Memory

• Study of capacity of STM

  Miller (Immediate Digit Span Test)
• Study of duration of STM

  Peterson and Peterson (Trigrams)

  24 students given a consonant syllable and a three digit number

  They were asked to recall the consonant syllable after a retention intervals of 3. During this interval they had to count backwards from their three digit number. Participants were 90% correct after 3 seconds, 20% correct after 9 and only 2% correct after 18 seconds.

  Suggesting it is less than 18 seconds.
• Study of duration of LTM

  Bahrick (Highschool photos recall)

  400 people of various ages 15 years 48 years differences

  Given a free recall to recall as many class mates as they could. Then they were given 50 photos, some with people from their school year book. Bahrick found that recall after 15 years of graduation was 90% accurate from photos, and after 48 years was 70%. With free recall it was about 60% accurate and 30%.

  Showing that it is possibly an unlimited duration for LTM.
• Study of encoding


  Baddeley (Semantically and Acoustically Similar/Dissimilar words)

  
  

  He found that participants had difficulty remembering acoustically similar words in the STM and in the LTM struggled with semantically similar words.

  He concluded that STM is largely encoded acoustically whereas LTM is encoded semantically.
• Capacity of STM


  7+_ 2 units
• Capacity of LTM


  Potentially unlimited
• Duration of STM


  30 seconds
• Duration of LTM


  potentially unlimited
• Encoding in STM


  Mainly acoustically
• Encoding in LTM


  Mainly semantically
• MSM of memory


  Sensory Register-> Attention->STM->(Maintenance rehearsal or) elaborative rehearsal->LTM->(Retrieval, Interference, Rehearsal)
• What does the MSM model suggest

  It attempts to explain how memory works

  Memory Consists of multiple stores

  There is a sequence between these stores
• Evaluate the MSM


  • The STM and it being more than one store and its location
  • We do not need rehearsal for information to have to go to the LTM
  • Too simplified into just 3 components
• What does the Central Executive do


  directs attention to particular tasks and controls the 2 slave systems (phonological loop, visuo-spatial sketchpad)
• What does the phonological loop do

  processes and retains the order of heard information

  can be divided into 2 substores
• What can the phonological loop be divided into

  phonological store (stores heard information, inner ear)

  articulatory process (subvocal repetition, inner voice)
• What does the visuo-spatial sketchpad do

  plans spatial tasks and stores visual or spatial information
• What can the visuo-spatial sketchpad be divided into


  Visual cache (visual information)

  Inner scribe (processes spatial relations)
• What does the episodic buffer do

  integrates information from all other STM stores
• Evaluate the WMM


  Lack of evidence for the CE

  Supporting evidence for separate stores of STM (Hitch and Baddeley)

  Lieberman stated that the visuo-spatial should be divided into two separate components: one for visual and one for spatial as the sketchpad presumes that all spatial was first visual, but it cant be as blind people have good spatial awareness
• Name the three types of LTM

  Episodic, Procedural, Semantic
• Outline the two ways interference can explain forgetting

  Proactive interference - This is where old information interferes with trying to learn new information.

  
  

  Retroactive interference - This is where new information has interfered with old information.
• Define retrieval failure


  Retrieval failure occurs when there is an absence of cues. This is an explanation for forgetting based on the idea that cues are needed in order to recall information.

  Cues are things that serve as a reminder as they have a meaningful link or an environmental cue to a memory.
• Outline and show evidence for the encoding specificity principle

  This states that a cue does not have to be exactly right in order to retrieve information but rather the closer it is the more useful it will be.

  A study was conducted where participants had to learn 48 words belonging to 12 categories. Participants had to recall as many words as they could in one of two conditions, the first being where they are given a cue (the categories) and the second being free recall. Average words recalled were 60% compared to 40% showing that having cues learnt at the time of encoding can significantly help recall information.
• Outline context dependent forgetting

  The context you are in when learning something can act as a cue and if that context dependant cue is not there then retrieving information can be difficult.

  Godden and Baddeley investigated this by having participants either learn a set of words on land or underwater (scuba divers), half of each groups had to go to the opposite condition and now all participant had to recall as many words as they could. They found that participants who were in the same context as where they learnt the information were able to recall much more than if in a different context.
• The accuracy of EWT is affected by...

  age, anxiety, leading questions, post event discussion
• Study of leading questions and EWT

  Loftus and Palmer (traffic accident videos)

  45 participants were shown 7 films of different traffic accidents. 'How fast were the cars going when they _ each other'. The verb was replaced with either smashed, collided, bumped, hit or contacted. The results showed an average of 10mph mean difference between contacted and smashed.

  smashed, hit and a control group. One week later they were asked whether they had seen any glass and found that while most said no, more people in the smashed condition did say yes.
• Outline post event discussion with evidence

  The memory of an event may be incorrect or altered after discussing it with others/being questioned about it multiple times.

  Gabbert investigated this by putting partners in pairs where each watched a different video of the same event. Pairs in one condition were encouraged to discuss the event before they individually recalled what occurred. A high amount of witnesses that discussed the event went on to make mistakes when recalling the event.
• Study of anxiety and EWT

  Johnson & Scott (Weapon Focus Effect)

  Participants were told to sit in a waiting room, an argument and then saw a man run through the room with either a pen covered in grease (low anxiety) or a knife covered in blood (high anxiety). Afterwards they asked the participants to identify the man from a set of photos. They found that those in the knife condition had an accuracy of 15% lower of those in the pen condition.
• Explain evidence for anxiety having a positive effect on accuracy


  A study was done where they questioned 58 witnesses to bank robberies. The witnesses were either victims (bankers) or bystanders (customers), these can link to high and low anxiety, relatively of course. They found that those who would have experience the most anxiety were able to recall much more than the people with lower anxiety.
• Weapon Focus may not be caused by anxiety


  weapon focus may not be caused by anxiety and rather by surprise. participants were to watch a thief, hairdressing salon carrying either scissors (high threat low surprise), handgun (high both), a wallet (low both) or a raw chicken (low threat high surprise). They found that identification of suspect was lowest when in high surprise conditions.
• Techniques used in a cognitive interview


  reinstate Context - allow for emotional and contextual cues.

  
  

  Recall everything - Smaller things may trigger a bigger memory/piece smaller things together.

  
  

  Change order - Remove Schemas.

  
  

  Change perspective - Remove Schemas.
• Limitations of a Standard Interview

  Close ended questions

  Don't maximise recall

  Short answers

  Brief questions to elicit facts

  Witness concentration broken by interruptions
• Cognitive Interview Evaluations


  • Meta-analysis of 53 studies on average there was a 34% increase in correct information generated from CI compared to the standard interview.
  • Time consuming and expensive to set up for the long-term in police departments.
  • Recall everything and reinstate context are equally stronger together.
  • Lots of inaccurate info may be said - Quantity>Quality