Working Memory

Question 1

The Modal Model of Memory:

Atkinson & Shriffin (1968)

Answer 1

Sensory Memory: Large multi-modal capacity, but very brief
Short-term Memory (STM): Limited Capacity Storage (7+ items), 15 – 30 seconds, information easily lost
Long-Term Memory (LTM): Unlimited Storage, encoded based on meaning

Question 2

Evidence for STM & LTM Stores

Answer 2

Amnesic patients have preserved STM, but impaired LTM

Patient KC, has intact digit span (see video on study direct), but he has no long-term memory for events

Question 3

Modal Model & Long Term Recency

Answer 3

Task: Free Recall of US Presidents
Results: Clear recency effect despite recall from LTM
Also, providing a continual distractor on every trial does not
abolish recency effect!

Question 4

Main Problems with the Modal Model

Answer 4

Difficult to explain long-term recency effects
Role of rehearsal in encoding from STM to LTM?
(repetition does not guarantee good LTM & you
remember things that you don’t rehearse)
NOT a single STM or LTM store

Question 5

Evidence for multiple STM Stores

Answer 5

Dual Task Method
Press a button to indicate whether the sentence is True or False:
A precedes B – AB (true)
B does not follow A – AB (false)
Repeat a string of digits at the same time.
Results: Increasing digit load increases reasoning time, BUT no effect on errors.

Question 6

Working Memory Model

Baddeley & Hitch (1974)

Answer 6

Baddeley and Hitch argued that working memory must
comprise different components.

Dual Task Method
Press a button to indicate whether
the sentence is True or False:
A precedes B – AB (true)
B does not follow A – AB (false)
Repeat a string of digits at the same time.
Results: Increasing digit load increases reasoning time, BUT no effect on errors.

Question 7

Evidence for Phonological Store

Answer 7

1. Phonological Similarity Effect
2. Word Length Effect
3. Irrelevant Speech Effects
4. Brain Evidence

Question 8

Irrelevant Speech Effects

Answer 8

Recall series of visually presented digits:
Recall disrupted if study accompanied by:
(1). Spoken Words
(2). Nonsense Syllables
Recall not disrupted if study accompanied by:
(1). Silence
(2). Noise / tones
Salame & Baddeley (1982)
• Irrelevant speech gains access to the phonological store and corrupts the memory trace
• There is a filter based on “speech-like” sound that gates access to the store

Question 9

Phonological Store: Brain Evidence

Answer 9

Paulescu et al. (1993)
1. Short-Term Memory Tasks
Verbal Task: Participants rehearsed a string of letters followed by a question
“B”, “Y”, “L”, “P”, “S” Was the letter “E” present?
Visual Control Task: Presentation of Korean characters followed by a question
Was the character present?
à Verbal task requires both the phonological store and articulatory loop
2. Matching Tasks
Verbal Task: Monitor each letter & press a button if it rhymes with “B”
“B”, “Y”, “L”, “P”, “S” Press a button if the letter rhymes with “B”
Visual Control Task: Monitor each Korean character & press a button if it matches
Does the character match?

Question 10

The Visuospatial Sketchpad

Answer 10

Necessary for holding online a sequence of
visually guided actions.1. Visual Cache: passively stores visual information
about form and colour (similar to phonological store)
2. Inner Scribe: stores spatial and movement
information and can rehearse the contents of the
visual cache (similar to articulatory loop)

Question 11

The Central Executive

Answer 11

Most complex and least understood component of WM model
The CE coordinates processing in the slave systems by
controlling and allocating attention
Adopted the Norman & Shallice (1986) model of attentional
control
Actions are controlled by two processes:
1. Habits or schemas guided by environmental cues
2. An attentionally limited controller (supervisory attentional system)
The CE carries out processing such as monitoring behaviour,
switching attention, inhibiting inappropriate actions

Question 12

Manipulating the Central Executive

Answer 12

Baddeley et al. (1998)
Task: Random number generation (tapping number keys) while simultaneously engaging in other tasks
Results:
1. Redundancy in randomness (i.e., being less random) increases with digit load
2. Random generation and other tasks such as verbal fluency strongly engage the CE

Question 13

Brain Evidence for Central Executive

Answer 13

Two Tasks: 1) Semantic judgement task (is it a
vegetable?) on verbally presented words, and 2)
Spatial rotation task on visually presented items.
Performed separately or together (dual task).
Results:
1. No activation in prefrontal cortex if the tasks
are performed separately (but activation
elsewhere in brain)
2. Activation in prefrontal cortex if tasks are
performed together

Question 14

Problems with the standard WM Model

Answer 14

Issues with the phonological store:
Articulatory suppression typically reduces digit span for visually
presented words from 7 to 5
• But not a devastating impact!
• It should prevent information from getting into phonological store!
A span of around 16 words is possible if the words are presented
as prose (e.g., a meaningful sentence)

Question 15

The Episodic Buffer

Answer 15

“A limited capacity temporary storage system capable
of integrating information from a variety of sources”
Episodic: integrates information across space & time
• Can be preserved in densely amnesic patients with impaired long-term
episodic memory
Multi-dimensional coding (not phonological, visual or spatial in
nature)
Enables long-term memory to interact with working memory
Controlled by the central executive
• CE can retrieve info from the EB, manipulate it and modify it if necessary