Memory

• Anxiety


  Affects the accuracy of eyewitness testimony
• Anxiety can create arousal and changes that all affect the accuracy of eyewitness testimony
• Anxiety has both behavioral and physical effects
• Research on coding


  •Baddeley (1966) gave a list of words to 4 groups of participants to remember.

  •Acoustically similar (words that sound similar) e.g cat, can, cab.

  •Acoustically dissimilar (words that sound different) dog, few, cow

  •Semantically similar (words with similar meanings) e.g great, big

  •Semantically dissimilar (words with different meanings) e.g good, hot
• Coding: Baddeley’s findings. 


  •Participants were shown the original words and asked to recall them in the correct order.

  •Recalled immediately (STM): did worse with acoustically similar words.

  •Recalled 20 mins later (LTM): worse with semantically similar.

  •STM: stored acoustically, LTM semantically.
• Coding


  The format in which information is stored in various memory stores
• Capacity


  the amount of information that can be held in memory store
• Duration 


  The length of time information can be held in memory.
• Capacity: Digit Span


  Jacob’s (1887)

  •Researcher read out 4 digits and the participant repeated this.

  •If they got it correct, the researcher would read out 5 digits and so on until they cannot recall the order correctly (This is the individuals digit span)

  •Mean span for numbers was 9.3

  •Mean span for letters was 7.3
• Capacity: memory span and chunking


  •Miller (1956) made observations of everyday practice.

  •He noted that most things come in 7’s e.g seven days of the week, 7 deadly sins, 7 notes on the musical scale.

  •He thought that the capacity/span of STM was 7 items, plus or minus 2.

  •He noted that people could recall five words as easily as five letters.

  •We do this by chunking(grouping sets of digits or letters into units or chunks)
• Multi store model (Atkinson and Shiffrin 1968,1971) 


  A representation of how memory works in terms of 3 stores such as the sensory register, short term memory and long term memory.

  •Describes how info is transferred from one store to another and what makes second memories last and what makes some memories disappear
• Sensory register:


  •All stimuli from the environment pass into the sensory register.

  •Part of memory comprises several registers, one for each of the 5 senses.

  •Coding is modality specific (depends on the sense)
• Sensory register 


  •Coding for visual info (iconic)

  •Coding for auditory info (echoic)

  •Capacity is high E.g one million cells in one eye, storing data.

  •Duration of material in the ST is very brief (less than half a second)

  •Info passes further into the memory system only if you pay attention to it.