Memory

• Short term memory

  • coding is acoustic
  • capacity of +7/-2 items
  • duration is approx 18-30 seconds
• Long term memory

  • coding is semantic
  • capacity is unlimited
  • duration is unlimited
• One strength for short term memory

  • Support of capacity - Jacob’s completed a similar experiment using digits with 443 female students. He called this a digit span experiment using numbers instead of words. His results were similar to Millers with 7.3 being the average recall. This supports Millers study as it suggests the results are valid. Millers study is also reliable as it is easy to copy and is especially reliable as the results are the same.
• One strength for short term memory

  • Controlled research for duration - Peterson and Peterson conducted a well controlled study and many extraneous variables would have been controlled. However, in previous trigrams maybe similar to the one being recalled, memory interfered with the new information causing the pot to make a mistake. This challenges validity of the study 
• Long term memory

  • episodic - relates to experiences a person has had or events from their life
  • procedural - involved in knowing how to do certain skills
  • semantic - involves knowing and recalling facts, concepts and meanings
• One strength of long term memory

  • clinical evidence - in the case of HM, episodic memories are impaired but semantic memory was fine as he still understood the meaning of words. This supports the fact that there are different memory stores and they are stored in different parts of the brain. Is also tells us what happens when memory is damaged. However, case studies lack control of variables as we don’t know what other factors affected the behaviour
• One weakness for long term memory

  • conflicting neuroimaging evidence - researchers reviewed evidence regarding the location of semantic and episodic memory. Semantic memory is in the left side of the prefrontal cortex and episodic memory is in the right. Other researcher links the left prefrontal cortex with episodic and the right with semantic. This challenges neurophysiological evidence to support types of memory as there is a poor agreement on where each type is located 
• One strength for long term memory

  • real life application - as people age, they experience memory loss. Research shows this seems to be specific to episodic memory due to being harder to recall memories of personal events and experiences that occurred recently though past episodic memories remain intact. Researchers devised an intervention to improve episodic memories in older people. The trained ppts performed better on a test of episodic memory after training than a control group. This shows that distinguishing between types of LTM enables scientific treatments to be developed 
• Multi store model of memory

  • sensory register - main stores are ionic and echoic, duration is brief and has a high capacity
  • short term memory - capacity of 5-9 items, duration approx 18-30 seconds, coding is acoustic
  • long term memory - capacity is unlimited, duration is unlimited and coding is semantic
• One strength of the multi store model

  • areas associated with STM and LTM - brain scan images of the parts of the brain that are active when a person is doing particular tasks. Research has found that the prefrontal cortex is active when people work on a task in STM. Research has found that the hippocampus is active when people work on a task in LTM. This supports the multi store model as it suggests that the STM and LTM as separate stores as they has separate areas in the brain when active 
• One strength of the multi store model

  • case of HM - his brain damage caused by an operation to remove the hippocampus from both sides of his brain to reduce severe epilepsy he suffered. His personality and intellect remained intact but couldn’t form new long term memories but still remembering things from before the surgery. His STM was normal, he could retain verbal information for about 15 seconds. However, he couldn’t transfer information into LTM. This supports the multi store model as it suggests we must have separate stores as the LTM was damaged but the STM wasn’t.
• One weakness of the multi store model

  • case of KF - the MSM states that STM is a unitary store however evidence form people suffering from amnesia shows this is not true. KF was suffering with amnesia and his STM for digits was very poor when they read them out loud to him. But his recall was much better when he could read them to himself. Further studies show there could be another short term store for non verbal sounds such as noises. This challenges the MSM as it shows that the STM is a unitary store. This is because his visual memory was good but his acoustic memory was poor. 
• Working memory model

  • central executive - coordinates the activities of 3 subsystems in memory, monitors incoming data, very limited processing capacity
  • visuospatial sketchpad - stores visual and spatial information when needed, subdivided into the visual cache and inner scribe
  • phonological loop - deals with auditory information, preserves the order in which information arrives, subdivided into the phonological store and articulately process
  • episodic buffer - temporary store for information, integrates spatial and verbal information, maintains sense of time sequencing
• One strength of the working memory model

  • clinical evidence - KF had a poor STM ability for auditory information but processed visual information normally. His phonological loop was damaged but his visuospatial sketchpad was still intact. This supports the existence of separate visual and acoustic memory stores. 
• One weakness of the working memory model

  • lack of clarity over central executive - it is the least understood component of the working memory model. It needs to be more clearly specified that just being simply attention. This means the central executive is an unsatisfactory component and challenges the integrity of the WMM as it isn’t fully explained. 
• One strength of the working memory model

  • dual task performance - performance of each visual and verbal task was similar to when tasks were carried out separately. When both tasks were visual, performance declined a lot. Both visual tasks compete for the same subsystem. This supports the WMM as it shows separate subsystems.
• Interference theory

  • proactive interference - when an old memory interferes with a new one
  • retroactive interference - when a new memory interferes with an old one
• One strength of interference theory

  • real world application- Baddeley and Hitch asked rugby players to recall the name of teams they had played against during the season. They had all played for the same time but number of games they had played differed due to injury. Players who played the most games had the poorest recall as they had the most interference to memories. This shows that interference can be applied to at least some everyday situations
• One weakness of interference theory

  • other explanations of forgetting - interference is probably less likely to be an explanation of forgetting in everyday life. It may be an explanation in situations where the events are similar but not all events that we forget are. Lab studies may prove interference as an explanation as they create situations where events are similar but this is artificial. This suggests that forgetting may be better explained by another explanation like retrieval failure due to lack of cues
• One weakness of interference theory

  • validity issues - although lab studies are good, there is more chance of interference being shown in lab studies than in real life situation as it is an artificial situation. This is because the stimulus material is usually learning lists of words which isn’t something we would do in everyday life. We are more likely to remember birthday lists, shopping lists or ingredients for example. This is a problem because it may not be as much of an explanation in real life as it is in a lab so we cannot generalise the findings to real life 
• Retrieval failure

  • context dependent forgetting - can occur when the environment during recall is different from the environment you were in when you were learning 
  • state dependent forgetting - occurs when your mood or physiological state during recall is different from the mood you were in when you were learning 
• Research for context dependent forgetting

  • investigating the effect of environment on recall 
  • 18 differs from a diving club were asked to learn lists of 36 unrelated words of two or three syllables 
  • 4 conditions - learn in beach and recall on beach, learn in beach and recall underwater, learn underwater and recall on beach, learn underwater and recall underwater
  • they found that recall on beach was better than recall underwater so could suggest that learning and recalling words in the same location is easier
• Research for state dependent forgetting

  • 48 volunteer male medical students were randomly assigned to 4 groups
  • sober in both days, intoxicated both days, intoxicated on day 1 and sober in day 2, sober in day 1 and intoxicated on day 2
  • they were asked to do an avoidance task, a verbal rote learning task, a word association task and a picture recognition task
  • There were more errors on day 2 in the AS and SA condition that in the AA and SS conditions
  • Ppts who were sober at learning and recall and drunk at learning and recall performed the best 
• One strength for retrieval failure

  • real world application - help to overcome forgetting in everyday situations. Experienced being in one room and thinking they must go and get such and such item from another room. You go to the room and forget what you went in for until you return back to the room you were in before when you remember. This shows how research can remind us of strategies we use in real world to improve recall
• One weakness of retrieval failure

  • questioning context effects - not very strong in everyday life. Different contexts have to be very different before an effect is seen. It would be hard to find an environment as different as land and water. Evidence shows due to lack of contextual cues may not actually explain much everyday forgetting 
• One weakness of retrieval failure

  • recall vs recognition - the context effect may only be related to the kind of memory being tested. Godden and Baddeley looked at recall not recognition. When they look at recognition they found no context dependent effect, performance was the same in all 4 conditions 
• Eye witness testimony - misleading information

  • leading questions - a question that suggests a certain answer
  • post event discussion - when there is more than one witness and they discuss what they have seem with each other
• Research for leading questions

  • 45 student ppts watched 7 film clips of car accidents and answered a questionnaire about them
  • 5 conditions with a critical question changed in each - hit, contacted, bumped, collided and smashed
  • ppts estimations of speed were affected by the verb in the question - smashed showing the fastest speed
  • response bias explanation - the wording of the question has no real effect on the ppts memories but just influences how they decide to answer
  • substitution explanation - the wording of the leading question changed the ppts memory of the film clip
• One strength of misleading information

  • real world application - eye witness testimony improves the way the legal system works by protecting innocent people from faulty convictions based on unreliable eye witness testimony. 
• One weakness of misleading information

  • evidence against substitution - eye witness testimony is more accurate for some parts of an event than for others. Researchers showed ppts a video clip and asked misleading questions. Their recall was more accurate for central details rather than the peripheral ones. This suggests that the original memories for central details survived and were not distorted an outcome that is not predicted by the substitution explanation 
• One weakness of misleading information

  • Evidence challenging memory conformity - post event discussion changes the eye witness testimony so challenges the memory conformity. Researchers showed ppts 2 versions of the same film clip, one where the mugger had dark brown hair and the other one where the mugger had light brown hair. Ppts discussed the clips in pairs and didn’t report what they had seen or what they had heard but a blend of both. This suggest that memory is distorted through contamination by misleading post event discussion rather than memory conformity 
• Eye witness testimony - anxiety

  • anxiety - state of emotional and physical arousal, having worried thoughts and feelings of tension including increased heart rate and sweatiness
• Research for negative effects of anxiety

  • Johnson and Scott made ppts think they were taking part in a lab study
  • ppts were in the waiting room, they heard an argument in the next room
  • in one condition, a man walked out of the room with a pen and grease on his hands
  • in another condition, they heard the sound of breaking glass, a man then walked out holding a paper knife covered in blood 
  • ppts then had to pick out the man from 50 photographs
  • ppts in condition one 49% correctly identified him whereas in condition two 33% made a correct identification 
• Research showing positive effect of anxiety

  • Yuille and Cutshall - study of a real shooting in a gun shop in Canada where the shop owner shot thief dead
  • 21 witnesses, 13 agreed to take part
  • interviews were 4-5 months after the incident and compared with original police interviews straight after the shooting
  • witnesses asked to rate levels of stress on a 7 point scale and if they had emotional problems after the event
  • witnesses gave accurate accounts with little change in statements over 5 months
  • those who reported highest levels of stress were 88% accurate compared to 75% for less stressed 
• One strength of anxiety

  • support for negative effects - researchers used an objective measure of heart rate to divide ppts into high and low anxiety groups. Anxiety clearly disrupted ppts ability to recall details about the actor in London Dungeons Labyrinth. 17% accuracy in the high anxiety group and 75% in low anxiety group. This suggest that a high level of anxiety does have a negative impact on immediate eyewitness recall of a stressful event 
• One weakness of anxiety

  • unusualness not anxiety - may not have tested anxiety. The ppts may have focused on the weapon because they were surprised not because they were scared. Researchers conducted a study using scissors, a handgun, a wallet or a raw chicken as the hand held items in a hairdressing salon video. The eyewitness accuracy was significantly poorer in high unusualness conditions. This suggest the weapon effect produces less recall because of the unusualness of the situation not because of anxiety so tell is nothing about the effects of anxiety 
• Cognitive interview

  • Change perspective - witnesses should recall the incident from other peoples perspectives
  • Report everything - witnesses are encouraged to include every single detail of the event even if it may seem irrelevant
  • Reinstate the context - witnesses should return to the crime scene in their mind and imagine the environment and their emotions
  • Reverse the order - events should be recalled in a different order from the original sequence
• One strength of the cognitive interview

  • support for effectiveness - a meta analysis was conducted by researchers which combined data from 55 studies comparing the cognitive interview with the standard interview. They found the cognitive interview gave an average of 41% increase in accurate information compared to the standard interview. This suggests that the cognitive interview is an effective technique in helping witnesses to recall information stored in their memory that the standard interview wouldn’t be able to reach
• One weakness of the cognitive interview

  • time consuming - police officers may be reluctant to use the cognitive interview as it requires more time and training than the standard interview. This suggests that a complete cognitive interview is not a realistic method for police officers to use as it may not be completed properly and officers have a busy schedule so might not be a able to make time to conduct it
• One weakness of the cognitive interview

  • some elements are more valuable than others - researchers found that each of the 4 techniques used alone produced more information than the standard interview. They found that using a combination of report everything and reinstate the context produced a better recall than using all 4 parts. This casts doubt on the credibility of the cognitive interview as it may not be as effective with all parts rather than just using the most effective ones