Memory Studies

Memory Studies

1. MSM

   • ATKINSON & SHIFFRIN had idea that memory flows in one direction, and that there are three unitary and separate stores which different in Capacity, Duration and Encoding.
   • JACOBS (1987) 'serial digit span'. Sequence of letters or digits and using the serial recall procedure, asked ppts to repeat back letters or digits to him in the same order. FINDINGS: Found that the average STM span was between 5 and 9 items.
   • PETERSON&PETERSON: The Brown-Peterson technique. Ppts briefly shown consonant trigrams.Given an intereference task of counting backwards in 3's. Prevent reheasal. After intervals of 3, 6, 9, 12, 15 and 18 seconds, asked to recall the trigram. The interference task didn't affect recall after 3 seconds. As time increased, performance declined. After 18 seconds, the memory trace for the trigram had decayed. Duration of STM = 18s
   • BAHRICK ET AL (1975) Duration of LTM. Showed 400 ppts aged 17 - 74 years set of photos &list of names, some were old school friends, and asked to identify old school friends. Those that had left high school 48 years previously recalled 80% of names and 70% of faces. Duration of LTM = 48 years.
   • BADDELEY (1966) found that when ppts were given a STM task they were more likely to confuse acoustically similar words. When given a LTM task they were more likely to confuse semantically similar words.
   • MILNER (1956) attempted to treated patient HM's epilepsy. Removed hippocampus. Unable to form new LTM, STM unaffected.
   • CRAIK&LOCKHART (1972) suggested that enduring memories are created by the processing that you do rather than through maintenance rehearsal.

2. WMM

   • BADDELEY&HITCH (1974) STM not unitary store. Flexible and complex system. Consists of control mechanism (CE) assisted by two slave systems (PL & VSS)
   • BADDELEY ET AL (1973) gave ppts simple tracking task while carrying out either a visual or verbal imagery task. Ppts difficulty two visual tasks, because two visual tasks were competing for limited resources of vss. Ppts could successfully caarry out the tracking task while at the same time as performing a verbal task. Making use of separate resources of VSS and PL.

3. EWT - Misleading Info

   • LOFTUS&PALMER (1974) Asked ppts to estimate speed of cars in film w/ traffic accidents. Ppts in 5 conditions and asked specific q's about the crash. Asked "how fast were the cars going then they *** each other?" The word in *** differed in each cond. Either HIT/BUMPED/SMASHED/COLLIDED/CONTACTED. FINDINGS: Loftus&Palmer found the estimate of speed of ppts was influenced by verb used in q. Ppts gave higher estimates of 41mph with word "smashed". Compared to 34mph when word "hit" was used.
   • LOFTUS&PALMER (1974) also found that information given after the event also influenced ppts EWT. Ppts were divided into 3 groups and shown a film of a car accident. Condition 1 - Ppts were asked "how fast were the cars going when they smashed each other?" Condition 2 - asked "how fast were the cars going when they hit each other?" Condition 3 - Ppts were not asked any questions about speed. FINDINGS: When ppts were asked later "did you see any broken glass?" significantly more ppts who had been in the smashed condition mistakenly reported broken glass compared to those in condition 2 and 3.
   • LOFTUS (1975) conducted another experiment looking at post event information. Showed ppts film of events leading up to car accident. Condition 1 (control group): Ppts were asked q's consistent with what they had actually seen. Condition 2 - Ppts asked a question that included misleading info. FINDINGS: 17% of the ppts in the experimental group reported seeing a barn in the original film but only 3% of the control group made this error.

4. EWT - Anxiety

   • DEFFENBACHER ET AL (2004) A meta-analysis or 18 studies concluded that in some cases anxiety increased levels of EWT accuracy, in other cases anxiety decreased EWT accuracy. This contradiction can be explained by The Yerkes Dodson law, which says that there is a curvilinear relationship between anxiety and accuracy of EWT: moderate anxiety increases accuracy of EWR and very high or low anxiety decrease accuracy of EWT.
   • LOFTUS&BURNS (1982) carried out a lab exp. Cond 1 - Ppts were shown a film of a violent version of a crime in which a boy was shot in the face. Cond 2 - Ppts were shown a non voilent version of the same crime. FINDINGS: The ppts who had wathched the violent version had significantly impaired recall for events running up to the incident compared to the group who saw a non voilent version of the same crime.
   • LOFTUS (1979) Identified the 'weapon focus effect' which suggests that in violent crimes where a weapon is involved, anxiety may focus the witness on the weapon rather than other details of the event.
   • LOFTUS (1987) Investigated the weapon focus effect in a field experiment. In both conditions ppts heard a discussion in an adjoining room. Condition 1 - A man emerged from the room holding a pen with grease on his hands. Condition 2 - The discussion was more heated and a man emerged holding a knife covered in blood. FINDINGS: When asked to identify the main, ppts in condition 1 were more accurate.
   • CHRISTIANSON AND HUBINETTE (1993) carried out a survey of 110 people who hadwitnesses 22 genuine bank robberies. SOme of these people has been bystanders at the bank at the time of the d up whiole others had ben directly threatened by the robbers. they found that the people hwo had been subjected to the greatest amount of anxiety showed more detailed and accurae recall than the onlookers.

5. EWT - Age

   • ANASTASI&RHODES (2006) showed individ from 3 age groups (18 - 25, 35 - 45 adn 55 - 78) 24 photographs of people. Ppts had to rate the photographs for attractiveness. After a short delay while the ppts did a 'filler' activity, they were persented with 48 photographs, 24 of which had been seen previously and 24 rthat acted as 'distractors'. FINDINGS: They found that young and middle aged ppts were more accurate at recognising the original photogaphs than older ppts.
   • YARMEY (1993) stopped 652 (aged 18 - 65) in public places and asked them to recall the physical characteristics of a woman to whom they had just spoken to for 15 seconds 2 minutes earlier. FINDINGS: Although young and middle aged people were more confident in their recall, no differences in the accuracy of recall of older ppts.
   • MEMON ET AL (2003) young (16 - 33) and older (60 - 82) people witnesses a crime and then had to pick the prepretrator of the crime from a line up. FINDINGS: When the delay between the incident and identification was only 35 minutes there was no difference in accuracy of the two groups. However, when the identification task was a week later the older witnesses werfe significantly less accurate.
   • WARREN ET AL (2005) Gave children and adults a story to read and asked them 20 questions; 15 of those were misleading. They showed that children were less accurate in their recall and more likley to be influenced by leading questions than adults.
   • TERR (1979) investigated memories of 25 children (5 - 14 years) who were kidnapped on a school bus, driven around for 11 hours, and then buried underground for 27 hours and showed that the children had detailed memories off the incident after 13 months.

6. Cognitive Interview

   • Developed by FISHER&GIESLEMAN designed for use in police interviews.
   • GIESLEMAN (1985) compared the cognitive interview with a standard police interview and hypnosis. Standard police interview asks witnesses to recall the event and then answer detailed questions about the aspects of the event that the police think are important. Ppts watched a short film of a violent crime. Two days later, they were divided into three groups and interviewed by a police officer. FINDINGS: Correct responses.... Cognitive interviews - 41.1. Hypnosis - 38 Standard Police Interview - 29.4
   • STEIN&MEMON (2006) tested the effectiveness of the cognitive interview in Brazil. Compared to the standard police interviewing methos the cognitive interview increased the amount of correct information recalled suggesting that the cognitive interview provides a new approach to interviewing witnesses in Brazil suggesting it has practical applications across the world.
   • GIESLEMAN (1999) reviewed a number of studies and found that children under 6 years actually reported even slightly less accurately in response to cognitive interview teachniques. Not always the best technique to use.

7. Strategies for Memory Improvement

   • BOWER (1972) gave ppts 100 different cards, each card had two unrelated words on it e.g cat and brick. PArticipants in one group were asked to mentally produce and image to link the two and ppts in the other group were just asked to recall the words. It was found that people in the image condition recalled 80% when shown one word on the card while those in the other condition only recalled 45%
   • BOWER (1969) gave ppts 112 words to learn. If the words were organised into conceptual hierarchies recall was two - three times better than if the words were presented in a random order.
   • PAIVIO (1971) proposed that words and images are processed separately, so words that can be made into images are double encoded in memory increasing the likelihood that they will be remembered, this is called the dual coding hypothesis and is liked to the idea of the phonological loop and the visuo spatial sketchpad in Baddeley's working memory model.