Percep&on and Comprehension

Transcription

1 Percep&on and Comprehension MAR 3503 January 19, 2012

2 How do we take in informa&on? Exposure External S&muli Sights Sensory Receptors Eyes Percep&on Sounds Smells Ears Nose ANen&on Comprehension Tastes Touch/Movement Tongue Heat, pressure, & motor receptors Behavior

3 Psychophysics: Sensa&on and percep&on Sensa&on: The immediate response of our sensory receptors to basic s&muli such as light, color, sound, scent, touch, taste Sensa&on is physical Percep&on The process by which sensa&ons are selected and organized Percep&on is what we add to raw sensa&ons so that we can be interpreted Percep&on is psychological It s ac&ve It s rela&ve

4 What do we perceive? Absolute threshold The lowest intensity of a s&mulus that can be perceived via a sensory channel Basic method Ascending method of limits Start with a low value of a s&mulus (Ex. Sound) Increase un&l the person say I hear something Descending method of limits Start with a very high value of s&mulus Decrease un&l the person says I don t hear anything Absolute threshold can be quite low (indica&ng sensi&vity) But differs by individual

5 Subliminal percep&on The ac&va&on of sensory receptors by s&muli presented below the perceptual threshold We re anending to a s&mulus, and something flashes so quickly (e.g., 30 msec) that we can t consciously perceive it Can this kind of percep&on influence our behavior?

6 Subliminal percep&on In 1957, James Vicary repeatedly flashed a frame- long image that read either Drink Coke or Eat popcorn during a movie He claimed that popcorn sales increased 58% and soda sales increased 18% He later admined that the amount of data he had collected was so small as to be useless, but s&ll His claim opened the door to Cold War fears of subliminal propaganda

7 Subliminal percep&on works a linle Mere exposure showed us that subliminal percep&on of a s&mulus can lead to increased liking for the s&mulus Subliminal presenta&on of a word will lead you to recognize that word more quickly later on Subliminal exposure to adjec&ves can influence judgments of later targets But it s hard to make it subliminal for everyone May make the s&mulus too weak or too strong Need to get people to anend to the s&mulus loca&on Need to make sure the presenta&on is just at the right distance

8 Subliminal persuasion Par&cipants were thirsty when they came into the lab They then were exposed to subliminal thirst primes or neutral primes, to make sure thirst was on their mind They then read about two sports drinks: Power Pro (the best electrolyte balancing drink) and Super Quencher (the more thirst quenching drink) They then rated the two products as to how much they felt posi&vely about them, and took as many coupons as they wanted for either/both drinks Strahan, Spencer, & Zanna, 2002

9 Subliminal persuasion Thirst- prime par&cipants also chose more Super Quencher coupons (M = 5.31) than neutral prime par&cipants (M = 4.27) Strahan, Spencer, & Zanna, 2002

10 Subliminal persuasion Par&cipants were brought into the lab and given a salty treat that made them thirsty, or given no treat Then they were subliminally primed with the words Lipton Ice, which is a brand of iced tea Aker the priming they were given the op&on of two drinks, Lipton Ice or a bonled water They picked which one they would rather have at that moment They rated their inten&ons to drink each op&on in the future Karremans, Stroebe, & Claus, 2006

11 Subliminal persuasion Karremans, Stroebe, & Claus, 2006

12 Organizing principles of percep&on Percep&on is ac&ve! Gestalt psychology: When we see an item, we evaluate it as a whole thing, not as a collec&on of its &ny parts Percep&on of the whole is different from (and more important than) percep&on of the parts

13 Closure

14 Proximity

15 Similarity

16 Figure- Ground

17 Con&nua&on

18 Illusions

19 How do we perceive? One commonly- held view Realism: We see the world as it is. We simply register sensory inputs and report them back. Another (more accurate) view: Naïve realism: We believe we see the world as it is. Percep&on is an ac&ve, construc&ve process. We use prior informa&on, as well as current expecta&ons, goals and desires when interpre&ng incoming informa&on. The Gestalt principles give one illustra&on of the ac&ve nature of percep&on

20 We don t always perceive things as they are Is seeing believing? Or is believing seeing? Belief about a product can influence percep&on of the product New Coke, same old 7- up Coors banquet beer versus original drak Chocolate pudding flavors Light- colored appliances

21 Our bodies, our worlds Our physical self can affect how we see the outside world People mises&mate the slope of hills and distances all the &me But when we are low on resources encumbered by a heavy backpack, &red, older we see the same slopes and distances as steeper or longer When we have added resources, even social ones, these same obstacles appear less difficult to overcome ProffiN, 2006

22 Swinging at aspirins Sokball players were asked to es&mate the size of a sokball by choosing one of 8 circles They were also asked to report their stats The bener players chose a larger circle to represent the ball WiN & ProffiN, 2005

23 We see what we expect to see We perceive and interpret ambiguous s&muli in line with what we expect them to be Told was vodka & tonic Drank vodka & tonic Group 1 Group 2 Drank only tonic Group 3 Group 4 Told was only tonic Heart rate measured when they were approached by an anrac&ve female assistant Heart rate increased not for those who drank only tonic (Groups 3 & 4), but instead for those who thought they only drank tonic

24 Seeing what we (don t) want to see

25 Comprehension Is the process of understanding and giving meaning to that which we have just perceived Is intertwined with percep&on: We just saw how percep&on is expectancy- based This can make it difficult to say where percep&on ends and comprehension begins A key component of comprehension is categoriza&on which is the process of labeling or iden&fying a perceived object

26 Consequences of categoriza&on Categoriza&on evokes the schema of the category A schema is a set of associa&ons linked to a concept or category Ex. Luxury car Associa&ons can include: ANributes Benefits Drawbacks Users Use situa&ons Associa&ons can be: Unique/not unique Favorable/not favorable

27 Consequences of categoriza&on We then apply the evoked category schema to the new target If this is a luxury car, then it must be Because of this categoriza&on and schema- applica&on, we can then more easily Make inferences about the new target Evaluate the new target Include or exclude the new target in our considera&on set Decide whether we are sa&sfied/unsa&sfied with the new target

28 Consequences of categoriza&on The applica&on of schemas predicts that certain things will happen when categoriza&on goes wrong We may make incorrect inferences about what the target is, and what it should do Sunlight Dishwashing Detergent Maalox Whip Antacid So, it s important that people categorize your product correctly so that the right schema is evoked

29 Comprehension: Inferences To be successful at communica&on, we need to make inferences My pen stopped working It s hot in here Do you know how to get to the Reitz Union? Inferences are usually beneficial, but our tendency to make inferences can lead us astray

30 Misinterpreta&ons Technically true statements about products may encourage misinterpreta&ons and incorrect inferences Lysol kills flu and other germs on surfaces Ocean Spray cranberry juice has more food energy than orange or tomato juice

31 Misinterpreta&on Some types of true statements that lead to false inference Comparison omission Our gasoline gives you bener mileage BeNer mileage than what? Piecemeal informa&on Our car has more headroom than a Mercedes, more legroom than a Cadillac, more trunk space than a BMW Affirming the consequent Women who look younger use Oil of Olay Does not answer the ques&on, If I use Oil of Olay, will I look younger?

32 Affirming the consequent Essen&ally, it is this argument: If P, then Q. Q is true. Therefore, P is, too. The problem is that P isn t the only possible cause of Q. If Bill Gates owns Fort Knox, then Bill Gates is rich. Bill Gates is rich. Therefore, Bill Gates owns Fort Knox.

33 Summary There are methods for measuring what will and will not be perceived Subliminal may have small, but not large, effects on behavior Percep&on is an ac&ve process We organize what we see into meaningful s&muli What we perceive is influenced by prior expecta&ons, beliefs, and desires, and oken confirms those beliefs Comprehension involves giving meaning to what we perceive We need to categorize new s&muli We need to make inferences which can lead us astray Next &me: How does memory work?