Cornell Psych 1101 Day 14: Can We Trust Perception? (Pt. 2)

Can We Trust Perception? (Pt.2)

P S YC H 1101 : DAY 14 P ROF. DAVID P IZ AR RO CO R NE L L P S YC H . NE T

Do Beliefs, Desires, Motivations, Etc. Influence Perceptual Processes?

Perception Of Size “The New Look”

How Big Is A Quarter?

Bruner And Goodman (1946) •

10 year-old children asked to estimate the size of coins!

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Given a contraption that allowed them to make a circle of light bigger or smaller, and asked to make it the same size as various coins!

Rich kids vs. Poor kids!

Prediction: Poor children value the currency more than rich children, so the coins literally “loom large”

Assessing The “New Look” •

The “New Look” movement in psychology argued that yes!

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Desires and motives infuse perception: poor children see coins as larger!

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New look research received a number of criticisms!

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Poor children less familiar with coins!

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Assessments were not of actual perception!

Mixed results!

• • •

Memory!

Judgment!

Attentional shifts

The New “New Look” •

Estimates of a man’s walking speed are biased after thinking about fast animals like cheetahs or slow animals like turtles (Aarts & Dijksterhuis, 2002)!

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Interpretations of an ambiguous figure that can be seen as a woman’s face or as a man playing a saxophone depend on whether perceivers have been recently primed with the concepts of “flirtation” or “music” (Balcetis & Dale, 2003)!

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Perceptions of how steep a hill is become more extreme after participants jog vigorously for an hour (Bhalla & Proffitt, 1999)!

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The distance to a goal seems longer if people strap on a heavy backpack (Proffitt, Stefanucci, Banton, & Epstein, 2003)

The “New” New Look

E M ILY B ALC E TIS

DAVID D UNNING

D E NNIS P RO FFITT

1. Motivated Perception Of Ambiguous Figures

Balcetis & Dunning (2006) • • •

• •

Participants are introduced to a taste-testing study with two conditions:!

Desirable foods: Such as jelly beans!

Undesirable foods: Such as a can of beans!

Participants are assigned by playing a computerized card game!

Their assignment depends on whether they see a farm or sea animal

Horse Or Seal?

First Eye Movement Eye Movements Indicate

70

73

67

60 50 40

33 27

30 20 10

Horse

Seal Which Is Favorable Horse

Seal

2. Motivated Perception Of “Rival” Binocular Images

“View-Master”

Binocular Rivalry

Balcetis, Dunning & Granot (2010) • •

Subjects presented binocular images that were either letters or numbers!

Images presented at 300 ms (fast enough for a conscious experience, but not to start thinking about it)

More Likely To See “Winning�

Category

Letters

Numbers

Which is Desirable?

3. Motivated Perception Of Distance

Balcetis & Dunning (2010) • •

Are desirable things perceived to be closer?!

Manipulated how thirsty participants were!

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Thirsty: eat bowl of pretzels (40% of daily sodium)!

Quenched: drank up to four 8-oz. glasses of water!

Distance to object: self-generated response

How Far Away Is The Water?

(Actual Distance = 36 Inches)

Distance (in)

30 28 26 24 22 20

Thirsty

Quenched

Beanbag Toss:

Throwing Instead Of Reporting An Estimate

Valuable Gift Card

-9.1�

Worthless Gift Card

+1.3�

How Far Away Is The $100 Bill?

(Actual Distance = 55 Inches)

C H ANC E T O WIN! = 5 0 . 8 INC H E S

How Far Away Is The $100 Bill?

BE L ONG S T O E X P E R IM E NTE R = 5 8 .9 INC H E S

4. Motivated Perception Of Steepness

Fatigue Influences Steepness Estimates (Proffitt And Friends) •

Joggers: Before vs. After a run!

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Before = 21 degrees!

After = 28 degrees!

Wearing a backpack increases estimates of the steepness of a ramp

Conclusions? •

Motivations, beliefs, and desires can shape and bias what seem to be our basic processes involved in the way we attend to, remember, encode the world around us.!

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Studies can show us when and how bias can creep in, but at a very basic level our perceptions are reliable enough to give us fairly accurate access to the world around us.