Memory 3265

1. Memory 3265 • Course website address • http://www.yorku.ca/npark/memory_f_16

2. Introduction and History of Memory Research • History • Ebbinghaus (1885) is credited with being the first person to scientifically study memory • prior to Ebbinghaus relatively little was written about about memory

3. Introduction and History of Memory Research • History • however, people did write about factors affecting memory performance • attentiveness and rehearsal aid memory • Aristotle (4th Century BC) • proposed laws of associationism. Most important is the law of contiguity-- two events or experiences occurring closely in time will come to be associated with each other

4. Introduction and History of Memory Research • History • Romans (e.g., Cicero) and others were concerned with using mnemonics to assist memory • mnemonics generally remember something new by pairing it with already known information • developed the method of loci. In this method a person places items to be memorized in particular locations well known to the memorizer

5. Introduction and History of Memory Research • History • Ebbinghaus (1885) published Memory: A contribution to Experimental Psychology • first experimental study of memory; inspired by Fechner’s work on the psychophysical study of sensation • Investigated the factors associated with forgetting • Memory performance as a function of delay between learning and test

6. Introduction and History of Memory Research • History • experimental procedure of Ebbinghaus • Materials. Used nonsense syllables (CVC) to try and study acquisition and memory for brand-new stimuli • Participant. Ebbinghaus • Procedure. Presented nonsense syllables one at a time at a fixed rate of presentation. Studied list until he could recall entire list in serial order without error (method of complete mastery)

7. Introduction and History of Memory Research • History • experimental procedure of Ebbinghaus • Procedure (cont’d). After a delay Ebbinghaus relearned the list. • Dependent variable was the savings score, ie, the time or trials saved in learning list again. Example, initially took 1500 seconds to learn list; took 600 seconds to relearn list; savings = 900/1500 = 60%

8. Introduction and History of Memory Research • History • experimental procedure of Ebbinghaus • Results. Ebbinghaus produced his famous forgetting curve. There is a precipitous drop in retention shortly after a list was acquired

9. Ebbinghaus’ forgetting curve

10. Introduction • History • the tradition of Ebbinghaus • highly controlled experiments • simple stimuli • quantifiable dependent measures • reaction to its restrictiveness • Gestalt psychologists, Bartlett, and cognitivists

11. Introduction • History • Cognitive tradition (William James) • In his classic text, principles of psychology, James distinguished between different types of memory • Habits were 1 type of memory that mediated skills such as walking, writing, and singing • James believed these resulted from a concatenation of reflex mechanisms and pathways, which could combine to produce complex behaviors • Two other forms of memory according to James were: • Primary memory – now called short-term working memory • Secondary memory – now called long-term memory

12. Introduction • History • Cognitive tradition (William James) • James did not explicitly distinguish between habit and memory • Bergson (1911) proposed that representation of the past has two distinct types of memories – habits and memories • As we shall see, the distinctions proposed by James and Bergson continue to be made

13. Introduction • Other traditions • ecological validity • neuropsychology • Ecological validity • argues that the Ebbinghaus tradition is concerned with unimportant problems with little applicability to real world problems

14. Introduction • Ecological validity (cont’d) • this approach, spearheaded by Neisser (1978, 1982) is controversial • and there are strong critics of this approach (e.g., Crowder)

15. Introduction • Other traditions (cont’d) Neuropsychology • Neuropsychology: study of disorders of perception, memory, language, thought, emotion, and action in neurological patients • Gall proposed theory of cortical localization in which individual cognitive functions are mediated by specific brain regions (early 1800s) • No real evidence for this idea because he examined bumps on skull, which he related to cognitive functions (e.g., pride, vanity, language, and speech)– now called phrenology

16. Introduction • Other traditions (cont’d) Neuropsychology • Broca 1861 • 51 year old man; lost power to speak (“Tan” was one of the only speech sounds he could make) • Paralyzed on right side with a loss of sensitivity • Mouth not paralyzed; he could understand speech • Autopsy revealed damage to left inferior part of frontal lobe • on the basis of a brain-behaviour case study he claimed that language is localized to the inferior part of the left frontal lobe

17. Introduction • Broca (cont’d) • two important parts of claim • 1. Language can be dissociated from other cognitive functions • 2. Language function can be localized to a particular brain region

18. Introduction • Carl Wernicke (1894) • Reported case of a patient who could produce speech, but could not understand speech • Damage to left temporal cortex suggested that this was site for speech comprehension • this approach to understanding cognitive function led to the rise of the diagram makers (1860 - 1905)

19. Introduction • Logic of diagram makers • identify distinct syndromes, then attempt to theoretically link the different syndromes • for example, they identified what they believed were several distinct types of aphasia • Broca’s aphasia--speech is nonfluent; ie, short phrases, poor melodic content, limited grammatical form • Wernicke’s aphasia-- speech is fluent, but comprehension is impaired

21. Lichtheim’s Neuropsychological model of language Function Word concept elaboration 3 Auditory word centre (Wernicke) Motor word representations (Broca) Auditory input Speech motor output

22. Criticisms of diagram makers • Work of diagram makers has a contemporary flavour and is now appealing to 20th century eyes • Work was attacked for following reasons • 1. Postulated that the functions they hypothesized could be precisely localized; evidence do not support this claim • 2. Psychological concepts were inadequate; e.g., aphasia was a word-based deficit; evidence suggests that syntax is an important component of the deficit

23. Criticisms of diagram makers • Work was attacked for following reasons • 1. Postulated that the functions they hypothesized could be precisely localized; evidence do not support this claim • 2. Psychological concepts were inadequate; e.g., aphasia was a word-based deficit; evidence suggests that syntax is an important component of the deficit • 3. Did not carefully and systematically observe the patients on which theoretical ideas were based

24. Group study approach (1940-1970) • Rejected the single-case approach to neuropsychology in favour of the group study approach • clinical observations became an insufficient basis for theoretical speculation

25. Cognitive Neuropsychology • Use information processing models to describe cognitive function; these models are very similar to Lichtheim • note: you can conceptually ‘lesion’ information processing models • returned to the use of the case study • however, an experimental approach was used • attempt to use case studies to discriminate between different models of normal function

26. Cognitive Neuropsychology • Memory findings by early neuropsychologists • early investigators studied anterograde amnesia – impaired ability to recall newly learned information • Retrograde amnesia – loss of memories acquired prior to onset of brain trauma

27. Cognitive Neuropsychology • Ribot (1882) • Reviewed a large number of cases of retrograde amnesia following brain damage and head trauma • Memories acquired remotely prior to insult were better retained compared to memories acquired more recently before insult • This result is called Ribot’s law or the law of regression • Concluded that memories require time to be organized and consolidated

28. Cognitive Neuropsychology • Alzheimer (1906) • Reported the case of a patient with dementia now known as Alzheimer’s disease (AD) • Showed that 2 important symptoms of AD were: anterograde amnesia and retrograde amnesia (graded; i.e., remote memory better retained than more recent memory)

29. Introduction: Memory • What sorts of functions are subserved by memory? • Who am I? • If you have no memory of the events that you have experienced (autobiographical memory), then it would be difficult to answer this question • What do I know? • Semantic knowledge about the world

30. Introduction: Memory • What sorts of functions are subserved by memory? • Memory for actions • procedural memory; memory is expressed by performance rather than by recollection or verbal description • how do you tie your shoelace? • How do you play a musical piece • how do you use a hammer

31. Introduction: Memory • What sorts of functions are subserved by memory? • How do I learn? • Why do I forget? Is it functional?

32. Introduction: Memory Methodology • Distinctions • Learning refers to the the acquisition of new skills and information • Memory refers to the retention of what has been learned over time

33. Introduction: Memory Methodology • The memory process is composed of three main phases: • encoding or registration: transformation of information presented to a person into a form that can be retained • retention: storage of information • retrieval: recollection or remembering of stored information

34. Introduction: Memory Methodology • Incidental versus intentional memory • Explicit memory • conscious recollection of previous experience • e.g., tell me your telephone number • e.g., try to recall when you first decided to take this course • explicit memory can be intentional or unintentional • e.g., remembering an argument you had with your friend is explicit, but may be unintentional

35. Introduction: Memory Methodology • Measuring explicit memory • recall (free or cued) • recognition • Implicit memory • indirect memory test; conscious recollection not involved • e.g., mere exposure effect; word stem completion

36. Introduction: Memory Methodology • Episodic versus semantic memory • episodic memory is memory for events or episodes; • semantic memory is the memory necessary for language; it is a mental thesaurus, organized knowledge a person possesses about words, and other verbal symbols and their meaning

37. Introduction: Memory Methodology • Independent variables • factor that influence performance of some dependent measure • in memory research it is a factor that affects memory performance

38. Introduction: Memory Methodology • Types of independent variables • organismic: relatively permanent characteristics of an individual that affect memory performance • e.g., age, intelligence, health • antecedent variables: sleep, drugs, time of day

39. Introduction: Memory Methodology • Types of independent variables (cont’d) • task variables: • instructions (e.g., intentional vs incidental) • presentation conditions (e.g., rate of presentation) • stimulus variables (e.g., picture, word, type of word) • context in which task occurs

40. Introduction: Memory Methodology • Types of dependent variables • accuracy • number of items recalled, recognized • types of errors made • scoring criterion: strict…(need to operationalize) • What do you do about guessing? • speed • order in which items were recalled

41. Introduction: Memory Methodology • Some standard memory tasks • serial learning: recall items from a list in the exact order in which they were presented • free recall: recall as many items from a list in any order • cued recall: present cue-target pairs at study; at test present cue and have participant recall target

42. Introduction: Memory Methodology • Some standard memory tasks (cont’d) • Recognition test • multiple-choice test. Participant selects which of 2 or more alternative choices is correct • true-false test (yes/no test)

43. Non-traditional memory tasks • Autobiographical memory • memory of old TV shows • famous faces

44. Non-traditional memory tasks • Implicit memory has become increasingly popular • amnesics remember information when tested using implicit memory procedures; however, amnesics are unable to remember this information when they are tested using explicit memory procedures

45. Non-traditional memory tasks • Warrington and Weiskrantz (1970) • tested amnesics and controls on explicit and implicit memory tasks • subjects were presented a list of words to study; amnesics were much inferior to controls in their explicit recall and recogniton of the studied words • also tested memory on two implicit memory tasks (word fragment identification and word stem completion e.g., cha----); on these two implicit memory tasks amnesics performed as well as controls

46. Non-traditional memory tasks • Conclusion • amnesics may have selective damage to that part of the memory system that mediates explicit recollection of stored information