TEST OF IMPLICIT MEMORY

Four possible ways of combing implicit and explicit study and test instruction: Learning can be incidental or intentional, and the test can be an indirect or a direct measure.

Test Instructions

Indirect Direct
Study Instruction Incidental Cell 1 Cell 2
Intentional Cell 3 Cell 4

  1. Intentional learning: The S is aware that the situation will require a memory test and tries to memorize the information (intentional learning).
  2. Incidental learning: the instructions require that Ss focus on some information processing goal other than on remembering the information
  3. Direct test
    1. the S is aware of the particular learning episode that should be recalled, and the test instructions make direct reference to the learning episode (direct test).
    2. conscious or intentional recollection of previously studies information
    3. Examples: free recall, recognition
  4. Indirect test:
    1. occurs when the instructions refer only to the task at hand and do not make reference to prior events (Ss are not aware of the relationship between the test and study phase)
    2. memory is inferred from the change in performance
    3. Examples
      1. identification of briefly flashed words
      2. completion of incomplete word stems and fragments
  5. Cell 1 most studies for implicit memory
  6. Cell 4 studies for explicit memory
  7. Cell 2 many level of processing studies, implicit learning but explicit testing. E.g. Ss are not told of the memory test prior to study, but at test they are asked to refer back to the study episode



EXPERIMENTAL DISSOCIATIONS

  1. A dissociation occurs when one variable is shown to affect one test differently than another
  2. Tulving, Schacter, and Stark (1982)
    1. Phase I: Ss were asked to learn a list of words
    2. Phase II: 1 hour's later
      1. word-fragment completion test or
      2. recognition test
    3. Phase III: 7 days later
      1. same tests
    4. Result: Duration of retention interval affected the direct and indirect measures differently: Long retention interval resulted in worse performance on the direct test, but no effect on indirect test., see Fig. 2-6


THE CONCEPT OF MULTIPLE MEMORY SYSTEMS

  1. Early developments from the late 1960s - the early 1980s
    1. neuropsychological research revealed that severely amnesic patients retain some learning and memory abilities
      1. Milner and colleagues: normal motor skill learning in HM
    2. distinction between episodic and semantic memory (Tulving, 1972)
    3. Normal subject: dissociations between explicit and implicit memory tests
      1. Jacoby and Dallas, 1981, see overheads from Dr. Milliken's lecture
      2. Tulving, Schacter, and Stark (1982), see Fig. 2-6
  2. The question of whether dissociations between implicit and explicit memory require that
    1. we postulate multiple memory systems or
    2. whether they should be viewed in terms of different processes operating within a unitary system
  3. The multiple memory systems view is put forward most strongly by Tulving and Schacter.
  4. Key point: Many dissociations between direct and indirect tests of memory arise because the tests tap different underlying memory systems.
  5. What is a system?
    1. Schacter & Tulving (1994) defined a memory system by describing what a memory system is not.
    2. memory system
      1. is not a memory process
      2. is not a memory task
  6. Three main criteria
    1. Class-inclusion operations
      1. A memory system enables the organism to perform a very large number of tasks of a particular class or category
    2. Properties and relations
      1. A memory system must be described in terms of property list
        1. The rules of its operation
        2. The kind of information that is processed
        3. The neural substrate
        4. A statement about the system's evolutionary purpose
        5. Relationship to other systems
    3. Convergent dissociations
      1. Single dissociations provide no evidence for postulating a new memory system
      2. However, convergent dissociations (multiple single, or double dissociations) use
        1. a variety of tasks
        2. a variety of materials
        3. a variety of populations
        4. a variety of techniques
      3. Multiple dissociations will all converge on the same conclusion
  7. Examples for the Memory systems, see Fig. 2-7