4/29/10. Memory. Manufacture of memory. Overview. Manufacture of memory

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1 4/29/ Overview Memory Reconstructing the past The power of suggestion In pursuit of memory The three-box model How we remember Why we forget Autobiographical memories Manufacture of memory Manufacture of memory Memory is the capacity to retain and retrieve information. In ancient times, Philosophers compared memory to a soft wax tablet that would preserve anything that made an imprint on it. After the printing press, people thought of memory as a gigantic printing press. Today, in the audiovisual age, many people compare memory to a movie camera, automatically recording every event of their lives. But this is utterly wrong. Memory is selective. If it wasn t our heads would be cluttered with mental junk such as a phone number needed only once. Moreover, memory is not so much like playing back a tape but more like watching a few unconnected frames and figuring out what the rest may have been. Memory is a reconstructive process. One of the first scientists to make this point was Sir Frederic Bartlett in Bartlett asked people to read long unfamiliar stories from other cultures and then tell them back to him. People made interesting errors. The often changed details that did not make sense to them and added other details that did, sometimes adding a moral. 1

2 4/29/ Manufacture of memory Manufacture of memory In reconstructing their memories people draw from many sources. Take a minute to recall and write abut one of your early family holidays or a birthday. Say, before age 12. You may have some direct recollection but you may also have incorporated information from a family photograph. Was there one of that day? You may also take bits and pieces of other people s stories to build one story. Later, you may not be able to distinguish was was yours from what you got somewhere else. This is called source confusion. Manufacture of memory The fading flashbulb You may also experience confabulation Confabulation is the confusion of an event that happened to someone else with one that happened to you. A belief that you remember something when it never actually happened Confabulation is most likely when... You have thought or heard about the event many many times. Or when the image of the event contains a lot of easy to imagine, vivid details. Suppose you keep hearing the same story at family gatherings about the New Year s Eve party where your uncle Sam scared everyone by pounding a hammer in the wall and the whole wall collapsed. This is pretty colorful and easy to start imagining details. Of course, some unusual, shocking, or tragic events hold a special place in memory. Called flashbulb memories because of their surprise, illumination, and photographic detail. Many of you were just young kids, but take a few minutes to recall the attack on the World Trade Center on Sept 11,

3 4/29/ The fading flashbulb But even Flashbulb memories have errors, particularly after 15 months. Do you have the six canonical categories described by researchers typical across individuals for flashbulb memories? 1. the location (remembering where you heard the news) 2. the ongoing event (remembering what you were doing at the time you heard the news); 3. the informant (remembering who told you about the event) 4. emotional affect in others (noticing the emotional reactions of others) 5. emotional affect in self (noticing the emotional reactions of oneself); 6. and aftermath/consequentiality (remembering what you did after you heard then news). Many people are convinced they saw the first attack on Television as it was occurring. But that is impossible. No film crews knew in advance that is would happen! The eyewitness on trial The eyewitness on trial Because memory is reconstructive it is also vulnerable to Suggestion Factors influencing accuracy 1. Cross racial identification is notoriously bad Without Eyewitnesses many guilty people would go free But Eyewitnesses are not always reliable, indeed there are many tragic case of innocent people convicted 2. Even subtle changes in question wording from (e.g., crashed vs. hit produced higher speeds in a crash description, Line-ups are problematic you may just pick the person who looks MOST like the perpetrator. 3. Did you see THE broken headlight? more people said yes, the word the as opposed to a presupposes there was one!) 3

4 4/29/ Children s testimony Children s testimony If adults are suggestible it is not surprising that children really are 1. Especially when they are very young 2. When interviewers have expectations When asked if a visitor committed acts that had not occurred ( throw a crayon at a child? ) few 4 6 year olds said yes, but some 17%. When investigators used influence techniques taken from real child abuse 3. When told other children s memories (preschool age more susceptible than school age they may have a very strong desire to please) Investigations( telling the kids what other kids said he did, expressing disappointment if the answers were negative) MOST children said yes 80% 3 year olds, 52% 4-6 year olds. How can we measure memory? But what about Implicit memory? An Explicit Memory is conscious, intentional recollection of an event or item of information. Recall: The ability to retrieve and reproduce from memory previously learned material- Like short answer tests Implicit memories are those that affect our thoughts and actions even though we don t intentionally or consciously remember it) Recognition: The ability to identify previously encountered material Like multiple choice tests (can be tricky when wrong answers as similar to the right one as we know :-) but in general this is an easier task) 4

5 4/29/ Priming Priming A person reads or listens to information and is later tested to see whether the information affects performance on another type of task. A person reads or listens to information ( a list of words such as defend, define, deform). Later, even if they don t consciously remember the words those words are used in later tasks. Another example is the Tide study. Prime (moon, waves, earth). Later most subjects picked Tide as their favorite detergent AND gave a reason. ( MY mom uses it, I like the box ) This research has renewed the 1950 s subliminal advertising debate Drink Coke. But current research suggests the effects are small and advertisers would probably do better to be direct. Models of Memory Parallel distributed processing (PDP) Information Processing Models are based on computer metaphor. We encode information We store information We retrieve information Computer models are problematic The grandmother problem Human memory is probably more similar to a PDP in which knowledge is represented as connections among thousands of interacting processing units, distributed in a vast network, and all operating in parallel 5

6 4/29/ But the Three-box Model of memory is still best way to start to consider how this might work. Sensory memory A memory system that momentarily preserves extremely accurate images of sensory information Pattern recognition The identification of a stimulus on the basis of information already contained in long-term memory Information that is not quickly passed to short-term memory is gone forever. Short-term memory The value of chunking A limited capacity memory system involved in the retention of information for brief periods Also used to hold information retrieved from long-term memory for temporary use You have 5 seconds to memorize as much as you can. Working memory A memory system which includes STM and mental processes that control retrieval of information from LT memory and interpret that information appropriately for a given task Then draw an empty chess board and reproduce the arrangement of the pieces. Chunk Meaningful unit of information which may be composed of smaller units 6

7 4/29/ Long-term memory Conceptual grid The memory system involved in the long-term storage of information One way information is organized is in semantic categories (e.g., animals). Types of long-term memories Your turn What kind of memory is your memory for the fact that the earth is round? A. Procedural memory B. Semantic memory C. Episodic memory 7

8 4/29/ Your turn Contents of long-term memory What kind of memory is your memory for the fact that the earth is round? A. Procedural memory B. Semantic memory C. Episodic memory Procedural memories Memories for performance of actions/skills/ procedures Knowing how - (ex. to ride a bike) Declarative memories Memories of facts, rules, concepts, and life events; includes semantic and episodic memory Knowing that (ex. The earth is round, or what happened last weekend) Contents of long-term memory Serial-position effect Semantic memories General knowledge, including facts, rules, concepts, and propositions Episodic memories Personally experienced events and the contexts in which they occurred The tendency for recall of first and last items on a list to surpass recall of items in the middle of the list 8

9 4/29/ Your turn Your turn You are asked to recall the following list of letters: Z, S, E, R, F, V, B, H, U, I, K, M, N, G, B, F, O Which letters are you most likely to remember in long-term memory? A. Z, S, E, R B. U, I, K, M C. G, B, F, O You are asked to recall the following list of letters: Z, S, E, R, F, V, B, H, U, I, K, M, N, G, B, F, O Which letters are you most likely to remember in long-term memory? A. Z, S, E, R B. U, I, K, M C. G, B, F, O The biology of memory Brain areas involved in memory Forming a memory involves chemical and structural changes at the level of neurons. In short-term memory, changes within neurons temporarily alter the neurons ability to release neurotransmitters. In long-term memory, long-term potentiation, a long-lasting increase in the strength of synaptic responsiveness, occurs. Most researchers believe this is the process underlying learning and memory, yet exact biochemical changes are still debated. 9

10 4/29/ Consolidation Locating memories The process by which a long-term memory becomes durable and stable New brain imaging and testing shows that: During short-term memory tasks, areas of the frontal lobes show activity. During long-term memory tasks, the hippocampus shows activity. During encoding of pictures and words, the prefrontal cortex and areas adjacent to the hippocampus show activity. Procedural memories involve specific changes to the cerebellum. The formation of long-term memories involves the cerebral cortex. Hormones and memory Rehearsal Hormones released by the adrenal glands enhance memory. One of these, epinephrine, may modulate the level of glucose in the bloodstream. Memory formation may also be affected by the amount of glucose available in the brain. Maintenance rehearsal: rote repetition of material in order to maintain its availability in memory Elaborative rehearsal: association of new information with already stored knowledge and analysis of the new information to make it memorable

11 4/29/ Deep processing Mnemonics In the encoding of information, the processing of meaning rather than simply the physical or sensory features of a stimulus Strategies and tricks for improving memory, such as use of a verse or a formula MDAS ROYGBIV Thirty days hath September... Decay theory Forgetting curve The theory that information in memory eventually disappears if it is not accessed, use it or lose it. Applies more to short-term memory than to long-term memory Herman Ebbinghaus tested his own memory for nonsense syllables. Forgetting was rapid at first and then tapered off. 11

12 4/29/ Linton s forgetting curve Replacement In contrast to Ebbinghaus, Linton s memory for personal events was retained over a period of several years and then decreased rapidly. The theory that new information entering memory can wipe out old information In one study, researchers showed subjects slides of a traffic accident. The experimental group was misled into thinking there was a stop sign instead of a yield sign. Even after being debriefed on the purpose of the study, subjects insisted that they really saw the stop sign. The new information which came from the researchers replaced what the subjects saw. Interference Cue-dependent forgetting Similar items interfere with one another. Retroactive interference: forgetting that occurs when recently learned material interferes with the ability to remember similar material stored previously Proactive interference: forgetting that occurs when previously stored material interferes with the ability to remember similar, more recently learned material The inability to retrieve information stored in memory because of insufficient cues for recall Physical state can be a memory cue State-dependent memory: the tendency to remember something when the rememberer is in the same physical or mental state as during the original learning 12

13 4/29/ Mood-congruent memory Amnesia The partial or complete loss of memory The tendency to remember experiences that are consistent with one s current mood and overlook or forget experiences that are not. Retrograde: Can t remember the past Anterograde: Can t remember what s next In other words, ability to form new memories is impaired. The Movie-Memento Amnesia Causes The repression controversy Psychogenic amnesia: the causes of forgetting are psychological, such as the need to escape feelings of embarrassment, guilt, shame, disappointment Traumatic amnesia: the forgetting of specific traumatic events, sometimes for many years. This is more controversial Repression: in psychoanalytic theory, the selective, involuntary pushing or threatening of upsetting information into the unconscious Individuals are more likely to struggle with forgetting traumatic events. It is hard to distinguish repression from other forms of forgetting. EC * Read Lawrence Wright s Remembering Satan 13

14 4/29/ When should we question recovered memories? Childhood amnesia If a person claims memories of first year or two of life If over time the memories become more and more implausible If the therapist used suggestive techniques such as hypnosis, dream analysis, age regression, guided imagery, or leading questions The inability to remember events and experiences that occurred during the first two or three years of life Cognitive explanations: Lack of sense of self Impoverished encoding A focus on the routine Different ways of thinking about the world Memory and Narrative- The stories of our lives Human beings tell stories and live by the stories we tell the storytelling animal. Not exactly fiction, as in a child s Tell me a story! but used to organize and give meaning to our lives. We say I am this way because, as a small child this happened and then my parents Or let me tell you the story of how we met and fell and love Our stories rely heavily on memory.but memory is constantly reconstructed in response to current needs, beliefs etc. Our stories and memories are, to some degree, works of interpretation and imagination. And they reveal as much about our present as they do about our past. 14