Memory Flashcards
research on coding
Baddeley
- he gave different lists of words to four groups of participants (acoustically similar, acoustically dissimilar, semantically similar, semantically dissimilar)
- participants were shown the words and asked to recall them in the correct order
- he found that for the short term variation(immediately), the participants tended to do worse with acoustically similar words
- he found that for the long term variation(20 minutes), the participants did worse with semantically similar words
- therefore STM is coded acoustically and LTM is coded semantically
research into capacity of STM
Miller
- he made observations of everyday things and determined it was 7+- 2 items, as five letters can remembered as easily as 5 words
research on duration (STM)
peterson and peterson
- they tested 24 students and gave them each a trigram
- they then counted down from a three digit number in 2’s or 3’s until told to stop, to prevent mental rehearsal
- they found that after 3 seconds, average recall was 80% and after 18 seconds was 3%, suggesting that the duration of short term memory is 18 seconds unless verbally rehearsed
research on duration (LTM)
Bahrick
- 392 american participants between ages 17 and 74
- had students freely recall the names of their classmates with the picture, or with a word bank to go along with
for recognition
- 15 years had 90% accuracy
- 48 years had 70% accuracy
for free recall
- 15 years had 60% accuracy
- 48 years had 30% accuracy
this shows that long term memory may last up to a lifetime
coding, capacity and duration of the sensory register
coding : iconic, echoic, and other sensory stores
capacity : high
duration : milliseconds
coding, capacity and duration of STM
coding : acoustically
capacity : 7+- 2 items
duration : 18 seconds
coding capacity and duration of LTM
coding : semantically
capacity : unlimited
duration : lifetime
who created the multi - store model?
atkinson and shiffrin
evaluation of the MSM?
- shows that STM and LTM are separate stores
- may not be a valid model of how memory works in our everyday lives where we have to remember much more meaningful information
- KF shows that there are different processing stores in the STM and that its not unitary
- does not fully explain how long-term storage is achieved
types of long term memory and who made them
episodic, semantic, and procedural
tulving
episodic memory
time stamped, includes several elements, a conscious effort is required to recall
semantic memory
encyclopedia knowledge, not time stamped, more facts
procedural memory
unconsciously recalled, like riding a bike
evaluation of types of long term memory
- a strength is clive wearing and HM, as episodic memory was impaired due to brain damage, but not their semantic or procedural
- however these studies lack control, as researchers are unable to know what the memory of HM and clive wearing were like before their incidents
- however, a limitation is that neuroimaging evidence is conflicting as there are many areas that are located for each type of memory
- another strength is that it has real world application, as it allows psychologists to help people with memory problems by developing treatments to prevent memory loss
research into interference theory
Baddeley and hitch
- asked rugby players to recall the names of the teams they had played against during the rugby season
- found that those who played the most games had the poorest recall
- carried out in the real world so has external validity
McGeoch and McDonald
- studied retroactive interference by changing the amount of similarity between two sets of materials
- participants learned list of 10 words until they could remember them with 100% accuracy
- when participants were asked to recall the original list of words, the most similar material produced the worst recall
- therefore interference is strongest when the memories are similar
research into context-dependent forgetting
Godden and Baddeley
- studied deep sea divers to see if training on land helped or hindered their work underwater
- the divers then learned a list of words underwater or on land and then recalled them underwater or on land
- recall was 40% lower in non-matching conditions
- therefore external cues were different at learning from recall and this led to retrieval failure
research into state dependent forgetting
Carter and Cassaday
- gave antihistamine drugs to participants which made them slightly drowsy, creating a different internal physiological state
- the participants then learned lists of words either on the drug or off the drug, and then recalled the words either off the drug or on the drug
- they found that participants performed worse on a memory test if the states at learning and recall were different, as the cues were absent and there was more forgetting
evaluation of interference theory
LIMITATIONS
- in order for interference to play a part, information has to be similar, however this is only happens rarely for learned information, so is unlikely to be a full explanation for all forgetting
- tulving and psoka had participants memorize lists of words and recall was 70% for the first list and decreased after. However, the participants were then given the category name of the category and recall rose again to 70%. This shows that interference causes a temporary loss, however the information is still available, which is not predicated by the theory
SUPPORT
- Coenen and Gilles gave participants a list of words and had them recall them the next week. The group given the drug diazepam had better recall than the placebo group, as the drug prevented new information from being processed by the brain and therefore preventing retroactive interfernce
research into the negative effect of anxiety on recall
weapon effect
- Johnson and Scott
- participants believed that they were taking part in a lab study. While seated in a waiting rom participants in the low-anxiety condition heard a casual conversation in the next room and then saw a man walk past them carrying a pen and with grease on his hands. Other participants overheard a heated argument, accompanied by the sound of breaking glass. A man walked out of the room holding a knife covered in blood. This was the anxiety condition
- the participants later picked out the man from a set of 50 photos. 49% who had seen the man carrying the pen were able to identify him. 33% identified the man holding the bloody knife
- the tunnel theory of memory suggests that people have enhanced memory for central events. Weapon focus as a result of anxiety can have this effect
research into the positive effect of anxiety on recall
- anxiety triggers the fight or flight response, increasing alertness
- Yuille and Cutshall conducted a study of an actual shooting in Vancouver, Canada, when a shop owner shot a thief dead. There were 21 witnesses and 13 agreed to take part in the study. They were interviewed four to five months after and the number of details were compared to the original police report. The witnesses were also asked to rate how stressed they were on a seven point scale and whether they had any emotional problems since the event.
- they found that the witnesses were very accurate in there accounts after 5 months, with only slight details decreasing in accuracy such as color of things or approximate weight. The participants who reported the highest levels had were most accurate with 88% compared to 75% with the less stressed group
- this suggests that anxiety does not have detrimental effect on eyewitness testimony and may even enhance it
limitation of johnson and scott
- they may not have tested anxiety
- participants may have been surprised they saw a weapon instead of scared
- pickel conducted an experiment using scissors, a handgun, a wallet or a raw chicken as the hand held items in a hairdressing salon video. Eyewitness accuracy was significantly poorer in the high unusualness conditions (handgun and chicken).
this suggests that the weapon focus effect is due to unusualness rather than anxiety and therefore tells us nothing about the effects of anxiety on EWT
Support for negative effects of anxiety on the accuracy of recall
- valentine and mesout found that when participants went through the London Dungeon, the high anxiety group recalled the fewest correct details of the actor and made more mistakes
- also, 17% of the high-anxiety group correctly identified the actor in a line up compared to 75% correct identification in the low-anxiety group
- this study is good, as they wore wireless heart rate monitors to determine if they were in high or low anxiety
Support for positive effects of anxiety on accuracy of recall
- Christianson and Hubinette interviewed 58 witnesses to actual bank robberies in Sweden
- some were directly involved, other indirectly. they found that recall was more then 75% for all witnesses, the direct victims even more accurate
- these findings from actual crimes confirm that anxiety does not reduce the accuracy of recall for eyewitnesses and may even enhance it
- however, christianson and hubinnete interviewed their participants many months after the event, so the effect of anxiety is likely muddled with other effects, such as post event discussion, that the result don’t reflect the effect of anxiety.
- therefore a lack of control over confounding variables may be responsible for the findings, invalidating their support.
what are the steps of the cognitive interview??
- report everything
- say everything you saw, even if it seems not important - reinstate the context
- witness brings themselves mentally back to the scene of the crime
- related to context dependent forgetting - reverse the order
- prevents people from reporting their expectations of what happened rather than the actual events
- also prevents dishonesty - change perspective
- this is done to disrupt the effect of expectations and also the effect of schema on recall
