Memory Flashcards
Peterson and Peterson, 1959
Investigated duration of STM.
Trigrams.
Counting distraction task.
3 second interval = 80% accuracy of recall
18 second interval = 10% accuracy of recall
Bahrick, 1975
Investigated duration of LTM.
Recognition and matching tasks. Recalling school mates.
34 years after school = 90% accurate recall
48 years after school = 80% accurate recall
Baddeley, 1966
Investigated coding of STM and LTM.
Lists of words to recall that were acoustically different or similar and semantically different or similar.
Had to recall either immediately or wait.
STM codes acoustically (mistakes made in set 1 - acoustically similar).
LTM codes semantically (mistakes made in set 3 - semantically similar).
Miller and Jacobs, 1887/1956
Investigated capacity of STM.
Recalling strings of words or numbers.
Average of 7 numbers and 9 words remembered.
Miller claimed the STM has a capacity of 7(+or-)2.
Holds 5-9 items.
Wagenaar
Investigated capacity of LTM.
Wrote 2400 diary entries. Found that when recalling events rather than dates he could remember most of them. Shows capacity of LTM is very large.
Positives of memory research
Mostly lab studies - results reliable and replicable so we have confidence that this is how memory really works.
Practical applications for improving our memory/teaching techniques.
Some are field experiments - high external validity.
Distraction tasks ensure results fully reflect function of the memory, not rehearsal.
Negative of memory research
Lab studies - lack external validity.
Subjective on individual differences - some people may have a better memory than others which can skew results.
Components in the WMM
- Central executive
- Phonological loop
- Visuospatial sketchpad
- Episodic buffer
Central executive
- Decides what to pay attention to.
- Limited capacity (deals with one bit of info at a time)
- Modality free (doesn’t code)
Phonological loop
- Sound info, voice inside head when writing or thinking.
- Consists of articulatory control (rehearses words), phonological store (stores words).
- Duration of 2 seconds.
- Codes echoically (acoustically).
Visuospatial sketchpad
- Visual info, allows us to create mental images and navigate around our environment.
- Capacity of 3-4 items.
- Stores iconically (visually).
Episodic buffer
- Brings/chunks together material from sub-systems to create a single memory.
- Can handle 4 chunks of info at a time.
- Modality free (doesn’t code).
Strengths of the WMM
Practical applications:
- Dyslexia, knowledge of poor verbal memory means learning adapted to use visual memory instead (visuospatial sketchpad instead of phonological loop).
- Understanding of poor concentration in people with depression (overloaded central executive).
- Improving revision, don’t listen to music as it overloads phonological loop.
- In general, improvements to education systems.
Negatives of WMM
Reductionist - displays a complex situation as something very simple.
Support for WMM
KF case study - suffered damage to brain after motorcycle accident. He became verbally impaired. Visual memory remained unaffected. This shows that the STM has separate components for visual and verbal info, supporting the existence of phonological loop and visuospatial sketchpad.
Cognitive interview
- Report everything (releases linked memories)
- Recreate the context (releases cues, triggers memory)
- Change order of recall (gets rid of schemas)
- Change perspective (provokes deeper thinking)
Enhanced cognitive review
- Ask witness to speak slowly (slows thought process).
- Adopt the language of witness (relaxed, aids memory).
- Ask open ended questions (allows max info to be given).
Positives of Cognitive Interview
- Improves recall and lower rates of false conviction.
- Benefits economy, less people in prison more in work.
- Undergone peer review, a reliable technique.
Negatives of Cognitive Interview
- Time consuming, elongates the process which can be stressful for police and witnesses.
- Studies showed it increased amount of info by 81% but 61% of this was false. Leads to false conviction.
- Requires depth and detail, can be traumatising for witnesses to remember.
The Encoding Specificity Principle
Tulving - “the greater the similarity between the encoding event and retrieval event, the greater the likelihood of recalling the original memory”
Interference Theory of Forgetting
Occurs when one memory disturbs the ability to recall another. Most likely when memories are similar.
Proactive = old memories interfere with new ones. Retroactive = new memories interfere with old ones.
Support for the Interference Theory - Baddeley and Hitch (1977)
Rugby union players asked to recall the names of teams they had played that season.
Players who played all games forgot more names that those who had played less games due to injury.
This shows that learning the names of new teams caused distortion of the old ones/poor recall ability, supporting retroactive interference.
\:) = natural environment, high external validity. \:( = subjective on players' memories.
Retrieval Failure Theory of Forgetting
The failure to retrieve memories due to a lack of cues. When we encode a memory info (cues) are stored alongside it. Therefore when these cues are present in future, the original memory will be triggered and we will remember.
Context-dependant cues = from external environment
State-dependant cues = internal/how we feel
Positives of Retrieval Failure Theory
- Practical applications, help students to revise using cues that can trigger memories in exam. Eg, silence.
- Dementia, memory boxes to help recall.
Negatives of Retrieval Failure Theory
- Support is often held in lab, low external validity.
- Impossible to accurately measure memory. Everyone has different recall abilities so results can’t be generalised.
Support for Retrieval Failure Theory - Godden and Baddeley (1975)
Deep sea divers asked to learn and recall words:
1) learn on land, recall underwater
2) learn on land, recall on land
3) learn underwater, recall on land
4) learn underwater, recall underwater
Divers could recall more words when conditions matched. 40% less accurate recall when un-matched.
Supports retrieval failure. When external environment was the same, context-dependant cues were released that triggered memories of the words.
:( subjective on someone’s memory (inaccurate)
:( artificial task (ungeneralisable to everyday life)
Atkinson and Shiffrin (1968)
The Multistore Model of Memory.
Sensory register = gathers info from sense organs. If paid attention to it goes to…
Short term memory = info that is currently happening. If not rehearsed will be forgotten. If rehearsed passed on to…
Long term memory = info held longer here. Can be forgotten through trace decay.
The sensory register - coding
Raw, unprocessed. Seperate stores for each sense:
- echoic (sound)
- iconic (visual)
- gustatory (taste)
- olfactory (smell)
The sensory register - capacity
Sperling (1960) suggested 4 items when associating sounds/senses with memories.
The sensory register - duration
400 milliseconds (backed up by Sperling 1960).
Short term memory - coding
Accoustically (Baddeley 1966)
Short term memory - capacity
5-9 items 7(+or-2) Miller and Jacobs
Short term memory - duration
18-30 seconds (Peterson and Peterson)
Long term memory - coding
Semantically (Baddeley 1966)
Long term memory - capacity
Unlimited (Wagenaar)
Long term memory - duration
34-48 years (Bahrick 1975)
Evaluation of the MSM
Supporting lab research =
:) replicable and reliable
:( lacks external validity/unimportant tasks
Supporting case studies =
:) in depth/high external validity
:( unique to one person/cannot be generalised
Brain scans =
:) provide scientific proof to support MSM/reliable
:( reductionist/technology not advanced enough to give evidence of exact function of memory
Support for MSM - Clive wearing
Virus attacked hippocampus which caused STM loss. Only had 7 second memory. Could still remember childhood, proving that the STM and LTM are seperate and serve different functions.
Types of LTM
Explicit: episodic and semantic
Implicit: procedural
Explicit LTM
Memories we can put into words. Only recalled if consciously thought about.
Implicit LTM
Memories we can’t put into words. Don’t require conscious thought to be recalled. Know how to do them without thinking about it eg, riding a bike.
Episodic LTM
Specific events, people, places or objects and behaviours involved. Eg, a wedding.
Location = prefrontal cortex
Semantic LTM
Knowledge, facts, meanings and understanding. Eg, capital cities.
Location = temporal lobes
Procedural LTM
Memories of/knowing how to perform an action. Usually related to muscle memory. Eg, riding a bike, speaking with correct punctuation and grammar.
Location = neocortex areas
Support for types of LTM - Tulving (1972)
- Injected radioactive gold into 6 volunteers.
- PET scanned to detect its location, showing blood flow during thought.
- Required to think of 4 semantic and 4 episodic memories.
Greater cortical blood flow in the frontal lobes for episodic memories and in posterior regions for semantic.
Shows that episodic and semantic are different types of LTM that work separately to one another/control different processes.
:) brain scans scientific and accurate
:) lab study, replicable/reliable
:( sample very small, ungeneralisable
:( results from 3 p’s inconclusive, skewed accuracy of evidence.
Support for LTM - Clive Wearing
7 second memory due to damaged hippocampus. Couldn’t recall episodic memories. Semantic and procedural memories remained unaffected; could still walk and play the piano.
Shows that different types of LTM must exist and function separately from one another. Localised in different areas.
:) case studies very detailed with high external validity.
:( only occurred to one person, cannot be replicated or generalised which skews reliability of results.
The impact of anxiety on eyewitness testimony
Anxiety can influence someone’s ability to recall accurately. It differs from person to person. Studies into this are:
- Johnson and Scott
- Yerkes-Dodson curve
Johnson and Scott - Procedure
2 conditions:
-No weapon (p’s would hear convo about equipment failure. Would then see target running into reception holding pen with grease covered hands).
-Weapon (p’s would hear heated row and breaking glass. Target would run into reception with a bloodied letter opener).
Both groups shown 50 photos and asked to identify the target.
Johnson and Scott - Findings and conclusion
Witnesses of non-weapon condition correctly identified target 49% of the time. In weapon condition accuracy was only 33%.
Implies anxiety negatively impacts recall ability. Those in weapon condition may have felt pressure to provide correct info as it was a serious matter, therefore their memory became more distorted under the stress.
Weapon focus - could also distort memory. P’s focus on the weapon rather than target so cannot recall his face.
Johnson and Scott - evaluation
:) clear link between anxiety and recall.
:) leads to practical applications when using witnesses, measures can be taken to relax witness to prevent false testimony.
:( ethical issues - caused stress to p’s, weren’t protected from harm, consented to incorrect brief.
:( results are subjective on someone’s memory, might not be reliable representation of how recall is affected.
:( demand characteristics - unusual situation/knew they were meant to be taking part in study. Therefore may have adjusted recall to fit expected aims.
The Yerkes-Dodson curve
A model suggesting that we need an extent of anxiety to increase performance in memory tasks. Stress reaches an optimal point at which we can efficiently store/recall memories. Too low/too high causes distortion or memory loss.
Evaluating the Yerkes-Dodson curve
:) logical explanation as to why memory would be effected during a stressful event.
:( reductionist. Levels of stress are subjective and affect everyone differently. Makes explanation harder to generalise and produces inconsistent findings.
Types of misleading information
- Leading questions (set people up to answer a certain way. Makes someone question themselves and alters their memory).
- Post event discussion (conforming to the memories of others, distorts own recall of what happened).
- Repeat interviewing (causes witness to doubt own memory. Makes them feel wrong so change story on this basis).
ALL LEAD TO FALSE TESTIMONY!
Leading questions - Loftus and Palmer (1974)
Students divided into 5 conditions:
“Hit” (34mph) / “Bumped” (38mph) / “Collided” (39mph) / “Contacted” (32mph) / “Smashed” (41mph)
Watched video of cars smashing then asked “how fast were the cars moving when they…..into each other”
When asked if they saw broken glass, more people from “smashed” said they had than “hit” condition.
Loftus and Palmer (1974) - findings and conclusions
"contacted" = 32mph "smashed" = 41mph
Cars were moving at same speed in each video. The verb used elicited different responses. Shows that how question is worded alters perception of an event. This applies to EWT; the way an interviewer words a question can distort EW memories.
Loftus and Palmer (1974) - evaluation
:) controlled conditions, reliable/replicable results
:) practical applications, police can keep questions vague and open so recall is accurate (leads to decrease of false conviction and improves economy)
:( artificial setting, unrealistic task, hence cannot be sure this is how recall works in real world.
:( lacks validity, prone to demand characteristics.
Post event discussion - Gabbert
P’s divided into groups to watch different videos of same event. After watching, p’s required to discuss it (thinking they were talking about same clip) and then write down what they could remember.
Gabbert - findings and conclusion
Recollection from every participant contained info from the video they didn’t watch. 71% of recalled info was incorrect.
Shows that conferring with others distorts memory of what actually occurred/ creates new memories. This has similar effects in EWT, leading to false conviction.
Gabbert - evaluation
:) practical application - stopping EWs from conferring after an incident.
:) lowers rates of false conviction which is positive for economy as less people in prison more in work.
:( individual differences - not all people conform to memories of others, so may not provide any use in practical application and false conviction wont improve.
