120Ch8.docx

10/7/09 11:04 AM Memory Chapter 8 Memory The capacity and structures used for the retention and retrieval of information Involves three processes: The Three Box Model of Memory The processing of memories goes through three areas: encoding storage retrieval Level 1 of the Three Box Model Sensory Memory contains raw sensations, prior to perception Very large capacity material here only briefly (about ½ second on visual sensations, 2 seconds on auditory) Level 2 of the Three Box Model Short Term Memory (STM) Also called working memory Very limited capacity (7 +/- chunks of information) Very limited time (approx 30 seconds) Can keep info here longer with maintenance rehearsal Can store more info here with chunking STM Test: Chunking Test: Level 3 of the Three Box Model Long Term Memory (LTM) practically unlimited storage detail level varies info ma be permanent, but can be distorted can feed back into STM Picture of The Three Box Model of Memory: More on Long Term Memory There are three different types of long term memories Procedural Memory ? Memories of common physical procedures/muscle memory Mostly accessed implicitly (without thinking) Highly robust to amnesia Episodic memory ? memory of things that we have personally experienced (personal episodes) Semantic memory ? memory of general knowledge, facts, word meanings Examples: I know how to play a guitar = procedural I remember my first guitar lesson = episodic I know what a guitar is = semantic A Memory Test: Word List #1 pie good bitter taste chocolate soda sugar tart cake candy 1 A Memory Test: Word List #2 (don?t write anything down yet)! Conceptual Networks: Memories are stored and retrieved by connecting them to other memories Retrieval example: Is a canary a bird? Your brain instantaneously sifts through memory files called Conceptual Networks Improving Memory based on Conceptual Networks Retrieval of memories can be enhanced by activating as many connecting nodes as possible Elaborative Rehearsal involves connecting the new memory to existing memories Conceptual Networks explain the ?tip of the tongue? phenomenon ?Feeling of knowing?, but can?t access the info Retrieving and Reconstructing Memories Memories are generally not encoded and retrieved as whole clusters of details Rather, we store memories within schemas, or scripts ? adding details to a larger generic framework Memories are prone to ?reconstruction? because of the complex nature of our conceptual networks Reconstructing Memories Elizabeth Loftus showed all participants footage of the same car wreck, then asked ?How fast were the cars going when they ______ each other?? Contacted Hit Bumped Collided with Smashed into Loftus study continued? Result ? people guessed different speeds depending on the question: Contacted ? Hit ? Bumped into ? Collided with ? Smashed into ? Reconstructing Memories This is called the _____________________________, and has been implicated in other areas of memory distortion Flashbulb memory distortion Eyewitness testimony Flashbulb Memories Flashbulb memories: are highly rich, highly detailed memories of a significant moment in your life However, while we are often very certain of them, we are not often accurate Flashbulb Memories What?s wrong with this memory? December 4, 2001: "I was sitting outside the classroom waiting to go in, and I saw an airplane hit the tower--the TV was obviously on. And I used to fly myself, and I said, well, there's one terrible pilot. I said, it must have been a horrible accident. But I was whisked off there. I didn't have much time to think about it." January 5, 2002: "First of all, when we walked into the classroom, I had seen this plane fly into the first building. There was a TV set on. And you know, I thought it was pilot error, and I was amazed that anybody could make such a terrible mistake...." Flashbulb Memories Neisser?s Challenger study The day following the Challenger explosion, asked freshmen to describe in detail when/how they heard Asked them again 2 ½ years later Scored on similarity from 1-7 points Of 44 participants, only 3 scored perfect 7 Mean score was 2.95 Over half scored less than 2 Yet all recalled vivid, certain memories Memory Test: Word List #2 Write down all the words you can remember from the second list of words: mad hate hatred ire fear happy What happened?? Is the Misinformation effect present? Eyewitness Testimony So, if flashbulb memories aren?t correct, can we trust eyewitness testimony? Loftus?s car crash study shows how leading questions can distort memory Other studies asked questions about a yield sign or broken headlight, where there was none The more people repeat these memories, the more certain they become, even if more distorted Eyewitness Testimony Wells presented 253 people with a lineup of suspects related to a video they saw of a terrorist bombing All selected a suspect, although the actual suspect was not listed Certainty was very high for those told they?d picked correctly Biased Lineups A woman took 30 minutes to select a suspect from this lineup, but later reported she was ?150% sure of her selection Biased Lineups The witness was told the suspect was a ?black male?, but the lineup included only one African-American and four Hispanic suspects Eyewitness Testimony How to improve eyewitness testimony? Ask non-leading questions Interview immediately after crime Don?t use biased lineups Use open-ended lineups Use double-blind procedure for lineups Neither person nor interviewer know if actual suspect is included, or who s/he is Forgetting There are several theories on why we forget Decay theory memories decay over time applies mostly to STM and sensory memory Replacement as in eyewitness testimony, new Cue-dependent forgetting memories still exist, but you lack the cues to activate them in the conceptual network tip of the tongue effect applies to LTM Interference (in LTM) similar items interfere with one another Retroactive Interference Recently learned material interferes with the ability to remember silimar older material. I am currently learning French and now I can?t recall the Spanish I learned in high school. Proactive interference older material interferes with the ability to remember similar, more recently learned material I already know Spanish and I?m finding it hard to remember the French I am currently learning because I keep recalling the Spanish instead Repression ( False Memories) Freud argued that the ego protects itself by keeping traumatic memories out of consciousness Some research to support such a process New research, however, suggests that beta-blocker drugs can be used to reduce the emotional impact of traumatic memories over time Being tested to prevent PTSD, with some success Forgetting Decay Theory Replacement of memories As in eyewitness testimony, new or distorted information replaces accurate information Cue-dependent forgetting Memories still exist, but you lack the cues to activate them in the conceptual network Tip of the tongue effect Interference Similar items interfere with one another Retroactive Interference Recently learned material interferes with the ability to remember similar older material Proactive Interference Older material interferes with the ability to remember similar, more recently learned material Repression Freud argued that the ego protects itself by keeping traumatic memories out of consciousness Some research to support such a process New research, however, suggests that beta-blocker drugs can be used to reduce the emotional impact of traumatic memories over time Being tested to prevent PTSD, with some success Amnesia Two kinds of amnesia Anterograde ? inability to learn new memories more common form Retrograde ? inability to recall old memories less common form Less common form These types of amnesia are due to biological brain damage (usually damage to the hippocampus) 9