The Multi Store Model- Sensory and Short Term
Sensory Memory stores all information from neurons for a few milliseconds. This includes taste, smell, touch and sight.
It it then encoded into Short Term Memory (STM), or lost by decay.
- Peterson and Petersons trigrams study showed that, when rehearsal was inhibited by counting backwards, STM lasted about 18 seconds.
- Millers experiment, where participants were asked to repeat numbers immediately after the researcher said them, showed that STM had a capacity of abount 7 +/- 2 items.
- Baddley divided words into 4 groups; semantically similar, dissimilar, acoustically similar, disimilar. When asked to recall, participants strugle most wth acoustically similar, because mind struggles to diffrentiate similar sounding words. Therefore STM is acoustically encoded.
The Multi Store Model- Rehearsal Loop and LTM
The rehearsal loop rehearses information so it passes into the long term memory (LTM) or is lost by displacement.
- Duration-Bahrick did a study on multiple generations of college leavers to identify their peers eithe rby free recall or recognition (matching names to faces). 15 years after graduation, they could recognise 90% of peers, and after 48 years they were 60% accurate. Long term memory can be up to a lifetime. (it is uncertain to know whether the decrease in accuracy was due to loss of information by the system, or old age.)
- Capacity -No studies, but potentially unlimited.
- Encoding-Baddleys semantic/acoustic coding experiement, showed there was a little decrease in semantically similar words after a interval. Therefore, LTM is coded semantically.
Information in LTM can remain there or be lost by decay, displacement or interference. When thinking about something in the present, the information is passed back into STM by retrieval.
The Multi Store Model Evaluation
Trigrams- Peterson's experiment seems to justify the notion of the rehearsal loop. When rehearsal was stopped by an inhbitory task, infortmation couldn't pass to the LTM. This also justifies the idea of separate stores for LTM and STM.
However, quite an artificial task, reducing its ecological validity.
Primacy and Recency- When participants were shown a list of words, they remembered the first words and last words the best. This argues that the first words went through rehearsal to be remembered in LTM,and the last words are still present in STM.
artificial and psychologists argue that the last words aren't in STM, but are just more distinct.
Clive Wearing- suggests its more complicated as he can recall some items from LTM and STM but not others.Case study so very little population validity, but challenged theory.
Baddleys various studies showed memory isn't passive.
The Working Memory Model
The Central Executive- controls attention and the subsidary systems
Visuo-Spatial scratch pad- stores visual and spatial information for a few seconds.
The phonological loop-
- articulatory control- this rehearses acoustically coded items.
- phonological store- this stores acoustially coded items.
The Episodic Buffer- This combines information from the VS scratch pad, the phonological loop and long term memory. It plays a role in imagination and continuity of sight.
The Working Memory Model Evaluation
- articulation time- a study found that the time taken to articulate a word was key to how easily it was remembered. This supports the idea of the ariculatory control proces in the phonological loop, because it would take longer to rehearse more complex words.
- division of attention- a study by Baddeley showed that when particpants were given two visual tasks (e.g. followinga spot of light, and decribing the shape of a letter) they struggled more than when given a visual task and acoustic task (e.g. reciting the alphabet). This is because the two similiar tasks are competing for resources within one element of the working memory model.
- Psychologists argue that it is hard to disprove.
- We know the least about the Central Executive and its the most important element.
Eye Witness Testimony- Anxiety
Two sets of participants. One group overheard a conversation about equipment failure, and saw a man with greasy hands and a pen. The other group overheard an argument and then saw a man with a bloody knife.
The greasy group accuratley identified the man correctly 49%, and the bloody group 33% of the time. Loftus called this weapon focus.
Yuille and Cutshall
Looked at 13 real life witnesses to a armed robbery. They found that those closest in proximity to the crime had the most accurate and detailed recall of it.
Christianson and Hubinette
110 witnesses to 22 robberies. Found that victims were alot more detailed in their recall than bystanders, and this accuracy remained 15 months later.
Eye Witness Testimony- Anxiety evaluation
- Easily repeated
- Her research has been critiscised for its artificiality; that her results did not represent ecological reality.
- Also, participants were made to think it was a real situation and were decieved. This also means they were not fully aware of their right to withdraw. They were debriefed.
Yuille and Cutshall, Christianson and Hubinette
- Low control over extraneous variables, so they could lack internal validity.
- However, very high ecological validity, as they investigated real life victims and witnesses.
Practical Applications of research- witnesses and victims should be encouraged to make testimony in court.
Social Sensitivity- Loftus research seems to say that witnesses exposed to anxious situations may not be accurate in their identification and recall. people dont want to be seen as inadequate.
Eye Witness Testimony- Age
Opportunity study of 600+ people on a highstreet. He asked people of various ages to recall the appearance of a young woman they had talked to for 2 minutes 15 minutes earlier.
Anastasi and Rhodes
Participants split into 3 age groups, and shown 24 photos they had to rate for attractiveness. Then shown 48 photos and they had to recall the original 24. They found that recall got worse as you got older, with young people's highest average 90%, middle aged 93% older people 66%. They also found that participants were best as recognising faces of similar age to theirs e.g. older people were only 56% accurate when identifying a young face.
Found that younger children were more likely to choose anyone, and college students were more accurate.
Eye Witness Testimony- Age Evaluation
- big scale study- more population validity
- opportunity sampling- biased as only certain people would be on that high street
Anastasi and Rhodes
- Artificial- remembering a real face is different to a photo- low ecological validity.
- small scale
- be wary of children's decisions
- be wary if the witness is identifying someone of a very different age.
- Old people don't want to be seen as inadequate or underperforming, like Anastasi and Rhodes data suggests.
Eye Witness Testimony- Misleading Information
1) misleading info-
- participants watched a video of a car crash. one group of participants, amongst other questions, were asked 'how fast was the car going as it went past THE white barn' when there had been no white barn. A week later, 17.3% recalled a white barn when asked, whereas only 2.8% of the control group.
- After watching a video of a car crash, participants were asked questions about how fats the car was going when it made contact with the car. changing the adjectives had an effect on the estimated speed. 'contacted' = 31mph, whereas 'smashed'= 41mph.
3)blatantly misleading information-
- participants shown slides of a robbery than involved a red purse. 98% of participants identified it as fred. after reading a report that called the purse brown, only 2 participants were misled.
EWT- misleading info evaluation
- very good control within experiments.
Loftus has been critiscised:
- for artifiicality- her studies either use videos or photo slides, which would be very different to witnessing a real life event. for example, very few people would remember a white barn into a location they were actually in.
- demand characteristics- her laboratory studies are very prone to this, as people will be paying extra attention and commiting more than usual to memory, so as to impress or please the researcher.
- unfair memory tests- pyschologists have said that Loftus uses illogical memory tests, and therefore reduce the accuracy of participants.
- Police and investigators know to be very careful with their wording, so as to not result in biased witness accounts.
C - change the order of recall
By encouraging witnesses to recall the event in a different order, it encourages them to pick up new triggers that may be relevant to the investigation.
R- recall setting of the incident
Witnesses are asked to recall all smells, sights, sound and feelings they had around the time, so as to provoke new memories.
Witnesses are asked to recall every detail within the incident, however irrelevant it may seem.
Witnesses are asked to look at the incident from a different perspective, such as across from the road. This encourages objectivity within their report.
Cognitive interview evaluation
Gieselman- Partcipants were shown a clip of a violent crime, and 48 hours were asked to report on it. The cognitive interview brought about 41.5 correct items from the participants, compared to 39 for the standard interview. It also brought around more incorrect items, but not significantly more than standard interview. STUDENTS -less population validity. VIDEO- less ecological validity.
Konkhen- meta anaylsis of 53 studies and found 34% increase in correct recall with cognitive interview.
Studies have been done that show 'report everything' and 'mental reinstatement of scene' are the key improvers of recall.
Children actually perform worse in cognitive interviews.
Expensive and timeconsuming to train police in cognitive procedures.
- Acronyms- ROY G BIV
- Acrostics-Richard of York Gave Battle in Vain
The work because you have to process the information into a distinct and memorable form.
- method of loci- visualising a route you know well, then putting items from a list interacting with places along the way. works because it combines new information with old information in a meaningful way.
- Peg word- get words to ryhme with numbers e.g. one- bun, two-shoe. then get the items in the list to interact with the number items.
- Use of hierarchies- Studies show that people remembered 90% of organised words, and only 10% of unorganised words.