement rings get mushy). Use a cotton swab to wipe some blue food coloring on the tip of your tongue. Place the ring on your tongue. If you are a medium taster, you'll see only a few little “mushrooms" inside the ring's opening. If you're a supertaster, you'll find more than 25 of them within the circle. How many do you count?

Are you a supertaster questionnaire?

• http://www.bbc.co.uk/science/humanbody/body/interactives/supertaster/

Taste

DISCUSSION QUESTIONS

1.What might be some evolutionary advantages to being a supertaster -- for animals and humans?

2.What other factors might explain a person's food preferences?

Pair Talk

• 1. What is the difference between sensation and perception?

• 2. What is the weakest light that can be seen? The lightest touch that can be felt? What are these minimum detection levels called?

Hearing

• Sound waves:– Faster or slower than light waves?

• Many animals use sound more than humans.– For example?

• Dolphin clicks• Bats

Sound Characteristics

• Pitch– How high or low the sound is

• Timbre– Complexity of the tone

• Eg. Differences between guitar, piano, trombone

Sound Characteristics

• Intensity– Measured in decibels– Above 130: painful– 70 decibels: can disturb sleep: fridge– 50 decibels: can help sleep if sound is continuous

My what big ears you have!

• Does ear size make a difference?

eardrum

•Piece of skin stretched tightly over the entrance to the rest of the ear

Bones

•Vibration causes bones to vibrate too.

•3rd bone cochlea is filled with fluid and hair cells

Hair cells

•Give off electrical particles

Auditory

Nerve

•Electrical particle goes to the brain where sound is interpreted.

Why?

• Eyes in front?• Ears on the side?

How does sound affect you?How to listen?

• Bird Song http://www.youtube.com/watch?v=Yhx3umz0oDU&feature=related

• Video• http://www.ted.com/talks/

evelyn_glennie_shows_how_to_listen.html

Hearing Websites

• Hearing Loss: what it sounds like http://www.cdc.gov/niosh/mining/topics/hearingloss/hlsoundslike.htm

• Pets and hearing: http://www.safeandsoundpets.com/XL.html

• High Frequency tones http://www.freemosquitoringtone.org/

http://www.ted.com/talks/michael_shermer_the_pattern_behind_self_deception.html

• Michael Shermer says the human tendency to believe strange things -- from alien abductions to dowsing rods -- boils down to two of the brain's most basic, hard-wired survival skills. He explains what they are, and how they get us into trouble.

What’s This?

• In pairs, walk hurriedly around the room• The first student points to objects asking "What's this?" • The second student must quickly answer with anything that

the object is not. – If it's a doorknob, reply that it's The Hubble Telescope or a vampire. – This is surprisingly difficult for our pattern-based brains– It's the questioner's job to make sure that the answerer is not

making it easier by simply going through a list – If they are, a friendly and high-pitched "No!" from the questioner

can signal that the answer is not good enough. – This continues until brain-freeze occurs in the answering student,

which it will, then they switch roles and continue.

What’s This? Advanced Version

• A more advanced version can be done by NOT allowing for any association at all between

succeeding answers • EXAMPLE:

– "What's this?" "A telescope" "What's this?" "A magnifying glass"

• This answer receives a little "No!" from the questioner

Smell: Olfaction

• (Not good, Good, Very Good) in humans

• Odor and emotional event– Very hard to forget (Engen, 1987)

Odor Molecules attach to hair in

the nose

Electrical signal sent to Olfactory

bulb

Sends code to brain for

interpretation

• Animals release this odor chemical to communicate sexual interest

Smell and Taste• Smell is (less, more) important than taste in

eating.• What happens when you hold your nose and eat?Experiment

Get a yogurt containerBlindfold yourselfPlug your noseTaste the food and identify all of them. Use the toothpick or clean fingers

Pheremones in Humans

• ??• http://www.youtube.com/watch?

v=8qskcmabLuQ

Touch=Cutaneous Senses

3 types of receptors– Pressure– Changes in Temperature– Pain – Burn: Active Continuously: records injury or poison

Psychology and you, page 103

• In Focus problem• Your fingers are cold after handling ice or

snow. • You run your fingers under warm water, but

the water seems hot.• Can you think of a theory about cutaneous

receptors to explain this?

Task

• Your task is to develop a list of consequences for the loss of cutaneous senses.

• 1. What are the consequences for the loss of the ability to process touch information? (pressure, texture, vibration)

• 2. What are the consequences for the loss of the ability to sense temperature? Loss of the ability to sense pain?

• 3. What do these consequences suggest about how evolutionary pressures may have influenced the development of cutaneous sense?

Perception

• Put together sensory information so you can understand the input coming in.

• Involves Interpretation and Expectation.

Perceptual Constancies

• Brain need to keep things the same in order to maintain order and make sense of the environment.

• Causes use to experience illusions

Size Constancy

• Definition: The ability to remember how large an object is no matter where it is.

• Our perceptions of the size of objects are relatively constant despite the fact that the size of objects on the retina vary greatly with distance.

Do the railroad tracksget smaller?

Colour Constancy

• Colours are perceived as the same• Move apple to a darkened room, does it

change colour?• Only works with things we know the colour of

already.

• Are these fruit the same colour?• Why do we perceive them the same colour?

Brightness Constancy

• The tendency for a visual object to be perceived as having the same brightness under widely different conditions of illumination.

http://www.thefreedictionary.com/brightness+constancy

Example of Brighness Constancy:White Paper

• A sheet of white paper seen in the bright sunlight reflects a very different amount of light than the same sheet of paper seen later that night in a softly lighted room.

• Yet we perceive the paper as having the same whiteness in each case.

Shape Constancy

• Shapes of things stay the same.

Shape Constancy

• Everybody has seen a plate shaped in the form of a circle. When we see that same plate from an angle, however, it looks more like an ellipse.

Space Constancy

• The visual world appears to us as stable and unmoving despite continuing movement of the retinal image

http://kybele.psych.cornell.edu/~edelman/Course/perception/node21.html

Space ConstancyHow?

Space Constancy

• Things appear steady to us because we either focus on the outside as moving OR

• When driving, we use self-motion – Cars moving in front of us are held

steady in our minds– Only a major change in motion is

perceived.– Small changes in speed are not easily

perceived• Thus rear enders.

OR we perceive thatwe are moving

Depth Perception

• Ability to see objects 3D and to judge distance.

• Visual Cliff Experiment with babies• Showed babies have depth perception

from beginning.

Visual Cliff Experiment

• http://www.youtube.com/watch?v=4OelrPzpQ6Q

Case Study #1: page 111, Text

• Virgil

Seeing is BelievingCase Study

handout

How do you see Depth?

• See different things with each eye• Use the angle of the eyeball to gauge distance

Retinal Disparity

Texture Gradient

• We use texture to give us clues as to how far away the object is.

• Texture:– How smooth or rough something is

• Gradient:– Different levels of texture we see at different

distances

Task

• 1. List occupations in which good vision, hearing, or other senses would be important for success. Be sure to list the reasons why. Are there occupations in which poor ability in one of the senses would be dangerous?

Perceptual Organization

• Gestalt Psychology– Make things into wholes– Use Perceptual cues to make sense of things

Gestalt Principles of Perceptual Organization

• Principle of Common Region

Principle of similarity

• Here, organization depends on the shape.

Gestalt Principles

Principle of similarityGestalt Principles

Principle of Similarity

What principle is being illustrated

here?

Similarity, font

Gestalt Principles

Gestalt PrinciplesPrinciple of Proximity

– objects or shapes that are close to one another appear to form groups

Gestalt Principles

• Principle of Closure or Good Continuation– Elements group to form smooth lines

Figure Ground: Has to be one figure and one ground

• Reversible Figure

More examples Gestalt principles

• http://graphicdesign.spokanefalls.edu/tutorials/process/gestaltprinciples/gestaltprinc.htm#similarity

Illusions

We perceive something inaccurately=> misperception

http://www.impactlab.net/2006/03/09/amazing-3d-sidewalk-art-photos/

Colour Constancy Illusions

• http://www.ted.com/talks/beau_lotto_optical_illusions_show_how_we_see.html

Reversible Figure

• Necker Cube: 2 ways to view this cube

Reversible Figure

Illusion: paper shelf

• How is it done?

WHICH MOON IS IN LINE WITH THE RIGHT

SIDE OF THE ROAD?

Questions

• Critical Thinking:– Draw an original example for each of the following

principles of perceptual organization: similarity, closure, proximity, and figure ground. 2 points per = 8 points

Discuss in pairs: Page 120#2, #3, #5, #7

Then, we will discuss together

Sensation: Vision

• How is colour seen?

What is the sun or light bulb colour?

• White

When do you see colour?

• Waves of white light hit objects and bounce back to us at different speeds or frequencies.

• All the colours are absorbed in the banana except for yellow which is reflected back.

No such thing as colour

• Different light wavelengths have different names

• Eyes have different receptors for different wavelengths

Examples of different wavelengths

Which wavelengths do we not see?• Infrared: Radio, tv, microwaves• Ultraviolet: x-rays, gamma rays, cosmic rays

What do bees see?

http://cas.bellarmine.edu/tietjen/images/Bees&Flowers.htm

What do Snakes see? Snakes have two sets of eyes.

One set is the normal eyes that you see, and they detect color quite well.

But they also have vision pits that detect heat and “see” living creatures like an infrared

detector. Snake eye vision simulator program:

http://www.soft3k.com/Snake-Eye-Vision-p12913.htm

Light Waves and Shotgun pellets

Top ViewHeavy Rod concentration

Heavy Cone concentration

C o l o u re d c i rc u l a r m u s c l et h a t o p e n s a n d c l o s e s i n t o l a rg e r o r s m a l l e r c i rc l e s t o c o n t ro l t h e a m o u n t o f l i g h t c o m i n g i n t o t h e e ye

What part of the eyedo contact lenses cover?

Does the road makean acute or obtuse (more than 90, less than 180)

Angle?

Lens

Helps to focus objects to the back of the eye. If lens is not shaped correctly the images fall in the wrong spot.

• Glasses change the angle at which the image falls

Retina

• Lights hits the retina• Optic nerve area: no receptors thus blind spot• Experiment

– Draw this on a piece of paper– Close your right eye, look at the plus sign and then

move your face forward till dot disappears.– Close your left eye, look at the dot till the plus

disappears.

Blind Spot

Blind Spot Experiments

More Blind Spot ExperimentsTextbook page 94

Colour isseen by what part of the eye?

Heavy Rod concentration

Heavy Cone concentration

Colour: Rods and Cones

• Rods: violet – purple range see black and white with them.

• Sensitive in low light conditions• They keep blue objects visible in the darkness• Packed into the sides of the retina

Cones

• Used for daylight conditions• Respond best to red wavelengths• Don’t work with low light• Located in the center of the retina

Colour Defects

• Colour blindness– The inability to tell

the difference

between certain colours

• Most common form of colour blindness is which colour?

Colour Blind Test

Textbook: page 96

Afterimages

Occurs during the course of visual perception when the optical stimulus suddenly disappears.

Example:Put a piece of hot coal on a string. When not moving it is a dot, but when moving it becomes a line.

1765,Chevalier Patrice d’Arcy (1725–79): afterimage lasts as long as the time taken for the piece of coal to make one revolution, i.e., a minimum of 0.133 or 8/60th of a second. Consequently, in the case of film footage, 16 sequential images per second are perceived as continuous movement.

http://www.youtube.com/watch?v=jrhtpLHwifo&feature=relatedDownloaded from:http://wernernekes.de/00_cms/cms/front_content.php?idart=504

Afterimage: why does it occur?

Chemicals in the eye get used up when looking at images. Ie. Eyes get “bleached”

When you look away, the chemicals are still in your eye and you see the image (but in different colours).

Cones system tries to restore balance after looking at something. Don’t normally see them because images are replaced all the time.

Afterimages Occurs because the eyes want to stay in balance.

Try these:http://faculty.washington.edu/chudler/after.html

Super Taster Questionnaire, Visual Illusions

• Experience some on-line• Can you explain these illusions? Why are your

eyes being fooled?

Review

• From questions on page 97 of text. Do by yourself.• 1. What’s the difference between sensation and

perception?• 2. Why do some objects appear blue to us, while

others appear red?• 3. Why is there a blind spot?• 4. Name what each part of the eye does: rods, cones,

iris, lens• 5. What colours does a colour blind person usually not

see?

Subliminal Perception

• What is it?

• Does it work? Read page 98-99. Discuss in small groups

Subliminal perception occurs whenever stimuli presented below the threshold of awareness are found to influence thoughts, feelings, or actions.

Unconscious language learning

• Do they pick up on the concealed pattern when tested? “The answer is yes,” said Dr. Williams, whose research was funded by the Economic and Social Research Council. “We found significantly above-chance selection of sentence constructions that were ‘grammatically correct’ according to the hidden pattern. Yet, the participants had no awareness of what they had learned or how. Moreover, we were able to show learning of the same material by native speakers of two typologically very different languages, English and Cantonese.”

• Interestingly, picking up the hidden pattern unconsciously doesn’t always happen – if, for instance, the hidden pattern is linguistically unnatural, such as a correlation with whether an object makes a sound or not. “One explanation could be that certain patterns are more accessible to language learning processes than others. Perhaps our brains are built equipped to expect certain patterns, or perhaps they process some patterns better than others,” he added.

Make up 2 True or False Questions for the quiz tomorrow.

Subliminal Language Learning?• The research provides a window onto unconscious learning processes in

the mind and highlights an important element that has practical implications for language teaching. In each test, the learner’s attention was directed to the part of the sentence that contained the hidden pattern. By directing attention, it seems that other elements of the sentence construction are picked up unconsciously.

• “In a teaching situation, merely teaching the rules of a language may not be the only answer,” explained Dr. Williams. “Instead, using tasks that focus attention on the relevant grammatical forms in language could help learners access unconscious learning pathways in the brain. This would greatly enhance the speed of acquisition of a second language.”

• Provided by University of Cambridge

Subliminal Advertising

• http://www.youtube.com/watch?v=3iJWyiaXLLw