Reconstructive memory

1
Reconstructive memory

• Another insight.
• We dont just activate what we encoded.
• We reconstruct.
• Often inaccurate.

2
Eyewitness memory

• Loftus
• Phase I - Car stopping at an intersection.
• Either stop (or yield) sign.
• Phase II - Questions
• Did the car stopped at a yield (or stop) sign?
• Phase III - Recognition
• Stop sign vs Yield sign
• Phase II often influences Phase III

3
False Memory

• Roediger and McDermott (1995)
• Water, stream, lake, Mississippi, boat, tide,
  swim, flow, run, barge, creek, fish, bridge,
  winding
• Stream? Creek? Lake? River?
• Confidence level is high.

4
Why?

• Implicit activation during encoding.
• Reconstructive memory
• Fuzzy trace theory
• Verbatim memory
• Gist memory

5
Flashbulb memory

• Emotional events.
• Remember like taking a photograph.
• Accurate?
• Maybe or maybe not.

6
Implicit memory

• Unconscious retrieval - indirect test
• Big question
• How do you know implicit is different from
  explicit?
• Answer
• Experimental dissociation
• single dissociation
• double dissociation

7
Single dissociation

• One variable X affects one memory test but not
  the other test.
• Test A
• X
• Test B

8
Double dissociation

• One variable Xaffects one memory test but the
  other variable Y affects the other test.
• X Test A
• Y Test B

9

• Double dissociation is more difficult to obtain
  than single dissociation.
• Most of the evidence - single dissociation.

10
Jacoby (1983)

• Used
• implicit test - Perceptual identification
• explicit test - recognition test
• Manipulated - Study method
• Generate - hot - c_____
• Context - hot - cold
• No context - xxxx - cold

11

• Found
• Explicit test - Generate gt Context gt No context
• Implicit - No context gt Context gt Generate
• Study method influences explicit and implicit
  tests differently.

12
Kihlstrom (1980)

• Used
• implicit test - free association
• explicit test - free recall
• Compared - hypnotizability
• Very high
• high
• Medium/low

13

• Procedure
• Under hypnosis, they learned a list of words.
• Then, post hypnotic suggestion - you forget the
  words.
• After being awaken, they took the test.

14

• Found single dissociation.

15
Warrington and Weiskrantz (1974)

• Used
• implicit - word stem completion word fragment
  completion
• explicit - free recall and recognition
• Compared - normal vs. amnesic
• normal
• amnesic - Korsakoff Brain damaged

16

• Found
• single dissociation
• Amnesic patients have similar implicit memory as
  normal people.
• Amnesic condition does not wipe out all memories.

17
Schacter et al. (1991)

• Used pictorial material.
• Implicit - perceptual decision (possible objects)
• Explicit - recognition
• Manipulated - studying method
• perceptual - an object is facing left or right
• conceptual - which category (e.g., furniture)

18

• Found
• Single dissociation
• Encoding method influenced explicit memory but
  not implicit memory.

19
So, many concluded that..

• Explicit and implicit memories are different
  types of memory.

20
Theories

• What is the difference?
• Tulving
• Explicit - Retrieval from episodic memory
• Used to store personal memories.
• Encoding method matters.
• Implicit - Activation of semantic memory
• Used to comprehend language.
• Encoding method does not matter.
• Elephant is elephant no matter how you encode it.

21

• Roediger
• Implicit - Data driven process
• Activation of perceptual trace.
• The way it was presented matters.
• E.g., modality effect
• Auditory - Visual
• Visual - Visual
• Transfer appropriate processing

22

• Explicit - Conceptually driven process.
• Activation of conceptual trace - proposition.
• It doesnt matter how it was presented.
• No modality effect.
• Anderson
• Explicit - Declarative memory
• You can make it conscious.
• Study method - influences retrievability

23

• Implicit - Procedural
• You cannot make it conscious.
• E.g., swimming