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Memory

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  1. Memory Hermann Ebbinghaus (c. 1885): began the systematic study of memory Memory

  2. Memory • What is memory. Is it a single thing? • Are there neurologically independent memory processes (or systems) that correspond to psychologically useful components of memory models? • Are these independent memory systems localizable to any extent? • How is it stored? • How does memory happen? e.g. consolidation • What is the nature of the memory disorder in neurological disease and how does this relate to what we know about normal memory and the brain? Memory

  3. Spatial Metaphor • Memory is often thought of as a kind of physical space throughout which things are located -- and interconnected. This is true even for the earliest theorists, such as the British Associationists -- and Aristotle • Socrates likened memory to a wax tablet: blank, then there, then gone. • Note quote from Plato (also referring to Socrates): • ". . . like a man who has caught some wild birds - pigeons or what not -- and keeps them in an aviary he had made for them at home. . . Let us suppose that every mind contains an aviary stocked with birds of every sort, some in flocks apart from the rest, some in small groups, and some solitary and flying in any direction among them all.” • Similar to current models .. and Freud's Memory

  4. In contrast: Aristotle • Linked memory with reason, indicated that it decreased in old age. • external events generate movements in the sense organs (through spirits, or pneuma in blood): images are the subjective side of these movements. • And if these images are anchored to the past they are memories. • So memory is a faculty of sense perception. • But “voluntary memory” distinguished humans from other animals. He identified three laws of association: contiguity, similarity and contrast. • So here we have the other common theme -- associationism Memory

  5. Spatial Metaphor • Memory is often thought of as a kind of physical space throughout which things are located -- and interconnected. This is true even for the earliest theorists, such as the British Associationists -- and Aristotle • Socrates likened memory to a wax tablet: blank, then there, then gone. • Once rote memory was a virtue: texts, history, poems, were memorized • Note quote from Plato (also referring to Socrates): • ". . . like a man who has caught some wild birds - pigeons or what not -- and keeps them in an aviary he had made for them at home. . . Let us suppose that every mind contains an aviary stocked with birds of every sort, some in flocks apart from the rest, some in small groups, and some solitary and flying in any direction among them all.” • Similar to current models .. and Freud's Memory

  6. Questions regarding the spatial metaphor • How do we decide so quickly that we do not know something? The spatial memory metaphor requires a spatial search • An answer to this is "parallel search" .. but it is an answer without, as yet, a way to test it. • It is best for storage and retrieval of individual items. Yet we utilize past knowledge to react to novel information. . . the model must account for this. It is not just mistakes - an almost A is like an A -- but also the recognition and utilization of new...There appears to be some kind of "metaknowledge" that emerges from the individual experiences • It implies an inflexible storage system. . . But we can ask that the storage be reorganized .. almost instantly... Odd man out "shoe, shirt, rock,” • Okay..the shoe and shirt may be stored "closer to one another" but...which can be used to pound with? • The spatial metaphor may be too inflexible • We can cut and dice the brain with minimal to moderate memory loss Memory

  7. Karl Lashley cut the cortex every which way to disrupt memory connections: and failed • “This series of experiments has yielded a good bit of information about what and where the memory trace is not. It has discovered nothing directly of the real nature of the engram. I sometimes feel, in reviewing the evidence on the localization of the memory trace, that the necessary conclusion is that learning is just not possible.” (1950, pp. 477-478). Memory

  8. Memory

  9. The Multi-Store Model • George Miller (1956): The Magical Number Seven See Miller quotes • The concept of Working Memory first introduced by Miller, Galanter & Pribram (1960) in Plans & the Structure of Behavior • Atkinson & Shiffrin..sensory, short,long • rehearsal a key part of their model... • quantity of rehearsal important.....but quality of rehearsal also important -- ex. category organization • The Atkinson and Shiffrin model did more than separate memory into a set of independent parts. It proposed a series of stages through which information was filtered and passed into the nervous system. And these series of stages were not passive filters. The nervous system controlled, through various mental operations, the rate and type of information that reached ultimate long-term memory. See Miller quotes • Question: In short term store the material is in phonetic form due to rehearsal...In long-term store it is in semantic store..how does the transition occur? Memory

  10. Miller, G.A., The magical number seven, plus or minus two. Psychologcal Review, 1956. 63: p. 81-97. • “There is a clear and definite limit to the accuracy with which we can identify absolutely the magnitude of a unidimensional stimulus variable. I would propose to call this limit the span of absolute judgment, and I maintain that for unidimensional judgments this span is usually somewhere in the neighborhood of seven. We are not completely at the mercy of this limited span, however, because we have a variety of techniques for getting around it and increasing the accuracy of our judgments. The three most important of these devices are (a) to make relative rather than absolute judgments; or, if that is not possible, (b) to increase the number of dimensions along which the stimuli can differ; or (c) to arrange the task in such a way that we make a sequence of several absolute judgments in a row.” [Miller, 1956 #159] • “First, the span of absolute judgment and the span of immediate memory impose severe limitations on the amount of information that we are able to receive, process, and remember. By organizing the stimulus input simultaneously into several dimensions and successively into a sequence or chunks, we manage to break (or at least stretch) this informational bottleneck.” Memory

  11. The Multi-Store Model • George Miller (1956): The Magical Number Seven • The concept of Working Memory first introduced by Miller, Galanter & Pribram (1960) in Plans & the Structure of Behavior • Atkinson & Shiffrin..sensory, short,long • rehearsal a key part of their model... • quantity of rehearsal important.....but quality of rehearsal also important -- ex. category organization • The Atkinson and Shiffrin model did more than separate memory into a set of independent parts. It proposed a series of stages through which information was filtered and passed into the nervous system. And these series of stages were not passive filters. The nervous system controlled, through various mental operations, the rate and type of information that reached ultimate long-term memory. Memory

  12. Memory

  13. Memory

  14. Memory

  15. Atkinson & Shiffrin Model Sensory Store: Sperling...partial report Short-Term Store 1) Extremely limited capacity (about 7 chunks) 2) Fragile Storage Note: serial position effect List...count backward by threes...only the recency effect effected...they were in short-term and were immediately interfered with Disrupt the memory processes determine the critical pt. of entry in LTM ECS Inhibit protein synthesis (puromycin): task acquired but not retained but protein synthesis takes at least 10 seconds DIVISIONS OF LONG TERM MEMORY DECLARATIVE: Memory for facts and episodes PROCEDURAL: Memory for skills Memory

  16. Rehearsal Environmental Stimuli Sensory Memory Short-Term Memory Long-Term Memory Encoding Consolidation Attention DECAY DISPLACEMENT DECAY INTERFERENCE INTERFERENCE Forgotten Forgotten Failure to Retrieve Stage Model of Memory Circa 1970’s Memory

  17. Memory

  18. Smith, E. and J. Jonides (1997). "Working memory: A view from neuroimaging." Cognitive Psychology33: 5-42. Memory

  19. Memory

  20. Memory

  21. Baddeley, A. D. and G. J. Hitch (1974). Working memory. Recent advances in learning and motivation. G. A. Bower. New York, Academic Press. 8: 47–90. • Replaced short-term with working memory: a modality free central executive: an articulatory loop and a visuo-spatial scratch pad...now it is the "central executive" which has the limited capacity..its like an attentional resource system • The articulatory loop is serial and phonetic • individuals can recall as many words as they can read out loud in two seconds • Verbal rehearsal now becomes an optional tool • Several components of working memory (may be separate /phonetic & acoustic) • Working memory a more general utility Memory

  22. Baddeley, A.D., Is Working Memory Still Working? European Psychologist, 2002. 7(2): p. 85-97. Memory

  23. Levels of Processing • Craik & Lockhart • Imagery • Pavio • Dual-code system Memory

  24. Memory

  25. Memory

  26. Declarative and Non-Declarative Memory • Declarative memory encompasses the acquisition, retention, and retrieval of knowledge that can be consciously and intentionally recollected. • Such knowledge includes memory for events (episodic memory) or facts (semantic memory). Episodic memories are measured by direct or explicit tests of memory, such as free recall, cued recall, or recognition, that refer to a prior episode • Nondeclarative or procedural kinds of memory encompass the acquisition, retention, and retrieval of knowledge expressed through experience-induced changes in performance. • Nondeclarative memories are measured by indirect or implicit tests where no reference is made to that experience. Skill learning, repetition priming, and conditioning are classes of implicit tests that often reveal procedural memory processes dissociable from declarative memory. Memory

  27. Types of Amnesia Memory

  28. Case of H.M. the motor winder. • Poor memory from 1942, when he developed epilepsy, to 1953, when he received surgery. Very remote memories are intact. • Bilateral medial temporal region & associated brain structures: • normal digit span • serial learning....add 1 new each time • normals can learn 20 or so in <15 trials • H.M. 6 digits after 25 trials • same for "block-tapping" • loss of primacy in serial position curve • BUT, okay on Tower of Hanoi: Learning curve without awareness • replicated in rats in radial maze after bilateral hippocampus removal Memory

  29. Memory

  30. H.M.’s short-term memory • “. . . He was able to retain the number 584 for 15 minutes, by continuously working out elaborate mnemonic schemes. When asked how he had been able to retain the number for so long, he replied: • ‘It’s easy. You just remember 8. You see, 5, 8, 4 add to 17. You remember 8, subtract it from 17 and it leaves 9. Divide 9 in half and you get 5 and 4, and there you are 584. Easy.’ • “A minute or so later, H. M. was unable to recall either the number 584 or any of the associated complex trains of thought, in fact, he did not know that he had been given a number to remember because, in the meantime, the examiner had introduced a new topic.” Memory

  31. Milner, B., Corkin, S., & Teuber, H. L. (1968). Further analysis of the hippocampal amnesic syndrome: 14-Year follow-up study of H.M. Neuropsychologia, 6, 215-234. H.M. Bad at delayed face recognition Good on sorting Memory

  32. Memory

  33. Milner, B., Corkin, S., & Teuber, H. L. (1968). Further analysis of the hippocampal amnesic syndrome: 14-Year follow-up study of H.M. Neuropsychologia, 6, 215-234. Able to learn spatial material Unable to retain it Memory

  34. Memory

  35. Corkin, S. (1968). Acquisition of motor skill after bilateral medial temporal-lobe excision. Neuropsychologia, 6, 255-265. H. M. is not able to learn a novel visual-motor task as well as normals Memory

  36. Corkin, S. (1968). Acquisition of motor skill after bilateral medial temporal-lobe excision. Neuropsychologia, 6, 255-265. H. M. is learning something over sessions (though he doesn’t remember prior sessions Memory

  37. Milner, B. (1970). Memory and the medial temporal regions of the brain, Biology of Memory (pp. 29-50). New York: Academic Press. Verbal memory more impaired by left hippocampal removal Memory

  38. Milner, B. (1965). Visually-guided maze learning in man: Effects of bilateral hippocampal, bilateral, frontal, and unilateral cerebral lesions. Neuropsychologia, 3, 317-338. Opposite effect for visual maze learning – right hemisphere dominant – but still related to removal of hippocampus Memory

  39. Memory

  40. AMNESIC PATIENTS • Complaints about memory deficits are common among psychiatric and neurological patients. And in many cases of dementia, such as Alzheimer's, there are many cognitive disturbances, making assessment difficult. • There are two main deficits in amnesias: retrograde and anterograde amnesia • Though there are many variations patients suffering from the amnesic syndrome have some characteristics in common. They perform poorly on memory batteries -- but perform well on intelligence test. • They score particularly poorly on retention of new information, learning of unfamiliar faces • Amnesia is not usually a homogeneous entity Memory

  41. AMNESIA IS SELECTIVE • General intellectual ability is intact • Short-term memory is undisturbed (normal digit span, intact ability to maintain information in memory via rehearsal) • Can successfully recall a great deal of remote material • Difficulties: • When they are required to learn more information than they can hold in mind at once • Or when they are distracted from rehearsal • Difficulty recalling long-term information learned relatively near the time of the onset of amnesia • This means that the damaged neural system in amnesia does not interfere with: • Forming percepts • Deploying attention • Establishing short-term memory • P-3, new info wave: The amplitude of the P-3 wave predicts memory performance...not effected by medial temporal, so it must be part of an earlier processing stage Memory

  42. Unilateral Brain Damage • Tradition says left temporal bd = verbal memory deficits and right bd = visual-spatial memory deficits • Brenda Milner vs. Ina Samuels studies on left and right temporal lobotomy patients: left bd patients show rapid memory loss using verbal Peterson task and right bd patients show loss using visual trigrams in Peterson task. • Not necessarily true: • RHBD = subtle verbal memory deficits • LHBD = deficits with certain types of visual stimuli • RHBD patients reported to remember the same number of elements of a story, but not the gist of the story • Normals will paraphrase a section of the story: e.g. "felt sorry for her." rather than "touched by her story" • But right BD patients try for verbatim - they lose the efficiency of paraphrasing. • They might also introject personal material. • RHBD patients less likely to utilize semantic categories in random, categorized lists. • LHBD patients, remember fewer internal details versus outer configural features • N.A.: miniature fencing foil entered right nostril penetrated left diencephalon: loss specific to learning new verbal material. Left dorsomedial thalamus seems critical. Memory

  43. PRESERVED MEMORY FUNCTIONS IN MEMORY IMPAIRED PERSONS • Short-term memory • intact digit span • recency effect • Brown-Peterson test: controversial Baddeley & Warrington vs. Butters & Cermak • Skill Learning: • mirror writing • pursuit motor • tactual maze • jigsaw puzzles (repeated assembly) • mirror reading • Tower of Hanoi (not always replicated: difficulty?) Memory

  44. PRESERVED MEMORY FUNCTIONS IN MEMORY IMPAIRED PERSONS: Priming Effects • Successively less fragmented words until identified: = later exhibited savings • Evidence that priming can work if UNCONCIOUS; First present “motel” in a list of words. Then: • If the clue is identified as a clue it doesn't work, if "say first word that comes to mind", it may • e g. MOT for MOTEL Memory

  45. Zajonc preference bias • free associate to CHILD when BABY was previously given, produced more "BABY" associations • Claparede (1911) with a Korsakoff's patient pricked patient with hidden pin. Later patient withdrew hand, did not remember being pricked but said "sometimes people hide pins in their hands" • FURTHER EVIDENCE OF EFFORT-AUTOMATIC DISTINCTION: • Fragments of Words: • amnesic patients can solve words as well as normals • UNLESS told the fragment is a previously presented word • AND words with a single answer (ex. jui) impairs amnesic performance...probably because they have to search memory actively • [Is it extra-effortful, or inefficient, or does the search just run out?] • It’s clear that procedural skill is different from declarative...[DOES PRIMING MAKE THIS DISTINCTION?] • 1) Priming seems like declarative. . . but it may work underlying structure • 2) Or, priming is different from both declarative & procedural memory Memory

  46. What is the difference between declarative and procedural memory? • Declarative • cognitive • fast • single trial learning • familiarity • modality general • Procedural • slow • automatic • incremental learning • often modality specific Memory

  47. The Formation and Consolidation of Long-term Memory • Consolidation refers to the idea that memories are not preserved instantaneously, but take time -- the process by which memory becomes gradually more resistant to disruption. • But biological ideas have concentrated on the nature of the biologic change. Biological thinking conceptualizes a reconstructive biological process, adding, modifying, and preserving some of the original experience -- after the event. • Based on retrograde amnesia...head trauma, ECT, effects recent memories • In a Squires study ECT patients showed a decrement of 1 to 3 years in recalling one-season television shows. (animals minutes to weeks, but hard to test experimentally) • R.B, ischemic temporal damage, did not show retrograde amnesia • Post-encephalic cases show varying degrees of amnesia, some extensive. • CONCLUSION: THE medial temporal lobes perform some time limited function in memory storage. But gradually the long-term memory sites take over the consolidation function. • Since short-term memory remains intact the sites of permanent storage must be affected. Memory

  48. Consolidation theory would view amnesia as a deficit in STORING information • Milner originally suggested this as an explanation for HM. - could not "consolidate" information from short to long- term memory. • BUT It doesn't account for retrograde amnesia • BUT It doesn't account for specific losses. • Larry Squire proposed that consolidation takes days or even months of activation, reactivation, elaboration, and so on. Proposed this as specific to medial temporal region - not accounting for cases with retrograde Memory

  49. QUESTION: Is amnesia an actual disturbance of memory storage or is it a retrieval problem? • Not a SIMPLE retrieval deficit since ALL events are not effected. • Perhaps only intermediately remote retrieval is effected... • Argument for retrieval deficit...sometimes retrograde amnesia recovers . . if memories were erased they couldn't reappear [of course, the process might inhibit the memory in some way rather than erase it] • Following trauma the immediately preceding events do not recover... • 1) disruption sufficiently later will not affect memory • 2) disruption occurring intermediate times temporarily disrupts memory • 3) treatment soon after memory disrupts permanently • [but this doesn't refer to long-term loss] • So the problem may be that a process in intermediate memory which is necessary for the material to become long-term is disrupted . . so the material gradually fades out rather than gets permanently stored. Memory

  50. Modern period of semantic memory research • Stimulated by Elizabeth Warrington’s paper (Warringon, E., The selective impairment of semantic memory. Quarterly Journal of Experimental Psychology, 1975. 27: p. 635-657): 3 cases of progressive deterioration with semantic memory deficits • She was confirming Tulving’s model of semantic memory • Disorder was selective (not loss of general comprehension) • Disorder was global (to picture, or words, spoken or written) • Disorder was graded: knowledge of specific category attributes (camel has two, four, six legs?) was more impaired than the superordinate category (camel = mammal or insect?) Memory