Memory 2: STM

Question 1

How does STM store information?

Answer 1

Phonologically

Question 2

How did Conrad and Hull (1964) find out that phonological similarity disrupts verbal STM?

Answer 2

• Method - serial recall of consonants (same order as presentation)
  
  • Measuring memory span (digit/letter span) - maximum number of test items recalled in correct order
  • 2 conditions - letters being phonologically similar (B, D, G) or different (D, L, F)
  • Results - error rates are increased for phonologically similar letters (acoustically confusable) compared to phonologically distinct ones
  • STM stores info phonologically

Question 3

What is the capacity of STM according to Miller?

Answer 3

7 (+/-2) items or chunks

Question 4

What is chunking?

Answer 4

• Chunking increases capacity = converting high numbers of low-information-content items into low numbers of high-information-content items
  
  • Rhythm (phone numbers), meaning (acronyms)

Question 5

How did Glanzer and Cunitz (1966) find out that STM has a duration of 10-30 secs?

Answer 5

• Task - free recall of lists of one-syllable nouns
  
  • 3 conditions - immediate recall, delayed recall (10 secs), delayed recall (30 secs)
  • IMMEDIATE RECALL = Found serial position effects - primacy and recency
  • DELAYED RECALL = No recency effects, primacy was the same
  • STM decays between 10 secs and 30 secs, primacy effects reflect LTM not STM performance because for early items in the list, there is more time for sub-vocal rehearsal

Question 6

What is the structure of the phonological loop?

Answer 6

1) Phonological short term store - limited capacity and duration
2) Articulatory control process:
a. Sub-vocal rehearsal (prevent decay, refresh memory traces)
b. Translation of visual info into speech-based code for storage in phonological store

Question 7

What three effects does the phonological loop explain?

Answer 7

1) Phonological similarity effect
2) The word length effect
3) The irrelevant sound/unattended speech effect

Question 8

What is the phonological similarity effect? (Baddeley, 1966)

Answer 8

• Harder to recall words that sound similar
  
  • Task - serial recall of spoken word lists
  • 4 conditions: phonologically similar (mad, man, cap) or distinct words (pen, day, cow), semantically similar (big, huge, great) or distinct (old, late, thin) words
  • Recall more impaired for phon similar than phon distinct (supports Conrad and Hull)
  • Recall was the same for semantically similar and distinct

Effect of the phonological short term store - limited capacity and duration

Question 9

What is the word length effect? (Baddeley, 1975)

Answer 9

• Task - serial recall of visually shown words (encoded in ACP - visual to speech)
  
  • 5 conditions: word lists with either 1, 2, 3, 4, or 5 syllables
  • Recall drops with word length, so does reading speed
  • People can remember as many words as they can say in about 2 seconds
    If they read ~1.5 w/s, they recall ~55%.
    If they read ~1.9 w/s, they recall ~70%.
    If they read ~2.3 w/s, they recall ~90%.
    If they’d read ~2.5w/s, they’d recall ~100%.
  • Also, longer words take longer to recall, more complex (interference), and have more components (fragmentation - mixing ends and starts of different words)

Limited translation of visual info into speech-based code in the ACP

Question 10

What is the irrelevant sound/ unattended speech effect? (Colle and Welsh, 1976)

Answer 10

• Task - serial recall of auditory presented 8-letter lists
  
  • 2 conditions: with noise and without noise
  • More errors with noise - spoken words impair serial recall of verbal material because phon material is automatically encoded in the Phonological loop
  • Primacy and recency effect
  • Music disruptive while studying - vocal more than instrumental

Effect of phonological short term store - limited capacity and duration

Question 11

How did Phillips (1974) test STM of non-nameable visual material?

Answer 11

Task: Is the test pattern the same than the memory pattern?

- Memory display: Checkerboard patterns with 4x4, 6x6, or 8x8 cells (50:50 black and white). 
- Retention period: 0 to 9 seconds. 
- Test display: Identical pattern or one-cell change.

Question 12

How does STM of non nameable visual material change as retention period increases? (0-9 seconds) (Phillips, 1974)
What does this show about STM?

Answer 12

Almost 100% accuracy at immediate recall, longer retention means more decay and lower accuracy, accuracy decrease is more for larger matrices
- Small amounts of non-nameable visual material can be retained for short periods
- Larger amounts of material for longer time is error-prone
- Suggests existence of temporary short term store with limited capacity for non-nameable visual material - memory not just limited to phonological loop

Question 13

How is articulatory suppression achieved?

Answer 13

Secondary verbal task like counting backwards occupies ACP
(vocalisation and articulatory rehearsal of visual material prevented - can’t be fed into phonological store)

Question 14

How did Luck and Vogel (1997) test STM of visual material with prevented vocalisation?

Answer 14

• Detecting change in a picture of different coloured squares (larger or smaller set sizes), colour either same or one changes
  
  • Memory, retention period (900 ms)
  • 2 conditions - count to 3 (articulatory suppression) or don’t count to 3 during retention
  • Are test colours same as memory colours?

Question 15

What is the capacity of visual STM as found by Luck and Vogel’s experiment with prevented vocalisation?

Answer 15

• Results - accuracy decreases as a function of set size, from set 3
  Meaning Visual STM capacity is 3 items - same for both conditions showing no verbal disruption to STM - suggests visual component

Question 16

What is the chunk capacity of visual STM?

Answer 16

3.4 chunks capacity

Question 17

What are the two separate stores of STM?

Answer 17

1) Phonological loop - auditory and vocalised visual info
2) Visuo-spatial STM - non-vocalised visual information

Question 18

What are the two types of visuo-spatial STM?

Answer 18

1) Visual object memory (what is it) - Temporal, ventral, what stream
2) Spatial location memory (where is it) - Parietal, dorsal, where stream

Question 19

How is object memory tested?

Answer 19

Visual span - reproducing patterns in empty matrices

Question 20

How is location memory tested?

Answer 20

Corsi span - tap differently placed blocks in numbered order

Question 21

Double dissociation in neuropsychology patients provide further evidence for two separate auditory and visual STM stores - what were Patient KF’s deficits?

Answer 21

• Shallice & Warrington (1970) - Patient KF
  Verbal deficit - low digit span
  Intact visuospatial memory - normal visual and corsi span

Question 22

Double dissociation in neuropsychology patients provide further evidence for two separate auditory and visual STM stores - what were Patient MV’s deficits?

Answer 22

• Carlesimo et al. (2001) - Patient MV
  Spatial memory deficit (where) - low corsi span
  Intact visual object memory (what) - visual span for shapes
  Intact verbal memory - normal digit span

Question 23

What is dual task performance like for visual and verbal memory?

Answer 23

• People can concurrently perform an auditory and a visuospatial task, but not two of the same
  
  • Assumes that two tasks can be simultaneously performed only if they do not use the same cognitive resource

Question 24

What are the two functions of working memory? (Baddeley)

Answer 24

WM temporarily stores information (STM)

Also serves as a mental workspace, allowing to manipulate information to perform complex cognitive tasks (e.g., learning, comprehending, reasoning).

Question 25

What are the components of WM (Baddeley and Hitch, 1974)

Answer 25

- Central executive - attentional controller - selects and manipulates material in the subsystems - SUBSYSTEM - Visuospatial sketchpad - holds visually or spatially encoded items - SUBSYSTEM - Phonological loop - holds sequences of acoustic/ speech based items

Question 26

What is the function of the phonological loop?

Answer 26

Learning new words and languages

Question 27

Patient PV has a pure phonological loop deficit - how does this manifest?

Answer 27

- Digit span = 2 - Preserved visual STM, long-term memory, intelligence, and language skills (Italian speaker). - Is a shop keeper, raised a family, not affected in everyday life. i.e., seems to have a pure Phonological Loop deficit.

Question 28

Baddeley et al. (1988) did an experiment on Patient PV - PV and controls learn 8 pairs of Italian/Italian words and Italian/Russian words (spoken presentation of words), cued recall - one word is presented, the other must be recalled. How did they do, and what does this mean for the function of the phonological loop?

Answer 28

- Results - controls and PV perform equally with II condition, but PV performs much worse on IR (does not remember a single one) - She has no learning disability and no LTM impairment, but an inability to learn new words - Phonological loop seems to be involved in language acquisition - Learning words in a new language is a phonological effect

Question 29

What two effects can substantially impair the phonological loop's role in learning foreign language words?

Answer 29

Articulatory suppression Phonologically similar and longer words

Question 30

What is the function of the visuo-spatial sketchpad?

Answer 30

It aids visual/spatial imagery

Question 31

Shepard & Metzler (1971) studied mental rotation - involves the visuo-spatial sketchpad - Look at rotated objects (2 different angles) and say if they are the same or different objects - 3 conditions - 2D match, 3D match, non-match What did results show?

Answer 31

The greater the angle of rotation, the more time it takes to decide whether the two objects are the same. - Almost perfect linear relationship between rotation distance and time taken to mentally perform the rotation - Real world distance = mental distance

Question 32

Kosslyn et al. (1978) investigated mental travelling - participamts were asked to memorise the map and imagine a spot moving between the locations. e.g., Decide how long it takes to travel from the tree to the hut. What did results show?

Answer 32

Result - linear relationship (positive correlation) between location distance and time taken to mentally travel between the locations

Question 33

Milivojevic et al. (2003) conducted a mental folding experiment: - Participants answer: if shapes (net of a cube) are folded into a cube, do the arrows meet? Results showed what?

Answer 33

Linear relationship between number of folds and the time taken to mentally fold the shapes

Question 34

What do mental rotation, mental travelling and mental folding experiments tell us about WM?

Answer 34

WM provides a mental platform for spatial manipulations, e.g. rotations in three-dimensional space, navigating on mental maps.

Question 35

What is the function of the central executive?

Answer 35

Attentional controller of the sensory subsystems, not storage Monitors/co-ordinates the operation of subsystems by dividing limited central resources between them e.g. driving a car and chatting - visual driving is prioritised by central executive

Question 36

Baddeley et al. (1991) conducted single and dual tasks for these: Visuospatial pursuit tracking (keeping stylus in contact with a moving spot of light) Digit span (serial recall of digit lists) How did patients with Alzheimer’s Disease (AD) (assumed to have attention and executive deficits), healthy age-matched (elderly) controls, and healthy young controls perform on single and dual tasks?

Answer 36

- Results - Performance in dual is worse than single, difference is especially marked in those with AD - Increased deficits in dual task performance in AD patients suggests that central attentional resources are unequally distributed. i.e., the attentional control system of WM (Central Executive) can be selectively impaired