PSY 368 Human MemoryWorking Memory cont.

Demos and reviews

Baddeley’s Model

ArticulatoryControl

Visual scribe

Phonological Loop• Two parts: Phonological Store (PS) and

Articulatory Control Process (ACP)• PS - stores auditory info for 1-2 s and then it starts to

decay• ACP - recodes visual info into auditory code for storage

and controls rehearsal• 4 Main Effects in Serial Recall Task to account

for• Phonological similarity effect• Articulatory suppression effect• Irrelevant speech effect• Word length effect

Phonological Loop• Demos

Listen to list, recall words in order

RhinocerosZincGorillaTuberculosisMeaslesCalciumUraniumCarbonHippopotamusMumps

Listen to list, recall words in order

PlanetMusicianLandPropertyTrumpetHouseStarCometOrchestraMoon

Listen to list, recall words in order, while I read the words say ‘the’ aloud

BlockBrickStickBlueChewTrickPrickClueClickBlimp

Read list, recall words in order, while I read the words say ‘the’ aloud

GoldCodeBoldHoldToldColdModeSlowedHopeGoad

Listen to list, recall words in order, while I read the words say ‘the’ aloud

BronzeBookMagazineBikeCopperDressCopierSodaShoeRock

Phonological Loop

• Memory worse for items that sound alike than those that look alike or have similar meanings

• Visual items are recoded to auditory for storage and rehearsal by ACP

• List 1 (Easy to remember/dissimilar phonology and semantics): • PIT, DAY, COW, PEN, HOT

• List 2 (Only slightly harder than List #1/similar semantics) :• HUGE, WIDE, BIG, LONG,

TALL• List 3 (Much harder than List

#1/similar phonology) :• CAT, MAP, MAN, CAP, MAD• What happens if you prevent the recoding of

visual information into auditory information?

• Works for both auditory presentation and visual presentation of the letters.

• Phonological Similarity Effect

e.g., Baddeley (1966)

Phonological Loop• Articulatory Suppression Effect

• Engaging in an auditory task after study removes phonological similarity effect for visual items• Procedure: Say “the” aloud over and over

• No re-coding of visual info by ACP• Phonological info gets in directly, doesn’t need re-coding

Auditory presentation: PGTCD (similar sounding) harder to recall than RHXKW (different sounding)Visual presentation: PGTCD (similar sounding) recalled equally as RHXKW (different sounding)No re-coding, so no chance for

similar sounds to interfere

With suppression

Phonological Loop• Irrelevant Speech Effect

• Background speech presented during study decreases memory for visual items

Salame & Baddeley (1982)

96 7 8 32

‘one’ ‘four’ ‘five’ Semantically similar‘tun’ ‘sore’ ‘fate’ Phonologically similar‘tennis’ ‘double’ Phonologically differentQuiet control

Phonological Loop• Irrelevant Speech Effect

• Background speech presented during study decreases memory for visual items

Salame & Baddeley (1982)• Amount of disruption is determined

by phonological similarity• In other experiments

• showed no word-length effect for irrelevant speech

• If rehearsal is prevented, irrelevant speech effect disappeared

Conclusions:• Irrelevant speech interferes with recoding of visual info

to auditory

Phonological Loop• Word-length Effect

Results• Recall decreases as the

length of time it takes to say a word increases.

• Rehearsal takes longer for longer words - can’t rehearse as many times

Baddeley, Thomson, and Buchanan (1975)

• Retrieval from PS also takes longer due to auditory coding of items

• Reading rate correlated with memory ability• Digit span depends on language - how long it takes to

say numbers

• Potential Problems with the model• Some of the supportive results can’t be

replicated (e.g., irrelevant speech effect)• Model can’t explain all results:

• why word-length effect is larger for visual than auditory items

• why it differs based on serial list position• Why some effects persist after extended delays

(e.g., 5 mins)• Model is not precise in explanation of effects

Baddeley’s Model

Cowan’s Activation Model

• Cowan (1999)• WM = info that is

currently highly activated from STM or LTM

• Focus of attention• Emphasizes attention’s

role in activation• Activation of info when

attention is oriented to it• Activation will decay to

cause loss of info from WM (also interference)

STMWM

Cowan’s Activation Model

• Central Executive • Focuses attention and

other control processes• Capacity of about 4 chunks• Duration of 20s without

reactivation

• STM• activated items that are

just outside of attention - passive store• Things within attentional

focus are available to consciousness

STMWM

• Potential problems with the model• Only general descriptions so specific

predictions are hard to make• Activation is not operationally defined very

well - when is something is “activated”?• What causes decay? Passage of time isn’t

causal

Cowan’s Activation Model

Nairne’s Feature Model• Items represented in WM as individual

features (e.g., color, length, etc.)• Features indicate

• presentation info (e.g., font, size, gender of voice, etc.) • meaning info (e.g., what the item means, category,

etc.)• Stays the same regardless of presentation

• Features represented by -1 or +1 when studied (yes or no for a feature, 0 if no info for feature)

• Interference: Later items with same features overwrite feature info for previous items

Nairne’s Feature Model Bold Lower Upper BlueSCHOOL +1 -1 +1 -1fish +1 +1 -1 -1• “fish” presented after “SCHOOL”

- features in common can be overwritten - SCHOOL can become 0, -1, +1, 0- interference

During retrieval, item features are compared with items in memory - lost features can be updated and restored

Nairne’s Feature Model• Quantitative model - numerical

predictions are possible - can simulate data to generate predictions for studies• Simulations show that model can predict:

1) Recency effect2) Suffix effect3) Phonological similarity effect4) Word length effect

Summary of WM(1) Focus on processing (vs. storage)(2) Three main modern models

- Baddeley model - Central executive controls VS, PL, EB

- Cowan activation model - WM = attention focus, STM = activated

- Nairne feature model (quatitative)- Items coded as features with overwriting

interference

Exam 1 review