1. Aim: What is the difference between sensation and perception
Aim: What is the difference between sensation and perception? What role does nature and nurture play in our perception? What factors influence our perception?
Do Now:
Which box feels heavier? (Shhh! Don’t talk about it yet!)
Homework:
Read text pps. 202 – 209 & 220 – 229
Sensation and Perception Test Tuesday 11/21
Project Due Wed – Write up and Presentation 11/22

2. Context Effect
The context in which something is sensed impacts perception.

3. Sensation and Perception
sensation – the process of taking in energies from the environment and transforming those energies into neural energy (taking in info) - transduction
perception – the process of interpreting sensory information so that it has meaning (interpreting info)

4. The Case of Kenge Page ___
Define – nature, nurture.
What does the case reveal about the nature v. nurture debate?
Mbutu Pygmy Tribe in Congo

5. Differing Views of Perception
Empiricist:
start out as infants with a “blank slate”, everything comes from environment
Perception is influenced by values, expectations, experience and culture
Nativists View:
believe we are born with a certain amount of knowledge, preprogrammed

6. Constancy
Objects change in our eyes constantly as we or they move….but we are able to maintain content perception
Shape Constancy
Size Constancy
Brightness Constancy

7. Constancies

8. Constancies

9. Perception & Illusions are influenced by …
Biological Factors – sensory analysis
Psychological Influences (Gestalt, context, expectancies, mental sets/ schemas etc)
Socio Cultural Factors

10. Muller – Lyer Illusion
Which line is longer?

11. Explaining the Muller – Lyer Illusion
Our experience in a “carpentered” world shapes our perception of the lines in the Muller Lyer Illusion. Where would you expect people not to be fooled by this illusion?

12. Culture and Muller Lyer Illusion
Corners in our rectangular carpentered world teach us to interpret outward and inward arrowheads at the end of the line as a cue to the lines distance from us (it’s length).
The red line of the ticket booth looks shorter than the red line to the right.
But both are the same!

13. Which animal does the spear point to. It depends upon experience
Which animal does the spear point to? It depends upon experience. Those who have never seen a 2 D drawing or photo’s of 3D scenes have difficulty.

14. What is above the woman’s head
What is above the woman’s head? Answers depend upon the culture you come from. What will westerners say? East Africans?

17. Top-Down Processing
We construct reality using prior knowledge and experience
We fill in gaps based upon what makes
priming
I _ant ch_co_ate ic_ cr_am.
Considering the following sentence, (Wray & Medwell 1991; 98)
“If you aer a fluet reodur you wll hve no prblme reodng ths sntnce “
Based on our experiences and schemas.
If you see many old men in glasses, you are more apt to process a picture of an old man (even when you may be in error).

19. Olny srmat poelpe can raed tihs
Olny srmat poelpe can raed tihs. I cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid, aoccdrnig to rscheearch at Cmabrigde Uinervtisy. It deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh? yaeh and I awlyas tghuhot slpeling was ipmorantt! if you can raed tihs psas it on!!
This demonstrates that we can combine information into a gestalt and thus my recall things that we didn’t actuall see.

20. Priming Illustrates mental processing without awareness.
given info and then is later tested to see if it will affect performance
AKA subliminal suggestion

21. In a study subjects were asked to unscramble words.
Group A – sentences with polite words
Group B – sentences with rude words
Group C – neutral words
At end of experiment. Experimenter was always talking to research assistant. How do they get his attention?
Only 10% of polite primed interrupt, 65%of rude primed interrupt, 35% of neutral interrupt!

22. Bottom-Up Processing Also called feature analysis.
We use the features on the object itself to build a perception.
Takes longer that top-down but is more accurate.

24. Bottom-up vs. Top-down Processing
bottom-up processing – the operation in sensation and perception in which sensory receptors register information about the external environment and send it up to the brain for interpretation (part to whole)
song for first time
top-down processing – the operation in sensation and perception, launched by cognitive processing at the brain’s higher levels, that allows the organisms to sense what is happening and to apply that framework to information from the world (whole to part)
favorite song

25. Advantages / Disadvantages of Top Down Processing?
PRO - Allows us to identify sounds images quickly, even before full examination is done!
CON - Mistakes!! Bias!!
We use this 90% of the time!!!

26. Pro’s & Con’s of Bottom Up Processing
Opposite of Top Down
takes longer, but is more accurate
EX: Overheads

27. Read this out loud. What happened? Why?

28. AMES ROOM

29. Ames Illusion Distorting rooms
Many judgments of size, shape or distance which may seem absolute are relative in the sense that they depend on other features in the visual field.
Objects of the same size and apparent distance will give different size retinal images

30. What do you see? Why? We look for patterns, organize things, etc
Sometimes we see things that aren’t there or was not intended.
Helps us survive and make sense and organize world
Face on mars
Base in California

31. Gestalt Psychology

32. Gestalt Principles
a school of thought interested in how people naturally group/ organize their perceptions according to certain patterns
We innately look at things in groups and not as isolated elements and try to find patterns
main principle: the whole is different from the sum of its parts -- computer screen image (sum) pixels (parts)
closure
proximity
similarity
continuity
Figure Ground
Phi Phenomena

33. Gestalt Principles: Proximity
proximity: object near each other  see them as a unit (4 columns; not 16 squares)

34. Gestalt Principles: Similarity
similarity: objects that are similar  seen as a unit/group (columns of circles and squares; rows of circle and squares)

35. Gestalt Psychology
Common Direction/ Continuity (objects that form a continuous form are perceived as same group)

36. Gestalt Principles: Closure
closure: disconnected or incomplete figures  fill in the spaces and see them as complete figures
Kanizsa triangle

37. Perceived Motion Stroboscopic effect (flip book effect) Phi phenomenon
Autokinetic Effect (if people stare at a white spotlight in a dark room, it appears to move.)

38. Gestalt Rules – Define each of the following. Page 13 of packet.
Figure/ Ground
Simplicity
Proximity
Closure
Similarity
Continuity

39. Applying Gestalt to designing…
Which is more appealing? Why?

40. We have a tendency to organize things to better understand them….
Concept maps help us organize and make sense of information
Use it when we study

41. Think of an example (anything) that reflects or illustrates Gestalt Psychology…