Participants were divided into four groups which were acoustically similar, acoustically dissimilar, semantically similar and semantically dissimilar. Participants were presented with the list a total of 4 times and each time was interrupted to try to prevent rehearsing. They were then presented with a 20-minute interval task and afterwards were asked to recall their list. Semantically dissimilar words were recalled the most telling us that encoding in LTM is semantic.
Summary of study on capacity of STM and LTM Summary of study on duration of STM Peterson & Peterson- Showed PPs a list of nonsense trigrams and asked them to count back from 400 in 3 second intervals for a duration ranging from 3 to 18 seconds. Found that duration of STM was 18-30 seconds maximum. Summary of study on duration of LTM Bahrick- 400 participants aged between 17 and 74 were tested using different methods including free-recall tests, photo-recognition test, name recognition tests and photo-name matching test. PPs performed less well on free recall tests (30% after 48 years) but were much better in the photo-name test (90% after 60 years).
Models of memory Description of the multi-store model of memory, plus evaluation inc. research Atkinson & Shiffrin- Multi-Store Model which consists of three parts – sensory, short term and long term stores. Rehearsal is required in order for information to move across stores and retrieval is needed to access the information. If information is not rehearsed it will decay. Description of the working memory model, plus evaluation inc. research Baddeley & Hitch- Working Memory Model which consists of three parts – central executive, phonological loop (store and articulatory control system) and the central executive.
Memory in the real world Knowledge of what Eye Witness Testimony (EWT) is- The evidence provided in court by a person who witnessed a crime, with a view to identifying the perpetrator of the crime. The accuracy of eyewitness recall may be affected during initial encoding, subsequent storage and eventual retrieval. Loftus & Palmer’s (1974) study on EWT- Reconstruction of an Automobile Disaster. 9 student PPs per 5 conditions (bumped, contacted, hit, smashed and collided). All watched a video then asked to estimate speed. Smashed the highest (40.8mph) and contacted the lowest (31.8mph). PPs in second part of experiment then asked a leading question about broken glass. 16/50 of the smashed condition PPs said yes in comparison to 7/50 in the hit condition.
Knowledge of the factors which affect the accuracy of EWT anxiety- Christianson and Hubinette (1993) Anxiety and EWT – real incidents involving high levels of stress lead to more accurate, detailed and long lasting memories. Deffenbucher (2004) Carried out a meta-analysis of 18 studies, looking at the effects if heightened anxiety on accuracy of EWR. It was clear that there was considerable support for the hypothesis that high levels of stress negatively impacted on the accuracy of EWM.
Age- Parker and Carranza (1989) Compared the ability of primary school children and college students to correctly identify a target individual following a slide sequence of a mock crime. In the photo identification task, child witnesses has higher rate of choosing ‘somebody’ than adults witnesses, although they were also more likely to make errors of identification than college students. Weapon focus effect- Loftus(1987) In violent crimes, arousal may focus attention on central details e.g. a weapon. Loftus et al identified weapons focus effect. 2 conditions, one involving weapon the other not. Condition 1 (less violent) people was 49% accurate in identifying man. Condition 2 (more violent) people were 33% accurate. Suggests weapon may have distracted them.