paper 1

• Coding


  The process of converting information between different forms
• Baddeley's research on coding

  1. Gave different lists of words to four groups of participants to remember

  2. Group 1: acoustically similar words

  3. Group 2: acoustically dissimilar words

  4. Group 3: semantically similar words

  5. Group 4: semantically dissimilar words
• Participants tended to do worse with acoustically similar words when recalling immediately from short-term memory, and worse with semantically similar words when recalling after 20 minutes from long-term memory
• Capacity


  The amount of information that can be held in a memory store
• Jacobs found the mean span for digits was 9.3 items and the mean span for letters was 7.3
• Peterson and Peterson's research on duration of short-term memory

  1. Tested 24 students, 8 trials each

  2. Given a consonant syllable to remember

  3. Also given a 3-digit number to count backwards from to prevent mental rehearsal

  4. After 3 seconds, average recall was 80%

  5. After 18 seconds, it was about 3%
• This suggests that short-term memory duration is about 18 seconds unless the information is repeated
• Bahrick's research on duration of long-term memory

  1. Studied 392 participants aged 17 and 74

  2. Tested recall using photo recognition and free recall

  3. Photo recognition was about 90% accurate within 15 years of graduation

  4. Free recall was about 60% accurate after 15 years, dropping to 30% after 48 years
• This shows that long-term memory may last a lifetime
• Baddeley's study


  • Identified a clear difference between short-term and long-term memory stores
  • The idea that short-term memory uses mostly acoustic coding and long-term memory mostly semantic coding has stood the test of time
• One limitation of Baddeley's study was that it used quite artificial stimuli rather than meaningful material
• Capacity research may have overestimated short-term memory capacity
• Duration research used artificial, constant syllables that do not reflect most everyday memory activities
• Multi-store model of memory

  Representation of how memory works in terms of three stores: sensory register, short-term memory, and long-term memory
• Types of long-term memory

  • Episodic
  • Semantic
  • Procedural
• Working memory model


  Central executive, phonological loop, visual spatial sketchpad, episodic buffer
• Explanations for forgetting


  • Proactive interference
  • Retroactive interference
  • Retrieval failure due to absence of cues
• Factors affecting the accuracy of eyewitness testimony

  • Misleading information
  • Anxiety
• Improving the accuracy of eyewitness testimony


  Use of the cognitive interview
• Sensory register

  Receives a raw sense of impressions, attention passes information to short-term memory
• Short-term memory

  Temporary active store, keeps information for around 18 seconds, capacity of 7 +/- 2
• Long-term memory


  Very long duration/permanent memory storage, theoretically unlimited capacity
• Baddeley found that we tend to mix up words that sound familiar when using short-term memory, and words with similar meanings when using long-term memory
• There may be more than one short-term memory store, as evidenced by a client with a memory disorder who could remember non-verbal sounds but not verbal information
• Cognitive tests of memory models are often highly artificial and conducted in lab environments, lacking mundane realism and ecological validity
• Episodic memory

  Events/experiences time-stamped, recalled consciously
• Semantic memory

  Facts, meaning, and knowledge recalled consciously
• Procedural memory


  Unconscious memories of skills, often learned in childhood
• Clive Wearing has retrograde amnesia for his musical education (episodic) but can still play the piano (procedural), suggesting semantic and procedural memory are separate
• Herlitz (1997) found females did better on episodic tasks but no difference in semantic tasks, suggesting episodic and semantic memory are separate
• Phonological loop


  Processes sound information, contains a primary acoustic store with a capacity of 2 seconds
• Visuo-spatial sketchpad


  Stores visual and spatial information, limited capacity of 4 objects
• Central executive


  Receives sensory information, filters and passes it on to the slave systems, limited capacity
• Episodic buffer


  Added to the working memory model in 2000 as a general store to combine information from the other components and long-term memory
• After a brain injury, KF had a selective impairment to his verbal short-term memory but not his visual functioning, suggesting the phonological loop and visuo-spatial sketchpad are separate processes
• Dual task performance research suggests the phonological loop and visuo-spatial sketchpad are separate systems with distinct capacities
• Interference


  Where two lots of information become confused in memory, overwriting or blocking each other
• Types of interference


  • Proactive
  • Retroactive
• Similarity


  Interference is more likely when two pieces of information are similar, termed response competition
• Time sensitivity


  Interference is less likely when there is a time gap between the instances of learning