Memory processes


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Memory processes

  2. 2. ENCODING AND TRANSFER OF INFORMATION • Forms of Encoding • Short-Term Storage • Long-Term Storage • Transfer of Information from Short-Term Memory to Long-Term Memory • Rehearsal • Organization of Information
  3. 3. • Each one represents a stage in memory processing: • Encoding refers to how you transform a physical, sensory input into a kind of representation that can be placed into memory. • Storage refers to how you retain encoded information in memory. • Retrieval refers to how you gain access to information stored in memory.
  5. 5. SHORT-TERM STORAGE • Conrad and colleagues (1964) • Participants were visually presented with several series of 6 letters at the rate of 0.75 seconds per letter. The letters used in the various lists were B, C, F, M, N, P, S, T, V, and X. Immediately, after the letters were presented, participant were asked to write down each list of 6 letters in the order given. Instead of recalling the letters they were supposed to recall, participants substituted letters that sounded like the correct letters. • Another group of participants simply listened to single letters in a setting that had noise in the background. • Thus, we seem to encode visually presented letters by how they sound, not by how they look.
  6. 6. SHORT-TERM STORAGE • The Conrad experiment shows the importance in short-term memory of an acoustic code rather than a visual code. • Baddeley (1966) argued that short-term memory relies primarily on an acoustic rather than a semantic code. • Acoustically confusable words – map, cab, mad, man, cap • Acoustically distinct words – cow, pit, day, rig, bun • Semantically similar words – big, long, large, wide, broad • Semantically dissimilar words – old, foul, late, hot, strong
  7. 7. SHORT-TERM STORAGE • Thus, encoding in short-term memory appears to be primarily acoustic, but there may be some secondary semantic encoding as well. • We are more prone to forgetting visual information than acoustic information. • Ex. Remembering a telephone number from long ago, more likely to remember how it sounds when you say it to yourself than to remember a visual image of it.
  8. 8. LONG-TERM STORAGE • Most information stored in long-term memory is primarily semantically encoded. (Grossman & Eagle, 1970) • Participants were remembering words by clustering them into categories. (Bousfield, 1953) • Encoding of information in long-term memory is not exclusively semantic. There is also evidence for visual encoding. (Frost, 1972) • Acoustic information can be encoded in long-term memory. (Nelson & Rothbart, 1972)
  9. 9. LONG-TERM STORAGE • Functional Magnetic Resonance Imaging (fMRI) studies have found that the brain areas that are involved in encoding can be, but do not necessarily have to be, involved in retrieval. • Anterior medial prefrontal cortex and right fusiform face area (encoding/retrieval) • Left fusiform face area (encoding) • Left parahippocampal place area PPA (encoding) • Medial temporal and prefrontal regions (memory processes in general)
  11. 11. TRANSFER OF INFORMATION FROM SHORT-TERM MEMORY TO LONG-TERM MEMORY • When competing information interferes with our storing information we speak of interference. • When we forget facts just because time passes, we speak of decay. • Some forms of nondeclarative memory are highly volatile and decay quickly. • Other nondeclarative forms are maintained more readily, particularly as a result of repeated practice (of procedures) or repeated conditioning (of responses).
  12. 12. • Entrance into long-term declarative memory may occur through a variety of processes: • By deliberately attending to information to comprehend it. • Making connections or associations between the new information and what we already know and understand. • We make connections by integrating the new data into our existing schemas of stored information. This process of integrating new information into stored information is called consolidation. TRANSFER OF INFORMATION FROM SHORT-TERM MEMORY TO LONG-TERM MEMORY
  13. 13. • Metacognition – our ability to think about and control our own processes of thought and ways of enhancing our thinking. • Metamemory strategies – one component of metacognition; involve reflecting on our own memory processes with a view to improving our memory. TRANSFER OF INFORMATION FROM SHORT-TERM MEMORY TO LONG-TERM MEMORY
  14. 14. REHEARSAL • One technique people use for keeping information active; repeated recitation of an item • Practice effects • Overt – aloud and obvious to anyone watching. • Covert – silent and hidden
  15. 15. REHEARSAL • Elaborative – the individual somehow elaborates the items to be remembered. Such rehearsal makes the items either more meaningfully integrated into what the person already knows or more meaningfully connected to one another and therefore more memorable. • Maintenance – the individual simply repetitiously rehearses the items to be repeated. Such rehearsal temporarily maintains information in short-term memory without transferring the information to long-term memory.
  16. 16. REHEARSAL • People’s memory for information depends on how they acquire it. • Their memories tend to be good when they use distributed practice, learning in which various sessions are spaced over time. • Massed pratice – learning in which sessions are crammed together in a very short space of time. • The Spacing Effect • To maximize the effect on long-term recall, the spacing should ideally be distributed over months, rather than days or weeks.
  17. 17. SLEEP AND MEMORY CONSOLIDATION • There are 5 different sleep stages that differ in their EEG patterns. Dreaming takes place during stage 5, the so-called REM sleep. REM sleep is particularly important for memory consolidation. • Better learning with increases in the proportion of REM-stage sleep after exposure to learning situations. • The positive influence of sleep on memory consolidation is seen across age groups. (Hornung et al., 2007)
  18. 18. SLEEP AND MEMORY CONSOLIDATION • People who suffer from insomnia, a disorder that deprives the sufferer of much-needed sleep, have trouble with memory consolidation. (Backhaus et al., 2006) • Prolonged sleep deprivation seems to affect such cell development negatively (Meerlo, 2009). Thus, a good night sleep, which includes plenty of REM-stage sleep, aids in memory consolidation.
  19. 19. NEUROSCIENCE AND MEMORY CONSOLIDATION • Cells of the hippocampus that were activated during initial learning are reactivated during subsequent periods of sleep. It is as if they are replaying the initial learning episode to achieve consolidation into long-term storage. • The hippocampus acts as a rapid learning system. It temporarily maintains new experiences until they can be appropriately assimilated into the more gradual neocortical representation system of the brain.
  20. 20. NEUROSCIENCE AND MEMORY CONSOLIDATION • The benefits of distributed practice seem to occur because we have a relatively rapid learning system in the hippocampus that becomes activated during sleep. • These rapidly learned memories become integrated into our more permanent long-term memory system.
  21. 21. ORGANIZATION OF INFORMATION • Participants create their own consistent organization and then group their recall by the subjective units they create. • Mnemonic devices are specific techniques to help you memorize lists of words (Best, 2003). • Thus, when choosing a method for encoding information for subsequent recall, you should consider the purpose for recalling the information.
  22. 22. • The use of mnemonic devices and other techniques for aiding memory involves metamemory (our understanding and reflection upon our memory and how to improve it). • Reminders – external memory aids—to enhance the likelihood that we will remember important information. • Ex. Taking notes, shopping lists, timers and alarms, asking people to help you remember things. • Forcing Functions – physical constraints that prevent us from acting without at least considering the key information to be remembered. • Ex. To ensure that you remember to take your notebook to class, you might lean the notebook against the door through which you must pass to go to class.
  23. 23. MNEMONIC DEVICES • Categorical Clustering – organize a list of items into a set of categories. • Interactive images – create interactive images that link the isolated words in a list. • Pegword system – associate each new word with a word on a previously memorized list and form an interactive image between the two words. • Method of loci – visualize walking around an area with distinctive landmarks that you know well, and then link the various landmarks to specific items to be remembered.
  24. 24. MNEMONIC DEVICES • Acronym – devise a word or expression in which each of its letters stands for a certain other word or concept • Acrostic – form a sentence rather than a single word to help you remember the new words. • Keyword system – form an interactive image that links the sound and meaning of a foreign word with the sound and meaning of a familiar word.
  25. 25. TRANSFER OF INFORMATION INTO LONG- TERM STORAGE MAY BE FACILITATED BY SEVERAL FACTORS: • Rehearsal of the information, particularly if the information is elaborated meaningfully. • Organization, such as categorization of the information. • The use of mnemonic devices • The use of external memory aids, such as writing lists or taking notes • Knowledge acquisition through distributed practice across various study sessions, rather than through massed practice.
  26. 26. RETRIEVAL • Retrieval from Short-Term Memory • Parallel or Serial Processing? • Exhaustive or Self-Terminating Processing? • The Winner—a Serial Exhaustive Model—with Some Qualifications • Retrieval from Long-Term Memory • Intelligence and Retrieval
  28. 28. PARALLEL OR SERIAL PROCESSING? • Parallel processing refers to the simultaneous handling of multiple operations. • Serial processing refers to operations being done one after another.
  29. 29. EXHAUSTIVE OR SELF-TERMINATING PROCESSING? • Exhaustive serial processing implies that the participant always checks the test digit against all digits in the positive set, even if a match were found partway through the list. • Self-terminating serial processing implies that the participant would check the test digit against only those digits needed to make a response.
  31. 31. INTERFERENCE THEORY • Refers to the view that forgetting occurs because recall of certain words interferes with recall of other words. • Retroactive interference (or retroactive inhibition) occurs when newly acquired knowledge impedes the recall of older material. (new information inhibits the ability to remember old information) • Proactive interference (or proactive inhibition)occurs when material that was learned in the past impedes the learning of new material. (old information inhibits the ability to remember new information)
  32. 32. INTERFERENCE THEORY • Serial-position curve represents the probability of recall of a given word, given its serial position (order of presentation) in a list. • Recency effect refers to superior recall of words at and near the end of a list. • Primacy effect refers to superior recall of words at and near the beginning of a list.
  33. 33. DECAY THEORY • Asserts that information is forgotten because of the gradual disappearance, rather than displacement, of the memory trace.
  34. 34. THE CONSTRUCTIVE NATURE OF MEMORY •Autobiographical Memory •Memory Distortions • The Eyewitness Testimony Paradigm Repressed Memories • The Effect of Context on Memory
  35. 35. • Reconstructive – involving the use of various strategies(e.g., searching for cues, drawing inferences) for retrieving the original memory traces of our experiences and then rebuilding the original experiences as a basis for retrieval. • Constructive – prior experience affects how we recall things and what we actually recall from memory.
  36. 36. AUTOBIOGRAPHICAL MEMORY • Refers to memory of an individual’s history. • Flashbulb memory – a memory of an event so powerful that the person remembers the event as vividly as if it were indelibly preserved on film. • Surprising • Important • Emotional
  38. 38. 1. TRANSIENCE • Memory fades quickly. • The state or fact of lasting only for a short time. • General deterioration of a specific memory over time. • This is especially true with episodic memory, because every time an episodic memory is recalled, it is re-encoded within the hippocampus, altering the memory each time you recall it. Transience is caused because of interference.
  39. 39. 2. ABSENT-MINDEDNESS • is where a person shows inattentive or forgetful behavior. • so lost in thought that one does not realize what one is doing, what is happening, etc.; preoccupied to the extent of being unaware of one's immediate surroundings. • This form of memory breakdown involves problems at the point where attention and memory interface. Common errors of this type include misplacing keys, eyeglasses, or forgetting appointments because at the time of encoding sufficient attention was not paid on what would later need to be recalled.
  40. 40. 3. BLOCKING • Tip-of-the-tongue phenomenon • People sometimes have something that they know they should remember, but they can’t. • Blocking is when the brain tries to retrieve or encode information, but another memory interferes with it. Blocking is a primary cause of Tip of the tongue phenomenon (a temporary inaccessibility of stored information).
  41. 41. 4. MISATTRIBUTION • People often cannot remember where they heard what they heard or read what they read. Sometimes people think they saw things they did not see or heard things they did not hear. • Ex. Eyewitness testimony • It entails correct recollection of information with incorrect recollection of the source of that information. For example, a person who witnesses a murder after watching a television program may incorrectly blame the murder on someone she saw on the television program. This error has profound consequences in legal systems because of its unacknowledged prevalence and the confidence which is often placed in the person's ability to know the source of information important to suspect identification.
  42. 42. 5. SUGGESTIBILITY • People are susceptible to suggestions, so if it is suggested to them that they saw something, they may think they remember seeing it. • Examples: • You witness an argument after school. When later asked about the "huge fight" that occurred, you recall the memory, but unknowingly distort it with exaggerated fabrications, because you now think of the event as a "huge fight" instead of a simple argument. • A witness' testimony is altered because the police or attorneys make suggestions during the interview, which causes their already uncertain observations to become distorted memories. • Your parents tell you that you have always been a good singer, so from then on you believe you have talent when really your parents were falsely encouraging you.
  43. 43. 6. BIAS • The sin of bias is similar to the sin of suggestibility in that one's current feelings and worldview distort remembrance of past events. This can pertain to specific incidences and the general conception one has of a certain period in one's life. This occurs partly because memories encoded while a person was feeling a certain level of arousal and a certain type of emotion come to mind more quickly when a person is in a similar mood. Thus, a contented adult might look back with fondness on their childhood, induced to do so by positive memories from that time which might not actually be representative of their average mood during their childhood.
  44. 44. 7. PERSISTENCE • People sometimes remember things as consequential that, in a broad context, are inconsequential. • Ex. Someone with many successes but one notable failure may remember the single failure better than the many successes. • This failure of the memory system involves the unwanted recall of information that is disturbing. The remembrance can range from a blunder on the job to a truly traumatic experience, and the persistent recall can lead to formation of phobias, post-traumatic stress disorder, and even suicide in especially disturbing and intrusive instances.
  45. 45. THE EYEWITNESS TESTIMONY PARADIGM • May be the most common source of wrongful convictions in the United States (Modafferi et al., 2009).
  46. 46. WHAT INFLUENCES THE ACCURACY OF EYEWITNESS TESTIMONIES? • In general, people are remarkably susceptible to mistakes in eyewitness testimony. They are generally prone to imagine that they have seen things they have not seen (Loftus, 1998). • Line-ups • Confessions • Feedback to eyewitnesses affected participants’ testimony • Level of stress
  47. 47. CHILDREN AS EYEWITNESSES • Children’s recollections are particularly susceptible to distortion. • The younger the child is, the less reliable the testimony of that child can be expected to be. • When a questioner is coercive or even just seems to want a particular answer, children can be quite susceptible to providing the adult with what he or she wants to hear. • Children may believe that they recall observing things that others have said they observed. • The testimony of children must be interpreted with great caution.
  48. 48. CAN EYEWITNESS TESTIMONIES BE IMPROVED? • Gary Wells (2006) made several suggestions to improve identification accuracy in line-ups: • Presenting only1 suspect per line-up. • Making sure that all people in the line-up are reasonably similar to each other. • Cautioning witnesses that the suspect may not be in the line-up at all.
  49. 49. REPRESSED MEMORIES • Are memories that are alleged to have been pushed down into unconsciousness because of the distress they cause. • Do repressed memories actually exist? • Some therapists may inadvertently plant ideas in their client’s heads. In this way, they may inadvertently create false memories of events that never took place. • Showing that implanted memories are false is often extremely hard to do.
  50. 50. REPRESSED MEMORIES • Roediger-McDermott (1995) paradigm • 15 words strongly related to the word sleep • Why are people so weak in distinguishing what they have heard from what they have not heard? • Source-monitoring error, which occurs when a person attributes a memory derived from one source to another source. • Spreading activation, every time an item is studied, you think of the items related to that item.
  51. 51. THE EFFECT OF CONTEXT ON MEMORY • Emotional intensity • Mood • State of consciousness • Environmental context cues • Encoding Specificity refers to the fact that what is recalled depends largely on what is encoded.
  52. 52. QUIZ 1. What is the main difference between two of the proposed mechanisms by which we forget information? (3pts) 2. Explain flashbulb memory. (2pts) 3. Make a list of 10 or more unrelated items you need to memorize. Choose one of the mnemonic devices mentioned, and described how you would apply the device to memorizing the list of items. Be specific. (5pts) 4. What are three things you learned about memory that can help you learn new information and effectively recall the information over the long term? (5pts)
  53. 53. ASSIGNMENT 1. In what forms can knowledge be represented in our mind? 2. What kinds of codes does dual-code theory comprise? 3. What is a proposition? 4. What is mental rotation? 5. What is image scaling? 6. How do we mentally scan images? (2pts) 7. What is representational neglect? 8. What kind of mental model did Johnson-Laird propose? 9. What is the difference between visual and spatial imagery? (2pts) 10. What is cognitive map? 11. What is a text map? 12. Name some heuristics that people use when manipulating cognitive maps.