EFEMENA
MEMORY 15/11
15 NOVEMBER :09 / LIBRARY
End: 19 NOVEMBER :30 / HOME
1. Coding, capacity and duration of memory
2. The multi store model of memory
3. Types of long term memory
4. The working memory model
5. Explanations for forgetting
6. Factors affecting the accuracy of eyewitness testimony
7. Improving the accuracy of eyewitness testimony
Coding, capacity and duration of memory
Proposed by Atkinson and shiffrin. MMM is a structural model with 3
separate stores with information passing between them in a linear way
● Sensory memory
● Short term memory
● Long term memory
Coding / encoding
Format or type of information stored in each memory store. Types of
encoding: visual, acoustic, semantic
● Coding for STM = acoustic - as sound
● Coding for LTM is semantic - through its meaning
● Coding for sensory memory = raw unprocessed information and
modality specific
○ 5 sensory registers that are modality specific
○ echoic - sound/auditory information encoded acoustically
○ iconic - visual information encoded visually
Research support
Baddely gave participants ¼ word list to learn. 4 lists in total.
, 1. Acoustically similar (sounds the same)
2. Acoustically dissimilar (sounds different)
3. Semantically similar (same meaning)
4. Semantically dissimilar (different meaning)
Participants recalled immediately after (STM) or after 2 minutes (LTM).
Participants did worse with acoustically similar words in STM shows that
STM is encoded acoustically. Participants did worse with semantic similar
words in LTM shows LTM encoded semantically
Capacity
Maximum amount of information that can be retained in memory
● STM = 7+-2 (millers magic number)
○ Capacity can be increased through chunking
○ Jacobs found mean letter span was 7.3 and mean digit span was
9.3
● LTM = unlimited capacity
● Sensory memory = large capacity
Research support
STM: Miller reviewed existing research on STM and found we can hold 7
items in memory plus or minus 2. STM stores chunks rather than individual
numbers/enters. Explains why we can recall phone numbers more than 7
digits.
LTM: Standing et al gave participants a sequence of 2560 photographs after
36 hours the participants could identify the correct photo when paired with a
scene 90% of the time . ltm is an unlimited store
Sensory: Sperling flashed a grid of letters on the screen for 0.05 seconds
participants on average recalled 4/5 letters correctly. asked to recall from a
particular row and was able to recall 3/4 letters. show high capacity
Duration
How long a memory trace can be held for before its forgotten
● Sensory register = brief duration of 0.5 seconds
● STM = 18 - 30 seconds duration
, ● LTM = unlimited duration
Research support
Peterson and Peterson research into short term memory duration. Using 24
psychology students. Nonsense 3 letter consonants to remember and to
recall after 3,6,9,12,15,18 seconds. Interference task to prevent rehearsal.
80% accuracy after 3 seconds. 10% accuracy after 18 seconds.
Bahrick et al research into long term memory duration. 392 american
graduates were shown photographs from high school year groups and asked
to identify them. 14 years of graduating 90% were able to match the names
and face. 47 years of graduation 60% were able to match names to face.
Most people could remember certain information for almost a lifetime.
Supports long term memory has lifetime duration and is semantically
encoded.
Evaluation of coding, capacity and duration
Limitation: Miller's study on capacity of STM didn’t take into account other
variables and factors that can affect capacity for example age. Jacobs'
research acknowledged that STM gradually improved with age.
Limitation: Miller's findings on the capacity of STM hasn’t been replicated.
Cowan reviewed studies and concluded 4 was the limit and Miller's magic
number of 7+-2 was inaccurate. Lacks reliability.
Limitations: Petersons and Peterson's study on duration of STM has low
ecological validity. Unlikely people in real life would want to memorise
random 3 letter trigrams. Can’t be applied to realistic examples of memory.
Lacks mundane realism
Limitation: frost found out that LTM recall was related to visual categories
and is not exclusively semantic. Reduces reliability of baddeley study which
found LTM was encoded for semantically.
The multi store memory model
Proposed by Atkinson and shiffrin. MSM is a structural model with 3 separate
stores with information passing between them in linear way
● Sensory memory
MEMORY 15/11
15 NOVEMBER :09 / LIBRARY
End: 19 NOVEMBER :30 / HOME
1. Coding, capacity and duration of memory
2. The multi store model of memory
3. Types of long term memory
4. The working memory model
5. Explanations for forgetting
6. Factors affecting the accuracy of eyewitness testimony
7. Improving the accuracy of eyewitness testimony
Coding, capacity and duration of memory
Proposed by Atkinson and shiffrin. MMM is a structural model with 3
separate stores with information passing between them in a linear way
● Sensory memory
● Short term memory
● Long term memory
Coding / encoding
Format or type of information stored in each memory store. Types of
encoding: visual, acoustic, semantic
● Coding for STM = acoustic - as sound
● Coding for LTM is semantic - through its meaning
● Coding for sensory memory = raw unprocessed information and
modality specific
○ 5 sensory registers that are modality specific
○ echoic - sound/auditory information encoded acoustically
○ iconic - visual information encoded visually
Research support
Baddely gave participants ¼ word list to learn. 4 lists in total.
, 1. Acoustically similar (sounds the same)
2. Acoustically dissimilar (sounds different)
3. Semantically similar (same meaning)
4. Semantically dissimilar (different meaning)
Participants recalled immediately after (STM) or after 2 minutes (LTM).
Participants did worse with acoustically similar words in STM shows that
STM is encoded acoustically. Participants did worse with semantic similar
words in LTM shows LTM encoded semantically
Capacity
Maximum amount of information that can be retained in memory
● STM = 7+-2 (millers magic number)
○ Capacity can be increased through chunking
○ Jacobs found mean letter span was 7.3 and mean digit span was
9.3
● LTM = unlimited capacity
● Sensory memory = large capacity
Research support
STM: Miller reviewed existing research on STM and found we can hold 7
items in memory plus or minus 2. STM stores chunks rather than individual
numbers/enters. Explains why we can recall phone numbers more than 7
digits.
LTM: Standing et al gave participants a sequence of 2560 photographs after
36 hours the participants could identify the correct photo when paired with a
scene 90% of the time . ltm is an unlimited store
Sensory: Sperling flashed a grid of letters on the screen for 0.05 seconds
participants on average recalled 4/5 letters correctly. asked to recall from a
particular row and was able to recall 3/4 letters. show high capacity
Duration
How long a memory trace can be held for before its forgotten
● Sensory register = brief duration of 0.5 seconds
● STM = 18 - 30 seconds duration
, ● LTM = unlimited duration
Research support
Peterson and Peterson research into short term memory duration. Using 24
psychology students. Nonsense 3 letter consonants to remember and to
recall after 3,6,9,12,15,18 seconds. Interference task to prevent rehearsal.
80% accuracy after 3 seconds. 10% accuracy after 18 seconds.
Bahrick et al research into long term memory duration. 392 american
graduates were shown photographs from high school year groups and asked
to identify them. 14 years of graduating 90% were able to match the names
and face. 47 years of graduation 60% were able to match names to face.
Most people could remember certain information for almost a lifetime.
Supports long term memory has lifetime duration and is semantically
encoded.
Evaluation of coding, capacity and duration
Limitation: Miller's study on capacity of STM didn’t take into account other
variables and factors that can affect capacity for example age. Jacobs'
research acknowledged that STM gradually improved with age.
Limitation: Miller's findings on the capacity of STM hasn’t been replicated.
Cowan reviewed studies and concluded 4 was the limit and Miller's magic
number of 7+-2 was inaccurate. Lacks reliability.
Limitations: Petersons and Peterson's study on duration of STM has low
ecological validity. Unlikely people in real life would want to memorise
random 3 letter trigrams. Can’t be applied to realistic examples of memory.
Lacks mundane realism
Limitation: frost found out that LTM recall was related to visual categories
and is not exclusively semantic. Reduces reliability of baddeley study which
found LTM was encoded for semantically.
The multi store memory model
Proposed by Atkinson and shiffrin. MSM is a structural model with 3 separate
stores with information passing between them in linear way
● Sensory memory
