Lecture 7.pdf

PSYC 5140 Cognitive Psychology Lecture 7: Long-Term Memory: Encoding, Retrieval, and Consolidation Fall 2023 Instructor: Urs Maurer Getting Information Into LTM • Encoding: the process of acquiring information and transforming it into LTM • Retrieval: transferring information from LTM to working memory • Consolidation/reconsolidation: “transforming…memories from a fragile state…to a more permanent state” • Ways of getting info into LTM: – Maintenance rehearsal 1st way to access LTM: STM rehearsal, repeat information to encode • Repeating information without consideration of meaning or connection to other information • Poor transfer to LTM – Elaborative rehearsal Use the meaning of what we already know • Using meanings and connections to help transfer information to LTM • Results in better memory than maintenance rehearsal LTM : Decorative and semantic coding. STM : visual and audio coding. 1st thoery Levels of Processing Theory • Levels of processing theory (Craik & Lockhard, 1972): Memory depends on how information is encoded – Encoding can influence the ability to retrieve memories How encoding process information at a more shallow level we pay attention to literal information of meaning : poor memory we pay attention to the meaning: better memory • Depth of processing – Shallow processing • little attention to meaning • focus on physical features • poor memory – Deep processing • close attention to meaning • better memory Levels of Processing Theory Craik & Tulving (1975): presented words to subjects and asked: 1. A question about the physical Shallow features of the word 7 • “bird” => is it printed in capital letters? 2. A question about rhyming • “train” => does it rhyme with “pain”S 3. A fill-in-the-blanks question • “car” => “He saw a ---- on the Deep street” •Then they were given a memory test to see how well subjects recalled the words They hear and process information about their meaning - remember 80% of the word pay attention to physical features: poor memory : remember fewer words How do we know deeper processing is? how do we remember words better? Beware of Circular Reasoning! • Problem with levels of processing theory • Which task causes deeper processing? – Using a word in a sentence – Deciding how useful an object might be on a desert island • Because memory is better? • Depth of processing has not been defined independently of memory performance – Therefore, this is circular reasoning • Current memory research – Levels of processing rarely used – But idea that retrieval is affected by how information is encoded is still accepted Diﬀerent factor encode influence remembering information Other Factors that Aid Encoding • 1 Visual imagery: “images” in the head – Can connect words visually – These connections can enhance memory • Used paired-associate learning – First, list of word pairs presented – Then, the first word of each pair is presented Remember the words only • Group A was asked to repeated the pairs • Group B was asked to form a mental picture of the two items interacting visual image help better memory • Group B remembered twice as much as group A (Bower & Winzenz, 1970) Other Factors that Aid Encoding • Self-reference effect: memory is better if asked to link words to yourself relate to self =the most Semantic task = more • “Printed in small case?” • “Rhymes with happy?” • “Means the same as happy?” • “Describes you?” • Words become linked to something subject knows well (him/herself) • Richer, more detailed representations result in better memory Rogers et al. (1977), similar procedure as Craik & Tulving Other Factors that Aid Encoding Actively • Generation effect: generating material yourself, rather than passively receiving it, enhances learning 1st group • Read group: read these pairs of related words. King-crown; horse-saddle; lampshade 2nd group • Generate group: fill in the blank with a word that is related to the first word. If the ppt are generating word themselves has King-cr…; horse-sa…; lamp-sh… better memory than reading the words. (Slameka & Graf, 1978) Demonstration • Get paper and pen ready • Read the following words • Write them down, AFTER I cover them apple desk shoe sofa plum chair cherry coat lamp pants grape hat melon table gloves Demonstration • Now write down the words you remember • Order does not matter Demonstration • Jenkins & Russell (1952): Retrieving memory when information and words are in the same group e.g. apple, melon • Similar items are grouped together • Subjects spontaneously organize items as they recall them One word is a retrieval cue of another word • Remembering words in a particular category may serve as a retrieval cue – Retrieval cue: a word or other stimulus that helps a person remember information Organization, Comprehension, and Memory • Presented minerals (or other items like animals, clothing, transportation) in a form of tree in 2 groups – One group: tree was based on meaning (e.g., metals, stones) – Other group: tree had arranged items randomly • Results (Bower et al., 1969) – Organized group: remembered 73 words SubCategory – Random group: remembered 21 words • Conclusion – Organizing material to be remembered leads to better recall Organization, Comprehension, and Memory • Bransford & Johnson (1972): if organization helps memory, preventing it should reduce the ability to remember • Presented participants with difficult-to-comprehend information – Experimental Group 1 first saw a picture that helped explain the information – Experimental Group 2 saw the picture after reading the passage – Control Group did not see the picture • Group 1 outperformed the others. – Having a mental framework of comprehension aided memory encoding and retrieval Group 1 memorise better, recall information better when they have seen the picture at the time of encoding information Organization, Comprehension, and Memory If the balloons popped, the sound wouldn’t be able to carry since everything would be too far away from the correct floor. A closed window would also prevent the sound from carrying, since most buildings tend to be well insulated. Since the whole operation depends on a steady flow of electricity, a break in the middle of the wire would also cause problems. Of course, the fellow could shout, but the human voice is not loud enough to carry that far. An additional problem is that a string could break on the instrument. Then there could be no accompaniment to the message. It is clear that the best situation would involve less distance. Then there would be fewer potential problems. With face to face contact, the least number of things could go wrong. (p. 719) Organization, Comprehension, and Memory See the picture first then read the text = make more sense of what the paragraph is about Organization, Comprehension, and Memory If the balloons popped, the sound wouldn’t be able to carry since everything would be too far away from the correct floor. A closed window would also prevent the sound from carrying, since most buildings tend to be well insulated. Since the whole operation depends on a steady flow of electricity, a break in the middle of the wire would also cause problems. Of course, the fellow could shout, but the human voice is not loud enough to carry that far. An additional problem is that a string could break on the instrument. Then there could be no accompaniment to the message. It is clear that the best situation would involve less distance. Then there would be fewer potential problems. With face to face contact, the least number of things could go wrong. (p. 719) Other factors that aid encoding Some information stand out because it is rare Wertheimer Köhler Von Restorff Koffka The von Restorff Effect, or “Isolation” Effect – an encoding advantage for distinctive stimuli (e.g., a female researcher in 1930’s Germany). You remember the woman because it is only one woman = Isolation eﬀect Other factors that aid encoding • Relating words to survival value • 2 word learning groups 1) “survival” group (Nairne et al., 2007,2008) – Imagine that you are stranded in the grasslands of a foreign land without any basic survival materials. – Rate each word on a scale from 1 to 5 how relevant it is for finding steady supplies of food and water and protection from predators 2) “vowel counting” group – Count number of vowels in each word Think about the meaning of words help better memory • Results – Linking words to survival created better memories than counting vowels, but also better than elaborative task (visual images, linking words to oneself) • Conclusion – Whether this is related to evolution is debated – But again shows that linking words to something meaningful and potentially important enhances memory Organization, Comprehension, and Memory Retrieval practice effect (Karpicke & Roediger, 2008) v Practising retrieval Practising retrieval - Participants studied Swahili-English word pairs (e.g., mashua-boat) First study phase and test: some pairs were known, some not Groups were treated differently in Repeat study phase and subsequent test Results: Groups 1 and 2 had similar recall after 1 week, Group 3 weaker recall Conclusion: Recall depended on test and not study phase Retrieval Practice Group 1 reading group & 2 reading test retesting is better than rereading = for remembering the materials • Which results in a stronger memory trace? – Re-reading the material – Being tested on the material • Roediger and Karpicke (2006) had participants read a passage and then either – Reread the passage (rereading group) – Take a recall test (testing group) • Then tested recall after a delay; testing group performed better • Testing Effect Retrieval Practice • Which results in a stronger memory trace? • – Re-reading the material Methods richness of representations in memory – Being testedthat on increase the material by providing connections Roediger and Karpicke (2006)between had the material to be remembered and other material in memory aid encoding participants read a passage and then either – Reread the passage (rereading group) – Take a recall test (testing group) • Then tested recall after a delay; testing group performed better • Testing Effect Retrieving Information from LTM • Before material that has been encoded can be used, it must be retrieved – Similar to how a computer works! • Retrieval: process of transferring information from LTM back into working memory (consciousness) Bring it back to working memory – Most of our failures of memory are failures to retrieve – e.g. remembering the answer to test questions, after the exam ☺ retrieve something = forget in exam • Retrieval cues: stimuli that help us remember information stored in our memory – e.g. returning to a particular place stimulates memories associated with that place – e.g., leaving home thinking that you forgot something – go back and often remember (location as retrieval cue) Retrieving Information from LTM • Two types of recall procedures: – Free recall: subjects are simply asked to recall stimuli – Cued-recall: cue presented to aid recall of the previously experienced stimuli • Increased performance over free-recall = Retrieval cue • Tulving & Pearlstone (1966) • Subjects should remember a list of words – Birds (pigeon, sparrow), furniture (chair, dresser), professions (engineer, lawyer) • Categories not indicated in original lists • Two groups in recall – Free recall: write down as many words as possible – Cued recall: asked to recall and provided with names of categories (birds, furniture, professions) • Results: – Free recall group remembered 40% – Cued recall group remembered 75% They have the category name as a cue word Retrieving Information from LTM The cue: most eﬀective to the person who created them Mantyla (1986): Retrieval cues most effective when created by the person who uses them 1. Presented a list of 504 nouns to subjects • Banana, freedom, tree 2. S were asked to write 3 words they associated with each noun • Banana: yellow, bunches, edible •Test phase: 1. S for half the nouns got the 3 words they had generated, for the other half they got 3 words another S had generated 2. A control group: never saw nouns Matching conditions of encoding and retrieval • Retrieval can be increased by matching the conditions at retrieval to the conditions that existed at encoding • Three different ways to achieve matching: context = encoding = retrieval 1 – Encoding specificity: matching the context in which encoding and retrieval occur 2 – State-dependent learning: matching the internal mood present during encoding and Internal retrieval – Transfer-appropriate processing: matching the task involved in encoding and retrieval related the task itself the condition location match with the condition when retrieving Matching the context 1 Encoding Specificity When you learn something under the water, you remember better when you are also under the water. • Encoding specificity states that we encode information along with its context • “Diving experiment” (learn words): – Two learning conditions: • • Underwater On land – Two testing conditions: • • Underwater On land (Godden & Baddeley, 1975) Encoding Specificity another version of experiment: • Encoding specificity states that we encode information along with its context • Noisy/quiet learning experiment: – Two learning conditions: • • Wearing headphones (cafeteria noise) Quiet – Two testing conditions: • • Wearing headphones (cafeteria noise) Quiet – Best recall: when the test condition matched the study condition retrieving time and encoding time are matched Sad / happy mood when testing 2 State Dependent Learning • Learning is associated with a particular internal state – Such as mood or state of awareness • Memory will be better when a person’s internal state during retrieval matches his/her internal state during recall • Happy/Sad learning experiment: – Two learning conditions: • • • Thinking positive thoughts and listening to “merry” music Thinking negative thoughts and listening to “melancholic” music Subjects started the learning task when they reached “very pleasant” or “very unpleasant” mood – Two testing conditions: • • • Thinking positive thoughts and listening to “merry” music Thinking negative thoughts and listening to “melancholic” music Subjects started the test when they reached “very pleasant” or “very unpleasant” mood same mood in testing and learning perform better. diﬀerent mood in testing and learning Internal state is the same or diﬀerent 3 Focus on the meaningful task Matching the Cognitive Task • Transfer-appropriate processing: phenomenon whereby the results of a memory task will be better if the type of processing used during encoding is the same as the type during retrieval • Morris et al. (1977) Two encoding conditions 1. Meaning: answered based on the meaning of the word • The blank has a silver engine • Target word: train Correct answer: Yes 2. Rhyming: answered based on the sound of the word • Blank rhymes with car • Target word: building Correct answer: No • ➔ subjects were asked to process words differently Subjects were then presented with a series of test words. Some words rhymed with target words presented during encoding, some did not Learning the word through rhyming task = Focus on the rhyming in test = perform better Transfer-appropriate processing • Levels of processing theory would predict that the meaning group should have gotten higher recall – Thinking about meaning of words results in deeper relations compared to listening to how words sound • Instead, the rhyming group performed better • Morris’ experiment shows that deeper processing at encoding does not always result in better retrieval Spacing Effect in Learning • Spacing effect in learning distribute time on a several day a week instead of revising two days before the exam – Distributed practice increases memory performance • Possible explanation: – More variable retrieval cues (Barick et al., cit. by Cepeda et al., 2008) Learning 1 situation = Cues are more valuable = help retrieval Consolidation • New memories are fragile and can be disrupted • Müller and Pilzecker (1900): • Two groups of S • Both learned lists of nonsense syllables • Immediate group: • Learned one list • Immediately learned a second list • Delay group: • Learned one list • Waited 6mins • Learned the second list Delay group learnt better with a delay time Immediately presenting the second list interrupted the forming of a stable memory for the first list Learning the 2nd list interrupted the 1st list Consolidation • Consolidation: the process that transforms new memories from a fragile state to more permanent state • Recall: Synapses are small spaces between the end of one neuron and the cell body or dendrite of another neuron – When signals reach the end of a neuron, they cause neurotransmitters to be released on to the next neuron • Two types of consolidation: • Synaptic consolidation occurs at synapses, happens rapidly • Systems consolidation involves gradual reorganization of circuits in brain • Happen together, at different speeds, at different levels Information Storage at the Synapse • Hebb (1948) – Learning and memory represented in the brain by physiological changes at the synapse – Repeated activity can strengthen the synapse by causing: • Structural changes • Greater transmitter release ↑ • Increased firing ↑ – Neural record of experience • because it happens in hundreds of thousands of synapses after an experience Information Storage at the Synapse • Long-term potentiation (LTP) Repeated stimulation make synapse response more – Enhanced firing of neurons after repeated stimulation – Structural changes and enhanced responding • Neural records of an experience: Changes that occur in the hundreds or thousands of synapses that are activated around the same time by a particular experience – Specific experience is represented by the pattern of firing across thousands of neurons Consolidation The case of HM highlighted the importance of the hippocampus in forming new memories But how? • Standard model of consolidation 1a. Incoming info activates number of areas in the cortex • Experience involves many sensory and cognitive areas 1b. Cortex communicates with the hippocampus 1c. Hippocampus coordinates communication between different regions in the cortex memory experience - hippocampus replace the activiation when we had the experiences = recent memory Consolidation The case of HM highlighted the importance of the hippocampus in forming new memories But how? • Standard model of consolidation 2. Reactivation: hippocampus replays neural activity associated with memory • Activity occurs in the network connecting the hippocampus and the cortex Hippocampus is like a glue for recent memory and overtime the involvement of hippocampus become weaker = remote memory = brain area directly connect = hippocampus not involve Consolidation The case of HM highlighted the importance of the hippocampus in forming new memories But how? Standard model of consolidation 3. This activity helps form direct connections between the various cortical areas Hippocampus acts like a “glue” binding together the representations of memory from different cortical areas Retrieval depends on hippocampus during consolidation; after consolidation hippocampus is no longer needed The Fragility of New Memories Someone has amnesia trauma to the head does not remember memory before the trauma • Retrograde amnesia: loss of memory for events prior to the trauma – Can extend back minutes, hours, or even years • Graded amnesia: memory for recent events is more fragile than for remote events immediate /Recent memory is aﬀected more because recent memory is not consolidated – According to the standard model: this gradual decrease corresponds to the changes in the connections between the hippocampus and the cortical areas • Standard model: Hippocampus is strongly active when memories are first formed • Stage 1 • Becomes less involved as memories are consolidated (2, 3) • For remote memories: the connection between the cortical areas themselves are sufficient for retrieval Consolidation • Multiple trace hypothesis – Questions the assumption that the hippocampus is important only at the beginning of consolidation – The hippocampus has been shown to be activated during retrieval of both recent and remote episodic information (Gilboa et al., 2004) • Subjects saw pictures of themselves • Some taken very recently, some distant past • Hippocampus was active during both conditions – Semantic (gist) information can be established in Neocortex and will survive damage to hippocampus Consolidation Do you know? Semantic Do you member? Episodic – The response of the hippocampus can change over time (Viskontas et al., 2009) • Participants learned picture-picture pairs, followed by a remember/know paradigm • Hippocampal activity was associated with “remember” responses in an immediate test • At 1 week, hippocampal responses were still strong for items participants still remembered (RR), but not for items that were merely familiar (RK). RR= epsiodic after 10 mins still episodic after 1 week more semantic memory fewer episodic memory Not for those semantic after 1 week = After 10 mins episodic memory the distinctive point: episodic and semantic memory after one week – Different role of hippocampus for episodic and semantic memories Consolidation and sleep: Enhancing memory • Learning English-German vocabulary words in 2 groups (Gais et al., 2006) – Sleep group: studied, went to sleep within 3 hours – Awake group: studied, stayed awake for 10 hours – (additional control groups tested) • Sleep group forgot much less material than awake group • Consolidation appears enhanced during sleep Consolidation in sleep depends on expectation • Wilhelm et al. (2011) • Learning position of cards in “memory” game before sleeping – Expectation group: • Told that they would be tested later on task – Non-expectation group: not told to be tested the same task • Told that they would be tested on another task • After sleep expectation group was better than non-expectation group Remember better after sleep if expected to be tested the test Are Memories Ever “Permanent”? • We update our memories – We are constantly learning new things and modifying information stored in memory • When a memory is retrieved it becomes fragile – As it was originally formed – When fragile, it needs to be consolidated again ➔ Reconsolidation – During this process, updates can take place When we retrieve memory - it becomes fragile, Nader et al. 2000 The rat receive a shock of anti biotic = prevent the synapse change fear condition experiment receive the shock of anti biotic learns to freeze learns to freeze Receive the shock of anti biotic learn to show freeze response when the rat hear the tone An antibiotic that prevents changes at the synapse that are responsible for the formation of new memory Nader et al. 2000 DAY 1 tone only An antibiotic that prevents changes at the synapse that are responsible for the formation of new memory Nader et al. 2000 tone Prevent from learning the fear condition response the rat did not learn rat does not freeze 2. The rat learn the fear condition 2. Receive the antibiotic 2. The rat freeze because it learnt rat freezes rat does not freeze The memory become fragile the memory cannot be consolidated An antibiotic that prevents changes at the synapse that are responsible for the formation of new memory Are Memories Ever “Permanent”? • We update our memories – We are constantly learning new things and modifying information stored in memory • When a memory is retrieved it becomes fragile – As it was originally formed – When fragile, it needs to be consolidated again ➔ Reconsolidation – During this process, updates can take place • Erasing memories: – https://www.youtube.com/watch?v=Dan68pTqpxQ (from min 11) Form memory stable forever -> ask if memories last forever -> it becomes fragile PTSD study • Practical outcome of reconsolidation: possible treatment of PTSD memory can be unstored • Brunet et al. (2008): – Reactivated the person’s memory for the traumatic event – Administered propranolol • Blocks activation of stress hormone receptors in the amygdala Researchers are using virtual reality as a form of exposure therapy to help deal with posttraumatic stress. – Two PTSD groups: • • Group A: listened to 30-second recording of the traumatic experience, then received propranolol Group B: listened to 30-second recording of the traumatic experience, then received placebo Listen to the recording -> remember the traumatic memory -> receive the drug -> small physiological eﬀect – A week later they listen to the same 30-second recording – Group A showed smaller increases in heart rate and skin conductance Measure physical reaction Hupbach et al. 2007 • Day 1: S studied a list of words naming everyday objects reminded group is reminded, memory is fragile and consolidate again new information can alter the memory • Day 2: – “Reminder” group: • was reminded of their learning on Day 1, without actually recalling the objects • Immediately they learned another list – “No reminder” group: • Learned another list • Day 3: both groups were asked to remember list 1 – “Reminder” group: • Recalled 36% of list 1 • Also mistakenly recalled 24% of list 2 – “No reminder” group: • Recalled 45% of list 1 • 5% of words from list 2 Improving Learning and Memory • Elaborate - associate what you are learning to what you already know • Generate and test – The generation effect • Take breaks – Memory is better for multiple short study sessions (the spacing effect) – Consolidation is enhanced if you sleep after studying (in other words, no all nighters!) • Avoid the “illusion of learning” – Familiarity does not mean comprehension Summary • Levels of Processing Theory: Depth of processing affect recall • Encoding: Methods that increases richness of representations in memory aid encoding • Three different ways to achieve matching: – Encoding specificity, State-dependent learning, Transfer-appropriate processing • Information Storage at the Synapse • Standard model of consolidation • Consolidation & the fragility of new memories Some Questions to Consider • What is the best way to store information in long-term memory? • What are some techniques we can use to help us get information out of long-term memory when we need it? • How is it possible that a lifetime of experiences and accumulated knowledge can be stored in neurons? • How can the results of memory research be used to create more effective study techniques?

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