PERCEPTION“Every man takes the limits of his own field of vision for the limits of

the world.” ~ Arthur Schopenhauer

Class participation

You will need your notebook for …

1. Notes2. To participate in some of the activities*Some activities may be more effective in certain locations in

the room. Feel free to quietly move around the room.*Please ask questions and participate .

KI To what extent do you agree or disagree with this information?

Important DEFINITIONS

Knowledge, knowledge claim, a priori knowledge, empirical knowledge, empiricism, truth, certainty, definition, multi-modal perception, interference, confirmation, coherence, independent testimony, common-sense realism, realsim, scientific realism, phenomenalism, counter-claim/argument, rebuttal, WYSIWYG, AOK, WOK (PERL), KI

*RED = Terms NOT in this chapter in your text

GOALS, Chapter 4, PerceptionBy the end of this presentation, you should…

• Be able to notice those times in your everyday life when your senses are unreliable

• Understand that perception is an active, not passive, process and how it affects your view of the world

• Be aware that reason plays a role in interpreting your sensory info

• Understand and be able to discuss the basic philosophical problems with empirical knowledge

• Finally, understand and be able to discuss the meaning of the overarching phrase: “the mental construction of reality”

Optical illusions show how we see ~ Beau Lotto (TED)

Why are we watching this Tedtalk? • It exemplifies the unreliability of empirical data

This is an interactive presentation.

While you watch …1. Raise your hand to answer the questions Lotto asks the TED

audience2. Write the following notes

1. Thesis2. 3 main ideas3. 3 main examples4. Conclusion

TOK1 A, E , H

Is ALL Knowledge gained through your perceptual

experience?What do you think?

So, what is an important source of knowledge

about the world?

YOUR

“Do you feel me, man?”“I see what you mean.”“Smell ya later, homie.”

Perception = Sensation + Interpretation

But even more influences our sensations and interpretation.

»Intensity»Interest»Mood»Expectations»Memory (Past experiences)

Is seeing believing?

To what extent do our senses shape our perceptions and consequently our ‘vision’ of reality?

Before you respond, consider what we discussed about logic and language:

1.Is it possible for an argument to be both valid and false?2.What about language? Can individual words hold denotative meaning that contradicts the connotative meaning of an entire phrase?

Another ‘take’ on reality

Cropping and Photo manipulationAnatomy of a photograph – Cropping http://zombietime.com/sf_rally_september_24_2005/

anatomy_of_a_photograph/National Geographic – King Tut could walk. Could his pyramids? http://www.museumofhoaxes.com/hoax/photo_database/

image/the_case_of_the_moving_pyramids

To what extent can our perceptions be biased by the photographer?

To what extent could this statement be perceived as both true and false?

To what extent is what you see reality?

Is ‘seeing’ CREATING reality?

• Does the falling tree still make a sound if no one is there to hear it?

• Where were you before you came to this class? Is it still there?

• Schroedinger’s Cat experiment

Is all knowledge gained through our perceptions?

To what extent can we gain knowledge without the

influence of EMPIRICAL data?

Optical “Illusions” -- MISINTERPRETATION

Misinterpretation of information can occur as a result of our visual perceptions.

A. Visual perception is affected by…– the shape of the sense-organ– light of various wave lengths falling on the retina– unconscious interpretation

B. Visual perception is also affected by …– context– figure-foreground– visual grouping– expectations (a priori, our hypotheses)

Perception Experiments Contents• Quote• Goals• Bending Pencil• Childhood Perceptions • Schrödinger's Cat• Magritte’s pipe• Spinning woman• Rotating Silhouette Pirouette &

Optical Illusions • “I am shrinking your head!” • Awareness Test/Basketball• Photographic manipulation• 2 Eyewitness Sites • Bandana Bandit – Eye-Witness• Plato’s Allegory of the Cave

http://www.youtube.com/watch?v=69F7GhASOdM

• Photo manipulation

• Social Perceptions – What’s is a name? Freakonomics

• Piaget’s Stages of Development• Appearance vs Reality/3/CIC (SICK)• Theories of Reality /3/CPRS

– Role-Play CSP1. TOKA 2. TOKE3. TOKH

Audio “Illusions” 1

Shepherds Ascending Tones

• This is a recording of Shepard’s paradox synthesized by Jean-Claude Risset. Pairs of chords sound as if they are advancing up the scale, but in fact the starting pair of chords is the same as the finishing pair. If you loop this sample seamlessly then it should be impossible to tell where the sample begins and ends.

• Read more at http://listverse.com/2008/02/29/top-10-incredible-sound-illusions/

Audio “Illusions” 2McGurk EffectDo not play the clip above until you have read this text. When

you play this clip for the first time, play it with your eyes closed. Listen to what the man is saying. Now, play it again with your eyes open. Do you hear BA-BA, GA-GA, or DA-DA? Most adults (98%) think they are hearing “DA” – a so called “fused response” – where the “D” is a result of an audio-visual illusion. In reality you are hearing the sound “BA”, while you are seeing the lip movements “GA”.

Read more at http://listverse.com/2008/02/29/top-10-incredible-sound-illusions/

Audio “Illusions” 3

Virtual BarbershopThis is a demonstration of the stereo effect. Listening to it, you feel as

though you are in a barber’s chair, with the barber moving around you, clipping away at your hair. As the barber “moves” to your right, the volume increases slightly in the right channel and decreases in the left. Similarly, increases in the volume of sound from the clippers give the impression that he is bringing them closer and closer to each ear. The illusion demonstrates our ability to locate sounds in space; by comparing the inputs to the two ears, we can work out where a sound is coming from.

Read more at http://listverse.com/2008/02/29/top-10-incredible-sound-illusions/

Selectivity – MISS SOMETHING – Life of the party

A. Our mind would overload if we were constantly aware of everything

B. Stimuli (life of the party, safety)1. Motion2. Intensity3. Contrast

C. Subjective Factors D. Interference by other WOKs1. Interest2. Mood/Feelings3. Emotions4. *Beliefs5. *Prejudices6. *Culture

Well, don’t she

just think she’s

Miss

Somethin’?!

What is the Stroop Effect?The famous "Stroop Effect" is named after J. Ridley

Stroop who discovered this strange phenomenon in the 1930s.

It suggests that our perceptions can be affected by “INTERFERENCE” from other WOKs (modalities), in this case, language.

So does this mean language dominates our perceptions?

Interactive Stroop Effect Experiment

• In this experiment you are required to say the color of the word, not what the word says. For example, for the word, RED, you should say "Blue.”

• As soon as the words appear on your screen, say the list as fast as you can.

• Write down your time.

INTERFERENCE

Does this mean language dominates our perceptions?

What do you think would happen:

1. If you tried this experiment with a very small child who had not yet learned to read?

2. If you tried this experiment with someone who was just learning to speak English?

3. If you used the same order of ink colors but wrote non-color words?

4. If you made up an experiment of your own?

Selective Memory -- MISREMEMBER

Eyewitness Testimony = unreliable

Test yourself as an eyewitness:1. http://www.youramazingbrain.org/testyourself/

eyewitness.htm2. http://www.open.edu/openlearn/body-mind/psychology/

misidentification-can-you-identify-the-criminalCertainty/Uncertainty 1. http://www.youtube.com/watch?v=u-

SBTRLoPuo&list=PLdytkEIS9zGTkmbU-L4AdwDutj4GTFDmp&index=2&feature=plpp_video

Answer these questions about the crime

Test 11. How was the man who entered the store dressed? 2. What kind of and colour of car was the woman driving

who parked at the curb?3. What is the hair colour of the woman who parked her

car?4. Describe the first guy who ran from the store (Hair

colour? Glasses? Height? Race? Age? Anything else?)

~ Now, let’s check the accuracy of your memory.

Answer these questions about the crime

Test 21. Describe the person who committed the theft

(Hair colour? Glasses? Height? Race? Age? Anything else?)

2. Did the perpetrator use a key to enter the room?3. What was taken?

~ Now, let’s check the accuracy of your memory.

STOP TOK A

Memory, Perception, and Knowledge

1. How does memory affect our perceptions? 2. If we can’t rely on our memories 100%, then what can we say

about the role our perceptions play in the search for knowledge?

3. What other issues does the unreliability of our memories raise?

KI To what extent can our individual testimonies be influenced by group/cultural expectations?

Ex. Societal judgments of gender, race, or ethnicity.

*Reword 1 and 2 above as KIs.

So how do you distinguish between Reality and ULTIMATE

Reality?

There are 3 primary ‘Tests’:1.Confirmation Theory2.Coherence3.Independent Evidence

Checking Evidence

*Counter-claim rebuttal: Despite its fallibility, sensory data is reliable enough to support our knowledge claims.

3 Perception Tests1. Confirmation, by another sense2. Coherence, a priori experience of the world3. Independent Testimony, our own

experience + numerous others’ experiences STOP TOK H

Confirmation Theory 1

• Can you think of an old childhood game that tests perceptions? – In one game, one person says to the other: “Ok. Now, close your eyes and tell me when I am touching

the inside of your elbow.” What usually happens?In another game, one person pretends to ‘crack an egg’ on

another’s head.Why do you think we enjoy these games? What can they

suggest about perception? About (self-)deception?

Confirmation Theory 2

• Have you ever been inside a building and listened to see if it’s raining? Do you still ‘look’ anyway before leaving the building?

• What about: If it hurts it’s real?

• Bending pencil in water.

Coherence

• Does what you see fit in?– Does it match with familiar patterns? Familiar

experiences?• If not, you must be mistaken.• Do you ‘see’ something dangerous with this

type of reasoning?• Bending pencil in water.

3 Theories of Reality & Perception @ Philosophy

1. Common-sense realism – what we perceive mirrors the world: WYSIWYG• Counter-claim: But, the shape of our sense-organs

influences/limits our perceptions. Stop2. Scientific realism – the world exists as an independent reality,

and is v diff from the way we perceive it [elbow-floor = prob not]

3. Phenomenalism – is the “permanent possibility of sensation” & to makes no sense to say the world exists independent of our experience of it. What evidence exists byond our interactions? But it also does not mean the world does not exist independent of our interactions with it.

Ex. “To be is to be perceived.” ~ George Berkley. [collapsing wave functions/realities = quantum physics] It follows empiricism to the extreme.

Do you believe in WYSIWIG?

• If you do, you are a Common-sense Realist– In other words, you perceive the world as it is.

• But do you always ‘Get’ what you see? – Not according to the Scientific Realist.

• Instead, they suggest we don’t really see the world for what it is.

• What about Phenomenalism? Well, if you believe in this, you better prove it! If not, sheer NONSENSE, my friend!– But see, therein lies the crux. Math and logic, often

applied to offer proof, lack a clear connection to the senses.

Ultimate Reality @ Philosophy

KI: To what extent do our perceptions give us knowledge of ultimate reality? (“Reality is a shared hallucination”)

Psychology of perception – the world/reality does not exist independent of our interactions with it

1. Pain, taste, colour [Africa, South America] (fire, cola, grass) – pain and taste result from the interaction bw our senses and smthg else, ultimate reality is colourless

2. The tree in the forest [sound 1, sound 2 – definitions/language] sound is the result of vibrations in the air. Vibrations occur, whether someone ‘hears’2 them or not.

3. Tables in the clsrm – what happens when we’re not in the clsrm? [common-sense realism]

Realism … Rescue 911 @ Philosophy

1. Reasonable evidence – although an independently existing reality cannot be proven, the evidence we have about our senses, and the consistency and coherency of our experiences w the world, strongly suggest its existence.

Ex. Fire (collapsing reality unnecessary? No ashes does not prove false, but ashes proves true – based on the prior evidence of our collective experiences w fire [multiple independent testimonies]

2. Independent Testimony – the majority of ppl have a strong INTUITION that the world exists independent of our perception of it. Again, empirical evidence suggests this; despite multiple perceptions of the same object (colour of sky), the sky and its essence exist.

*most scientists are intuitive realists TOKE, TOKA

Perception requires the application of

LOGIC/REASON

Conclusions

Empirical evidence …• plays a key role in most AOKs• requires reasoning and checking evidence• is limited by the physical nature of our our sense-organs and

selectivity• is invaluable in our everyday life (pragmatic, utilitarian)• is reliable unless there is strong evidence to contradict it• although < CERTAIN, provide a strong foundation for

knowledge when it is consistent and coherent w other WOKs, such as reason and intuition

Did you reach your GOALS? Chapter 4, Perception

So now …

• Will you be able to notice those times in your everyday life when your senses are unreliable?

• Do you understand that perception is an active, not passive, process and how it affects your view of the world?

• Will you be aware that reason plays a role in interpreting your sensory info?

• Do you understand and will you be able to discuss the basic philosophical problems with empirical knowledge?

• Finally, do you understand and will you be able to discuss the meaning of the overarching phrase: “the mental construction of reality”?

What do YOU think?

To what extent do your senses “construct” or constrict

reality?

Resources

• Van de Lagemaat• Alchin• Various sites to be included later

Additions1. Empirical knowledge2. Stroop Test: Selective Attention