1. Memory
How does memory work?

2. The Modal Model Basic info-processing model of memory
Atkinson-Shiffrin 1968
The modal model
Sensory Registry
Short-Term
Memory
Long-Term
Memory
Attention
Rehearsal

3. Sensory Memory Recall Sperling
Participants view a briefly presented array of letters.
Tone cued participants to recall items.
Change the duration between presentation of array and the recall tone
Partial report suggested sensory memory is rather large but has a short duration

4. Short-term memory
The theory of STM was brought about during the cognitive revolution and is a product of the information processing perspective
It proposed that attended information went into an intermediate short-term memory where it had to be rehearsed (processed) before it could go into a relatively permanent long-term memory.
STM is biased toward keeping recent information available and has a limited capacity to do so.
Memory span - the number of elements one can immediately repeat back

5. Short-term memory
In a study of memory span, participants might rehearse digits by saying them over and over again to themselves
With each rehearsal of an item, it was assumed there was a probability that the information would be transferred to a relatively permanent long-term memory
If the item left short-term memory before a permanent long-term memory representation was developed, however, it would be lost forever
One could not keep information in short-term memory indefinitely because new information would always be coming in and pushing out old information from the limited short-term memory

6. Short-term memory One of the questions with STM regarded its duration
What determines the duration of STM?
Decay?
Gradual loss of memory “strength” over time.
Interference?
Access to information is blocked by the retrieval of other information
Overwriting?
Original memory trace is altered

7. Decay Brown-Peterson Paradigm
“You will not be shocked during this experiment”
Study unrelated information
‘T’ ‘K’ ‘B’
“wood” “dog” “candy”
Count backward by 3’s
Prevent rehearsal
Vary duration of counting
Recall studied items

8. Brown-Peterson Interval of counting (sec.) Decay
100
Proportion of correct recalls 1 18
Interval of counting (sec.)
Decay
(on average) memory information is accessible up to 18 seconds.

9. Decay Reconcilable with sensory memory
Use it or lose it.
Once memory is established, decay is constant
What constitutes “established”?
Is it always ~18sec.?

10. Very Rapid Forgetting
Sebrechts, Marsh, & Seamon (1989) based on Muter (1980)
Used a modified Brown-Peterson paradigm with false trials.
B-P task
Acoustic (shallow)
Long E sound?
Semantic
Is it animate?
Reading
say the stimuli aloud
Exp 1 regular B-P experiment
Exp 2 “Surprise” memory test

11. Sebrechts, Marsh, Seamon
Ss presented words sequentially and made a yes/no decision for each word presented or just read aloud depending on condition
Countdown followed
Brown-Peterson trial
WOOD KEY TIME
382
Recall

12. Sebrechts, Marsh, & Seamon
Forgetting within 6 seconds
Expectation of retrieval is necessary to maintain information in memory, but also elaboration can have an effect
So again the idea of decay doesn’t provide for the whole story
100
B-P
Proportion Recalled
.27
.44
Acoustic
.35
.55
Semantic
.52
.73
Reading
Non-Exp
Expect
LOP
Proportion of words recalled*
Surprise Trials 1 18
Interval of counting (sec.)
*They looked also at the strict scoring i.e. remembering the whole trigram,
the pattern was the same but with poorer performance overall

13. Interference Memory is more active
Newly encountered information (if used) limits the access to previous information.
Interference is often confounded with “decay”

14. Interference Waugh & Norman (1965)
Present a set of 16 digits at a fixed interval.
1 digit per second
4 digits per second
Last digit in the set served as a probe, and had previously been presented once
Report the digit that appeared after the probe digit had appeared in the list the first time (target)
Manipulate the number of digits that appear between target and the probe
Retention interval
If forgetting is a function of decay (time) then there should be less recall for slower rate (16 secs) vs. faster rate (4 secs)
If interference then should be little to no difference between the two

15. Number of items between target & probe
Waugh & Norman
100
Proportion Correct
1 Cond.
4 Cond. 1 13
Number of items between target & probe
More about the number of items that interfered rather than decay
over time

16. Interference
So the Waugh and Norman results suggest interference from additional information can disrupt memory for particular items
Two types of interference
Retroactive Interference
New information interferes with previously learned information
Proactive Interference
Previously learned information interferes with the acquisition of new information

17. Interference
A possible explanation for interference is that when given cue, information associated with cue interferes with other info also associated with cue
More items a cue is stored with the less effective it will be in retrieving any one particular item
Recall fan effect
But along with interference as another possible explanation of forgetting, the Sebrechts et al., shows other factors will have a say in how forgetting occurs
Expectancy
‘Depth’ of encoding

18. The decline of STM
The idea of a short-term passive ‘store’ fit in with the current information processing models
Rapid forgetting
Transient nature suggests different type of store
Amount of rehearsal controlled the amount transferred to LTM
More rehearsal more remembering
Info had to ‘do time’ before getting to LTM

19. The decline of STM Problems
Loss similar for better learned material (initial rapid loss followed by slower loss later)
Rehearsal by itself won’t determine what makes it to LTM:
Chunking
7 + 2
What may be chunked and how chunking occurs can depend on a variety of factors and varies across individuals
Depth of processing (Craik & Lockhart, 1972)
The Sebrechts article was an example of how DoP had a role even if there was decay
Some experiences gain immediate access to LTM
E.g. traumatic events
Such findings suggested there was more to short-term memory functioning than as a passive storage device

20. Working Memory
Function: short-term retention and manipulation of information.
Active memory
Issues regarding working memory
How long?
How much?
What type?
Capacity
Forgetting curve (Brown-Peterson)
Miller’s 7 +/- 2

21. Baddeley Model of WM Based on perceptual codes Acoustic
Visual and Spatial
Information can be retained separate from its use for a short time
Coordinating process guides the use of retained information
Central Executive
“Slave” systems
“Rehearse” information for a short time
Perceptually based

22. Baddeley’s Model of WM Central Executive Visuo-Spatial Sketchpad
Phonological
Loop
Central Executive
Coordinates the Slave Systems
Response Selection
Guides Attention
Maintains visual and
spatial information
Maintains acoustic
information

23. Phonological Loop Two components
Phonological store
Articulatory control process
Subvocal articulatory rehearsal
Traces within the store decay over a period of about two seconds unless refreshed by rehearsal, a process akin to subvocalization and one that is dependent on the second component, the articulatory system
Important for long-term phonological learning
e.g., language learning

24. Some evidence for the loop
Phonological similarity effect
PGTVCD vs. RHXKWY
Similar phono code leads to confusion
Irrelevant speech effect
Colle & Welsh (1976): even a foreign language can interfere with immediate recall of items
Because of the nature of the code, the language gains access to the phono store
Articulatory suppression
Operation of the loop is disturbed if overt or cover articulation takes place
Vocalization utilizes same system as subvocal rehearsal, and hence can lead to difficulty learning verbal information
Word length effect
Span decreases as the length of a word increases
Less can be rehearsed within the ~2 sec time frame

25. Visuo-spatial Sketchpad
Temporarily maintains and manipulates visuospatial information
Plays an important role in spatial orientation and in the solution of visuospatial problems
Both visual (imagery) and spatial component
Possibly two different systems

26. Some evidence for the sketchpad
Baddeley & Lieberman (1980)
Visual tracking interferes with imagery mneumonic
Irrelevant picture effect
Same result even from just looking at visual stimuli

27. Central Executive Most complex and least understood component of WM
Model suggests CE coordinates the activity of the two slave systems
Other potential roles
Coordinating retrieval strategies
Selective attention
Suppression of habitual responses
Task switching
Temporary activation of long term memory
Binding of sensory and conceptual information

28. Assumptions and Predictions
Slave systems are independent of each other
It is possible to do a both a verbal task and a spatial task at the same time
Extremely difficult to do two verbal (or two spatial) tasks at the same time.
Dual-Task Paradigm
Participant must perform more than one task at a time
Slave systems have limited capacity
Span
Slave systems can function autonomously from the Central Executive
Can do “Central Executive tasks” and slave system tasks at the same time
Central Executive coordinates information based on current goals
Implies intentional (conscious) control of WM
Coordination involves many processes.

29. The Episodic Buffer
“A limited capacity temporary storage system that is capable of integrating information from a variety of sources”
Controlled by the CE
Feeds information into and retrieves information from LTM
Uses a common “multidimensional” code
The Episodic Buffer makes the link between Working Memory and LTM more explicit

30. Working Memory Today

31. Long-term memory
Basically includes anything retained that did not occur few moments earlier
Source of information that does not come from the environment

32. Learning
Storage of information in memory as a consequence of experience
Process of acquiring new associations among stimuli, responses and outcomes.
What is Learned?
How is it Learned?
Associative theories
Learning
Cognitive theories
Encoding and Retrieval

33. Classical Conditioning
Characterized by the generalization of a fixed or previously learned behavior
Responses are elicited from stimuli
Unconditioned stimulus (US)
Elicits a response without training
Shock
Unconditioned Response (UR)
Elicited without training by a (US)
Smacking whoever gave you the shock
Conditioned Stimulus (CS)
That which through training elicits a particular response
Pretty flowers
Conditioned Response (CR)*
Response to the conditioned stimulus
Smacking whoever gives you pretty flowers

34. Operant / Instrumental Conditioning
Based on the principle of reinforcement
What is reinforced?
What is reinforcing?
Development of associations between particular responses and consequences of the response (outcomes).

35. Basic Mechanisms of Operant Conditioning
Behaviors have consequences
Consequences are contingent on behaviors
Organisms adapt behavior to match contingencies
Consequences usually satisfy a “drive”
Biological need
Motivational need
Well-being of individual

36. Consequences of Behavior
Reinforcement or Punishment
Reinforcement
Consequences of behavior increase the probability of response (behavior)
Punishment
Consequences of behavior decreases the probability of response
Both Reinforcement and Punishment can be positive or negative
Positive: presentation of stimuli
Negative: removal of stimuli
The result is a table of contingencies…

37. Reinforcement and Punishment
Response
Increase (rein.)
Decrease (pun.)
Positive Reinforcement
(reward)
Positive Punishment
(punishment)
Apply a stimulus (+)
Stimulus
Negative Reinforcement
Negative Punishment
(omission)
Remove a stimulus(-)

38. Associative Learning Accounts for certain types of memory phenomena
Memory Structure
Highly practiced information
Habitual responses
Stimulus generalization
Assumes memory mechanism is the same as associative mechanism (single system)

39. Associative Memory
Associative memory theory alone cannot account so well for other phenomena
Free Recall
No cue
Subjective organization
Von Restorff Effect
Effect of stronger memory for a salient item in a series
Sensory Memory
“Direct” memory of sensory information
Short-term representations
No Practice
Complexity of language acquisition/production
Systematic memory distortions

40. Beyond association
Although simple associative mechanisms described by classical and operant conditioning may account for some aspects of learning, more was needed
Subtle shift from learning theories to theories of memory, which emphasized knowledge representation in an information processing system
Focused on encoding and retrieval processes to help explain memory performance in a variety of settings
Levels of Processing
Encoding specificity
Transfer appropriate processing

41. Basic Mechanisms of Memory
Encoding
Acquisition of Information
“Learning” ?
Maintenance
Retaining information
Retrieval
Using information
How do the processes of Encoding and Retrieval influence what is remembered?

42. Levels of Processing Craik & Lockhart (1972)
Formalized the notion of “depth” of processing and demonstrated how it affects memory.
There are “depths” to which information can be processed
Shallow: encoding information in terms of its physical or sensory characteristics
Deep: encoding information in terms of meaning
Levels (for words)
Structural
Is it all caps?
Shallow
Phonetic
Does it rhyme with _?
Semantic
Is it an animal?
Deep

43. Proportion correctly recognized
Levels of Processing
100
Proportion correctly recognized
CAPS?
Rhyme?
Animal?

44. Levels of Processing
Such results suggests that deeper levels of processing produce more permanent retention than shallow levels of processing.
Distinctiveness and elaboration may be responsible for the effectiveness of deep levels of processing
Other results
Intention to learn does not change LOP pattern of results (Hyde & Jenkins, 1973)
Generation effect (Slamecka and Graf, 1978)
Self-reference task encourages especially deep levels of processing (Rogers, Kuiper, & Kirker 1977
Problem: What is “deep” and what is “shallow?”
Circular logic
If processing is deep then retention will be better.
If retention was better, then processing must have been deeper.
There is no precise way to measure ‘depth’

45. Encoding-Specificity Principle
Information is available to the extent to which retrieval cue matches encoding
Tulving and Thomson, (1973)

46. Morris, Bransford, & Franks (1977)
Had people make one of two judgments at presentation
Shallow: Rhyming (Does it rhyme with hat?)
Deep: Semantic (Does it have a tail?)
Two test conditions
Recognition
Rhyming
“Hat”
“Did you see a word that rhymes with X?”
Test Condition either matched or mismatched original encoding

47. Morris, Bransford, & Franks
Rhyme
Semantic
Recognition
TEST
PRESENTATION + -

48. Morris, Bransford, & Franks
LOP effect for standard test.
But opposite for rhyming test
Deep processing does not always enhance memory

49. Transfer Appropriate Processing
Memory performance depends on the extent to which processes used at the time of learning are the same as those used when memory is tested
LOP approach assumed that semantic processing was always superior to non-semantic processing
The transfer appropriate processing approach demonstrates that a form of encoding which is “shallow” for one purpose might be “deep” for another.
Conclusion
Memory not just a function of depth of processing
Depends also on the match between encoding processes and type of test

50. Interaction of Encoding and Retrieval
Context Congruency
Godden & Baddeley
Divers memorized a list of words
Half learned the words on dry land
Half learned words underwater
Tested either on dry land or underwater

51. Recap LEVELS OF PROCESSING emphasizes operations at encoding
semantic/elaborative processing better for LTM
ENCODING SPECIFICITY
emphasizes that information about retrieval cue must be encoded at study for cue to be effective
TRANSFER APPROPRIATE PROCESSING
memory best when processes at test match processes used at study
*For another view, see Nairne, 2002

52. Different Methods of Retrieval
What is your name?
Automatic
What is the Capital of Australia?
Generate & recognize
What are you doing next Tuesday at 1200?
Schema + Search
What is the layout of your house?
Spatial
Is “FLORB” a word?
Direct access
What was Beethoven’s telephone number?
General knowledge search

53. Basic Mechanisms General Principles of Memory Strength Congruity
Background
Contextual
Congruity
Between encoding and retrieval
Organization
Distinctiveness
Segregate item in memory
Spacing
Massed vs. Distributed
Recency and Primacy

54. Spacing Old rule: Spacing learning enhances recall
Bahrick family and foreign language learning 

55. Spacing Why does it work?
Varying encodings may lead to more associations
Reminds of earlier presentation, so may reinforce earlier learning (perhaps increasing baseline activation)

56. Recency and Primacy Demonstrated in the serial-position curve
Learn a list of items in order…
..and reproduce the list in order
Position in List
Proportion Recalled
100
Beg.
Mid.
End

57. Recency and Primacy Primacy Recency
Memory advantage for items initially encountered.
Rehearsal?
Distinctiveness?
Recency
Memory advantage for items recently encountered.
Working memory?

58. Retrieval Many different theories about how retrieval takes place.
Information Processing Theories
Modal Model, LOP, TAP
Associative Theories
ACT-R, TODAM
Search Models
SAM, REM
Trace Theories
Perturbation Model
Connectionist Models
PDP, EPIC
Biological-Based Theories
HERA, CARA
Differ…
What and how information is retrieved.
Memory trace
Reconstruction
Share…
Emphasis on information available at retrieval
Cues
Contextual information
Something guides retrieval
Memory as a Decision