1. Memory Implicit memory
PSY 368 Human Memory
Memory
Implicit memory

2. Outline Theories accounting for Implicit vs. Explicit memory
Experiment 2 Signal detection analysis
Process-dissociation procedure, working through our example (probably not time, so after break)

3. Memory Tasks Test Instructions Study Instructions
indirect
direct
incidental
implicit memory
expts.
Levels of Processing
intentional ?
explicit memory
Study Instructions
Implicit Memory: Often defined as "memory without awareness”
Also “Non-declarative” & “procedural” (Squire, Knowlton, & Mesen, 1993)

4. Implicit/Explicit Dissociations
Many demonstrations of different effects depending on whether implicit or explicit tasks are used
Amnesic patients
Levels of processing manipulations
Pleasantness vs. vowel comparisons
Generation effect
Divided attention
Picture-word superiority
Note. Most of we’ve talked about concern repetition priming effect (study “horse” and respond “horse”)

5. Accounting for Implicit/Explicit Dissociations
Four major approaches have been proposed
The Activation view
Multiple Memory systems view
Transfer appropriate processing view
Bias View
Explicit contamination

6. Accounting for Implicit/Explicit Dissociations
Four major approaches have been proposed
The Activation view
Multiple Memory systems view
Transfer appropriate processing view
Bias View
Explicit contamination

7. The Activation View
Priming on indirect tests is attributable to the temporary automatic activation of preexisting representations.
Because it is automatic, it occurs without elaborative processing and thus has little to no contextual information
Weak Point
Can not explain priming over long time periods
Some implicit priming over days or even weeks (e.g., Sloman, et al, 1988)
Can not explain priming without pre-existing representations
The least popular of the four views

8. Accounting for Implicit/Explicit Dissociations
Four major approaches have been proposed
The Activation view
Multiple Memory systems view
Transfer appropriate processing view
Bias View
Explicit contamination

9. Multiple Memory Systems
Many dissociations between direct and indirect tests of memory arise because the tests tap different underlying memory systems.
Squire (1987)

10. Multiple Memory Systems
Many dissociations between direct and indirect tests of memory arise because the tests tap different underlying memory systems.
Tulving (1984)

11. Multiple Memory Systems
What is a system?
It is NOT a process
It is NOT a task
Some different ways that systems have been defined
Schacter and Tulving (1994)

12. Multiple Memory Systems
What is a system?
Functional Dissociations
Task that taps into system A that has no effect (or a different effect) in System B
Different neural substrates
System A involves different brain areas than System B (brain damage cases and neural imaging studies)
Stochastic independence
Performance on System A task uncorrelated with performance on a System B task
Functional incompatibility
Could involve different rates of forgetting
Function carried out by System A can not be done by System B
Schacter and Tulving (1994)

13. Multiple Memory Systems
What is a system?
Schacter and Tulving (1994)
System
Other Name
Subsystems
Characteristics
Procedural
Nondeclarative
Motor skills
Non-conscious
operation
(indirect)
Cognitive skills
Simple
conditioning
Simple associative learning
Perceptual
representation
Visual word form
Auditroy word form
Structural
description
Primary
memory
Working memory
Visual
Conscious
(direct)
Auditory
Semantic
Generic
Spatial
Factual
Relational
Knowledge
Episodic
Personal
Autobiographical
Event memory
If you “know how to do something”
Allows you to automatically recognize things
See earlier in the semester
Factual information (chpt 10)
Memory of events

14. Multiple Memory Systems
Buckner et al (1995) PET study
Brain areas
Brain imaging studies found that different areas of the brain are used when completing implicit and explicit tasks
Note: more than one structure involved in each type of memory
Perceptual vs. conceptual tasks use different brain areas

15. Multiple Memory Systems
Gabrieli et al (1995) Case study of MS
Brain areas
Brain imaging studies found that different areas of the brain are used when completing implicit and explicit tasks
Studied lists of words
Perceptual identification and recognition task
Intact performance on explicit tests of recognition and cued recall
Intact performance on implicit test of conceptual memory
Impaired performance on implicit tests of visual perceptual memory
Perceptual vs. conceptual tasks use different brain areas
MRI of MS’s brain
Suggests a specific deficit in visual implicit memory

16. Multiple Memory Systems
Buckner & Koutstall (1998) fMRI study
Brain areas
Different kinds of implicit tasks seem to involve different areas
Perceptual vs. conceptual tasks appear to use different brain areas
Conclusion: brain area involvement may be a function of type of processing and type of memory
(A) Horizontal sections from two levels show fMRI activation maps for a “shallow encoding” task contrasted with fixation and for a “deep encoding” task contrasted with fixation (averaged data from 12 normal subjects; K-S statistical activation map threshold = P < 0.001; brighter colors indicate greater significance; functional data overlie averaged anatomic image; right shown on the right). Both tasks share certain brain areas in common such as posterior visual areas whereas only the deep encoding task shows increased activation of left inferior and dorsal prefrontal areas (indicated with yellow arrows). These robust activations (P < 10−8) are at peak coordinates [Talairach 1998 atlas (91) (x, y, z)] -40, 9, 34 and -46, 6, 28 for the more dorsal activations and -40, 19, 3 and -43, 19, 12 for the more ventral prefrontal activations. The direct contrast between the deep and shallow encoding tasks also indicated that these regions differed significantly. (B) A horizontal section showing left dorsal prefrontal cortex activation in an amnesic patient during a “deep encoding” task, collected in collaboration with Verfaellie, Schacter, and Gabrieli. Robust activation was detected at -46, 3, 31 similar to normal subjects. The time course of activation within this region is shown to the right. Repeating items across the deep encoding task revealed significantly reduced activation (priming) as indicated by the time course (+, fixation control condition). This latter finding suggests that priming-related changes are present at a functional–anatomic level in amnesia, consistent with preserved behavioral priming often observed in amnesia.

17. Multiple Memory Systems
Stochastic Independence
Hayman and Tulving (1989)
Measure correlation between explicit and implicit task performance
If not correlated (independent), then tasks measure different processes
Forgetting
Tulving et al. (1989) showed a difference in forgetting rate for recognition and fragment completion
Confirmed with other tasks (stem completion)

18. Multiple Memory Systems
Strengths
Fits well with dissociations found
In patients
In experiments
Problem
Hard to find consensus on what the systems are
May be “too easy” to posit a new system

19. Accounting for Implicit/Explicit Dissociations
Four major approaches have been proposed
The Activation view
Multiple Memory systems view
Transfer appropriate processing view
Bias View
Explicit contamination

20. Transfer Appropriate Process
The key to good performance is similarity of processes involved in encoding vs. retrieval, be it implicit or explicit, perceptual or conceptual test
Implicit and explicit may refer to different processes, yet the key to performance is matching processes.
A consequence: conceptual processing is the common core in free recall and implicit conceptual tasks, hence performance on these two types of task should be equal.
Overlap
determines
retrieval
success
Processes
at encoding
Processes
at test
Perceptual implicit memory tasks: better if retrieval involves similar perceptual processes to the ones used in encoding.
Conceptual tests: TAP predictions on conceptual implicit memory tests are identical to TAP predictions for explicit memory tests.
 Perfromance on implicit conceptual memory tests should match performance on free recall.
Free recall is supposed to be the essential conceptual test. Why? Retrieval cues, as in cued recall, may involve, or trigger, perceptual processing. By contrast, free recall is entirely conceptual.
A consequence: conceptual processing is the common core in free recall and implicit conceptual tasks, hence performance on these two types of task should be equal.
 If the processing involves concepts, that assures matching processes. Category exemplar generation vs. free recall: both involve concept activation (based on relational information), therefore perfromance in the two types of task should be equal.

21. Transfer Appropriate Process
N. R. Brown, U of Alberta
Transfer Appropriate Process
Assumes:
Performance depends of match between processing at study and processing at test.
Analogous to encoding specificity.
Two-types of Processes (Jacoby, 1990)
Data-driven (perceptual) – processing of physical features.
Conceptually-driven (semantic) – processing for meaning
Typically confounded, however, it is possible to un-confound test-type from process-type
Psyco 350

22. Mixing Implicit and Explicit Effects
Jacoby (1990) proposed that implicit vs. explicit memory is confounded with two different kinds of memory processes (associated with two kinds of information)
Memory system
Mode of Processing
Declarative
(Episodic)
Procedural
(Priming)
Perceptual
(Data-driven)
Perceptual identification
Word Fragment Completion
Meaning based
(conceptually-driven)
Free Recall
Recognition
Explicit contamination

23. Transfer Appropriate Process
N. R. Brown, U of Alberta
Transfer Appropriate Process
Data-driven
(Perceptual):
fragment completion
stem completion
anagram completion
lexical decision
perceptual identification
Conceptually-driven
(Semantic):
word association
doctor  ??
category-instance generation
“name a mammal”
general knowledge
“The capital of the US is …?”
Psyco 350

24. Transfer Appropriate Process
N. R. Brown, U of Alberta
Transfer Appropriate Process
Blaxton (1989)
Goal to demonstrate
data-driven processing can affect direct tests
data-driven processing do not necessarily affect indirect tests
Data-driven
Conceptually-driven
Direct
Graphic-cued
Recall
Free Recall
Indirect
Fragment
Completion
General
Knowledge
Psyco 350

25. Transfer Appropriate Process
N. R. Brown, U of Alberta
Transfer Appropriate Process
Blaxton (1989)
S’s saw or heard lists of words (key IV here)
Target word: bashful
graphic-cued recall: looks like “bushful”
free recall
frag completion: b_sh_u_
General knowledge: “Name one of the 7 dwarfs”
Data-driven
Conceptually-driven
Direct
Graphic-cued
Recall
Free Recall
Indirect
Fragment
Completion
General
Knowledge
Psyco 350

26. Transfer Appropriate Process
N. R. Brown, U of Alberta
Transfer Appropriate Process
Blaxton (1989)
Predictions
Systems view: modality match should affect only indirect tests (if indirect tap separate system, then modality should affect them in the same way)
for both implicit tests: visual > auditory
for both explicit test: visual = auditory
Data-driven
Conceptually-driven
Direct
Graphic-cued
Recall
Free Recall
Indirect
Fragment
Completion
General
Knowledge
Same pattern of results regardless of modality
Visual better than auditory for both
Psyco 350

27. Transfer Appropriate Process
N. R. Brown, U of Alberta
Transfer Appropriate Process
Blaxton (1989)
Predictions
TAP View: modality match should affect data-driven tasks only. (priming depends on match between study/test processing match & not on indirect vs direct):
for both data-driven tests: visual > auditory
for both conceptually-driven tests: visual = auditory
Data-driven
Conceptually-driven
Direct
Graphic-cued
Recall
Free Recall
Indirect
Fragment
Completion
General
Knowledge
Visual should be better than auditory
Visual and auditory should be about the same
Psyco 350

28. Transfer Appropriate Process
N. R. Brown, U of Alberta
Transfer Appropriate Process
Results
Priming Effect (V > A) for data- driven tasks only:
indirect: frag completion
direct: graphemic-cued recall
Not all indirect tests display priming effect.
Gen Know (indirect, conceptual): V = A
Blaxton (1989)
Conclusions
Support view that processing rather than system is what is important
Psyco 350

29. Accounting for Implicit/Explicit Dissociations
Four major approaches have been proposed
The Activation view
Multiple Memory systems view
Transfer appropriate processing view
Bias View
Explicit contamination

30. The Bias View Proposed to account for repetition priming effects.
Prior presentation of an item can bias subsequent processing of the item on later presentations (if you see it once, you are more likely to interpret in the same way later)
Multiple systems attributes this to 3 separate systems, but doesn’t really offer an explanation
TAP’s answer is considered circular (you respond faster the second time because of transfer appropriate processing, which was developed to account for priming effects)
Explicit contamination

31. The Bias View Bias View’s account for repetition priming effects.
Bias entails both cost and benefits
Cost : There will be an advantage if prior processing is appropriate for the current task
Benefits : There will be a disadvantage if prior processing is inappropriate for the current task
2. Second See ambiguous woman
3. People are more likely to interpret the ambiguous picture as the same person as the unambiguous picture
Explicit contamination
1. First See
Old Woman
Young Woman
2. Second See
Ambiguous
-> Old Woman
-> Young Woman
1. First See one of old woman and young woman

32. Comparing the theories
TAP
Multiple Systmes
Strengths
Processing perspective
No “need” for separate systems (true of Bias view too)
Bias View may be seen as a complement to the TAP view
Weaknesses
Doesn’t explain impact of conscious awareness
Trouble with finer grain distinctions between tasks
Strengths
Good fit for deficit data (but may be too easy to propose “new systems”)
Weaknesses
Has troubles with some data showing differential decline in memory performance with aging
Sometimes difficult to make specific predictions in advance

33. Implicit Memory Summary
Implicit memory is memory without awareness.
Implicit and explicit tasks are not “process pure”
PDP offers a measurement method for processes
Implicit memory is different memory from explicit memory by experimental dissociations.
There is 4 main accounts for implicit memory
Probably a complex relationship between systems and processes

34. Experiment 2
Recall that for experiment 2 you each collected data from three participants.
IV – levels
Prediction: our instructions would lead participants to shift their criterion for what counts as old vs. new.
Signal detection analysis

35. Signal Detection Theory
Recognition accuracy depends on:
Whether a signal (noise/target memory) was actually presented
The participant’s response
Thus, there are four possible outcomes:
Hits
Correctly reporting the presence of the signal
Correct Rejections
Correctly reporting the absence of the signal
False Alarms
Incorrectly reporting presence of the signal when it did not occur
Misses
Failing to report the presence of the signal when it occurred
CORRECT
Used to further investigate two possible processes involved in recognition
Recognition - Old/New response + Remember/Know judgment for “Old” items
Remember = consciously recollect details of the item’s presentation
Know = sure an item was presented, but can’t recall any of the details of
Presentation
R/K responses for correct “Old” items have been shown to differ for the
following effects:
Typically studied pics are better remembered than words (picture superiority
effect) R: Pics > words and K: words > pics
Generate similar or related word
Hot - ?
Cat - ?
vs. reading hot-cold and cat-dog
INCORRECT

36. Signal Detection Theory
Calculating d’ and C (or β)
Discriminability (d’):
Step 1) Look up the z-score for the average Hit and False Alarm rates.
Step 2) Apply the formula d’ = zHIT – zFA, where zFA is the z-score for FAs and zHIT is the z-score for Hits.
Criteria C (or β):
Take the negative of the average of zHIT and zFA. This is the criterion value C.
Remember that positive C values indicate a conservative response bias, while negative C values indicate a liberal response bias.
Used to further investigate two possible processes involved in recognition
Recognition - Old/New response + Remember/Know judgment for “Old” items
Remember = consciously recollect details of the item’s presentation
Know = sure an item was presented, but can’t recall any of the details of
Presentation
R/K responses for correct “Old” items have been shown to differ for the
following effects:
Typically studied pics are better remembered than words (picture superiority
effect) R: Pics > words and K: words > pics
Generate similar or related word
Hot - ?
Cat - ?
vs. reading hot-cold and cat-dog

37. Experiment 2 N=21 per condition Neutral
Target
Lure
“Old”
Hit
15.05
0.75
False Alarm
2.48
0.12
N=21 per condition
Neutral
Total possible hits or false alarms = 20
Target
Lure
“Old”
Hit
12.05
0.60
False Alarm
1.14
0.06
Conservative
Averages
Proportions (avg/20)
Target
Lure
“Old”
Hit
16.95
0.85
False Alarm
4.38
0.22
Liberal

38. Experiment 2 http://memory.psych.mun.ca/models/dprime/ d’ = 1.85
Target
Lure
“Old”
Hit
15.05
0.75
False Alarm
2.48
0.12
d’ = 1.85
C = 0.25
Neutral
Target
Lure
“Old”
Hit
12.05
0.60
False Alarm
1.14
0.06
d’ = 1.81
C = 0.65
Conservative
Target
Lure
“Old”
Hit
16.95
0.85
False Alarm
4.38
0.22
d’ = 1.81
C = -0.13
Liberal

39. Experiment 2 d’ Neutral d’ = 1.85 C = 0.25 Conservative d’ = 1.81
stimulus intensity
probability
Noise
Signal
(remember)
d’ = 1.85
C = 0.25
Conservative
d’ = 1.81
C = 0.65
Liberal
d’ = 1.81
C = -0.13

40. Experiment 2 Neutral d’ = 1.85 C = 0.25 Conservative d’ = 1.81
- Criterion +
Neutral
stimulus intensity
probability
Noise
Signal
(remember)
d’ = 1.85
C = 0.25
New
Old
Conservative
d’ = 1.81
C = 0.65
Liberal
d’ = 1.81
C = -0.13

41. Experiment 2 Neutral d’ = 1.85 C = 0.25 - Criterion +
stimulus intensity
probability
Noise
Signal
(remember)
d’ = 1.85
C = 0.25
New
Old

42. Experiment 2 Conservative d’ = 1.81 C = 0.65 - Criterion +
stimulus intensity
probability
Noise
Signal
(remember)
New
Old
Conservative
d’ = 1.81
C = 0.65

43. Experiment 2 Liberal d’ = 1.81 C = -0.13 - Criterion +
stimulus intensity
probability
Noise
Signal
(remember)
New
Old
Liberal
d’ = 1.81
C = -0.13