Memory

Coding - the format in which information is stored in the memory stores.

Baddeley researched coding; he gave four groups of participants different word lists to learn (acoustically similar, acoustically dissimilar, semantically similar, semantically dissimilar). When tested on their short term memory (STM) recall they did worse with acoustically similar words, and when tested on long term memory (LTM) they did worse with semantically similar words. This shows that coding is mainly acoustic in STM, and mainly semantic in LTM.

Capacity - the amount of information that can be held in a memory store. Joseph Jacobs came up with a technique to measure digit span, the mean span for digits = 9.3 items, mean span for letters = 7.3.

Miller noted that things come in 7's, e.g 7 days of the week. Capacity of STM is 7+-2. People also do chunking to make memory better.

Duration - length of time information can be held in memory.

Duration of STM - Peterson and Peterson tested 24 students; students were given a consonant syllable (trigram) to remember and also a 3 digit number, students had to count back from this number in order to prevent rehearsal, they were told to stop at different retention intervals.

Duration is between 18-30 seconds.

Duration of LTM - Bahrick studied people between ages of 17 and 74. They took part in a photo recognition test (school year book), and a free recal test (names). People could still remember 70% for photo recognition and 30% for free recall.

Duration is up to a lifetime.

Artificial stimuli - limitation of Baddley's study into coding. Word lists had no meaning to participants.

Lacking validity - limitation of Jacobs study into capacity. There were confounding variables that weren't controlled.

Not so many chunks - limitation of Miller's research. Cowan concluded capacity of STM was only 4 chunks.

Meaningless stimuli - limitation of Peterson and Peterson's study. Lacked internal validity, wouldn't have to remember random numbers in real life.

Higher external validity - strength of Bahrick at al.'s study. Real-life meaningful memories were studied.

Multi-store model (MSM)

Sensory register - memory store for senses; vision (iconic store) and hearing (echoic store). High capacity and duration of less than half a second.

STM - limited capacity store. Maintenance rehearsal occurs when we repeat things to ourselves, it will then got into LTM.

LTM - permanent memory store. When we want to recall memories it has to be retrieved from LTM back into STM.

Supporting research evidence - research from Baddelyand others into coding, capacity and duration.

More than one type of STM - this is a limitation. Shallice and Warrington studied a man (KF) with amnesia. STM poor when digits read to gim, but better when he read them to himself.

More than one type of rehearsal - Craik and Watkins said there's maintenance rehearsal and elaborative rehearsal, because elaborative rehearsal is needed to transfer information into LTM.

Endel Tulving proposed 3 different stores for LTM.

Episodic memory - store for personal events, e.g who you are, family, day-to-day happenings.

Semantic memory - meaning of things, facts, knowldge.

Procedural memory - knowledge of how to do things, e.g riding a bike, tying shoes.

Clinical evidence - cases of HM and Clive Wearing; episodic memory was impaired, but semantic and procedural memories were unaffected.

Neuroimaging evidence - Tulving et al. used PET scanner and found that episodic and semantic memoried were recalled in the prefrontal cortex, both in a different hemisphere (episodic- right, semantic- left).

Real-life applications - Belleville et al. episodic memories can be improved in older people who have a mild cognitive impairment (trained participants in this performed better than a control group).

WMM - representation of STM; a dynamic processor of different types of information using sub units coordinated by a central decision-making system.

Central executive (CE) -co-ordinates the activities of the 3 subsystems in memory, allocates processing resources to activities and has no storage capacity.

Phonological loop (PL) -processes information in terms of sound; includes written and spoken material. The phonological store (stores words you hear) and the articulatory process (allows maintenance rehearsal - capacity is 2 seconds worth of what you can say).

Episodic buffer -brings material from subsystems into single memory.

Visuo-spatial sketchpad - processes visual and spatial information. Logie - visual cache - stores visual data, inner scribe - reccords arrangement of objects.

Baddeley- limited capacity of 3/4 objects.

Clinical evidence - Shallice and Warrington found that KF had poor auditory memory but good visual memory; showing he had a damaged PL but the VSS was fine.

Dual-task performance - Baddeley et al. participants find it harder to do two visual tasks than doing a visual and a verbal task at the same time. Meaning there must be a seperate slave systm (VSS) for processing visual input.

Lack of clarity over CE -  CE is too simple, it needs to be more specific than just "attention".

Interference -  forgetting because one memory blocks another.

Proactive interference (PI) -forgetting occurs when older memories interfere with newer memories.

Retroactive interference (RI) - forgetting occurs when newer memories interfere with older ones.

Degree of forgetting is greater when memories are similar because interference is stronger (McGeoch and McDonald)

Evidence from lab studies -  well controlled studies show interference effects (McGeoch and McDonald).

Artificial materials - learning lists of words isn't something you have to do every day.

Real-life studies -  Baddeley and Hitch did a study involving rugby players, and accurate recall didn't depend on how long ago the matches took place, the number of games they played in the meantime was important. This supports interference.

Retrieval failure -  form of forgetting due to not having the necessary cues to access the information.

Cue -  a trigger of information that allows us to access a memory.

Encoding Specificity principle (ESP) -  Tulving came up with this; recall is best when a cue is present at encoding and retrieval. Such cues are used in many mnemonic techniques.

Context-dependent forgetting -  Godden and Baddeley; divers had to learn a list of words either underwater or on land, and recall in either condition. Creating for conditions. Accurate recall was 40% worse in non-matching conditions.

State-dependent forgetting -  Carter and Cassaday; participants had to learn words on/off drug and recall on/off drug (4 conditions), recall was best when conditions matched.

Supporting evidence -  research into contect-dependent and state-dependent forgetting.

Questioning context effects -  Baddeley argues context effects aren't strong in real-life. Contexts have to be very different before an effect is seen.

Recall versus recognition - Godden and Baddeley replicated their underwater study but used recognition test instead of recall. They discovered there was no context-dependent effect.

Eyewitness testimony (EWT) -  the ability to remember details of events observed.

Misleading information - incorrect info given to eyewitness usually after event, e.g leading questions, post event discussions.

Leading questions - Loftus and Palmer; pparticipants watched clips of car accidents and were then asked leadning questions about the accident (they were given different verbs ("hit", "smashed", "bumped" etc.) within the question. The estimated speed was higher for the verb "smashed" than the verb "contacted" by 8.6mph. The response-bias explanation (words influence answer) and the substitution explanation (words change the memory) are used to explain this.

Post-event discussion - Gabbert et al. when individuals discuss what they saw from different clips of the same crime, people will mistakenly recall something they didn't actually see. This is called memory conformity. In a control group this didn't happen.

Useful real-life applications -  Loftus reported that police need to be careful about the question they ask, and make sure it isn't leading, or the facts will get distorted.

Artificial tasks - film clips don't affect people in the same way a real accident would; they lack the stress, and emotions can have an influence on memory.

Individual differences - Anastasi and Rhodes found that certain age groups are more accurate than others, but all age groups were more accurate when identifying people their own age (own-age bias).

Anxiety - a state of emotional/physical arousal, it can affect accuracy and detail of EWT.

Anxiety has negative effet on recall - Johnson and Scott; participants believed they were just waiting to take part in study. Two conditions - low anxiety and high anxiety. 46% of participants in the low anxiety condition correctly identified him. But only 33% in the high anxiety condition managed to. The tunnel theroy explains this (focus narrows to the weapon; source of anxiety).

Anxiety has positive effect on recall - Yuille and Cutshall; study of real life shooting. Little change in amount remembered/ accuracy after 5 months;  participants who reported feeling the highest amount of stress were most accurate.

Explaining contradictory findings - Yerkes and Dodson; came up with Yerkes-Dodson law, performance will increase with stress, but only to a certain point.

Weapon focus effect may not be relevant - Pickel; eyewitness accuracy poorer in unusual conditions than threatening conditions.

Field studies somethimes lack control - post-event discussions, extraneous variables.

Ethical issues - may lead to psychological harm for no reason other than for the purpose of research.

Cognitive interview (CI) - method of increasing accuracy of eyewitness memory during interview.

1) Report everything - include even unimportant details.

2) Reinstate the context - picture scene and recall emotions (conext-dependent forgetting).

3) Reverse the order - recall from end and work back; disrupts expectations.

4) Change perspective - put your self in someone else's shoes.

The enhanced cognitive interview (ECI) - Fisher et al. add social dynamics, e.g use just the right amount of eye contact.

CI is time consuming - takes longer than standard police interview and requires special training.

Some elements may be more valuable than others - Milne and Bull; combination of report everything and reinstate the context provides better recall than other conditions. This increases credibility of CI because at least some parts of it are good.

Support for effectivness of ECI - Kohnken et al. a meta-analysis combined data from 50 studies and the ECI consistently provided more correct information than the standard police interview.