Lecture 6 Long-Term Memory PDF

2023-10-9 PSYC 5140 Cognitive Psychology Lecture 6: Long-Term Memory: Structure Fall 2023 Instructor: Urs Maurer Tree of Memory Memory Sensory Short Term Long Term Implicit Subdivide Explicit Declarative Procedural fact Classical Priming Conditioning motor we learn and memorise it Epi...

2023-10-9 PSYC 5140 Cognitive Psychology Lecture 6: Long-Term Memory: Structure Fall 2023 Instructor: Urs Maurer Tree of Memory Memory Sensory Short Term Long Term Implicit Subdivide Explicit Declarative Procedural fact Classical Priming Conditioning motor we learn and memorise it Episodic Semantic Memory about fact and knowledge Long-Term Memory Think about LTM as • “Archive” of information about past events and knowledge learned • Works closely with working memory • Storage stretches from a few moments ago to as far back as one can remember • More recent memories are more detailed Verus old memory Long-Term Memory LTM STM is more than 15 - 20 seconds LTM is above 30 seconds just to be sure it is not STM This guy must have been pretty tired after standing for ten years straight… 1 Distinguishing LTM from STM: Serial Position ~ • Murdoch (1962) studied the distinction between short-term and longterm memories using the serial position curve • Read stimulus list • • • • • • • • Bed Clock Dream Night Turn Toss Artichoke Alarm Sequence of words Procedure: the order doesn’t matter show out how many words you remember Result: recency effect: STM (repeat information to go to LTM) Primacy effect: LTM • Write down all words remembered, in any order Distinguishing LTM from STM: Serial Position [tens] • Let’s count: • • • • • • • • Bed Clock Dream Night Turn Toss Artichoke Alarm Serial Position Curve Serial Position Effect ~ 1. Primacy effect – remembering words at beginning of list better than middle because of rehearsal => Transfer to LTM • The first word receives 100% of attention • With the second word => attention gets split between two words • … • Less rehearsal for later words Serial Position Curve Rundus (1971): tested the primacy effect • Memory better for stimuli presented at beginning – Primacy effect gave more time to rehearse info, more likely to enter LTM Second experimental group: Repeat words out loud during 5 seconds intervals between words How many times words were repeated Primacy effect blue line: repetition Serial Position Effect 1. Primacy effect – remembering words at beginning of list better than middle because of rehearsal => Transfer to LTM • The first word receives 100% of attention • With the second word => attention gets split between two words • Less rehearsal for later words 2. Recency Effect – remembering words at the end of list better than middle because of lack of interference => words still in STM Serial Position Curve • Glanzer & Cunitz (1966): tested the recency effect: – Memory better for stimuli presented at end of list – Stimuli still in STM Second experimental group: Counted backwards for 30 seconds right after hearing the last word of the list Make sure it is LTM not STM => Prevented rehearsal, also information lost from STM 2 Coding in short-term & long-term memory • Another way to distinguish between LTM & STM: compare the way information is coded by the two systems – Coding refers to the form in which stimuli are represented • Physiological approach: how a stimulus is represented by the firing of neurons • Mental approach: how a stimulus is represented in the mind Which coding is for STM and for LTM? • Visual Coding – STM: Recalling visual patterns – LTM: when visualizing a person from the past Visual images stay in LTM e.g. your old schoolmate face • Auditory Coding: Coding: auditory – STM: Phonological similarity effect – LTM: “hearing” the beginning of the next song on a playlist sound stays in LTM Coding in short-term & long-term memory • Semantic encoding in short-term memory – Wickens et al. (1976) Procedures – Subjects were presented with either words from a or b Group 1 – They listen to three words, counted backwards for 15secs, then recalled Group 2 Group 2 perform better when semantic meaning change Coding in short-term & long-term memory result same category decrease Different category rebound What does this effect tell us about coding in STM? •Release from proactive interference depends on the words’ categories •Placing words into categories involves the meaning of words •Recall happened 15secs after hearing the words •Semantic coding in STM LTM interact with STM Sachs (1967) on the encoding of information into LTM interruption/ distraction is 30 seconds Coding in Long-Term Memory • Semantic encoding in long-term memory • Recognition memory: identification of a previously encountered stimulus • Sachs (1967) procedures – Subjects listened to a tape recording of a passage – Recognition memory was then measured • Did they remember the exact wording, or the general meaning Coding in Long-Term Memory – Recognition: The to-be-remembered information is presented, along with other stuff (distractors) and the subject must distinguish new from old. • e.g. multiple choice questions – Free recall: Minimal information from experimenter • Experimenter simply says “Remember” and the context is usually implied, occasionally described. • e.g. feel in the blanks exam questions – Cued Recall: Experimenter also gives part of the information, or some related information. Sachs (1967) • Which one of the following sentences is identical to a sentence in the passage 1) 2) 3) 4) Galileo, the great Italian scientist, sent him a letter about it. He sent Galileo, the great Italian scientist, a letter about it. He sent a letter about it to Galileo, the great Italian scientist. A letter about it was sent to Galileo, the great Italian scientist. are asked immediate 1. We are good at detecting changes in meaning LTM 2. We are not as good in detecting changes in sentence form 3. The ability to detect any change declines with time 4. The decline is sharper for syntactic changes (that don’t effect meaning) Spoken words in phonological in STM are lost Relate to distinguish STM and LTM Locating Memory in the Brain • Neuropsychology – The hippocampus is responsible for one’s ability to encode new long-term memories – Henry Molaison (H.M.) – surgery for epilepsy Procedural memory are still existing • No hippocampus STM and LTM are working independently STM is still working • https://www.youtube.com/watch?v=KkaXNvzE4pk (H.M. cartoon, 5:25) • https://www.youtube.com/watch?v=_7akPs8ptg4 (surgeon’s grandson, 6:26) – Clive Wearing- Parts of his medial temporal lobe were destroyed • medial temporal lobe: hippocampus, amygdala, and other structures in the temporal lobe Patient – K.F. – brain injury in a motorbike accident • Damage to parietal lobe • Poor STM Neuropsychological Approaches to the Study of STM • Lesion Studies: – Patient HM and other dense amnesics have a symptom profile, suggesting, among other things, that STM and LTM are independent: – Impairments in: • Acquiring new episodic and semantic memories (explicit LTM encoding) • Primacy effect in free recall (explicit LTM encoding) – Spared abilities: • • • • • Recall events prior to the resection (explicit LTM retrieval) Learn new motor skills (implicit LTM) Digit span (STM) Peterson task (STM) Recency effect in free recall (STM) Neuropsychological Deficits in Verbal STM • Patient KF and other patients showed the opposite pattern of memory problems, completing the double dissociation between STM and LTM: – Impairments in: 4 • Peterson task (STM) • Recency in free recall (STM) • Reduced digit span – Spared ability for: • LTM The Importance of Double-Dissociations • Neuropsychological Double-Dissociations: STM LTM K. F. Impaired Normal H. M. Normal Impaired No parietal no hippo – Allows one to infer the partial independence of cognitive functions underlying the two cognitive tasks – Helps to rule out the possibility that a single patient group cannot perform one task simply because it is more difficult than the other task Ranganath & D’Esposito 2001 • Participants viewed faces during a working memory task (Experiment 1A) – Instructions: Indicate whether the second face is the same as the first. • Then, viewed faces from the same set in a long-term memory task (1B) with an encoding and retrieval part. – Instructions: “Encode these faces...”(then, after they’d seen the whole list and had an anatomical scan of 5-10 minutes) “Did you see this face before?” • Note very similar protocol, designed to directly compare STM/WM maintenance and LTM encoding… (ITI: intertrial interval) Functional MRI Ranganath & D’Esposito 2001 Background: Hippocampus is crucial for LTM. Is it also important for STM? Like the patient HM Results: Hippocampus increased strongly in delay (WM maintenance) for novel faces, but less so for familiar faces Hippocampus Parahipp ocampal Gyrus Conclusion: Hippocampus is also involved in STM Transient hippocampus activation may not be detected in LTM tasks with fMRI Types of Long-Term Memory • Tulving (1985) proposed that episodic and semantic information handled different types of information. – They can further be distinguished based on the type of experience associated with each Difference between episodic and semantic • Episodic – Memory for a specific instance or episode (“experience”). – Involves “mental time travel” Only 2 questions about episodic he had difficulty to do that – No guarantee of accuracy • Semantic – Memory for conceptual information (“facts”) – Does not involve mental time travel e.g. remember brother died but no personal memory e.g. can’t remember ever he changed a tire before/ his mom has done it Good LTM Remember how to change a flat tire Types of Long-Term Memory • Evidence for distinction – Type of experience (previous slide) – Neuropsychology – fMRI responses Episodic vs. semantic LTM: Neuropsychology • Episodic and semantic show a double dissociation – K. C.: • No episodic memory: he can no longer relive any of the events of his past. • Intact semantic memory: He is aware of the fact that his brother died 2 years ago, but does not remember any personal experiences with him • https://www.youtube.com/watch?v=tXHk0a3RvLc (patient K.C./Tulving, 5:13) Another case: opposite pattern – “Italian woman”: • Intact episodic memory: able to remember events in her life • No semantic memory: had trouble remembering meaning of words, even couldn’t remember that Italy was involved in WW2 – https://www.youtube.com/watch?v=00wBirzwT9g (encephalitis, 7:55) – https://www.youtube.com/watch?v=yAQs2pmN3Sg (“brain on fire”, 1h) Separation of Episodic and Semantic Memories Somewhat independent between semantic and episodic Separation of Episodic and Semantic Memories • Levine et al. (2004) – Subjects (n=5) kept diaries on tape describing everyday personal events – Also provided tapes with facts from their semantic knowledge • Compare detailed episodic autobiographical memories with semantic knowledge • Results: – Yellow: increased activation for episodic memory – Blue: increased activation for semantic memory • Evidence from brain-imaging experiments that retrieving episodic and semantic memories activate different areas of the brain Interactions Between Episodic and Semantic Memories • Knowledge affects experience e.g. if you know the rules of baseball, you’d enjoy playing – Semantic memory guides experience => influences episodic memories – Will you remember these great moments in curling? https://youtu.be/iYcYaUBaEeI?t=30s • Episodic memory can be lost, leaving only semantic – Acquiring knowledge may start as episodic but then “fade” to semantic (“source amnesia”) • Semantic memory can be enhanced if associated with episodic – Autobiographical memory: memory of specific experiences, includes semantic and episodic – Personal semantic memory: semantic memories that have personal significance different brain area activate episodic and semantic memory Familiarity and Recollection Two aspects are important • Familiarity: associated with semantic memory – Not associated with circumstances under which memory was acquired – e.g.: when a person seems familiar, you might remember his name, but not any specific experiences • That person looks familiar. Where did I meet him? • There’s Roger. Where did I meet him? But we don’t remember why or where we met the familiar person • Recollection: associated with episodic memory – Details about what was happening when the knowledge was acquired • There’s Roger, who I met at the coffee shop last Monday. We talked about the weather. i exactly remember why and where, detailed information about meeting the person ask ppt if your memory is familiarity or recollection The Effect of Time • Typical research findings are that forgetting increases with longer intervals from the original encoding – Remember/Know procedure • Remember if a stimulus is familiar and the circumstance under which it was encountered? • Know if the stimulus is familiar but don’t remember experiencing it earlier? • Don’t remember the stimulus at all – Semanticization of remote memories • Loss of episodic details for memories of long-ago events Remote memory becomes semantic The Effect of Time • Petrican et al. (2010) • Presented descriptions of events that had happened over a 50-year period to older adults • Results: – Complete forgetting increases with time – Remember response decreased much more than know response • Conclusion: – Memories from 40-50 years ago had lost much of their episodic character – Illustrates semanticization of remote memories • Knowledge that makes up semantic memories is initially attained through personal experiences, that are the basis of episodic experiences – Memory of these experiences fade, only the semantic episodic -> lost detail -> semantic memories remain Cross sectional semantic semantic episodic Epsisodic Mental Time Travel? Using a cueing task, Addis et al. (2007) asked people to remember events associated with specific key words, or to imagine future events. A widely distributed network of areas associated with memory processes (but also with memory, visualization, and social cognition) were active in both tasks. Constructive episodic simulation hypothesis: suggestion episodic is used to asmiliate future event - Episodic memories are extracted and recombined to construct simulations of future events - Main role of episodic memory: simulate future scenarios (rather than remembering the past) Types of Long-Term Memory So far we have considered memory for facts and events. These are things we know explicitly. What does it mean to know something implicitly? Implicit memory For example: riding bicycle, take a turn, your body knows you lean a bit You ask why did your body turn? Because your body learn • Implicit/non-declarative: memory that unconsciously influences behavior – When learning from experience is not accompanied by conscious remembering Professional cyclists often brush up on their Newtonian mechanics before big races…(kidding) – Procedural (skill) memory – Priming: previous experience changes response without conscious awareness Conscious awareness: you learn from your past experience * STM and LTM are interdependent. *Procedural memory is different. * Implicit Memory: Procedural Memory • Skill memory: memory for actions • No memory of where or when learned* (or else this memory doesn’t much influence performance) • Perform procedures without being consciously aware of how to do them • People who cannot form new episodic memories can still learn new skills – H.M. learned the mirror drawing task after a couple of days of practicing • Each day he couldn’t remember he had done the task before • Many cognitive skills involve procedural memory Knowlton et al. (1996) tested Parkinson’s (PD) patients and amnesics (AMN) on a probabilistic “weather prediction” task. can still this task Whereas AMN patients learned well, PD patients did not. Ppt pick up the rule implicitly In contrast, when asked a set of simple multiple-choice questions about the task they’d just performed, AMN patients were close to chance, whereas PD patients did as well as controls. …this was a key finding dissociating declarative and procedural memory... Priming • Presentation of one stimulus changes the way a person responds to another stimulus – Social Priming: • https://www.youtube.com/watch?v=vI0fFEffDd8 (cold/hot drink, 4:34) • https://www.youtube.com/watch?v=5g4_v4JStOU (aging, 5:12) – But see poor replicability of social priming effects: https://www.nature.com/articles/d41586-019-03755-2) Repetition Priming • Presentation of one stimulus affects performance on that stimulus when it is presented again • Graf and coworkers (1985): tested patients with amnesia to ensure that people don’t remember the presentation of priming stimulus – Tested explicit memory and implicit memory – Tested three groups 1. Amnesia patients with Korsakof’s syndrome (do not have the ability to form any explicit LTM) 2. Patients without amnesia being treated for alcoholism 3. Patients without amnesia who had no history of alcoholism Repetition Priming See the first letter to do the task use in implicit memory to do the task explicit task Medical Alcoholic Amnesia inpatients controls patients Subjects were asked to read a 10-word list and rate how much they likes each word They were then tested in one of the two following ways: 1. They were asked to recall the words they had read 2. A word completion test, which is a test of implicit memory Implicit Memory in Everyday Experience How much advertisement are influencing our behaviour • Perfect and Askew (1994) – Propaganda effect: more likely to rate statements read or heard before as being true, simply because they had previously been exposed to them – More likely to rate advertisement they has seen in passing as “true” • https://www.youtube.com/watch?v=EUA4Q5aoG74 Implicit Memory: Classical Conditioning • Pairing a neutral stimulus with a reflexive response • Remember poor Little Albert! • Not remembering the name of a familiar person, but having positive or negative feelings about them dont remember the name of the person (explicit) still remember the positive/ negative feeling toward the person (implicit) e.g. Youtube remove hippocampus, important to create new memory Tree of Memory Memory Sensory Short Term Long Term Implicit Explicit Declarative Episodic Procedural Semantic Classical Priming Conditioning Tree of Memory Memory Sensory Short Term Long Term Implicit Explicit Declarative Episodic Procedural Semantic Classical Priming Conditioning