Psyco 350 Lec #5 – Slide 1 Lecture 5 – Psyco 350, B1 Winter, 2011 N. R. Brown.
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Transcript of Psyco 350 Lec #5 – Slide 1 Lecture 5 – Psyco 350, B1 Winter, 2011 N. R. Brown.
Psyco 350 Lec #5 – Slide 1
Lecture 5 – Psyco 350, B1Winter, 2011
N. R. Brown
Psyco 350 Lec #5 – Slide 2
Outline
• Baddeley’s Model of Working Memory– Phonological Loop
– Visuo-spatial sketchpad
– Central Executive
– Problems w/ WM
• An Alternative Perspectives on WM– Reading& Operation Span tasks
– Cowan’s Embedded Processes Mode
– WM Capacity as Executive Control
Psyco 350 Lec #5 – Slide 3
The Phonological Loop
Phonological Store
Phonological Store: holds small amount of speech based information
Articulatory Control Process: Based on inner speech
Auditory Presentation
VisualPresentation
Psyco 350 Lec #5– Slide 4
Phonological Loop
• Speech-based System: – phonological similarity – irrelevant speech – articulartory suppression
• 2-s Capacity:– word length effect
– cross-linguistic Δ’s
– developmental Δ’s
Psyco 350 Lec #5 – Slide 5
Evidence for the Phonological Loop
Instructions:
• You will see 6 letters, 1/s. • Recall them in order, at the signal.
Psyco 350 Lec #4 – Slide 6
Evidence for Phonological Loop
• Phonological Similarity Effectsimilar sounding list < dissimilar sounding lists
_______ vs _______
• Implies: representation is speech-based not meaning based.
Psyco 350 Lec #4 – Slide 7
Evidence for Phonological Loop
• Irrelevant Speech Effect– Recall impaired if items are accompanied by other
verbal material.
– Effect found w/: same-language words, same-language non-words, foreign words.
• Interpretation: “unattended (linguistic) material was gaining access to
the phonological store.”
-- Baddeley, p. 53
Psyco 350 Lec #5 – Slide 8
Evidence for Phonological Loop
• Articulartory Suppression– concurrent (overt or covert) articulation, decreases
word span.
(“the, the, the…” ; “one, two, three, one, two..)
– concurrent articulation decreases• the phonological similarity effect • word length effect.
• Interpretation: articulation of irrelevant items dominates ACP - Words
cannot be “rehearsed” or recoded into phonological code
Psyco 350 Lec #4 – Slide 9
Evidence for Phonological Loop
• Word Length Effect
word span decrease as # of syllables/word increases.
• Recall depends of reading rate.– # words recalled ≈ 2 * (reading rate)
• reading rate = # words read / s
Psyco 350 Lec #4 – Slide 10
Phonological Loop – Capacity of Phono Store
Baddeley et al (1975)
Task: serial recall
Materials:5-word lists
Manipulation: syllable length
Results:• recall , as syllable
length • recall predicted by
reading rate.• cf. STM predictions
Psyco 350 Lec #4 – Slide 11
Phonological Loop – Capacity of Phono Store
Baddeley et at (1975)• linear relation between
reading time & recall• Interpretation:
– capacity of phono loop
~ 2 s of speech materials• Reason
– fast fading phono trace– rehearsal refreshes trace. – if not rehearsed within 2
s, most info lost.
Psyco 350 Lec #4 – Slide 12
Phonological Loop – Capacity of Phono Store
Baddeley et at (1975)• Implications:
– across languages, digit span should be related to mean syllable length of digits.
– digit span should increase w/ age, because speech rate does.
Psyco 350 Lec #4 – Slide 13
Cross-Linguistic Δs in Digit SpanNaveh-Benjamin & Ayers (1986)
As predicted:• span larger
for languages w/ short digits than long
• span ≈ 2 X reading rate
Psyco 350 Lec #4 – Slide 14
Age-related Δs Digit SpanHulme (1984)
As predicted:• span w/ age• span ≈ 2 X speech
rate
-----------------------Overt or covert articulation
serves to maintain items in the phonological store by refreshing their fading traces. The faster it can run, the longer the memory span
Psyco 350 Lec #4 – Slide 15
Phonological Loops: Functions• Learning to read:
Children with impaired reading ability have reduced memory spans and have difficulties in tasks which require the manipulation of phonological information (e.g. given Stop, reply Top).
• Language comprehension:STM patients some difficulty in comprehending verbose or complex sentences e.g.
“The boys pick the apples” = OK;
“The two boys pick the green apples from the tree” = Impaired
• Vocabulary acquisition
There is a strong correlation between non-word repetition (which strongly taxes the phonological loop) and vocabulary size (Gathercole & Baddeley, 1989)
Psyco 350 Lec #4 – Slide 16
Psyco 350 Lec #4 – Slide 17
VSSP
• Function:– “construction, maintained, & manipulation of
mental images.” – Radvansky, p. 97
• Assumptions:– Independence of VSSP & Phonological Loop
Psyco 350 Lec #4 – Slide 18
Independence of VSSP & Phonological LoopBrooks (1968)
• Dual Task Experiment– Goal to demonstrate:
• spatial response mode interference w/ spatial processing
• verbal response mode interferes w/ verbal processing
• cross-modal tasks produce little interference
Psyco 350 Lec #4 – Slide 19
Independence of VSSP & Phonological LoopBrooks (1968)
• Design (2X3)
TASK X RESPONSE MODE
image scanning pointing
grammatical decision tapping
vocal
Psyco 350 Lec #4 – Slide 20
Brooks (1968): Image Scanning Task
Given a block letter & starting point:
If current corner is top or bottom “yes”
Otherwise ”no”
Psyco 350 Lec #4 – Slide 21
Brooks (1968): Response Modes
While performing target task:• Vocal – say “yes”/”no” • Taping – left tap = “yes”; right tap = “no” • Pointing – point to successive “y”/”n” pairs on
response sheet
Psyco 350 Lec #4 – Slide 22
Brooks (1968): Pointing
Psyco 350 Lec #4 – Slide 23
Brooks (1968): Results
• Spatial response mode:– interfered w/ spatial task
– did not interfere w/ verbal task
• Verbal response mode:– interfered w/ verbal task
– did not interfere w/ spatial task
>><<≈≈
Psyco 350 Lec #4 – Slide 24
Brooks (1968): Interpretation
• Task X Mode interaction indicates:– separate & limited pool of resources for verbal
& spatial task
• image scanning task & spatial response mode draw on the limited resources of the VSSP.
• grammatical decision task & vocal response mode both draw on the resources of the phonological loop.
Psyco 350 Lec #5 – Slide 25
Visuo-spatial sketchpad
Operations:
• Mental rotation
• Mental scanning
• Boundary extension
• Dynamic memory
Supports:
Spatial problem-solving (moving a couch
Prediction of dynamic consequences.
Psyco 350 Lec #5 – Slide 26
Mental Rotation: VSSP @ Work
Shepard & Metzler (1971)
Materials: Pairs of 3-d(ish) objects in a variety of orientations.
Task: timed same/different judgment
Psyco 350 Lec #5 – Slide 27
Mental Rotation: VSSP @ Work
Shepard & Metzler (1971)
Materials: Pairs of 3-d(ish) objects in a variety of orientations.
Task: timed same/different judgment
Psyco 350 Lec #5 – Slide 28
Mental Rotation
• Results:– RT w/ angular
disparity
• Interpretation:“mental rotation has
characteristics that mimic physical rotation….It is almost as if people are actually mentally turning the object about in their VSSP.”
– Radvansky, p. 99
Psyco 350 Lec #5 – Slide 29
Problems w/ Baddeley’s WM
Influence of LTM on STM tasks• chunking• proactive interference (Keppel & Underwood, 1962) &
release from proactive interference (Wickens, 1972).
• semantic similarity can span
• span: high frequency words > low frequency words
Problems with Phonological Loop• under suppression: span > 0 for visually presented
words.
Psyco 350 Lec #5 – Slide 30
Current WM Model
Episodic Buffer
• Information is bound together in the episodic buffer
– This creates the episodic memory trace
– Working memory interacts with long-term memory
Psyco 350 Lec #5 – Slide 32
Central Executive (Baddeley)
• Most complex and least understood component of WM
• Coordinates activity of slave systems & supplements their attentional resources
• Other potential roles: – coordinating retrieval strategies– temporary activation of LTM,
–selective attention–suppression of habitual responses.
Psyco 350 Lec #5 – Slide 33
Alternatives Perspectives On WM
Motivated by:• Problems w/ Baddeley’s Model• A need to better understand executive
functioning• Predictive power of span task.Three Related Issue1. Reading/Operation Span as a measure of
“capacity”2. WM contents as the active portion of LTM3. WM as executive attention
Psyco 350 Lec #5 – Slide 34
Measuring WM Capacity
• Key Idea: Performance on complex cognitive task reflects a number of different capacities– retrieval efficiency
– processing efficiency
– “attention-free” capacity of relevant slave system
– attentional management (ability to focus on relevant info & inhibit irrelevant info.
– etc.
• WM span tasks developed to measure relation between WM and performance on complex cognitive tasks
Psyco 350 Lec #5 – Slide 35
WM Memory Span
• WM span = # of words recalled
• Demonstrates capacity for holding load while processing.
• Large individual differences in WM span (2-6 items)
• WM span measures predict performance on IQ, achievement tests (e.g., SATs), & g.
• digit/word span uncorrelated with IQ/SAT tests
Psyco 350 Lec #5 – Slide 36
WM Memory Span – Two Interpretations
1. Domain Specific Capacity: Efficient processing of immediate task, leaves additional resources for maintaining load.
– Accounts for dual task performance (e.g. Brooks)
2. Domain General Capacity: General ability to “control attention to maintain information in an active quickly retrievable state.” Engle, 2009, p. 20.
Psyco 350 Lec #5 – Slide 37
An Alternative: WM as Information in an Active State
Psyco 350 Lec #5 – Slide 38
WM as Activation: Cowan’s Embedded Processes Model
• Central Executive: directs and controls voluntary processing.
• Encoding:– Incoming info activities
representation in LTM
Psyco 350 Lec #5 – Slide 39
WM as Activation: Cowan’s Embedded Processes Model
Central Notation:
LTM in one of 3 states:
1. Dormant
2. Activated – fades (decays) unless
reactivated
3. “In focus” (of attention)– limited to 4 items
Psyco 350 Lec #5 – Slide 40
Span from Active Perspective
Two components:1. read-out from focus
2. activated material, retrieved before decay
Predictions:• factors LTM, span
– concreteness (Walker & Hulme, 1999)– word frequency (Roodenrys & Quinlan, 2000)
• Span > 0 when rehearsal suppressed