Memory

• DVD-in-the-Head


  • Encoding: record on an electronic disk
  • Storage: store the DVD in a drawer
  • Retrieval: play the disk back on a DVD player
• Sensory memory (SM)


  • Accurately holds perceptual information for a very brief amount of time
  • Iconic memory (<1s)
  • Echoic memory (3-4s)
  • High capacity, very brief
  • Sensory store: store for sight, sound, touch, sell, taste
• Mnemonics


  Strategies for remembering large amounts of information, usually involving imaging events occurring on a journey or with some other set of memorized cues
• Short term memory


  • Limited duration
  • ~20 secs (15-30 secs)
• Capacity of STM


  • About 7+2 chunks of info
  • Information grouped into a meaningful unit
• Working memory


  • STM = the "space" used to hold information presently requiem
  • WM = manipulation of that information for whatever task you are doing
  • Central executive - boss of working memory
  • Phonological loop (e.g. repeating a phone number to memorize it)
  • Episodic buffer (in middle)
  • Visuospatial "sketchpad" (e.g. doing double digit multiplication or long division)
• Measuring your working memory capacity

  • Digit span task
  • Corsi task
• Long term memory (LTM)


  • Memory that persists over time without conscious activation
  • Events in your life, facts about the world, motor skills, etc.
  • "Long term" sometimes means a few minutes - doesn't have to be years
  • Can last indefinitely
  • Can be retrieved and brought into working memory
• Serial position effect


  • Primacy effect - remember first words better
  • Recency effect - remember last words better
• Types of long term memory


  • Explicit memory
  • Implicit memory
• Explicit memory


  • Out there, obvious, conscious
  • Knowing "what"
  • Expressed verbally
  • Conscious awareness
  • Aka "declarative memory"
• Episodic memory


  • Specific time, place; time travel back to this and remember
  • Personally experienced
  • Prospective memory: future events
• Semantic memory


  • Facts
  • General knowledge
• Implicit memory


  • Unconscious, memories you have but can't consciously access
  • Knowing "how"
  • Expressed behaviorally
  • Awareness not necessary
  • Aka "Non-declarative memory"
• Procedural memory


  • Skills
  • "How to" do something
• Priming


  Exposure to something influences behavior
• Amnesia


  • Retrograde amnesia: cannot remember events prior to brain damage
  • Anterograde amnesia: cannot later remember events that occur after brain damage
• Case study: Patient HM

  • Anterograde amnesia
  • Unable to form new specific memories
  • Had difficulty transferring explicit memories from STM → LTM due to removal of hippocampus
  • Performance improved on a mirror tracing task even though he didn't remember doing it before
• Case study: Patient KC


  • Sever retrograde and anterograde amnesia
  • Hippocampus, frontal, occipital, all around damaged
  • Old semantic memories intact but not episodic
  • Could not retain episodic memories
  • Had facts about the car and stuff, but couldn't recall episodes of it happening and doesn't know how he knows
• Retrieval


  • NOT like playback of a video
  • Depends on cues/hints that help bring information to mind
• Context and memory


  • Context may be many different things
  • Encoding specificity principle: memory is improved when information available at encoding is also available at retrieval
  • The more similar the retrieval situation is to the encoding situation, the better the retrieval
• Context effects


  • The effects of studying and context
  • Test taking and similar context of rooms
  • Use of imagery and mental time travel
  • Vary the places that you study to prevent leaving your memory in one place
• How to measure what you know?

  • Recall
  • Recognition
  • Savings
• Memory failures


  • Depends on our interpretations and expectations of experiences in our memory
  • Schemas: organized knowledge structures or mental modals that we've stored in memory
• Interference


  • Proactive: When old info interferes with ability to retrieve new info
  • Retroactive: New info interferes with ability to retrieve old info
• Blocking


  • Failing to recall something, even when you know it
  • Tip of the tongue error
• Loftus et al. (1979)

  • "Did another car pass the red datsun when it was stopped at the yield sign?"
• Point of subjective equality


  Our probability of saying the lines are at the same length, response is at 50% means you perceive one is longer and one is shorter
• Point of objective equality

  Both lines are 160 pixels regardless of perception