Lecture 8 – Psyco 350, B1
Fall, 2011
N. R. Brown
Psyco 350 Lec #8– Slide 1
Outline
• Factors that influence Storage:
–
–
–
–
Rehearsal
Organization
Generation
Levels of Processing
• Encoding & Retrieval – context effects
– Independent Contexts
– Interactive Contexts
• Forgetting
–
–
–
–
decay
retrieval failure
interference
Inhibition (directed forgetting)
Psyco 350 Lec #8– Slide 2
Craik & Lockhart’s Interperation
•
•
•
•
Cog system organized hierarchically
input processed @ different levels: sensory  semantic
product of earlier analysis is input to latter analysis
Memory trace “simply [a] record of those analysis”
“deeper more semantic analysis yields records that are
more durable.”
===========================================
But why?
Traces:
– richer, more elaborate – “more stuff”
– semantic encoding more distinctive
Psyco 350 Lec #8 – Slide 3
Criticisms of Levels
Nelson (1977) :
• circularity = there is no independent measure
of depth in the framework
• how can you rank order these “levels”?
– Is it green?
– Is it an animal?
– Does it contain an R?
– Is it GORF reversed?
– Does it rhyme with DOG?
Psyco 350 Lec #8 – Slide 4
Value of Levels
• places emphasis on processes
• introduced a technique—incidental learning
with an orienting task—for studying encoding
processes
• fits well with transfer appropriate processing
view.
Psyco 350 Lec #8 – Slide 5
Context & Memory
• Context:
-- stimuli present “at the same time” as the target
eventn = content + contextni + contextnj…
Context encoded (almost) automatically w/ content
• encoding context can serve as retrieval path
• test context can serve as a retrieval cue
General Principle:
when test context ≈ study context, performance 
Psyco 350 Lec #8 – Slide 6
Two Types of Contexts
•
Independent
–
–
•
external – environmental, location
internal – physiological, emotional
Interactive
–
semantic: strawberry – JAM vs traffic – JAM
Encoding Specificity Principle:
“The probability of recalling an item at test
depends on the similarity of its encoding at
test and its encoding at study”
-- Anderson, p 206
Psyco 350 Lec #8– Slide 7
State-Dependent Memory
General Approach for studying context effects:
materials studied in StateX
materials tested in StateX or StateY
State-dependent memory effect observed when
memory is better when study & test states
match than when they mismatch.
Psyco 350 Lec #8– Slide 8
Context-Dependent Memory:
Godden & Baddeley, 1975
Study
land
underwater
X
Test
.
land
underwater
===========================================
Participants: 16 divers
Materials: 40 words
Results:
LL >> LU
UU >> UL
Psyco 350 Lec #8– Slide 9
Mood-Congruent Memory
Eich & Metcalfe (1989)
• Induce mood by using music.
• Read or generate during study
Study-Test Design:
Study
happy
sad
X
Psyco 350 Lec #8– Slide 10
Test
happy
sad
.
Mood Congruence: Eich & Metcalf (1989)
Results:
• Generation Effect:
– generate >> read
• Mood Congruence:
– H/H >> H/S
– S/S >> S/H
• “floor” effect for read condition?
Psyco 350 Lec #8– Slide 11
State-Dependent Memory: Alcohol
Goodwin et al (1969)
• Manipulation: 10 oz of 80 proof vodka; 24 hr study-test delay
• Standard 2 X 2: (I)ntoxicated/I, S(ober)/S, I/S, S/I
• Results: (a) S/S < SI; (b) I/I < I/S; (c) S/I < I/I
• Point (C) encoding better when sober.
Psyco 350 Lec #8– Slide 12
State-Dependent Memory: Marijuana
Eich et al (1975)
• Manipulation: m(arijuana) vs t(obacco); 4 hr studytest delay.
• Standard 2 X 2: m/m, t/t, m/t, t/m
• Results: (a) t/t > t/m; (b) m/m >m/t; (c) t/m > m/m
• Point (C) encoding better when straight.
Psyco 350 Lec #8– Slide 13
State-dependent Memory
State-dependent effect strong for recall than
recognition.
• Reason: recall requires more cues, and state
provides context cues
Sober@study >> Blasted@study, regardless of
test state.
• Reason: attention, comprehension, &
elaboration processes more effective when
sober.
Psyco 350 Lec #8– Slide 14
Interactive Contexts
General idea:
• event traces encode meaning
• meaning emerges from the meanings of the
focal element and its semantic context.
 retrieval cues that access encoded meaning
will be more effective than those that do not
Retrieval Cue:
–
A hint that can be used to evoke an item that has been learnt
but cannot be spontaneously recalled
Psyco 350 Lec #8– Slide 15
Encoding Specificity w/ Interactive Contexts
Thomson & Tulving (1970)
Aim: demonstrate that recall depends on match
between encoded and cued meaning.
Materials: 24 word pairs
• Design: Input Contexts (2) X Output Cues (3)
Input Contexts:
Strong: hot – COLD
Weak: wind – COLD
Output Cues: strong, weak, no-cue
Psyco 350 Lec #8– Slide 16
Results: Thomson & Craik (1970)
Strong
Output Cue
Weak
No Cue
Strong Input
83%
4%
30%
Weak Input
33%
73%
30%
• Recall best when input & output match
• Mismatch misdirects search.
Psyco 350 Lec #8– Slide 17
LoP & Encoding Specificity
Fisher & Craik (1977)
Aim: Demonstrate LoP and ES in same Exp.
Design:
Encoding Task X Encoding Response X Retrieval Cue
rhyme
YES
rhyme
category
NO
category
sentence
sentence
Psyco 350 Lec #8– Slide 18
Fisher & Craik (1977): Encoding Tasks
Target Word: train or house
Encoding Tasks:
rhyme: Does the word rhyme with brain?
category: Is it a form of transportation?
sentence: John took the ____ to Cleveland?
Psyco 350 Lec #8– Slide 19
Fisher & Craik (1977): Results
LoP
.22
.58
.51
• LoP Effect:
– Category ≥ Sentence >> Rhyme
Psyco 350 Lec #8– Slide 20
Fisher & Craik (1977): Results
.22
.58
.51
• LoP Effect:
– Category ≥ Sentence >> Rhyme
• Encoding Specificity :
– encoding-retrieval cue matches > mismatches
– example: Transfer Appropriate Processing – match re:
processing
•
Why is cat/rhyme (43%) > rhyme/rhyme (40%)?
Psyco 350 Lec #8– Slide 21
Encoding & Retrieval: Main Points
• Memory Trace is combination of the “stimulus”
and the context.
• Context broadly defined
– environmental, physiological, semantic,
procedural
• Performance depends on:
– encoding processes
– similarity between study context & test context
Psyco 350 Lec #8– Slide 22
Forgetting – General Approaches
• Decay – information in memory fades w/ time &
disuse.
“Memory trace spontaneously deteriorates over time.”
-- A.B.
• Retrieval failure – retrieval cues do not access
sought after information.
• Interference – retrieval of sought-after-information
hindered by presence of other information.
“memory either masks or obliterates other information”
Psyco 350 Lec #8– Slide 23
Ebbinghaus(1885): The 1st Forgetting Function
• Task: learned lists of 13 CVCs to criterion (2 perfect
runs through list).
• Manipulation: Study-test delay
• Dependent Variable: savings in relearning
Psyco 350 Lec #8– Slide 24
Ebbinghaus(1885): The 1st Forgetting Function
• Main Findings:
– rate of forgetting decreases w/ time
• Interpretation:
– forgetting driven by decay; information lost at a
constant rate.
Psyco 350 Lec #8– Slide 25
Decay: In Principle Problem
• Robust evidence for:
– Proactive Interference
– Retroactive Interference
• To provide decay, it is necessary to:
– control PI; all prior experience must be held
constant
– control RI; all subsequent experience must be
help constant.
Psyco 350 Lec #8– Slide 26
Decay: The Consensus
• "The definitive decay experiment is, as far, we know
impossible... It is currently impossible to isolate the decay
effect, or to separate it from interference... Even though it
[Decay] is extremely controversial and has not been
demonstrated to anyone's satisfaction, it [Decay] has been
routinely incorporated as a subprocess into many recent
memory models." -- Houston, pp. 246-247
• "Unfortunately it's [Decay Theory] wrong, at least as far as longterm memory is concerned." --Ashcraft, p.224
Psyco 350 Lec #8– Slide 27
Decay: Empirical Problems
Very Long-term Memory (Permastore):
• for high school classmates (Bahrick et al, 1975)
• for foreign languages (Bahrick, 1984)
Psyco 350 Lec #8– Slide 28
Bahrick et al., 1975
Recognition of names & faces
(almost) unaffected by passage
of time.
Psyco 350 Lec #8– Slide 29
Bahrick, 1984
Forgetting halted
after 3 years.
Psyco 350 Lec #8– Slide 30
Anderson's Defense of Decay
1. Decay Functions Exist
A number of long-term forgetting functions look
like power-law, decay functions – demonstrate
that information is lost at a constant rate.
2. The Physiological Argument.
“It may be that there is not explanation of decay at the purely
psychological level....It has been shown that synaptic
efficacy deteriorates with lack of use, and apparently this
deterioration follows a power law. Thus, it may be that
mechanism underlying the very powerful lawful functions."
--Anderson, p. 175
Psyco 350 Lec #8– Slide 31
Decay Functions in Autobiographical Memory
Brown et al. (in prep)
Percentage
of Retrieved Events
36
Bosnia
Montenegro
Serbia
32
28
24
NYC
A2
20
Canada
16
Denmark
Israel
12
8
4
01
12
23
34
45
56
67
78
89- 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
-2
1
>2
1
0
Estimated Event Age (Years)
Psyco 350 Lec #8– Slide 32
Decay Functions in Autobiographical Memory
Brown et al. (in prep)
Percentage
of Retrieved Events
36
Bosnia
Montenegro
Serbia
32
28
24
NYC
A2
20
Canada
16
Denmark
Israel
12
8
4
01
12
23
34
45
56
67
78
89- 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
-2
1
>2
1
0
Estimated Event Age (Years)
• word-cue method:
– respond to word cue w/ 1st AM that comes to mind.
– estimate date of retrieved event
• Participants:
– age: 20-30 yrs old
– locations: 7 countries
Psyco 350 Lec #8– Slide 33
Anderson's Defense of Decay
1. Decay Functions Exist
A number of long-term forgetting functions look
like power-law, decay functions – demonstrate
that information is lost at a constant rate.
2. The Physiological Argument.
“It may be that there is not explanation of decay at the purely
psychological level....It has been shown that synaptic
efficacy deteriorates with lack of use, and apparently this
deterioration follows a power law. Thus, it may be that
mechanism underlying the very powerful lawful functions."
--Anderson, p. 175
Psyco 350 Lec #8– Slide 34
Retrieval Failure
• Premise:
– Information not lost from memory.
– Cause of forgetting: absence of correct cue.
– forgetting from an Encoding Specificity perspective
Psyco 350 Lec #8– Slide 35
Retrieval Failure: A demonstration
Tulving & Pearlstone (1966)
Materials: 48 words – 12 categories X 4 instances
Group:
Uncued – free recall
Cued: cued with the 12 category names
Results: Cued (62%) > Uncued (40%)
Conclusion: In uncued condition, information was
available, but not accessible.
Availability = probability information was stored
Accessibility = degree to which info can be retrieved
Psyco 350 Lec #8– Slide 36
Interference
Interference – retrieval of sought-after-information
hindered by presence of other information.
• Negative Transfer
– Previously learning impedes new learning
• Proactive Interference (PI)
– Older knowledge impedes access to new knowledge
• Interference forward in time
• Retroactive Interference (RI)
– New knowledge impedes access to old knowledge
• Interference backward in time
• Associative Interference
– atemporal -- related knowledge competes with target
Psyco 350 Lec #8– Slide 37
Associative Interference: The Fan Effect
Anderson (1974)
Study:
26 sentence – The person is in the location.
Test:
Time recognition of presented & recombined
sentences
Design:
sentences/person (1 or 2) X sentences/location (1 or 2)
Psyco 350 Lec #8– Slide 38
The Fan Effect: Anderson (1974)
Design:
sentences/person (1 or 2) X sentences/location (1 or 2)
1. The doctor is in the bank (1-1)
2. the fireman is in the park (1-2)
3. The lawyer is in the church (2-1)
4. The lawyer is in the park (2-2)
Psyco 350 Lec #8– Slide 39
Anderson (1974): Results
• RT  60 msec/link i.e., additional links INTERFER w/
retrieval.
• Explanation:
– activation passed to target , as # of links 
• Additional finding – “chunking” decreases fan effect.
Psyco 350 Lec #8– Slide 40
Studying PI & RI
• Classic studies: paired associate learning
– study: cue-target word pairs (CUP-tree)
– test: given cue, recall target (CUP-???)
– manipulate presence, timing & similarity of
additional targets
Psyco 350 Lec #8– Slide 41
Studying PI & RI
Design
Proactive
Retroactive
List 1
A-B
D-E
A-B
A-B
List 2 Test
A-C A-?C?
A-C A-?C?
A-C
D-E
A-?B?
A-?B?
Exp
Control
Exp
Control
General Findings:
•
•
Cued Recall: Control > Experimental
Similarity Effects: the more similar B is C, the more
server the interference.
Psyco 350 Lec #8– Slide 42
PI & RPI: Background
Brown & Peterson Task Review
• Task: learn triplet  filled delay  recall triplet
• Finding:
– recall drops off very rapidly w/ delay
• Original Interpretation:
– Forgetting caused by decay in STM
– Forgetting indicates the rate of loss from STM
• Alternative Interpretation (Keppel & Underwood):
– Forgetting caused by PI from similar materials
• Implication: PI should be reduced when new list
differs from prior lists.
Psyco 350 Lec #8– Slide 43
Release from PI: Wickens (1972)
• Task: Standard Brown-Peterson Task
• Procedure:
– Trials 1 though 3: triples drawn from same
semantic category
– Trial 4: triple drawn from different category
Psyco 350 Lec #8– Slide 44
Wickens (1972): Materials
Psyco 350 Lec #8– Slide 45
Wickens (1972): Results
• PI  (recall ) across
same-category trials.
• when category changes,
Recall 
Release from PI
• RPI  as similarity
between initial category
and new category 
• Finding generalize to realworld material (news stories)
Psyco 350 Lec #8– Slide 46
Gunter, Berry, Clifford (1981): RPI w/ News Stories
• Replicates Wickens with news stories.
e.g., 3 sets of political stories  1 human interest story
Psyco 350 Lec #8– Slide 47
RPI: Activation-Discrimination Interpretation
Activation:
• Concepts activated when accessed
• Activation decays rapidly
Retrieval: search some (cued) portion of memory for
most active concepts.
-------------------------------------------------------------------------PI: difficult to discriminate between many activated
concepts.
RPI: relatively easy to select active concepts among
inactive ones.
Psyco 350 Lec #8– Slide 48
RI -- Recent learning impedes recall of prior
material
Slamecka (1960) – a lab demonstration
Materials: 20-word long sentences drawn from
text books.
Study: Sentence present 1 word/3 seconds
Test: Verbatim recall
Design:
# Learning Trials X # Interpolated Trials
2
0
4
4
8
8
Psyco 350 Lec #8– Slide 49
Slamecka (1960): Results
IMPORTANT:
study-test delay constant
across interpolation
conditions
• Recall  w/ # learning
trials (rehearsal effect)
• Recall  w/ #
interpolated trials (RI)
Psyco 350 Lec #8– Slide 50