Memory Flashcards
Coding
The format in which information is stored.
Who Did Research On Coding?
Baddely
Process of Baddely’s Experiment on coding
Group 1 - Accoustically similar Group 2 - Acoustically disimilar Group 3 - Semantically similar Group 4 - Semantically disimilar They were given a list of original words in wrong order. Had to recall in correct order. (LTM 20 Min Interval)
Result of Baddley’s Experiment For coding STM
Confusion between acoustically similar words
Result of Baddley’s Experiment for coding in LTM
Confusion between semantially similar words
Conclusions for Baddley’s Experiment on coding
STM - Acoustic confusion, coded acoustically
LTM - Semantic confusion, coded semantically
Positive Evaluation for Baddley’s Experiment on coding
Cause and effect is shown.
Replicable
Makes cognitive sense - Shopping list = words aloud. Recall of book = recall of plot
Negative Evaluation of Baddley’s Experiment on coding
Artificial Stimuli - Cautious about generalising
Lacks EV
Small difference in recall between semantic lists = semantic coding is STM.
What is Capacity?
Amount of information that can be held.
Research for Capacity
Jacobs and Miller
Method for Jacob’s Study on capacity
Aim - See how much info STM can hold at one time
Developed a technique - Digit Span
Research gave a certain number of digits then the PP recalled in correct order. If recalled correctly, amount of digits increased. Determines individuals digit span.
Results of Jacob’s Study on capacity
- 3 letters
9. 3 words
Positive Evaluation(s) of Jacob’s Study on capacity
Supported by other research - More validity
Negative Evaluation(s) of Jacob’s Study on capacity
Conducted a long time ago - Lacked adequate control
Lacks EV - Lacks Mundane realism
May not have controlled for confounding variables - reduces validity
What Did Miller’s Study Discover?
Instead as keeping the information as individuals, the unit of informaiton can be increased by chunking.
What is Miller’s Magic Number?
7 +/- 2 (5-9 chunks)
Evaluation Points For Miller’s Study
Evaluation Points For Miller’s Study
Lacks EV
Miller may have overestimated STM capacity
Cowan reviwed the research and found it was only 4 chunks.
Evaluation of Capacity
Other factors at play - Age and practice effects
Nowadays limitations of STM seen as due to processing limitations associated with STM
What is Duration?
Length of time information can be held
Who Conducted STM Duration Research?
Peterson and Peterson
Method for Peterson and Peterson’s Study on duration
Each student was given a nonsense triagrams (3 consenants), as well as a 3 digit number. The student had to count backwards from this number (prevents mental rehearsal) told to stop counting at different intervals.
Results for Peterson and Peterson’s Study on duration
Amount recalled correctly:
3 seconds - 90%
18 seconds - 5%
(Significant difference between them)
Conclusion for Peterson and Peterson’s Study on duration
STM has a very short duration unless it is rehearsed, I.e. Mental Rehearsal.
Positive Evaluation of Peterson and Peterson’s Study on duration
Operationalised - Replicable
Controlled for confounding variables (counting backwards)
People do try and remember phone numbers - relevance
Negative Evaluation of Peterson and Peterson’s Study on duration
Artificial situation - Lacks EV
Methodology flawed - Different triagrams used in each trial (interference)
Memory trace disappears if not rehearsed - Alternate explanation = information is displaced.
Evaluation of Duration in STM
Brief duration is due to displacement as it has limited capacity.
Little way in research considering the duration in other forms of stimuli I.e Visual Images.
Who Did a Study on Long Term Duration?
Bahrick et al.
Method of Bahrick’s Study
400 American PPs aged 17-74 Y/O.
Recall was tested:
Photo Recognition - School year book pictures
Free Recall - Names of people graduating in their class.
Results of Bahrick’s Study
15 years of leaving - 90% in both correct
Up to 48 years (correct):
80% names
70% faces
Conclusions from Bahrick’s Study
LTM can last a very long time, potentially a lifetime.
Positive Evaluation(s) of Bahrick’s Study
High EV - Real life memories
Negative Evaluation(s) of Bahrick’s Study
Confounding Variables are not controlled for - People could have looked at the year book. (rehearsal)
Evaluations of Duration of LTM
LTM may be seen as lost but actually is just a problem with memory access
Type of testing technique used may affect findings
Who Devised the Multi-Store Model?
Atkinson and Shiffrin
What is the Multi-Store Model?
An explanation of how the memory works in terms of 3 stores: Sensory Register STM LTM Through flowing Storage systems
Describe the structure of the Multi-Store Model
Sensory information =(attention)= short term memory[rehearsal]=(transfer>)or (retrieval
What is the Sensory Register?
A short duration store that holds information we have gained through the 5 senses.
How is the Sensory Register Mainly Coded?
Via all 5 senses. Mainly iconic (visual) and echoic (acoustic)
What is the Duration of the Sensory Register?
Less than half a second
What is the Capacity of the Sensory Register
Very High
Describe Sperling’s Research into the Sensory Register’s Capacity
Flashed a 3x4 grid of letters for 1/20th of a second. A different tone indicated for each row.
Recall was high.
Capacity for SR is very large.
How is STM Coded?
Mainly Acoustic
Capacity of STM?
7 +/- 2 (5-9)
Duration of STM?
Max 30 seconds
How is the LTM Coded
Mainly Semantically
Capacity of LTM?
Unlimited
Duration of LTM
Very long time - Lifetime
Was Case Study Supports the MSM?
Case of HM:
Case of HM:
Man underwent surgery, his hippocampus was removed. When his memory was assessed, he thought it was 4 years ago. LTM was damaged but STM performed well. (Indicates sepperate stores)
Positive Evaluation(s) of MSM
First cognitive explanation - went on to progress and gave a greater understanding.
Considerable evidence - shows they’re different.
Supported by amnesia cases.