WORKING MEMORY MODEL
PHONOLOGICAL LOOP EPISODIC BUFFER VISUO-SPACIAL SKETCH PAD
LONG TERM MEMORY
STRENGTHS OF WMM
- Takes into account the types of memories (acoustic/semantic)
- Much more detail than the multi-store model of memory
- It applies to every day tasks such as reading (phonological loop), problem solving (central executive) and navigation (visio-spacial sketch-pad).
- supported by dual task studies (Baddely and Hitch)
- The working memory model does not over emphasise the inportance of rehearsal for STM retention, in contrast to the multi-store model.
WEAKNESSES OF WMM
- There is little direct eidence for how the central executive works and what it does. the capacity of the central executive has never been measured.
- Working memory only involves STM and so is not a comprehensive model of memory
- the working memory model does not explain changes in processing ability that occurs as the result of practice or time.
- Lieberman (1980) criticises the WMM as the visuo-spacial sketch pad implies that all spacial information was first visual (they are linked). He points out that blind people have excellent spacial awareness although they have never had any visual information. Lieberman argues that the visuo-spacial sketch oad should be seperated into two different components: one for visual info and one for spacial info.
MULTI-STORE MODEL OF MEMORY
- Duration- 0.25 to 0.5 seconds
- Capacity- All sensory experience (v. karger capacity)
- Encoding- Sense specific (e.g. different stores for each sense)
- Duration- 0-18 seconds
- Capacity- 7 +/- 2bits
- Encoding- mainly auditory
- Duration- Unlimited
- Capacity- Unlimited
- Encoding- Mainly Semantic (but can be visual and auditory)
STRENGTHS OF MSM
- The model can account for primary and recenccy effects
- The model is influential as it has generated a lot of research into memory
- The model is supported by amnesiacs (HM- head injury=long term memory loss: remembers little personal and public events that have happened in the last 45 years; his short term memory stays in tact)
WEAKNESSES OF MSM
- Oversimplified when it suggests that both short term and long term memory each opperated in a single, uniform fashion.
- The model suggests rehearsal helps to transfer information into LRM but this is not essential- we do not rehearse information such as swimming which we can recall easily, but we are unable to recall information which we have rehearsed eg notes when we are revising
- The models main emphasis was on structure and tends to neglect the process elements of memory (it only focuses in attention and rehearsal)
- The multi-store model has been criticised for being passive/one way/linear.
- Refers to the account given by people of an event they have witnessed eg a robbery or a road accident- incl. details of perpetrators, and of the crime scene etc.
- EWT is and important area of research in cognitive psychology and human memory.
- Juries tent to pay close attention to EWT and generally find it reliable.
- reliability of ewt can be effected by
2. Leading questions (Loftus and Palmer, '74)
3. Age of Witness
- Almost always associated with real life crimes or violence.
- Clifford and Scott (1978) found that people who saw a film of a violent attack remembered fewer of the 40 items of info about the event than a control group who saw a less stressful version. As witnessing a real crime is probably more stressful than taking part in an experiment, memory accuracy may well be even more effected in real life
Loftus and Palmer (1974)
- Aim- to test their hypothesis that language used in EWT can alter memory
- 45 American students formed an opportunity sample. it was a lab experiment with 5 conditions.
- Procedure- PPs were shown slides of a car crash and were asked to describe what happened as if they were witnesses. they were then asked specific questions including: "About how fast were the cars going when they (hit/smashed/collided/bumped/contacted) eachother?"
- Thus, the Iv was the wording of the question and the DV was the speed reported by the PPs.
- Findings- the estimated speed was affected by the verb used. The verb implied info about the speed, which systematically affected the PPs memory of the accident.
AGE OF WITNESS
- In some court cases, often those dealing with sensitive issues such as abuse, quite young children have to act as witnesses.
- Witnesses are sometmes called upon to identify a criminal in an identity parade and they are often reluctant to make a positive identification
- According to Dekle et al, Children are more willing than adults to make positive identification but often of the wrong person.
- Children also seem to be more susceptible than adults to absorbing post-event information into their origina memory representation.
POOLE AND LINDSAY (AGE OF WITNESS)
- Engaged children aged between 3-8yo in a science demonstration
- the parents of the children read them a story which contained some of the elements of the science demonstration.
- The children were then asked about the science demonstration and wit was found that they had incorporated much of the new info from thier parents story into their own memory of the event.
- When prompted, older children realised that they had been mislead and that their account of the actual demonstration was different from the one they had previsously given, and thus extracted the post event information. Younger children did not seem able to do this
- Used as a means of improving retrieval of memory during EWT
- A questioning technique used by the police to enhance retrieval of information from the witnesses memory
- Mentally reinstate the environmental and personal context of the crime
- Report the incident from someone elses perspective
- Recount the incident in reverse order
- report every detail even if it seems un-important