Immediate Memory

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1) Provide a historical perspective on the study of the conscious portion of memory.

2) Present the key components of the ‘modal’ model of memory (Atkinson & Shiffrin) along with the empirical data that support/contradict the model.

3) Discuss several reasons why researchers have become dissatisfied with the ‘modal’ model.

4) Describe the architecture of the WM model and the empirical data that support/contradict the model.

  • Central executive
  • Phonological loop
  • Visuo-spatial sketchpad

5) Review two recent attempts to update the WM model:

  • Activation models
  • Feature models

Historical Perspectives on Immediate Memory

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Different theories … different names

  • Working Memory
  • working memory
  • STM
  • primary memory

Theoretically neutral terms

  • Immediate memory
  • Contents of consciousness

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Out with the old, in with the new

  • Unitary vs. multi-faceted construct
  • Associationism vs. strategic behavior
  • Behaviors vs. peering inside the box

Limited Capacity of Immediate Memory

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Demo:

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Q: how much information can it hold?

A1: 7 +/- 2 items

A2:

Q: Why do capacity constraints matter?

A:

Q: But what would be sufficient proof?

  • Different properties
  • Respond differently to experimental variables
  • Make separate contributions to memory

Let’s give it a name

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Conscious / Unconscious
Waugh & Norman / Primary / Secondary
Atkinson & Shiffrin / STM / LTM

We are going to use the A&S terminology because:

  • STM and LTM captures an important distinction between the two proposed memory systems
  • A&S introduced terminology to describe the subjects mental activity
  • rehearsal
  • search
  • transfer

Distinguishing STM & LTM: Different Properties I

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STM / LTM
Capacity / 7  2 / functionally infinite
Duration / relatively brief / relatively long
Serial Position Effects / Recency / Primacy

Supportive Data for Serial Position Effects:

  • Rundus & Atkinson (1970) – # of rehearsals correlated with primacy, not recency.

Distinguishing STM & LTM: Different Properties II

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More on Serial Positions Effects:

Glanzer & Cunitz (1966) – distractor tasks eliminate recency; no effect on primacy.

Distinguishing STM & LTM: Different Properties III

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Maintenance of information

STMrehearsal

EX: new cutie’s phone #

LTMrehearsal is not necessary

EX: current email address

old email addresses

Effect of Decay

STMRapid

LTMSlow, but measurable

Effect of interference

STMhuge

EX: new cuties’ phone #

LTMrelatively minor

EX: current email address

But: old phone #s / email addresses

Distinguishing STM & LTM: Experimental Manipulations and Separate Contributions

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Experimental Manipulations

What does it take to eliminate primacy and recency?

  • How can you get rid of primacy?

A: Presentation rate

  • How can you get rid of recency?

A: Delay recall (Craik, 1970)

Confusion errors

STM (short RI, lists)phonological confusions

LTM (long RI, lists) semantic confusions

Separability of function

Two letters: HM

  • Normal LTM
  • Highly impaired STM (across delays)
  • Specific implications
  • Transfer
  • Neural correlate

Critics of the two-store model

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Primacy / Recency effects

  • Primacy without rehearsal
  • Recency with RIs of several weeks
  • Continual distractor paradigm
  • Bjork & Whitten (1974)

Is rehearsal necessarily correlated with memory?

Confusion errors are not so cut and dried

  • STM - some semantic confusions
  • LTM - some phonological confusions

True separability is logically impossible

  • Semanticity affects STM
  • LTM retrieval must involve STM

The next step: Working Memory

Baddeley & Hitch (1974)

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Q: What made modal model revolutionary?

A: introduction of terminology to describe covert mental activities like rehearsal, storage, transfer,

Working Memory (Baddeley & Hitch, 1974)

Emphasized processes over contents

Why jump on the WM bandwagon?

  • Digit spanvs. working memory span
  • Builds on the advantages of the modal model
  • More in step with cognitive revolution
  • Can I remember new cutie’s phone # vs.
  • Is it safe to cross Rte. 9?
  • Reactive parenting
  • Mental wandering

Architecture of the Working Memory model

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Theoretical approach

Immediate memory= workbench of the mind

  • What do you need to build a house?
  • General Contractor
  • Expertise
  • Workers
  • Tools
  • Raw Materials

Working Memory

  • Central Executive
  • Strategies, experience
  • Phonological Loop
  • Phonological store
  • Articulatory control process
  • Visuo-spatial sketch pad
  • Mental capacity / energy (limited)

Working memory: Overview

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The CE co-ordinates all mental activity.

  • How the problem will be solved: sub-steps needed to arrive at a solution
  • Schedules tasks
  • Allocates limited resources
  • Chooses which subsystems to employ: what each subsystem will do
  • How to efficiently co-ordinate different tasks to maximize available resources

Two lackies:

Phonological Loop

Auditory / linguistic information

VSSP

Visual information

Working memory: Behavioral support for the

existence of the Central Executive

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Concurrent task paradigm –

Primary task: mental arithmetic

Function of CE?

Secondary tasks:

  • random sequence generation
  • abstract line drawings
  • simple motor sequence.

Typical results:

Which has the biggest dual task cost?

Problems:

circularity

Relation to personal experience:

cognitive failures

Working memory: Neuropsych support for the

existence of the Central Executive

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Dysexecutive syndrome – Frontal lobe damage

Case study

  • EVR –lost decision making ability

Behavioral tasks

  • Wisconsin Card Sort
  • Verbal fluency tasks
  • Copying simple motor behaviors
  • Stroop task

Two classes of errors

  • Perseveration
  • inferior and orbital frontal cortex
  • Distraction
  • dorsolateral frontal cortex

Neuroimaging data

Frontal lobe activation consistently tied to adoption of strategic behavior

  • Detecting novelty
  • Difficult conditions of the Stroop

Working Memory: Training the Central Executive

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Space Fortress improves with practice.

Big Question: How do we know this relates to CE?

A: Because Space Fortress training improve pilot performance

Bigger Question: What does Space Fortress have to do with Piloting?

A: Nothing, except…the ability to pay attention to multiple streams of information simultaneously and to co-ordinate a variety of actions simultaneously.

Biggest Question: Why is this such a big question?

A: Because ultimately, your evaluation of the CE is tied to the extent to which you see a connection between piloting and Space Fortress and medical decision making, and Stroop, and crossing the street.

Working Memory: Phonological Loop

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Phonological store

Function: temporarily holds auditory input

Articulatory control process

Function 1: converts visual information into articulatory code

Function 2: refreshes memory traces in Phonological Store via subvocal articulation (i.e., talking to yourself)

Capacity of Phonological loop

Decay rateFixed

Rehearsal ratefunction of both stimulus and personal factors

Demo: Articulation rate

Phonological loop: what is it good for?

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Phonological similarity effect – immediate memory is worse for similar sounding items than for items that sound different.

Why?

Word-length effect – longer words are more difficult to remember. Demo

Why?

Articulatory suppression – repeating a nonsense syllable ‘bap’ impairs memory.

Why?

Secondary prediction: larger effect on visual presentation than auditory presentation. Why?

Irrelevant speech effect - Recall visually presented consonants either in silence or while listening to irrelevant speech

Prediction:

Explanation:

Effect of articulatory suppression:

Effect of irrelevant music:

Note: data are mixed

Martin, Wogalter, & Forlano (1988)

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What was the goal of the research?

They wanted to examine whether unattended speech/music would affect reading comprehension.

Why were they interested in that?

  • Does background noise mask inner speech?
  • Is phonological representation necessary?
  • Previous data were mixed
  • Auditory vs. visual presentation
  • Meaningfulness of stimuli
  • verbatim recall or comprehension

Experiment 1: Speech vs. Music?

Method:

  • continuous spoken speech
  • random speech
  • instrumental music
  • random tones
  • silence.

Results:

  • Continuous and random speech worse than control

Martin, Wogalter, & Forlano (1988) II

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Experiment 2 – Music vs. language

Method:

  • Sung lyrics vs. spoken lyrics vs. no lyrics
  • with or without musical accompaniment.

Results:

  • Sung lyrics not different from spoken lyrics but both were worse than no lyrics.

Experiment 3 – speech more distracting in general?

Method:

  • Speech vs. musical background

Results:

  • Music more disruptive than speech

Experiment 4 – Semanticity?

Results:English < Russian = White noise

Experiment 5– Phonology?

  • English non-words had no effect

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What is the overall interpretation?

  • Phonological interference does not affect comprehension
  • Relation to WM model? Function of PL?

Balch and Lewis (1996)

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Theoretical question: How does music produce CDM?

Place, mood, smells

Empirical question: How will manipulating various aspects of the music affect CDM?

Experiment 1:

Key manipulations:Melody and Tempo

Results:

  • Changing melody did not reduce memory
  • Changing tempo did

Experiment 2:

Key manipulations:Tempo and Timbre

Results:

  • Changing timbre did not reduce memory
  • Changing tempo did

Experiment 3:

Key manipulation: Timbre and Tempo

Results:

  • Timbre change did not affect emotionality
  • Tempo change did

Balch and Lewis (1996)

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Experiment 4:

Key manipulation:

Tempo at encoding

Induced mood at test

Results:

Match facilitated memory even though

music was not presented at test

Implications:

Music influences memory by manipulating mood.

Mood explains everything.

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Questions:

  1. What are the implications of mood-dependent memory for how memory functions?
  2. So, you and your roommate are studying for your Memory exam. S/he says, do you mind if I turn on the stereo? What do you say?
  3. What do you think about IMing, texting, and so forth while studying?
  4. How should our legal institutions resolve the issue of driving while talking on the cell phone?

Fürst and Hitch (2000)

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Theoretical Question: Do the phonological loop and central executive make independent contributions to strategic memory tasks?

Empirical Question: Will secondary tasks designed to stress the CE and PL produce differential performance deficits on a primary mental arithmetic task?

What are the three component processes of mental math?

Experiment 1:

Q: What does the PL do?

A: temporarily stores articulatory information

Q: How would you interfere with the PL?

A: articulatory suppression

Method:

  • Articulatory suppression or silence
  • Math problem remained in view or not

Results:

  • AS interfered with performance, but only if the problem was removed from view.

Interpretation:

  • PL holds temporary results of calculations

Fürst and Hitch (2000): What about the CE?

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Experiment 2:

Q: How does the CE contribute to mental math?

A: Strategic behavior; specifically: carrying

Q: How did they tax the CE?

A: Trails task

Method:

Completed trails task with visible math problems

Results:

  • Dual task decreased math performance
  • Vast majority of errors were carries
  • Trails task varied inversely with # of carries

Experiment 3:

Q: Did # of carries influence trails performance because carrying takes time?

A: Length of trails task unrelated to # of errors

Dual task influenced errors on trail task

Fürst and Hitch (2000): What does it all mean?

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Implications:

  • PL: retains needed problem information
  • CE: strategic behavior (carrying)
  • Independent functions constitutes convincing evidence for WM architecture

Questions:

  • How can we explain discrepancies with previous research regarding the role of WM in carrying during mental arithmetic?
  • Forgetting a carry common; mistakenly including a carry was uncommon. What does that imply?
  • Are the functions of the PL and CE completely independent?

Critiques of Working Memory

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Consistency

  • Word length effects
  • Irrelevant speech effects
  • Is articulatory rate related to speaking rate?
  • Neuropsych data:

If reduced spans caused by faulty ACP, then should be immune to articulatory suppression. Some are, some are not.

Model is overly descriptive

EX: Why are phonologically similar items more confusable than phonologically distinct items?

Qualitative rather than quantitative

  • Makes it difficult to falsify

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Overall evaluation

  • Extremely valuable
  • Needs further development / specification

What else is out there? Feature models

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Feature model (Nairne, 1990)

  • Similar to the way a computer represents information (binary code)

How might you represent a person?

Important features of Feature Models

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One data point is meaningless

  • It's the overall pattern
  • Thus, you don't need many features to distinguish between objects ( 20).

320 = 3.5 billion

Two kinds of features

  1. Modality-dependent
  2. Modality-independent.
  • Note: feature models do not posit different stores for different kinds of information.

How do feature models work?

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Distinction between primary and secondary memory

Primary memoryconsciousness.

Secondary memorystorehouse of knowledge

Primary functions

Primary Memory:

  • assemble and maintain cues that will aid subsequent memory searches.

Secondary Memory:

  • permanent storage of knowledge

How does memory work?

Encoding:

1st items features are activated

2nd items features are activated

  • overlap and interfere with 1st item

3rd items features are activated

  • overlap / interfere with items 1 and 2

Test:

Match degraded cues with items in secondary memory

How do Feature Models account for different effects?

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Recency

Features of final object are not overwritten

Suffix Effect

Features of final item ARE overwritten

Phonological similarity

Similar items have more overlapping features. Therefore, will be harder to distinguish from one another at test

Articulatory suppression

Features of the repeated item are incorporated into the cue used to retrieve each item. Therefore, items are less discriminable from one another.

Word-length effect

The more features, there are, the more opportunities there are to make mistakes.

EX: 5-piece jigsaw puzzle vs.

100-piece jigsaw puzzle

Evaluation of Feature Models

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Negatives:

weak on SP effects

Positives:

Much more explicit model than WM

Question to ponder:

How could you use feature models to simulate the advantage of spaced over massed practice?