Upcoming:Read Expt 1 in Brooks for Tuesday

Read Loftus and Sacks For Thursday

Read Vokey Thursday the 6th

Idea Journals Due on the 6th!

The textbook Cognition will be on reserve in the library.

Feature Integration Theory•Early visual system parses scene into features represented in “feature maps”

•“Attention Spotlight” can be moved across an overlay of these feature maps to bind features together

Feature Integration Theory

• What term does Treisman use to describe the bundle of features at a specific location?

Feature Integration Theory

• Object Files are mental (neural?) representations of the features associated with an object– whenever an object is selected by attention its

features are bound and an object file is “opened”– when the features of that object change, the object

file is updated

Feature Integration Theory

• How did Treisman et al. test whether the visual system uses object files?

Feature Integration Theory

• Priming: observers are faster to respond to something they’ve just seen

Feature Integration Theory

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Feature Integration Theory

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G

N

Feature Integration Theory

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Feature Integration Theory

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Feature Integration Theory

+G

Feature Integration Theory

What Letter?

Feature Integration Theory

• What was the result?

Feature Integration Theory

• What was the result?– Naming was faster if the prime occurred in the

same box, even though the object had moved

Feature Integration Theory

• What was the result?– Naming was faster if the prime occurred in the

same box, even though the object had moved

• Interpretation?

Feature Integration Theory

• What was the result?– Naming was faster if the prime occurred in the

same box, even though the object had moved

• Interpretation?– visual system establishes object files (e.g. a box

with a G in it) and updates them as the location and features of the object change

Overview of Memory

• Atkinson-Shiffrin Model

Sensory Signals

Sensory Memory

Short-Term Memory

Long-Term Memory

ATTENTION

REHEARSAL

RETRIEVAL

“Types” of Memory

• Sensory Memory– brief ( < 1 second)– preattentive / parallel processing (very

large capacity)

Sensory Memory

Capacity

• Describe a simple experiment that could measure the capacity of “memory”

Capacity

• Describe a simple experiment that could measure the capacity of “memory”

• Briefly present some letters or digits and then ask the subject to report them– Called “whole report”

Capacity

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Capacity

F S F EG S A UT O C G

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Capacity

“Recall as many letters as you can”

Capacity

• George Sperling - Systematic investigation of memory capacity

– Result: subjects accurately recall 3 or 4 items

– What can you conclude from this result?

Capacity

• Could it be that subjects had encoded but failed to retrieve the information?

Capacity

• For example: what if recalling interferes with memory?

• How could you modify the experiment to measure the instantaneous capacity, before any forgetting can occur?

Capacity

• Partial Report - briefly present letters or digits and ask subject to report only some of them

“Report the letters in the row indicated by the arrow”

Capacity

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Capacity

U E S BO D W AI B V S

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Capacity

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Capacity

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Capacity

Which Letters?

Capacity

• Partial Report

• Result: subjects can recall any 3 or 4 letters that are indicated by the arrow !

Capacity

• Partial Report

• Result: subjects can recall any 3 or 4 letters that are indicated by the arrow !

• What does this mean about the capacity of memory?

Capacity

• There is some part of the perception system that stores huge amounts of information…

– in fact, if only a single letter is probed, instantaneous capacity is seen to be unlimited

Duration

• There is some part of the perception system that stores huge amounts of information…

• But for how long? How would you design an experiment to measure the duration of this high-capacity memory system?

Duration

• There is some part of the perception system that stores huge amounts of information…

• But for how long? How would you design an experiment to measure the duration of this high-capacity memory system?

• Vary the onset of the probe

Duration

• Partial Report

Probe Delay

# of letterspotentially recalled

500 ms0 ms never

0

4

10

Duration

• Partial Report

Delay

# of letters potentiallyrecalled

Interpretation:1. Information dwells in a brief storage “buffer”2. duration of storage lasts about 1/2 of one second

500 ms0 ms never

0

4

10

Iconic Memory

• a brief storage of “raw data” in the visual system

Echoic Memory

• Auditory information is stored in a similar sensory “buffer”– Echoic memory seems to last for several seconds

Properties of Sensory Memory

1. Brief (iconic ~500ms; echoic ~2 seconds)

Properties of Sensory Memory

1. Brief (iconic ~500ms; echoic ~2 seconds)

2. Virtually unlimited capacity

Properties of Sensory Memory

1. Brief (iconic ~500ms; echoic ~2 seconds)

2. Virtually unlimited capacity

3. pre-attentive