Transcript PERCEPTION revised 2012-13

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. Notes
2. 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, counterclaim/argument, rebuttal, WYSIWYG,
AOK, WOK (PERL), KI
*RED = Terms NOT in this chapter in your text
GOALS, Chapter 4, Perception
By 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
audience
2. Write the following notes
1. Thesis
2. 3 main ideas
3. 3 main examples
4. 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 manipulation
Anatomy 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/imag
e/the_case_of_the_moving_pyramids
To what extent can our perceptions be biased by
the photographer?
To what extent is what you see reality?
To what extent could this statement be perceived as both
true and false?
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
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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=6
9F7GhASOdM
Photo manipulation
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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 CSP
1. TOKA
2. TOKE
3. TOKH
Audio “Illusions” 1
Shepherds Ascending Tones
• This is a recording of Shepard’s paradox synthesized by JeanClaude 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-10incredible-sound-illusions/
Audio “Illusions” 2
McGurk Effect
Do 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 audiovisual 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-10incredible-sound-illusions/
Audio “Illusions” 3
Virtual Barbershop
This 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-10incredible-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. Motion
2. Intensity
3. Contrast
C. Subjective Factors
D. Interference by other WOKs
1. Interest
2. Mood/Feelings
3. Emotions
4. *Beliefs
5. *Prejudices
6. *Culture
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.ht
m
2. http://www.open.edu/openlearn/bodymind/psychology/misidentification-can-you-identify-thecriminal
Certainty/Uncertainty
1. http://www.youtube.com/watch?v=uSBTRLoPuo&list=PLdytkEIS9zGTkmbUL4AdwDutj4GTFDmp&index=2&feature=plpp_video
Answer these questions about the crime
Test 1
1. 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 2
1. 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 Theory
2.Coherence
3.Independent Evidence
Checking Evidence
*Counter-claim rebuttal: Despite its fallibility,
sensory data is reliable enough to support
our knowledge claims.
3 Perception Tests
1. Confirmation, by another sense
2. Coherence, a priori experience of the world
3. 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. Stop
2. 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 …
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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
Additions
1. Empirical knowledge
2. Stroop Test: Selective Attention