exam 1 a week from tuesday (tue 16 oct) –6-8pm in chemistry (not in psych auditorium)...

Exam 1

• A week from Tuesday (Tue 16 Oct)– 6-8pm in Chemistry (not in Psych auditorium)

– Meredith’s sections in 1400 Chemistry

– Everyone else in 1800 Chemistry

• Will cover:– Lectures 1-9 (up to and including this Thu)

– Textbook: Chapters 1, 2, 3, 4, and 7

– Articles: Kohler, Sacks, McCloskey, Kosslyn

• Review sheet is posted on coursetools (look under Resources)

Observer Perspective

• Another distortion in visuospatial processing

• People tend to subjectively stretch area around them and shrink other areas

• Report distance from familiar place to unfamiliar place to be longer than reverse

• E.g., Perspective from NYC

Visual Imagery

Lecture Outline

Issues: (a) Perception vs. imagery(b) Depictive vs. propositional code(c) Compromise theory

1. Perception and imagery1.1. Depictive and propositional codes

1.2. Imagery phenomena: scanning, zooming, transforming

2. Theory of mental imagery2.1. Differences between imagery & perception

2.2. Compromise theory

Propositional vs. Depictive

• Propositional– The globe is on the desk

– ON (GLOBE, DESK)

• Depictive

Propositional vs. Depictive• Issue: Is the representation that underlies imagery propositional or depictive?

Propositional:

Depictive:

George Washingtonhas

white hair

wooden teeth

has has

thin lips

Perform two tasks simultaneously, if they interfere then they must require the same mental system.

Interference effects

Auditory Detection Visual Detection

Auditory imagery

Visual imagery

Interference

Interference

(None)

(None)

Kosslyn: Image Scanning

Kosslyn: Image Scanning

Demand Characteristics?

• Perhaps subjects think you want them to act like they’re scanning an image, so they act that way– Subjects infer the experimenter’s implicit demands

• Or perhaps experimenters expect a certain set of results and this biases results

• But get similar results when experimenters and subjects told that theory predicts scanning short distances takes longer

Image Zooming

Far Near

Mental Rotation

Mental Rotation

Mental Rotation

Mental Rotation

Mental Rotation

127° 90° 45° Comparison

Intermediate Rotations

Imagery isn’t just like perception

• Perception has metric qualities that images don’t

• Example: Bisected rectangle with diagonal lines

Metric Qualities of Perception

1"

1"

AB1

B2

Part-Whole Relationships

• Quickly glance at this Star of David then look away

Part-Whole Relationships

• Using imagery: Did it contain a parallelogram?

Part-Whole Relationships

• Using perception: Does it contain a parallelogram?

Part-Whole Relationships

• Using perception: Does it contain a parallelogram?

A Duck

Ambiguous Figures

• That figure was actually ambiguous

• Using imagery: What else could that figure have been?

Ambiguous Figures

• Using perception: What else could that figure be?

Compromise Theory (Kosslyn)1 - Basic code is propositional (for long term storage)1 - Basic code is propositional (for long term storage)

2 - Propositional code used to create depictive image2 - Propositional code used to create depictive image

3 - Depictive image can be scanned, zoomed, etc.3 - Depictive image can be scanned, zoomed, etc.

George Washingtonhas

white hair

wooden teeth

hashas

thin lips

generateimage

Visual Imagery and Cortex

Ventral

Dorsal

Visual Cortex

Dorsal

Parietal Lobe

Temporal Lobe

Memorize Grid Letters

Image Complexity

Ordered Image Construction

Ordered Image Construction

Ordered Image Construction

Imagery vs. Motor Control

Lecture Outline

Issues: (a) Perception vs. imagery(b) Depictive vs. propositional code(c) Compromise theory

1. Perception and imagery1.1. Depictive and propositional codes

1.2. Imagery phenomena: scanning, zooming, transforming

2. Theory of mental imagery2.1. Differences between imagery & perception

2.2. Compromise theory

Next Time

• Working Memory

• Read pp. 181-196 in the textbook

• Read article by Baddeley