1. Copyright © 2010 Pearson Education Canada10-1Copyright © 2010 Pearson Education CanadaCopyright © 2010 Pearson Education Canada Memory Chapter 10

2. Copyright © 2010 Pearson Education Canada10-2Copyright © 2010 Pearson Education Canada-2Copyright © 2010 Pearson Education Canada-2 Chapter Outline Reconstructing the PastReconstructing the Past Memory and the Power of SuggestionMemory and the Power of Suggestion In Pursuit of MemoryIn Pursuit of Memory The Three-Box Model of MemoryThe Three-Box Model of Memory The Biology of MemoryThe Biology of Memory How We RememberHow We Remember Why We ForgetWhy We Forget Autobiographical MemoriesAutobiographical Memories

3. Copyright © 2010 Pearson Education Canada10-3 Reconstructing the Past Memory reflects:Memory reflects: –The capacity to retain and retrieve information –The changes in the structures that account for this capacity –Reconstructive processes E.g., the case of H.M. (1926-2008) and memory impairmentE.g., the case of H.M. (1926-2008) and memory impairment

4. Copyright © 2010 Pearson Education Canada10-4 Manufacture of Memory Many metaphors over time that don’t acknowledge that memory is selectiveMany metaphors over time that don’t acknowledge that memory is selective –Bartlett’s (1932) studies and reconstructive memory –Reconstruction often involves source misattribution: the inability to distinguish an actual memory of an event from information you learned about the event elsewhere

5. Copyright © 2010 Pearson Education Canada10-5 The Fading Flashbulbs Unusual, shocking, or tragic events may hold a special place in memoryUnusual, shocking, or tragic events may hold a special place in memory Flashbulb memories: characterized by surprise, illumination, and seemingly photographic detailFlashbulb memories: characterized by surprise, illumination, and seemingly photographic detail –Events seem frozen in time and detail –But even flashbulb memories have errors!

6. Copyright © 2010 Pearson Education Canada10-6Confabulation ConfabulationConfabulation –Confusion of an event that happened to someone else with one that happened to you –Belief that you remember something when it never actually happened –False memories can be as stable over time as true ones

7. Copyright © 2010 Pearson Education Canada10-7 Conditions of Confabulation Confabulation is most likely when:Confabulation is most likely when: 1.You have thought, heard, or told others about the imagined event often (imagination inflation) 2.The image of the event contains lots of details that make it feel real 3.The event is easy to imagine

8. Copyright © 2010 Pearson Education Canada10-8 Memory & Suggestion Eyewitness testimony is important, but not always reliable …Eyewitness testimony is important, but not always reliable … –E.g., case of Thomas Sophonow Factors that influence eyewitness accuracy:Factors that influence eyewitness accuracy: –Cross-race identification, the wording of questions, leading questions, misinformation, suggestive comments

9. Copyright © 2010 Pearson Education Canada10-9 Children’s Testimony Can children be accurate eyewitnesses?Can children be accurate eyewitnesses? –Yes, but influenced by same factors as adults, especially repeated and suggestive questioning May lead them to say and come to recall events that never happenedMay lead them to say and come to recall events that never happened –E.g., Canadian case in Martensville, Saskatchewan in 1992

10. Copyright © 2010 Pearson Education Canada10-10 Children’s Testimony When asked if a visitor committed acts that had not occurred, both age and type of questioning makes a big difference!When asked if a visitor committed acts that had not occurred, both age and type of questioning makes a big difference! When investigators used techniques taken from real child-abuse investigations, most children said yesWhen investigators used techniques taken from real child-abuse investigations, most children said yes

11. Copyright © 2010 Pearson Education Canada10-11 In Pursuit of Memory Measuring how memory works generally evaluates two forms of memories:Measuring how memory works generally evaluates two forms of memories: –Explicit memory: conscious, intentional recollection of an event or of an item of information –Implicit memory: unconscious retention in memory, as evidenced by the effect of a previous experience or encountered information on current thoughts or actions

12. Copyright © 2010 Pearson Education Canada10-12 Explicit Memory Refers to conscious, intentional recollectionRefers to conscious, intentional recollection Assessed using recall & recognition tasksAssessed using recall & recognition tasks –Recall: the ability to retrieve & reproduce from memory previously encountered material –Recognition: the ability to identify previously encountered material Recognition usually easier than recall tasksRecognition usually easier than recall tasks

13. Copyright © 2010 Pearson Education Canada10-13 Implicit Memory Also tested using the relearning method: comparing time required to relearn material with initial learningAlso tested using the relearning method: comparing time required to relearn material with initial learning Common method is priming where a person is exposed to information & later tested to see if this influences behaviour or performance on another taskCommon method is priming where a person is exposed to information & later tested to see if this influences behaviour or performance on another task

14. Copyright © 2010 Pearson Education Canada10-14 Models of Memory Information-processing modelsInformation-processing models –Cognitive processes involve computer ideas of encoding, storing, and retrieving information –Information represented as concepts, propositions, images, or cognitive schemas –Includes the three-box model of memory Parallel distributed processingParallel distributed processing –Knowledge is represented as connections among thousands of interacting processing units, distributed in a vast network operating in parallel

15. Copyright © 2010 Pearson Education Canada10-15 Three-Box Model of Memory Three separate memory systemsThree separate memory systems Sensory, short-term (STM), long-term (LTM)Sensory, short-term (STM), long-term (LTM)

16. Copyright © 2010 Pearson Education Canada10-16 Sensory Register Sensory registerSensory register –A memory system that momentarily preserves extremely accurate images of sensory information –Specific to each sense (0.5 - 2 secs duration) –Identification of stimulus based on info in LTM –Information not transferred quickly to STM is lost

17. Copyright © 2010 Pearson Education Canada10-17 Short-Term Memory (STM) Short-Term MemoryShort-Term Memory –A limited-capacity memory system involved in the retention of information for brief periods –Used to hold information retrieved from LTM for temporary use (referred to as working memory) Working memory: STM + the mental processes the control retrieval of information from LTM & interpret information appropriately for given tasksWorking memory: STM + the mental processes the control retrieval of information from LTM & interpret information appropriately for given tasks

18. Copyright © 2010 Pearson Education Canada10-18 Short-Term Memory Capacity of STM limited, as reflected in Miller’s magic number 7 +/- 2 unitsCapacity of STM limited, as reflected in Miller’s magic number 7 +/- 2 units –Enhance capacity by chunking: creating meaningful units of information, often composed of smaller units E.g., CBC is one chunk of informationE.g., CBC is one chunk of information –Meaningful & emotional items will transfer quickly to LTM, others require more effort to transfer this material

19. Copyright © 2010 Pearson Education Canada10-19 Long-Term Memory (LTM) LTM is the memory system involving long- term storage of informationLTM is the memory system involving long- term storage of information How is information organized?How is information organized? –Semantic categories A larger grouping into which items similar in some characteristic can be placed (e.g., chair belongs to the category furniture)A larger grouping into which items similar in some characteristic can be placed (e.g., chair belongs to the category furniture) –Sound or look E.g., Tip-of-the-tongue (TOT) statesE.g., Tip-of-the-tongue (TOT) states

20. Copyright © 2010 Pearson Education Canada10-20 Organization of LTM

21. Copyright © 2010 Pearson Education Canada10-21 Contents of LTM Procedural memories: memories for the performance of actions or skills (“knowing how”)Procedural memories: memories for the performance of actions or skills (“knowing how”) Declarative memories: memories of facts, rules, concepts, and events (“knowing that”)Declarative memories: memories of facts, rules, concepts, and events (“knowing that”) –Semantic: general knowledge, including facts, rules, concepts, & propositions –Episodic: personally experienced events & the contexts in which they occurred

22. Copyright © 2010 Pearson Education Canada10-22 Types of LTM

23. Copyright © 2010 Pearson Education Canada10-23 Transferring Memories Serial position effectSerial position effect –The tendency for recall of the first and last items on a list to surpass recall of items in the middle of the list Primacy effect: recall will be best for items at beginning of listPrimacy effect: recall will be best for items at beginning of list Recency effect: recall will be best for items at end of listRecency effect: recall will be best for items at end of list

24. Copyright © 2010 Pearson Education Canada10-24 The Biology of Memory Forming a memory involves chemical and structural changes at the level of the neuronForming a memory involves chemical and structural changes at the level of the neuron –Long-term potentiation: a long-lasting increase in the strength of synaptic responsiveness Reflects Hebbian learning ideas; may involve glutamateReflects Hebbian learning ideas; may involve glutamate –Linked to memory consolidation: process by which the synaptic changes associated with recently stored memories become durable and stable, causing memory to be more reliable

25. Copyright © 2010 Pearson Education Canada10-25 Locating Memories Brain imaging and testing has demonstrated:Brain imaging and testing has demonstrated: –Frontal lobe activity linked to STM tasks –Hippocampal activity during declarative LTM tasks –Prefrontal cortex & areas adjacent to hippocampus active when encoding words & pictures –Procedural memories linked to changes in cerebellum –Cerebral cortex involved in formation of LTM

26. Copyright © 2010 Pearson Education Canada10-26 Brain Structures & Memory

27. Copyright © 2010 Pearson Education Canada10-27 Hormones & Memory Hormones released adrenal glands during stress & emotional arousal enhance memoryHormones released adrenal glands during stress & emotional arousal enhance memory –Combined effort of epinephrine and glucose may play a key role –Research on “sweet memories” Moderate levels of stress hormones optimalModerate levels of stress hormones optimal –Animal studies demonstrate that too much impairs memory

28. Copyright © 2010 Pearson Education Canada10-28 How We Remember 1.Effective encoding –Automatic encoding: accurate encoding that takes place automatically, without effort –Effortful encoding: to retain complex information, you might have to select the main points, label concepts, or associate the information with personal experiences or material you already know

29. Copyright © 2010 Pearson Education Canada10-29 How We Remember 2.Rehearsal –Maintenance rehearsal: rote repetition of material to maintain availability –Elaborative rehearsal: association of new information with already stored knowledge; analysis of new information to make it memorable Also involves deep processing versus shallow processingAlso involves deep processing versus shallow processing

30. Copyright © 2010 Pearson Education Canada10-30 How We Remember 3.Mnemonics –Mnemonics are strategies and tricks for improving memory, such as the use of verse or a formula –Involves active encoding strategies –Examples: Rhymes: Thirty days hath September …Rhymes: Thirty days hath September … Formulas: Every good boy deserves fudgeFormulas: Every good boy deserves fudge Use of visual images or word associationsUse of visual images or word associations

31. Copyright © 2010 Pearson Education Canada10-31 Why We Forget Forgetting curvesForgetting curves –Ebbinghaus & Linton

32. Copyright © 2010 Pearson Education Canada10-32 Why We Forget Five mechanisms account for forgetting:Five mechanisms account for forgetting: 1.Decay –Decay theory: information in memory eventually disappears if it is not accessed (applies better to short- term than to long-term memory) 2.Replacement –New information can wipe out old information –E.g., misinformation & the Stop Sign Study

33. Copyright © 2010 Pearson Education Canada10-33 Why We Forget 3.Interference –Retroactive interference: when recently learned material interferes with ability to remember similar material stored previously –Proactive interference: when previously stored material interferes with ability to remember similar, more recently learned material

34. Copyright © 2010 Pearson Education Canada10-34 Why We Forget 4.Cue-dependent memory –Cue-dependent forgetting: inability to retrieve information stored in memory because of insufficient retrieval cues State-dependent memory: tendency to remember something when the physical/mental state during original experience/learning matches current stateState-dependent memory: tendency to remember something when the physical/mental state during original experience/learning matches current state Mood-congruent memory: tendency to remember experiences that are consistent with one’s current mood (forget those that are not)Mood-congruent memory: tendency to remember experiences that are consistent with one’s current mood (forget those that are not)

35. Copyright © 2010 Pearson Education Canada10-35 Why We Forget 5.Amnesia –Psychogenic amnesia: loss of personal identity associated with psychological causes (e.g., need to escape feelings of embarrassment, guilt, shame, disappointment, emotional shock) –Traumatic amnesia: temporary memory loss involving burying of specific traumatic events for a long period of time Immune to distortion over time, occurs due to repression (controversial)Immune to distortion over time, occurs due to repression (controversial)

36. Copyright © 2010 Pearson Education Canada10-36 The Repression Controversy RepressionRepression –In psychoanalytic theory, the selective involuntary pushing of threatening or upsetting information into the unconscious Individuals are more likely to struggle with forgetting traumatic eventsIndividuals are more likely to struggle with forgetting traumatic events Hard to distinguish repression from other forms of forgettingHard to distinguish repression from other forms of forgetting –Researchers argue against special unconscious mechanism

37. Copyright © 2010 Pearson Education Canada10-37 Autobiographical Memory Childhood amnesiaChildhood amnesia –The inability to remember events and experiences that occurred during the first two or three years of life Explanations for infantile amnesia:Explanations for infantile amnesia: –Lack of sense of self –Impoverished encoding –A focus on the routine –Children’s ways of thinking about the world

38. Copyright © 2010 Pearson Education Canada10-38 Autobiographical Memory Memory and narrativeMemory and narrative –Narratives we compose simplify and make sense of our lives; profound influence on our plans, memories, love affairs, hatreds, ambitions, and dreams –Memories reconstructed according to culture, and present needs, beliefs, experiences –Central themes may serve as cognitive schemas –Reminiscence bump – important transitions in life stand out in memory

39. Copyright © 2010 Pearson Education Canada10-39 Memory & Myth Implications of memory reconstruction in eyewitness eventsImplications of memory reconstruction in eyewitness events Canadian cases of wrongful conviction based on mistaken memories:Canadian cases of wrongful conviction based on mistaken memories: –Thomas Sophonow –David Milgaard –Guy Paul Morin –Steven Truscott –Donald Marshall Jr.

40. Copyright © 2010 Pearson Education Canada10-40Copyright © 2010 Pearson Education Canada-40 End of Chapter 10 Copyright © 2010 Pearson Education Canada-40