Memory Chapter 7

1. MemoryChapter 7

2. Memory Studying Memory • An Information-Processing Model • Two Memory Tracks Building Memories • Encoding: Getting Information In • Storage: Retaining Information • Retrieval: Getting Information Out

3. Memory Forgetting • Encoding Failure • Storage Decay • Retrieval Failure

4. Memory Memory Construction • Misinformation and Imagination Effects • Source Amnesia • Children’s Eyewitness Recall • Repressed or Constructed Memories of Abuse? Improving Memory

5. Memory is the persistence of learning over time through the encoding, storage and retrieval of information

6. Building a Memory To remember any information or experience requires: • Encoding: getting information into our brain • Storage: retaining the encoded information • Retrieval: getting the information back out of memory storage

7. An Information-Processing Model A model of memory based on a computer (Atkinson & Shiffrin, 1968) • Experience is first recorded, for just a moment, as a sensory memory • Information is processed into short-term memory, encoded through rehearsal • Holds a few items briefly • Information moves to long-term memoryfor later retrieval

8. Updates to the I-P Model • Some memories are formed through unconscious processing, without our awareness • Working memory: a view of short-term memory that stresses conscious, active processes • Working memory is not just a storage shelf, but an active desktop for linking new and old information

9. Two-Track Processing: Automatic vs. Effortful • We automatically processvast amounts of everyday information • We remember new and important information through effortful processing

10. Automatic Processing • We automatically process information about • Space • “The definition was at the top of the right page” • Time • “I went to the store before lunch” • Frequency • “This is the third time I’ve seen her today!”

11. Effortful Processing • Requires close attention and effort • Memory can be improved through rehearsal, the conscious repetition of information • Rehearsal was the subject of one of many studies of memory by Hermann Ebbinghaus

12. Ebbinghaus’s Experiment • Studied his own learning and forgetting • Used lists of nonsense syllables • JIH, BAZ, FUB, YOX, SUJ, DAX, VUM, etc. • Tested his memory for the list every day. • The more he practiced out loud on day 1, the less time needed to relearn it on day 2

13. Effortful Processing • Spacing effect: we remember better if study or practice is spread over time • Cramming is less effective! • Testing effect: repeated quizzing of previously studied material also helps

14. Serial Position • Serial position effect: We remember the first and last items in a list best

15. Facts vs. Skills • H.M. and others with certain traumatic brain injuries cannot form new explicit memories • Cannot learn new facts • However, they can learn new skills

16. Two-Track Memory • Implicit memory: retaining skills or conditioning, often without conscious awareness • Explicit memory: memories of facts and personal events that can be consciously retrieved

17. Two-Track Memory

18. Sleep and Memory • Sleep supports memory consolidation • During sleep, the hippocampus and cortex display rhythmic patterns of activity, as if communicating with each other • The brain may be “replaying” the day’s experiences as it transfers them to the cortex for long-term storage

19. Building Memories • Encoding: Getting Information In • Storage: Retaining Information • Retrieval: Getting Information Out

20. Encoding Meaning • We may encode meaning rather than raw information • When asked to recall text, we often report the meaning, or gist, rather than the raw text • It can be difficult to remember things without a meaningful context

21. Encoding Images • We can more easily remember things we can process visually as well as meaningfully • Old Bailey (court in London)--Glen Bailey • Memorable sentences often evoke powerful imagery, or mental pictures • HOMES—the great lakes • On Old Olympus' Towering Top, A Finn And German Viewed Some Hops—the cranial nerves: • Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Spinal Accessory, Hypoglossal

22. Sensory Memory • Storage is extremely short, especially for visual sensory memory • Study: Sperling (1960) flashed nine letters for 1/20th of a second. • Sensory memory made the letters momentarily available for encoding.

23. Short-Term Memory: Duration • Study: Peterson (1959) presented 3-letter strings and prevented rehearsal • Result: letters 50% gone at 3 seconds, 90% gone at 12 seconds. • Conclusion—without rehearsal—doesn’t last long

24. Storage Capacities • Short-term memory capacity is limited • The Magical Number Seven, plus or minus two (George Miller, 1956) • 7 digits or 7 chunks of information • Long-term memory seems to have no limit and can endure for a lifetime

25. How Does the Brain Store Memory? • Memory is not stored like books in a library, in neat, precise locations. • Rather, different aspects of a memory are assigned to various groups of neurons. • Thus, to understand how memory works, we must study the brain

26. Synaptic Changes • Synapses are the sites where the signal from one neuron is received by another • Experience modifies the brain’s neural network: increased activity in a pathway strengthens connections between the neurons involved

27. Synaptic Changes • Kandel and Schwartz (1982) classically conditioned sea slugs to withdraw their tail when squirted with water (with electric shock). • As the slug learned, serotonin was released into certain synapses. These synapses then become more sensitive and able to transmit signals more effectively.

28. Synaptic Changes • Long-Term Potentiation (LTP): An increase in a synapse’s firing potential. A neural basis for learning and memory

29. Stress-Related Memories • Excitement of stress can enhance memories. • Stress  hormones  more available glucose to fuel brain activity  signals brain “something important has happened” • Do you suppose that is why the pilot at Nellis AFB had found it much easier to count air craft on the ground when he made high speed-low altitude runs over airfields • in hostile North Vietnam • than in peaceful England?

30. Flashbulb Memories • Emotion-triggered hormone changes help explain flashbulb memories, unusually clear memories of an emotionally significant moment or event • Do you remember exactly where they were on September 11, 2001?

31. Retrieval: Getting Information Out Evidence that something has been remembered: • The item can be recalled, on an essay exam • The item can be recognized, as on a multiple-choice test • Recognition memory is quick and vast • Relearningthe item may be easier than it was the first time

32. Retrieval Cues • Memories are linked together in the brain, in a storage web of associations. • These associations can serve as retrieval cues, any stimuli (events, feelings, places, etc.) linked to a specific memory • We haven’t been at the GOP (Garden of Paradise) but thinking back—Al was at the cash register on that occasion. • We’ve not been to Skewer’s for a couple years-but Hani showed us to our table. • The more retrieval cues you’ve encoded, the better chance of finding a path to retrieve the memory

33. Context Effects • Returning to the context where you experienced something can prime your memory of it • Godden and Baddeley (1975) had scuba divers learn lists of words on land or underwater, and then attempt to recall them in the same or different context

34. Context Effects • Sometimes being in a similar context to one previously experienced can trigger the eerie feeling of déjà vu (I’ve seen this before) • This can happen when the current situation is loaded with retrieval cues that remind us of earlier, similar experiences • Where was I went I originally learned this particular materials—in class or sitting at home

35. Moods and Memories • Mood-congruent memory: we more easily recall experiences that are consistent with the current (good or bad) mood • If we are in a good mood, we tend to remember good experiences • Teen ratings of their parents are tightly linked to the teen’s current mood • If your kid rates you as a parent after waking up grouchy, what kind of rating will he make?

36. Forgetting • Jill Price is unable to forget anything. • Why might this be a problem?

37. Seven Sins of Memory (Daniel Schacter, 1999) • “Sins” of forgetting and retrieval, problems with the way memory works • Absent-mindedness – inattention to detail leads to encoding failure • Transience – memory loss as unused information fades • Blocking – inability to access stored information

38. Seven Sins of Memory (Daniel Schacter, 1999) • Sins of distortion • Misattribution – confusing the source of information • Suggestibility – e.g., asking a leading question influences answer and subsequent memory • Bias – belief-colored recollections. Current feelings may alter a memory. • Sin of intrusion • Persistence – unwanted memories (e.g., PTSD)

39. Encoding Failure • We cannot remember what we have not encoded

40. Storage Decay • Forgetting is initially rapid, and then levels off • People who had studied Spanish in high school but not after were tested on vocabulary recall • One explanation may be a gradual fading of the memory trace, the physical changes in the brain as a memory forms

41. Retrieval Failure • We can sometimes fail to retrieve a memory because we don’t have enough information to access the pathway to it

42. Interference • Interference: the blocking of recall as old or new learning disrupts the recall of other memories • Learning new passwords may interfere with remembering older ones • Learning an hour before sleep can be good because of less interference (but still need rehearsal)

43. Forgetting • Forgetting, the loss of information in between sensation and retrieval, can occur at any stages • Sensory memory • Short term memory • Long term memory

44. Repressed Memories • Freud argued that we repress, painful or unacceptable memories to minimize anxiety • He argued that these repressed memories linger, and can be retrieved by some later cue or therapy • Today, many memory researchers think repression rarely, if ever, occurs

45. Memory Construction • Every time we “replay” a memory, we replace the original with a slightly modified version • What implications does this have for everyday life? • My wife and I can have very different memories of an event that we’ve both experience • And that divergence may grow over time

46. Misinformation • Misinformation effect: a memory that has been corrupted by misleading information • Loftus and Palmer (1974) has subjects watch a film of a traffic accident. “How fast were the cars going when they smashed into each other?” or “How fast were the cars going when they hit each other?”

47. Misinformation • People who were asked “smashed” version reported higher speeds • A week later, they were more likely to (falsely) recall seeing broken glass

48. False Memory and Eyewitness Testimony • Even hearing a vivid retelling of an event can implant false memories • Sample of 200 convicts later proven innocent by DNA testing • 79% misjudged based on faulty eyewitness identification • Leading questions (“Did you hear loud noises”) can lead to false memories

49. Imagination and Memories • Even imagining fake actions and events can create false memories • College students were asked to imaging specific childhood events (like breaking a window with their hand). 25% later recalled the event as actually having happened. • Possible cause: visualizing something and actually perceiving it activate similar brain areas

50. Source Amnesia • Source amnesia: faulty memory for how, when, or where information was learned or imagined • Sometimes experienced by songwriters and authors, who may unintentionally plagiarize something