memory Flashcards
Capacity
The amount of information that can be held in your memory
Encoding
How sensory input is changed into a format for use in memory.
sound , vision and meaning are all encoded differently
Duration
Length of time information remains in your memory
Short-term memory
Duration - 18 to 30 seconds
Capacity – 5 to 9 items
Encoding - mainly acoustic
Long-term memory
Duration – unlimited
Encoding - semantic
Capacity – unlimited
Long-term memory
Duration – unlimited
Encoding - semantic
Capacity – unlimited
Research on duration of the long-term memory - Bahrick
Bahrick et al
329 us ppts —> 17-74 years old
1) photo recognition from yearbooks with 50 photos
2) free recall test where participants to recall all the names of their graduating class
Findings of research on duration (LTM) after 15 years
90% photo recognition
Findings of research on duration long-term memory after 48 years
70% photo recognition
30% free recall
Shows that long-term memory may last up to a lifetime for some material
Research on duration for the short-term memory
Peterson and Peterson
24 students
Used trigrams like BNT
Had to count backwards to prevent rehearsal
Research on duration for the short-term memory
Peterson and Peterson
24 students
Used trigrams like BNT
Had to count backwards to prevent rehearsal
Findings on research of duration (STM)
After 3 seconds recall was 80%
After 18 seconds recall was 3%
This shows that short-term duration is 18 seconds unless we repeat or rehearse the information
Research on coding
Baddely
Gave different lists of word to 4 groups of ppts to remember
Group 1- acoustically similar
Group 2- acoustically dissimilar
Group 3- semantically similar
Group 4 - semanically dissimilar
Participants were shown the original words and asked to record them in the right order
Findings of the research on codingf
Tended to do worst on acoustically similar
They tended to do worst recalling from their long-term memory after the interval of 20 minutes for the semantically similar words
This suggests that information is
coded acoustically in stm
Coded semantically in LTM
Research on capacity
Jacobs
Measured digit span
The researcher reads out 4 digits which participants recall in the right order then the researcher reads out 5 digits then 6 digits to be recalled until it cannot be recalled correctly
Research on capacity findings
Mean span for digits – 9.3 items
Means span for letters - 7.3 items
Research on capacity
Miller
Made observations of every day practice
He noted things come in sevens e.g days of the week and deadly sins
So he thought STM capacity is 7+/-2
We recall 5 words/letters easier because we chunk this into groups
Evaluation on coding
Strength – baddeleys study identifies a clear difference between both memory stores , Led to msm
Weakness – lacks mundane realism as they use artificial stimuli with no real meaning to participants
Don’t relate to every day life so limited application
So if it was meaningful participants may use semantic coding even for simple tasks
Evaluation on capacity
Jacob’s study strength - can be replicated easy but however as it is an old study it can be critiqued for lacking adequate controls
So participants could’ve been underestimated due to extraneous variables from distractions
Counterpoint – better controlled studies have replicated Jacob study and got similar results so Jacob study is a valid test
Evaluation coding miller
Weakness - Overestimated short-term memory capacity
(Cowan 2001) found capacity of short-term memory is around 4+ or - 1
This suggest the lower end of the Millers Estimate of 5 items more appropriate
Evaluation of duration of STM
Peterson and Peterson
Weakness – artificial stimuli of trigrams we don’t study every day
Counterpoint -Not completely irrelevant as we do sometimes try to remember meaningless material
Lacks external validity as it doesn’t reflect every day memory
Evaluation of duration study -LTM
Bahrick study
Strength – high external validity as they investigated meaningful memories it doesn’t have a limited application
When studies conducted on long-term memory with meaningless pictures recall rates lowered ( Shepherd 1967)
His study reflects the real estimate of LTM‘s duration
Who discovered types of LTM
Tulving 1985
Implicit / declarative memory
People are not aware of these memories
Procedural
Explicit / declarative memories
Memories people are aware of
Semantic and episodic
Episodic memory
Our ability to recall events and episodes from our life
We recall memories such as events /people /objects to do with our life and we remember when they occurred
Hippocampus
Semantic memory
Our library / dictionary
Our knowledge of the world
Includes facts and knowledge of what words and concepts mean
Less vulnerable to distortion and forgetting
Less personal
Temporal lobe
Procedural memory
Knowledge of how to do things
Includes our memories of learned skills
We usually recall these memories without making a conscious effort
Cerebellum
Procedural memory
Knowledge of how to do things
Includes our memories of learned skills
We usually recall these memories without making a conscious effort
Cerebellum
Strength of types of LTM - clinical evidnce
Clive wearing / HM
Episodic memory —> severely damaged
Semantic memory —]relatively intact
Both patients still knew how to speak / play piano / walk/ what a dog was etc
Supports Tulvings view that there are different memory stores
One store can be damaged , whereas the others are unaffected
Counterpoint to clinical evidence for types of LTM
Case studies unique to a small amount of people send its hard to replicate the findings and control variables
As researcher can’t control how they’re memory was like before the injury and not everyone has the same brain injury as HM and Clive therefore failing to generalise the findings to the population
Ideographic research
Conflicting neuroimaging evidence for types of LTM
Weakness
Buckner and petersen
Reviewed evidence regarding location of semantic and episodic memory
They found semantic memory is located LEFT SIDE OF PREFRONTAL CORTEX
And episodic memory on THE RIGHT SIDE OF THE PREFRONTAL CORTEX
However other research swaps the types of LTM with the sides of the prefrontal cortex
Working memory
The part of your memory you are using when u are working on something
What are the 4 components of the WMM by Baddeley and Hitch .
Central executive
Phonological loop
Visuo- spatial sketchpad
Episodic buffer
Central executive and its functions
Drives the system
Key component of the WMM
Decides how attention of working memory is directed
Allocates the sub systems
Modality free
Limited capacity
Functions : reasoning and decision making
Phonological loop
Deals with auditory information and perseveres its order
Divided into 2 components
What are the names for the 2 components of the phonological loop?
Phonological store & articuatory control system
Phonological store
Holds words u can hear
Holds info in speech for 1-2 seconds
Articulatory control system
Holds words that heard / seen and are silently repeated ,looped like an inner voice
Used to rehearse verbal info from phonological store
Study support for phonological loop
Baddeley , Thompson , Buchanan 1975
They found people cope better with short words than longer words in working memory STM
Episodic buffer
Added in 2000
As Baddeley realised the model needed a more general store 4 temporary storage for information received by the central executive
Limited capacity
Buffer extra storage system but with limited capacity
Intergrates information from all other areas
Episodic buffer
Added in 2000
Visuo- spatial sketchpad
Capacity = 3-4 objects (limited)
Coding = visual
Stores and manipulates visiual information
Holds visual and spatial information for a very short time
What 2 components of visiual sketchpad code information in a visual form?
VISIUAL CACHE : a passive temporary store e.g about colour/form
INNER SCRIBE : an active rehearsal mechanism records arrangements of objects
LOGIE 1995
Working memory model - strength of research support baddeley 1975
-Participants were asked to perform two visual tasks or a visual and verbal task
Findings: Performance was better when the tasks were not using the same processing
this suggests that the VSS and the PL are separate systems and the capacity of the VSS can be overwhelmed
Working memory model - STRENGTH CASE STUDY OF KF - SHALLICE AND WARINGTON
They found KF has selective impairment to his verbal short-term memory caused by a brain injury however his visual short-term memory was not affected
Therefore, suggestion that there is two separate stores
CONTERPOINT: case studies we cannot generalise and brain injury is different for everyone
Weakness of the working memory model Low validity
Central executive has been criticised by other psychologists as a vague concept without a full explanation of its function
Baddeley admit the concept is vague and needs development
Explanations for forgetting : pro active interference
Remembering old information
Prophecy learn information interferes with the new information you’re trying to store
Explanations for forgetting: retroactive interference
Remembering the new stuff
A new memory interferes with the old one
What makes interference more likely?
Similarity
Research on the effects of similarity - McGeoch and mcondald
aimed to investigate retroactive interference
METHOD : six groups of participants each group learnt the same list of words, two syllable adjectives until 100% accuracy
Groups had to then learn a different second list
FINDINGS: most similar words produced the worst recalls
Suggested interference the strongest when the memories are similar
Proactive interference research support - GREENBERG AND UNDERWOOD
GREENBERG AND UNDERWOOD
The number of correctly recall words pairs decrease the more of the word pairs have been previously
Therefore, provides evidence as the previous learnt wordlist had caused confusion in the coding of later words
Proactive interference research support
GREENBERG AND UNDERWOOD
The number of correctly recall words pairs decrease the more of the word pairs have been previously
Therefore, provides evidence as the previous learnt wordlist had caused confusion in the coding of later words
Two weaknesses of interference
Low external validity
Much of the evidence and interference one from artificial laboratory experience Participants shown demand characteristics for lowers confidence in interference as an explanation of forgetting
Interference only explains forgetting when two set of information are similar and often when learnt close together and they are time sensitive
The theory struggles to explain many day-to-day examples of forgetting
Retrieve failure as an explanation of forgetting
explanation of forgetting based on the idea that we don’t have the necessary cues to access that memory
What are the two types of retrieval failure cues?
Internal cues : state dependent forgetting
external cues : context dependent forgetting
Encoding Specificity principle
TULVING
Research and discovered that if a queue is to help us recall information, it needs to be present at encoding when we learn the material and at retrieval
Research on context dependent forgetting
GODDEN AND BADDELEY
Studied divers who learned and recalled a group of words either underwater or on land
4 conditions
40% better recall on the same conditions where they had recalled and learnt words due to the same external cues
Research on the state dependent forgetting
CARTER AND CASSADAY 1998
gave antihistamine drugs to ppts which made them slightly drowsy
Participants who had learnt the words and recalled on the drug performed better
And participants who didn’t use a drug on recall and learning performed better
Strength of context cues
Psychological research into how forgetting works has a practical real world application
E.G students developing effective revision strategies and theories and police force using cognitive interview which has been developed based on this research
Factors affecting EWT - MISLEADING INFORMATION RESEARCH
LOFTUS AND PALMER
aim - effect of leading questions on a person recall
Procedure-
45 students Sharon the same clip of a car crash and series of questions about the accident. Leading question had the verb changed
HOW FAST WAS THE CARS GOING WHRN THEY HIT/SMASHED INTO EACH OTHER?
Findings
The smashed verb Resulted in participants recalling a mean speed of 40.8MPH
the hit verb resulted in participants calling a main speed of 34 mph
Conclusion
Leading question biased that eyewitness testimony of the event
Eyewitness testimony
A legal term referring to the use of eyewitnesses to give evidence in court
Probably the most valuable application of our memory to our everyday life, however there are a number of inaccuracies
What affects the leading questions of eyewitness testimony?
Response bias And substitution explanation
Response bias
The wording of questions has no rule effects on participants memories but just influences how they answer
Substitution explanation
The wording of a leading question actually changes the participants memory
Post event discussion
Occurs when there is more than one witness to an event
Witnesses may discuss what they have seen with eyewitnesses or other people. This may influence the accuracy of each witnesses recall of the event.
Post event discussion research
GABBERT 2003
Procedure:
study participants in pairs and watch the same crime film from different point of view
Meaning that participants could see an elements of the crime that the others couldn’t
Then both participants, then discussed what they had seen individually before completing a recall test
Findings
Found 71% of participants mistakenly record the aspects of events they did not watch but picked up on in discussion
Control group is no discussion there was 0%
Evidence of memory conformity
Why does the post event discussion affect eye witness testimonies?
MEMORY CONTAMINATION- Participants combine misinformation from other witnesses with their own memories
MEMORY CONFORMITY - gabbert et al concluded that witnesses go along with each other either to win social approval because they believe the other witnesses are right they are wrong
Unlike memory contamination the actual memory is unchanged
Anxiety
State of emotional and physical arousal
emotions include : worried, faults and feelings of tension
Physical changes include : increased heart rate and sweatiness
Negative effects of anxiety - (Johnson and Scott)
Naive participants outside the lab listen to conversations
Low anxiety condition - normal conversation about equipment and then a man walks out with greasy hands and a pen
High anxiety condition - hostile conversation breaking glass , furniture was knocked over when a man walks out with bloody hands and a knife
Then asked to identify the man out of 50 photos
49% recalled the man with the pen
33% recalled the man with the knife
Conclusion: Anxiety caused by knife increased focus more on the weapon then face (weapon focus)
Positive Effect of anxiety - (Yuille and Cutshall)
Interviewed witnesses of a deadly shooting 4 months after the event
Findings : witnesses resisted misleading information and those with the most stress (closest to shooter) produced most accurate EWT
Conclusion : Misleading information and anxiety may not be a significant problem for the eyewitness testimony in the real world
Yerks - Donson law of arousal
EWT accuracy increases as anxiety raises as witnesses become more however at a point anxiety becomes too high and more stress/distraction results in lower accuracy
Evaluation for Anxiety of EWT - Pickel
Did experiment to test this using surprising items in a hairdresser salon e.g raw chicken and handgun
Eyewitness testimony accuracy was significantly poor in high unusual situations
Suggest that weapon focus effect is due to participants being surprised at what they say rather than being scared and anxious
Studies on anxiety for eyewitness testimony accuracy - ethical issues
Raised by the Johnson and Scott study
e.g protection from psychological harm the experiment made participants feel anxious. This is unethical.
Studies on anxiety for eyewitness testimony accuracy - weakness of controls
Between the interview and the real life eyewitnesses may of experience many things that the research’s cannot control e.g PED
These extraneous variables may be responsible for the accuracy of recall
What are the four stages of a cognitive interview?
- Report everything - encourages witness report all details about the event, even if these details may seem irrelevant.
- Reinstate the context– trying to mentally re-create an image of the situation including details of the environment and the individuals emotional state.
- Change the order - the witnesses also describe the scene in a different chronological order
- Change Perspective. - trying to mentally re-create the situation from a different point of view
Enhanced cognitive interview
Encourages the witness to relax and speak slowly – reduction in anxiety may enhance recall
Offer comments to help clarify witnesses statements – may improve detail of statement
Encourage witness to speak slowly And engage in eye contact
Weakness of cognitive interview – kebbell and wagsstaff
Police interviewers have to be trained which can be expensive and time consuming
Weakness for cognitive interview - thames Valley police
Found that when they used a combination of report everything and reinstate in the context participants recall was significantly higher
Meaning that some parts of the progressive interview maybe more reliable than others
Supporting research for cognitive interview - Kohnken et al
Meta analysis of 53 studies and found 41% in amount of correct information generated
COUNTERPOINT : however there is also an increase of inaccurate information
