2.1 Thinking and Remembering
Problem 2
Problem A
Miller- basic unit in short-term memory= chunk- memory unit consisting of several
components that are strongly associated with one another
Short term memory can hold 7 chunks
Can organise adjacent numbers or letters to form single chunk
People engage in internal mental processes to convert stimuli to manageable
number of chunks
Brown/Peterson and Peterson: the Serial-Position Effect
Gave much of the first info about short-term memory
Demonstrated material held in memory for less than 1 minute is frequently
forgotten
Method: present participants with items, instruct them to remember. Given a distracting
task before asked to recall original items
Significance: memory is fragile for material stored only a few seconds
Serial position effect- U-shaped relationship between word’s position in a list and its
probability of recall
Recency effect- better recall for items at the end of the list
Viewpoint: this is because these items are still in short-term memory at the time of
recall
Primacy effect- enhanced recall for items at the beginning of the list
Viewpoint: these are easy to remember for 2 reasons 1) don’t need to compete
with earlier items 2) rehearse early items more frequently
Semantics can influence short-term memory
Wickens and Co: proactive interference- people have trouble learning new material
because previously learned material keeps interfering with their new learning
Release from Proactive Interference- when the category of items is shifted eg. From
letters to numbers
- Can also have release from PI when researchers shift semantic category of items
Semantic factors influence number of items that can be stored in short-term memory
Previously stored words can interfere with recall of new words that are similar in
meaning: degrees semantic similarity is related to amount of interference
Problem B
Baddeley & Hitch- replaced short-term store with working memory.
4 components:
1. Central executive- attentional system
- Limited capacity
- Resembles attention, deals with cognitively demanding tasks
2. Phonological loop- processing and storing info briefly in phonological form
- Limited capacity
- Preserves order that words are presented
, 3. Visual-spatial sketchpad- specialised for visual and spatial processing and
temporary storage
- Limited capacity
- Stores and manipulates spatial and visual info
4. Episodic buffer- temporary storage for integrated info coming from visuo-spatial
sketchpad and phonological loop
1-3 have 2 key assumptions:
1. If 2 tasks use same component, cannot successfully perform them together
2. If 2 tasks use different components, should be possible to perform them just as
well together, as separately
Central Executive
Most important component of working memory, involved in most complex
cognitive activities
Doesn’t store info
Prefrontal cortex most involved in central executive functions, but functions aren’t
entirely dependent on cortex
Associated with executive processes- processes that organize and coordinate
functioning of cognitive system to achieve current goals
Baddeley, 4 executive processes:
1) Focusing attention or concentration
2) Dividing attention between 2 stimulus streams
3) Switching attention between tasks
4) Interfacing with long-term memory
Miyake et Al
Method: several executive tasks administered
Results: 3 related, but separable executive processes:
1. Inhibition function- deliberately overriding dominant responses and to resisting
distraction eg. Stroop task
2. Shifting function- switch flexibly between tasks or mental sets eg. Task
switching
3. Updating function- monitoring and engaging in rapid addition or deletion of
working memory contents
Unity and Diversity Framework- Miyake and Friedman
- Each executive function consists of what’s common to all 3 executive functions
+ what is unique about that function
- No unique variance for inhibition function, so it correlates perfectly with
common executive functions- one’s ability to actively maintain task goals
and goal-related info, and use this info to effectively bias lower-level
processing
- Genetic factors contribute substantially to individual differences at unity and
diversity levels
- All three functions associated with prefrontal area activation, consistent with
diversity notion
- All three functions produced activity in other areas, consistent with unity
notion
Hedden and Gabrieli: several areas associated with both functions, other areas more
activated by inhibition than shifting, modest evidence of brain areas more activated by
shifting than inhibition
Significance: overlap in areas associated with shifting and inhibition, and evidence of
diversity
Dysexecutive Syndrome
Problem 2
Problem A
Miller- basic unit in short-term memory= chunk- memory unit consisting of several
components that are strongly associated with one another
Short term memory can hold 7 chunks
Can organise adjacent numbers or letters to form single chunk
People engage in internal mental processes to convert stimuli to manageable
number of chunks
Brown/Peterson and Peterson: the Serial-Position Effect
Gave much of the first info about short-term memory
Demonstrated material held in memory for less than 1 minute is frequently
forgotten
Method: present participants with items, instruct them to remember. Given a distracting
task before asked to recall original items
Significance: memory is fragile for material stored only a few seconds
Serial position effect- U-shaped relationship between word’s position in a list and its
probability of recall
Recency effect- better recall for items at the end of the list
Viewpoint: this is because these items are still in short-term memory at the time of
recall
Primacy effect- enhanced recall for items at the beginning of the list
Viewpoint: these are easy to remember for 2 reasons 1) don’t need to compete
with earlier items 2) rehearse early items more frequently
Semantics can influence short-term memory
Wickens and Co: proactive interference- people have trouble learning new material
because previously learned material keeps interfering with their new learning
Release from Proactive Interference- when the category of items is shifted eg. From
letters to numbers
- Can also have release from PI when researchers shift semantic category of items
Semantic factors influence number of items that can be stored in short-term memory
Previously stored words can interfere with recall of new words that are similar in
meaning: degrees semantic similarity is related to amount of interference
Problem B
Baddeley & Hitch- replaced short-term store with working memory.
4 components:
1. Central executive- attentional system
- Limited capacity
- Resembles attention, deals with cognitively demanding tasks
2. Phonological loop- processing and storing info briefly in phonological form
- Limited capacity
- Preserves order that words are presented
, 3. Visual-spatial sketchpad- specialised for visual and spatial processing and
temporary storage
- Limited capacity
- Stores and manipulates spatial and visual info
4. Episodic buffer- temporary storage for integrated info coming from visuo-spatial
sketchpad and phonological loop
1-3 have 2 key assumptions:
1. If 2 tasks use same component, cannot successfully perform them together
2. If 2 tasks use different components, should be possible to perform them just as
well together, as separately
Central Executive
Most important component of working memory, involved in most complex
cognitive activities
Doesn’t store info
Prefrontal cortex most involved in central executive functions, but functions aren’t
entirely dependent on cortex
Associated with executive processes- processes that organize and coordinate
functioning of cognitive system to achieve current goals
Baddeley, 4 executive processes:
1) Focusing attention or concentration
2) Dividing attention between 2 stimulus streams
3) Switching attention between tasks
4) Interfacing with long-term memory
Miyake et Al
Method: several executive tasks administered
Results: 3 related, but separable executive processes:
1. Inhibition function- deliberately overriding dominant responses and to resisting
distraction eg. Stroop task
2. Shifting function- switch flexibly between tasks or mental sets eg. Task
switching
3. Updating function- monitoring and engaging in rapid addition or deletion of
working memory contents
Unity and Diversity Framework- Miyake and Friedman
- Each executive function consists of what’s common to all 3 executive functions
+ what is unique about that function
- No unique variance for inhibition function, so it correlates perfectly with
common executive functions- one’s ability to actively maintain task goals
and goal-related info, and use this info to effectively bias lower-level
processing
- Genetic factors contribute substantially to individual differences at unity and
diversity levels
- All three functions associated with prefrontal area activation, consistent with
diversity notion
- All three functions produced activity in other areas, consistent with unity
notion
Hedden and Gabrieli: several areas associated with both functions, other areas more
activated by inhibition than shifting, modest evidence of brain areas more activated by
shifting than inhibition
Significance: overlap in areas associated with shifting and inhibition, and evidence of
diversity
Dysexecutive Syndrome
