Introduction and History of Memory Research

1
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

2
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

3
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

4
Introduction and History of Memory Research

• History
• Ebbinghaus (1885) published Memory A
  contribution to Experimental Psychology
• first experimental study of memory inspired by
  Fechners work on the psychophysical study of
  sensation

5
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)

6
Introduction and History of Memory Research

• History
• experimental procedure of Ebbinghaus
• Procedure (contd). Ebbinghaus was concerned with
  the rate of forgetting as a function of the time
  interval between initial learning and his attempt
  to recall the list. If he made one or more
  errors, Ebbinghaus restudied list until he could
  recite the list perfectly. The 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 500 seconds
  to relearn list savings 900/1500 60

7
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

8
Ebbinghaus forgetting curve
9
Introduction

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

10
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

11
Introduction

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

12
Introduction

• Other traditions (contd) Neuropsychology
• Neuropsychology study of disorders of
  perception, memory, language, thought, emotion,
  and action in neurological patients
• Broca 1861
• on the basis of a brain-behaviour case study he
  claimed that language is localized to the
  inferior part of the left frontal lobe

13
Introduction

• Broca (contd)
• 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
• this approach to understanding cognitive function
  led to the rise of the diagram makers (1860 -
  1905)

14
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
• Brocas aphasia--speech is nonfluent ie, short
  phrases, poor melodic content, limited
  grammatical form
• Wernickes aphasia-- speech is fluent, but
  comprehension is impaired

15
(No Transcript)
16
Lichtheims Neuropsychological model of
language Function
Word concept elaboration
3
Auditory word centre (Wernicke)
Motor word representations (Broca)
Auditory input
Speech motor output
17
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

18
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

19
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

20
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

21
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

22
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

23
Introduction Memory

• What sorts of functions are subserved by memory?
• How do I learn?
• Why do I forget? Is it functional?

24
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

25
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

26
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

27
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

28
Introduction Memory Methodology

• Episodic versus semantic memory
• episodic memory is memory for events or episodes
  it is stored in terms of its autobiographical
  reference to already stored information
• 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

29
Introduction Memory Methodology

• Independent variables
• factor that influence performance of some
  dependent measure
• in memory research it is a factor that affects
  memory performance

30
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

31
Introduction Memory Methodology

• Types of independent variables (contd)
• 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

32
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

33
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

34
Introduction Memory Methodology

• Some standard memory tasks (contd)
• Recognition test
• multiple-choice test. Participant selects which
  of 2 or more alternative choices is correct
• true-false test (yes/no test)

35
Non-traditional memory tasks

• Autobiographical memory
• memory of old TV shows
• famous faces

36
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

37
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

38
Non-traditional memory tasks

• Conclusion
• amnesics may have selective damage to that part
  of the memory system that mediates explicit
  recollection of stored information