memory

• duration 


  a term used to define the length of each memory
• encoding 


  the format of incoming information linked to different kinds of memory (auditory, visual etc)
• capacity 


  the amount of information that can be held in the memory stores (like STM and LTM)
• retrieval 


  recovering (remembering) information from storage, like an output
• sensory store/memory 


  holds an unlimited amount of information for 250 milliseconds
• short term memory 


  holds approximately 7 chunks of information for about 18-30 seconds
• long term memory 


  holds an unlimited amount of information for an unlimited amount of time
• types of encoding

  • haptic - touch
  • iconic - sight
  • echoic - sound
  • olfactory - scent
  • gustatory - taste
• sensory memory

  • duration: 250 milliseconds
  • encoding: modality specific
  • capacity: unlimited
• short term memory

  • duration: 18-30 seconds
  • encoding: acoustic
  • capacity: 5-9 items
• long term memory

  • duration: unlimited
  • encoding: semantic
  • capacity: unlimited
• serial position effect 


  the psychological tendency to remember the first (primacy effect) and last (recency effect) items in a list better than those in the middle
• central executive 


  part of the working memory model that is responsible for monitoring and coordinating the operation of the slave systems and relates them to the LTM
• visuospatial sketchpad 


  one of the slave systems in the woking memory model that process visual information (visual cache) and spatial information (inner scribe)
• phonological loop 


  one of the 3 slave systems in the working memory model that stores verbal and auditory information
• episodic buffer 


  one of the three slave systems in the working memory model that temporarily stores information from other components so retrieval can be improved
• procedural memory

  • part of the LTM responsible for memory of motor skills
  • does not involve conscious thought, so is non-declarative
  • partially strong memories, nearly immune to forgetting
• semantic memory

  • part of the LTM responsible for storing factual information (general knowledge)
  • does involve conscious thought, so is declarative
  • they are recalled from the left prefrontal cortex
• episodic memory

  • type of LTM responsible for storing information about time-stamped events
  • does involve conscious thought, so is declarative
  • they are recalled from the right prefrontal cortex
• explanations of forgetting

  • interference theory (retroactive and proactive)
  • retrieval failure due to absence of cues
• proactive interference 


  when previous memories interfere with recent similar memories
• retroactive interference 


  when recent memories interfere with previous similar memories
• encoding specificity principle 


  the greater the dissimilarity between the encoding event and retrieval trial, the greater the likelihood of forgetting an original memory - this is due to the mismatch of information
• absence of context cues

  when the external environment or context is different at recall to how it was during coding
• absence of state cues

  when the internal environment or state is different at recall and how it was during coding
• absence of organisational cues

  special type of context cue - help us arrange and structure knowledge/material, without this cue we can forget info if it cannot be organised into a meaningful format
• factors affecting the accuracy of eyewitness testimony

  1. misleading info including leading questions
  2. misleading info including post-event discussion
  3. anxiety
• leading questions 


  questions that either by form or context, suggests a desired answer or leads a witness to believe a desired answer is required
• Loftus and Palmer's procedure

  • using independent measures design, 45 students were shown 7 films of traffic accidents
  • the students were given questionnaires about what they had seen
  • "how fast were the cars going when they ____ into each other?"
• Loftus and Palmer's findings

  • "contacted" - 32mph
  • "hit" - 34mph
  • "bumped" - 38mph
  • "collided" - 39mph
  • "smashed" - 41mph
• Loftus and Palmer's conclusion

  there is a 9mph difference between the verbs "contacted" and "smashed", therefore the verb used did affect recall of speed even though all students saw the same clip
• factors that lead to post-event discussion

  • retroactive interference
  • memory conformity
  • repeat interviewing
• post-event discussion: retroactive interference

  • new info from what we see/hear after a crime can interfere with old info in our memory, this leads to source confusion
  • source confusion errors occur when individuals cannot accurately recall the origin of their memories - this interference can impact our recall because our actual memories are contaminated by new info
• post-event discussion: memory conformity

  • memory conformity signifies the convergence of eyewitness memories following discussions, leading to inaccuracies
  • eyewitnesses discuss testimonies with others, this could potentially change their testimony consciously or unconsciously
  • co-witnesses may reach a consensus view of what actually happened as they are influenced by the opinion of others who they believe are correct (ISI)
  • therefore, discussion after the event may contaminate recall
• post-event discussion: repeat interviewing

  • each time an eyewitness is interviewed, there is a possibility that comments from the interviewer will become incorporated into their recollection of events
  • due to the reconstructive nature of memory, repeated interviewing can damage the original memory of events
  • the interviewer may use leading questions, which alters the individual's memory of events (especially child witnesses)
  • every time an event is recalled it can lead to slight alterations in the memory, further influenced by subsequent discussions + interactions
• Gabbert et al (2003) - aim

  to investigate the effect of post-event discussion on the accuracy of eyewitness testimony
• Gabbert et al (2003) - procedure

  • 60 students from the university of Aberdeen and 60 older adults were recruited
  • pts watched a video of a girl stealing money from a wallet, they were either tested in pairs or individually
  • pts in pairs had watched different perspectives of the video (believed they saw the same video), only 1 person actually witnessed the girl stealing
  • pts in pairs then discussed the crime and then all pts answered a questionnaire to test their memory of the event
• Gabbert et al (2003) - findings

  • 71% of pts in pairs recalled info they had not actually seen
  • 60% said the girl was guilty, despite having not seen her commit the crime
• Gabbert et al (2003) - conclusion

  these results suggest that post-event discussion could contaminate eyewitness testimonies
• anxiety affecting the accuracy of eyewitness testimony

  1. anxiety level of the witness (Yerkes Dodson Law)
  2. weapon focus effect
  3. increased violence