Schacter Chapter 6 Memory PDF

Memory Chapter 6 1 2  Overview Information Processing Models Theoretical explanations for how memory works Encoding: getting information in Storage: retaining information Short term and long term memories Retrieval: accessing and using information Forgetting and m...

Memory Chapter 6 1 2  Overview Information Processing Models Theoretical explanations for how memory works Encoding: getting information in Storage: retaining information Short term and long term memories Retrieval: accessing and using information Forgetting and memory errors 3  Memory Memory provides more than an ability to consciously recall facts (e.g., what is my name, Ottawa is the capitol of Canada, etc.). All learning requires some form of memory. Classical and Operant conditioning rely on memory. So does learning to walk or talk. 4  Memory A Cognitive Psychology Definition: Mental systems, implemented by neural circuits, that store and retrieve information. Memory is not a unitary system. There are several different memory systems that serve different functions. 5  Information There are many technical definitions of information (e.g., information is any type of pattern that influences the formation or transformation of other patterns). You do not need to know them. Although information cannot be touched or seen, it does exist. However, it can have observable effects. Like Behaviourists, Cognitive psychologist use objective measures. Unlike, behaviourists they use those measures to make inferences about internal process (such as the storage of information A.K.A. memory). 6  Information Processing Encoding: the information is transformed into Encoding a form that allows it to be stored Storage: the information is maintain in the brain in a way that allows it to later be Storage retrieved Retrieval: the information is reactivated allowing into to be used or consciously Retrieval recalled in a form similar to what was encoded 7  Information Processing Models: Box & Arrow Diagrams Information processing models are functional models that provide explanations in terms of theoretical processes. They don't specify how these processes are implemented in the brain. Boxes: functional units that process &/or store information Arrows: connections between units that transfer information 8  Encoding Memory is not a passive recording system. The brain continuously processes all available information (sensory information, thoughts, feelings). How the information is processed (encoded) is one of the most important factors determining whether or not something will be remembered later. 9  Rehearsal Rehearsal (conscious repetition) is the simplest and least effective strategy for the effortful encoding of information. Ebbinghaus studied rehearsal by using nonsense syllables: TUV YOF GEK XOZ He used this type of meaningless information in order to ensure that Hermann Ebbinghaus encoding would not be automatic or influenced by his existing knowledge. 10  Rehearsal Ebbinghaus repeatedly rehearsed a list and then tested his recall (ability to reproduce the list from memory). The more he rehearsed the list the better his recall performance. When he tested himself the next day, recall was poor. Simple rehearsal leads to rapid forgetting. 11  Rehearsal and Distributed Practice The spacing effect was first noted by Hermann Ebbinghaus. You will develop better retention and recall, especially in the long run, if you use the same amount of study time spread out over many shorter sessions. Rehearsing 10 times and then 10 times a day later is better than rehearsing 20 times in row. 12  Effortful Processing Committing abstract & novel information to memory requires effort. How you process information during recall is even more important than how often you rehearse it. You remember new information better if you can understand it and relate it to what you already know. Such processing leads to durable and accessible memories. 13 Encoding 14  Deep vs. Shallow Processing Deep processing is encoding information by focusing on its meaning. Shallow processing focuses on physical features or simple (and often irrelevant) associations. Semantic Encoding (deep processing) involves understanding material and relating it to information already in memory. This type of processing usually leads to much greater retention (especially after long delays). 15  Levels of Processing Is the word in capitol letter? CHAIR Does the word rhyme with train? Brain Does the word fit in the sentence: gun “The girl put the ____ on the table?” 16  Making Information Personally Meaningful The self-reference effect, relating material to ourselves, aids encoding and retention. If you can make information personally meaningful you will find it easier to remember. 17  Mnemonics (nih-MON-iks) A mnemonic is any learning technique that aids memory. Many mnemonic techniques use vivid imagery and organizational techniques to improve both the encoding and retrieval of information. 18 Organizing Information for Encoding Information is easier to remember if it is organized. Organizing information into larger units (chunking) and organizing information into categories and subcategories (hierarchies) are effective encoding strategies. 19  Chunking Why are credit card numbers broken into groups of four digits? Four groups are easier to encode (memorize) and recall than 16 individual digits. Grouping works even better if we can assemble information into “chunks.” A chunk is a unit of meaningful information. By using knowledge from our long term memory we organize information into chunks to make it easier to store and retrieve. 20  Chunking Acronyms are a way of chunking information. HOMES: Huron, Ontario, Michigan, Erie, Superior ROY G.BIV: Red, Orange, Yellow, Green, Blue, Indigo, Violet Each letter of the acronym reminds us of the word we are trying to remember. 21  Hierarchy Grouping information into categories aids encoding. Complex information can be organized into hierarchies of categories and subcategories. 22  Storage Evidence indicates that memory is not a single system. There are memory stores. The different stores hold different types of information and are used for different cognitive purposes 23  Modal Model of Memory (Atkinson & Shiffrin, 1968) An early and influential model of memory that theorized that were 3 different types of memory stores: This model was very effective in explaining the data available at the time. Many concepts in this model continue to be used in modern models. 24  Modal Model: Sensory Memory A vast amount of information flows from our sense organs into our brains. This information enters sensory memory but we are not aware of it If we attend to information in sensory memory it is transferred to STM Encoding Sensory Short-term Long-term Events Encoding Memory Memory Memory Retrieval Consciousness 25 Remember these letters: R G T F M Q L Z S  Sperling (1960): Whole Report When asked to immediately recall as many letters as possible participants could recall 4.5 out of 12 letters (37.5%) on average R, F, T,.....???? Remember these letters: S E T L B P M A R  Sperling (1960): Partial Report Participants heard tone that told them which row of letters to report: Recalled 3.3 out of 4 letters (82.5%) on average Could report any of the rows M, A, R !!  Sperling (1960): Delayed Partial Report Presentation of tone was delayed for a fraction of a second after the letters were extinguished: Performance decreases rapidly with increasing delay intervals Results from Sperling (1960).  Sperling (1960) Results from immediate partial report indicates that visual sensory memory (iconic memory) has a large capacity Could report any row Results from whole report and delayed partial report indicates that iconic memory decays rapidly (< 1 second)  Sensory Memory Taken together, these results indicate that there are large capacity sensory memory stores. These memory stores, only maintain incoming information for a brief period of time. To become consciously aware of the information it must be encoded into working memory before the representations decay and are lost. The transfer of information is limited by the speed of attention  Modal Model: STM Short-term memory (STM) is the information store that is available to consciousness. The information may be incoming sensory (e.g. auditory or visual) or information retrieved from long-term memory. It has a limited capacity and short duration. Encoding Sensory Short-term Long-term Events Encoding Memory Memory Memory Retrieval Consciousness 34  Capacity of STM Most people can hold in their 28 STM about: 691 0473 7 digits 87454 7 letters 902481 7 words 5742296 64719304 But there is more information in 356718485 7 words than 7 letters or digits. 1028834729 47208274264 731093435138 35  Capacity of STM “The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information” (Miller, 1956). George Miller proposed that we can hold between 5 and 9 chunks information (for example, a string of 5 to 9 letters). George Miller 36  Chunking A list of 12 digits exceeds the capacity of most people's STM: 1-8-6-7-1-8-1-2-1-9-8-2 If you remember any Canadian history, you can chunk the numbers together in a meaningful way you can fit the information in STM: 1867 1812 1982. British North America Act, War of 1812, Constitution 37  Duration of STM How long does information in STM last? That depends on how the information is being processed. Information that is being used can be maintained for as long as it is needed. Information can also be refreshed in STM by use of maintenance rehearsal: mentally repeating the information in STM. 38  Duration of STM Peterson and Peterson (1959) measured the duration of working memory by preventing rehearsal. CHJ 547 MKT 544 HIJ CH?? 541 547 … 39  Duration of STM Without rehearsal, the duration of the working memory is about 20 sec. 40  Beyond the Modal Model In more modern theories the short-term memory has been re-conceptualized as Working Memory: a memory store utilized by conscious, active processing of information. This store does not merely hold information, it is used to process information to solve problems (e.g., doing a math problem or ordering at a fast food restaurant). 41 Working Memory 42  Modal Model: LTM Long-term memory (LTM) has no known limits to its capacity to store information. People can recall items from long-term memory even if they haven’t thought of them for years. Fifty years after graduation, people can accurately recognize about 90% of their high school classmates from yearbook photographs. Encoding Sensory Short-term Long-term Events Encoding Memory Memory Memory Retrieval Consciousness 43 Memory Feats 44 Forms of Long-Term Memory 45  Forms of Long-Term Memory Implicit/non-declarative: unconscious memory Knowledge that cannot be explicitly stated May not even be aware that learning has occurred Implicit learning can be detect by changes in performance Explicit/declarative: conscious memory Conscious recollection of events experienced and facts learned Can explicitly state (declare) what you know  Procedural Learning Procedural Memory: Skill memory, memory for doing things e.g., riding a bike No memory of where or when learned Perform procedures without being consciously aware of how to do them People who cannot form new LTMs can still learn new skills  Priming Priming: A change in response to a stimulus due to a prior presentation of the stimulus or a related stimulus Having encountered a stimulus before makes it easier for your brain to process it Responses are typically faster and more accurate Remembering the initial presentation of the stimulus is not required for priming to occur  Priming Not Primed Primed Primed stimuli are processed more efficiently by the brain. Priming is associated with reduced activity in various regions of the cortex that are activated when performing unprimed tasks. Priming saves processing time for the brain. 49  Two Types of Explicit Memory Episodic: Memory for personal events Memory that allows you to access specific events located at a particular point in time “Mental time travel” to relive earlier episodes Conscious recollection or “remembering”  Two Types of Explicit Memory Semantic: Memory for general knowledge and facts lacking reference to the episodic context in which it was learned Examples: World knowledge (Ottawa is the capitol of Canada) Vocabulary Rules, formulae, and algorithms “I know...”  Amnesia Retrograde amnesia: An impaired ability to remember information acquired before the onset of amnesia Cannot recall old memories Anterograde amnesia: An impaired ability to remember information acquired after the onset of amnesia Cannot form new memories 52  Anterograde Amnesia After losing his hippocampus in surgery, patient Henry Gustav Molaison (HM) (February 26, 1926 – December 2, 2008) remembered everything before the operation but suffered from anterograde amnesia. He could not make new explicit memories. Memory Intact No New Memories Surgery 53 Video: Amnesia (7m:38s) 54  Hippocampus Hippocampus – a neural centre in the limbic system that plays an important role in the formation of long term explicit episodic memories. The hippocampus is thought to act as an index that provides links to the various components that make up a memory. This is more important for the recall of new memories rather than old ones. 55  Episodic Memory Episodic memory relies on a network of brain areas (you don't need to memorize them all). These same areas are used when we imagine the future. Our past acts as a guide to out future. 56 Mirror Drawing: A difficult procedural tasks that improves with practice. Amnesiacs, such as H.M., improve at this task in much the same way that non-amnesiacs do. This improvement occurs despite the fact that amnesiacs cannot remember performing the task before.  Implicit Memory Processing The cerebellum plays an important role in forming and storing conditioned responses. The basal ganglia, next to the thalamus, helps control movement, and forms and stores procedural memory and motor skills. 58  Forming New Memories Initially new memories are fragile and are likely to be forgotten The fragility of new memories is also apparent in some cases of retrograde amnesia Newer memories are more likely to be forgotten (graded amnesia) Strong Better Memory Amnesia: Retention Poor Memory PAST Future Injury  Consolidation Consolidation: The time-dependent process by which new memory traces are gradually cemented and interconnected in memory Requires a variety of changes in the brain Memories become less reliant on the hippocampus as consolidation progresses Takes months or even years to complete  Consolidation Sleep has been shown to improve memory consolidation. This effect is largest for important information and for information that requires interpretation and understanding. 61 Information Storage at the Synapse Information is encoded in the brain by a pattern of structural changes across many synapses that cause groups of neurons to change their pattern of neural activity One type of synaptic change is called Long-term potentiation (LTP): Enhanced firing of neurons after repeated stimulation Structural changes at the synapse strengthens the connection and enhance responding of the neuron  Retrieval Information in long-term memory cannot be used until the information is retrieved back into working memory The likelihood of retrieval is dependent on the available retrieval cues: external information that is associated with the to be retrieved information in LTM  Retrieval Cues Memories in LTM are connected by a web of associations. Activity spreads along connections and accessing one memory aids in the retrieval of related information (memories cue each other). The more retrieval cues you have to a piece of information the more likely that you will be able to retrieve it. smell water hose Fire Truck fire smoke truck heat red 64  Encoding Specificity Encoding Specificity: Basic principle: information encoded into memory is associated with any other information available at the same time. This information can be external or internal. Effect: retrieval cues are more effective if they help re- create the encoding situation. First demonstrated in Godden & Baddaley's (1975) famous “Diving Experiment” Godden & Baddaley's (1975)  State-Dependent Memories Memories are also linked to our internal context (state-dependent memory) and are easier to recall when in the same state as the encoding state (state-dependent retrieval). “I wonder if you’d mind giving me directions. I’ve never been sober in this part of town before.” 67  Retrieval: Memory Improvements Retrieval can improve memory retention over long time spans (testing effect). 68  Seven Sins of Memory Transience Absentmindedness Blocking Memory Misattribution Suggestibility Bias Persistence 69  Transience Transience: Forgetting what occurs with the passage of time Memory fades quickly at first, then slowly over time. Memories become less detailed with time 70  Transience If memories encoded into LTM are rarely used they will become less accessible with time (decay). The more elaborately encoded a memory is the slower the decay process. Retroactive interference: Situations in which information learned later impairs memory for information acquired earlier Proactive interference: Situations in which information learned earlier impairs memory for information acquired later 71  Interference The more similar pieces of information are the more likely they will interfere with each other. 72  Absentmindedness Absentmindedness: Lapse in attention that results in memory failure Remember the Amazing Colour Changing Card Trick? Effortful encoding builds strong memories Intention to remember does nothing without effort 73  Blocking Blocking: Failure to retrieve information that is available in memory even though you are trying to produce it. Much “forgetting” is actually a failure to retrieve. Retrieval cues don't always work. Tip-of-the-tongue effect: being aware that you have encounter the information despite being unable to retrieve it. Often know some aspect of memory (e.g., know a word starts with a 'B'). Additional cues often allow retrieval. 74  Memory Misattribution Source memory: Recall of when, where, and how information was acquired Memory misattribution: Assigning a recollection or an idea to the wrong source 75  Suggestibility Suggestibility: Tendency to incorporate misleading information from external sources into personal recollections 76  Misinformation Effect Elizabeth Loftus and John Palmer asked people to watch a video of a minor car accident. Depiction of the actual accident. 77  Misinformation The participants were asked to estimate how fast the cars were traveling before the accident. Group A: How fast were the cars going when they hit each other? Group B: How fast were the cars going when they smashed into each other? Not surprisingly, Group B estimated higher speeds. 78  Memory Construction A week later they were asked: Was there any broken glass? Group 2 (smashed into) were more likely to report remembering broken glass than Group 1 (hit). There was no broken glass! 50 40 32 30 lass?(%) 20 BrokenG 14 10 0 1 2 Verb 79  Video: True or False (7m:06s) False Memories (4m:51s) 80  Memories of Abuse Some psychotherapists and many lay people believe that early childhood sexual abuse results in repressed memories that can be recovered through therapy. Are newly “recovered” memories of abuse repressed or constructed? Memory research indicates that these memories may be constructed. 81  Constructed Childhood Memories Abundant evidence exists that suggestion can lead to the creation of false childhood memories ('balloon ride' and 'lost in the mall' studies). Similar effects could lead to sudden 'recovery' of memories of childhood abuse. 82 Are Traumatic Memories Repressed and Recovered? Forgotten memories of minor events do reappear spontaneously when appropriate cues are present Actively searching for memories, however, is more likely to create detailed memories that feel real Because of the infantile amnesia, memories of events before age 3 are almost certainly to be constructions Memories retrieved under hypnosis or drugs are unreliable 83  Are Traumatic Memories Repressed and Recovered? We cannot prove that it is impossible for a memory to be repressed and latter recovered. But, We know that traumatic events usually form very durable and vivid memories (see persistence). Even if we want to forget them. We know that false memories can be created and the techniques used to “recover” memories are known to promote the formation of false memories. 84  Bias Bias: Distorting influences of present knowledge, beliefs, and feelings on recollection of previous experiences Consistency bias: Tendency to reconstruct the past to fit the present Change bias: Tendency to exaggerate differences between what we feel or believe now and what we felt or believed in the past 85  Persistence Persistence: Intrusive recollection of events that we wish we could forget Often occurs after disturbing or traumatic events Emotional experiences better remembered than unemotional ones 86  Emotions and Memory Strong emotions, especially stress, can strengthen memory formation. Flashbulb memories are exceptionally clear memories of emotionally significant moments or events. However, these memories are susceptible to the same errors as regular memories. 87  Video: Remembering what matters (8m:35s) 88 Emotions, the Amygdala, and Memory Emotions can trigger a rise in stress hormones that trigger activity in the amygdala, located next to the memory-forming hippocampus The amygdala increases memory-forming activity The memories are stored with more sensory & emotional details These details can trigger a rapid, unintended recall of the memory. 89  Adaptiveness of Memory Memory, as all of cognition, has been shaped by evolution to allow us to survive by utilizing our limited mental resources efficiently It attempts to retain and provide the information that we are likely to need It does not attempt to provide a complete and accurate recording of our lives 90