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The Modal Memory Model: Sensory Memory and Short-Term

(Working) Memory

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• 1960s Many models of memory proposed

• Atkinson & Shiffrin (1968)

– Sensory Memory

– Short-term Memory

– Long-term Memory

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William James

• Primary Memory

• Secondary Memory

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Atkinson & Shiffrin Model of Memory (1968)

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STM Bottleneck

STMSensory Memory

Long Term Memory

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Properties of the Different Memory Stores

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Characteristics of the Memory Stores

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Research on the A & S Model

• Serial Position Effect

• Recency Effect

• Kintsch & Buschke (1969)

• Behavioral Neuroscience Evidence

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Serial Position Effect Demo

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Serial Position Effect Graph

Recency Effect

Primacy Effect

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Rundus (1971)

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Questions

• How could we test the idea that the last few items are in STS?

• How can we test that the primacy effect represents LTS?

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Eliminating the Recency Effect

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Other Evidence: Kintsch & Bushchke (1969)

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Behavioral Neuroscience Evidence for the STM-LTM Distinction

• H.M. - Epileptic

- Temporal Lobes / Hippocampus

- STM ---> LTM disrupted

• K.F. - Damage to Left Cerebral Cortex

- LTM Normal

- STM capacity severely limited

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Behavioral Neuroscience Evidence for the STM-LTM Distinction

The dog bit the man and the man died.

vs.

The man the dog bit died.

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Evidence Against A & S

• More recent research challenges the strict

coding distinction

• Recency Effect challenged

• Neuroscience evidence

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Atkinson & Shiffrin Model of Memory (1968)

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The Sensory Store

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Lightning

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Lightning Demo

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Lightning Questions

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Sensory Memory

• Sensory memory or sensory register

• Visual, auditory, touch, taste, smell

• Relatively raw, unprocessed form

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Why Do We Need Sensory Memory?

• Stimuli change

• Maintain for selection and further

processing

• Integrate fragments of a stimuli into a single

unitary perception

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Classic Studies

• Sperling (1960)

• Averbach & Sperling (1961)

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A Tachistoscope

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*

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J Z G B

S X P L

R M Q F

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*

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Y Q C H

N D R J

V B K S

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Schematic of Typical Sperling Exp

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Number of Letters Recalled as a Function of Technique & Delay

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Iconic Memory

1. Location

2. Usefulness

3. Saccades

4. Nature of the code

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1 K 5 L

H J 3 B

7 D 8 T

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Demo 4.1: Examples of Sensory Memory

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Demo 4.2 Unitary Perception from Fragments

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Auditory Sensory Memory

• Neisser (1967) - Echoic memory and the echo

• Darwin, Turvey, & Crowder (1972)

• Differences from iconic memory

• Crowder (1982)

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An Echoic Memory Study

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Darwin, Turvey, & Crowder

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Discriminating Between Two Sounds (Crowder, 1982) Graph

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Short-Term Memory

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Short-Term Memory

• Nature of Forgetting

• Duration

• Nature of Code

• Capacity

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Short Term Memory

• Brown/Peterson & Peterson (1959)

• Trigram task

KHR

Delay / Distractor

Recall Trigram

0 – 18seconds

(947, 946, 945. . . 939)

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Trigrams

K X J

P L G

S Y T

H Z R

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Brown-Peterson Results

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STM--Nature of the code

• Conrad (1964)

• Visual display of letters

• Phonological confusions: (‘D’ for ‘E’ but not ‘F’ for ‘E’)

• Wickelgren (1965)

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Wickelgren (1965)

K Z L F

distractor tasks(copy down 4 new letters)

C B G D X M I W

recall original 4 letters

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Sensory Memory STM

Long Term

Memory

STM Capacity Limited

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Capacity of STM

• Limited Capacity (7 + 2)

• Digit Span Task

• Difficulties

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• Chunking

• Recoding:(1 4 9 2 ----> ‘1492’ Columbus)

• Chase & Ericsson (1982)

Capacity of STM (cont.)

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SF DIGIT SPAN DEMO

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SF Digit Span Experiment• Initial Session (8 digits):

Digit Series: 1, 0, 5, 3, 1, 8, 7, 4SF’s Recall: 105

31874• Later Session (11 digits):

Digit Series: 90756629867SF’s Recall: 907

56629867

SF’s Report: 9:07 a 2-mile time

• Still Later Sessions (22 digits):Digit Series: 4131778406034948709462SF’s Recall: 413.1 / 77.84 / 0603

494 / 870 / 946.2SF’s Report: 4:13.1 mile time

06:03 mile time 9:46.2 2-mile time

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Revisions to the STM Idea

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Brown & Peterson Revisited

• Decay vs. Interference

• Waugh & Norman (1965) - Probe digit task

• Varying the type of distractor task and stimulus material

• Keppel & Underwood (1962)

• PI = Proactive Interference

• Wickens et. al. - Release from PI

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Digit Probe Task: Waugh & Norman (1965)

16 digits -----> probe digit

5 1 9 6 3 5 1 4 2 8 6 7 3 9 4

9 8 3 7 5 7 1 4 9 3 8 6 2 7 5 2

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Effect of Presentation Rate vs. Number of Interfering Items on Recall (Waugh & Norman, 1965)

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Wickens, Born, & Allen (1963)Trial 1 – ‘HJX’

Trial 2 – ‘RLB’

Trial 3 – ‘ZNF’

Control Experimental ‘GST’ ‘493’

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Release from Proactive Interference

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Release from PI (Evidence for Semantic Codes)

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Release from PI as a Function of Semantic Similarity (Based on Wickens, et al., 1976)

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Working Memory

• Revision of STM

• 3 part system

• Baddeley

• Dual task paradigm

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Baddeley Working Memory Model

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Reasoning Task with Letter Recall

AB

‘A’ precedes ‘B’? T or F

‘B’ is preceded by ‘A’ . T or F

‘B’ does not precede ‘A’. T or F

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Reasoning Speed and Letter Recall

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Reasoning Times & Letter Recall Results

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Bradimonte Et al. (1992)

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Brandimonte (1992)

1. Study 6 pictures 1. Study 6 pictures while saying “la, la, la . . .”

2. Create mental image, subtract a specific part, and name it.

2. Create mental image, subtract a specific part and name it.

3. Number of correct items: 2.7

3. Number of correct items: 3.8

Condition 1 Condition 2

? Fish

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Pronunciation Time & Memory Span

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Memory Span and Pronunciation Rate

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Capacity of STM

• Difficult to Estimate

• Different meanings (storage capacity vs.processing capacity)

• Digit Span Task

• Miller – “The Magical Number Seven,Plus or Minus Two . . .”

• 7 ± 2