1. False Memories (Beth Loftus) Lost Mariner (Oliver Sacks)
Upcoming Reading
False Memories (Beth Loftus)
Lost Mariner (Oliver Sacks)

2. Cognition on reserve in Library
Extra Reading
Cognition on reserve in Library

3. Overview of Memory Atkinson-Shiffrin Model RETRIEVAL ATTENTION
Sensory Signals
Sensory Memory
Short-Term Memory
Long-Term Memory
REHEARSAL

4. “Types” of Memory Sensory Memory brief ( < 1 second)
preattentive / parallel processing (very large capacity)

5. Sensory Memory

6. Capacity
Describe a simple experiment that could measure the capacity of “memory”

7. Capacity
Describe a simple experiment that could measure the capacity of “memory”
Briefly present some letters or digits and then ask the subject to report them
Called “whole report”

8. Capacity +

9. Capacity
F S F E
G S A U
T O C G +

10. Capacity
“Recall as many letters as you can”

11. Capacity George Sperling - Systematic investigation of memory capacity
Result: subjects accurately recall 3 or 4 items
What can you conclude from this result?

12. Capacity
Could it be that subjects had encoded but failed to retrieve the information?

13. Capacity For example: what if recalling interferes with memory?
How could you modify the experiment to measure the instantaneous capacity, before any forgetting can occur?

14. Capacity
Partial Report - briefly present letters or digits and ask subject to report only some of them
“Report the letters in the row indicated by the arrow”

15. Capacity +

16. Capacity
U E S B
O D W A
I B V S +

17. Capacity +

18. Capacity +

19. Capacity
Which Letters?

20. Capacity Partial Report
Result: subjects can recall any 3 or 4 letters that are indicated by the arrow !

21. Capacity Partial Report
Result: subjects can recall any 3 or 4 letters that are indicated by the arrow !
What does this mean about the capacity of memory?

22. Capacity
There is some part of the perception system that stores huge amounts of information…
in fact, if only a single letter is probed, instantaneous capacity is seen to be unlimited

23. Duration
There is some part of the perception system that stores huge amounts of information…
But for how long? How would you design an experiment to measure the duration of this high-capacity memory system?

24. Duration
There is some part of the perception system that stores huge amounts of information…
But for how long? How would you design an experiment to measure the duration of this high-capacity memory system?
Vary the onset of the probe

25. Duration Partial Report 10 # of letters potentially recalled 4 0 ms
0 ms
500 ms
never
Probe Delay

26. Duration Partial Report Interpretation:10
# of letters potentially
recalled 4
0 ms
500 ms
never
Delay
Interpretation:
Information dwells in a brief storage “buffer”
duration of storage lasts about 1/2 of one second

27. Iconic Memory
a brief storage of “raw data” in the visual system

28. Echoic Memory
Auditory information is stored in a similar sensory “buffer”
Echoic memory seems to last for several seconds

29. Properties of Sensory Memory
Brief (iconic ~500ms; echoic ~2 seconds)

30. Properties of Sensory Memory
Brief (iconic ~500ms; echoic ~2 seconds)
Virtually unlimited capacity

31. Properties of Sensory Memory
Brief (iconic ~500ms; echoic ~2 seconds)
Virtually unlimited capacity
pre-attentive

32. Overview of Memory Atkinson-Shiffrin Model RETRIEVAL ATTENTION
Sensory Signals
Sensory Memory
Short-Term Memory
Long-Term Memory
REHEARSAL

33. Short-Term Memory
process by which we hold information “in mind”

34. Short-Term Memory process by which we hold information “in mind”
example: temporarily remembering a phone number

35. Characteristics of STM
Duration? Capacity?
How could one measure these parameters?

36. Characteristics of STM
Limited Duration
Brown-Petersen Task:
subject is given a trigram (e.g. C-F-W) to remember
vocal rehearsal is prevented by counting backwards
recall accuracy tested as a function of retention interval

37. Characteristics of STM
STM decays over seconds

38. Characteristics of STM
Limited Duration
Brown-Petersen Task Interpretation: rapid loss of information in STM (over a period of seconds…much longer than sensory memory)

39. Characteristics of STM
Limited Capacity
How might you measure capacity?

40. Characteristics of STM
Limited Capacity
George Miller
Subject is given longer and longer lists of to-be-remembered items (words, characters, digits)

41. Characteristics of STM
Limited Capacity
George Miller
Subject is given longer and longer lists of to-be-remembered items (words, characters, digits)
Result: Subjects are successful up to about 7 items

42. Characteristics of STM
Limited Capacity
What confound must be considered ?!

43. Characteristics of STM
Limited Capacity
What confound must be considered ?!
Recalling takes time !

44. Characteristics of STM
Limited Capacity
What confound must be considered ?!
Recalling takes time !
It seems that the “capacity” of STM (at least measured in this way) depends on the rate of speech - faster speech leads to apparently larger capacity
Some believe capacity is “2 - 3 seconds worth of speech”

45. Forgetting from STM Why do we “forget” from STM?
Does the memory trace decay?
not likely because with very small lists (like 1 item) retention is high for long intervals

46. Forgetting from STM Why do we “forget” from STM?
Does the memory trace decay?
not likely because with very small lists (like 1 item) retention is high for long intervals
Instead, it seems that information “piles up” and begins to interfere

47. Forgetting from STM
Interference in STM is complex and specific

48. Forgetting from STM Interference in STM is complex and specific
For example, severity of interference depends on meaning

49. Forgetting from STM Interference in STM is complex and specific
For example, severity of interference depends on meaning
Subjects are given successive recall tasks with list items from the same category (e.g. fruits)
final list is of either same or different category - how is good is recall on this list?

50. Forgetting from STM
Accuracy rebounds if category changes

51. Coding in STM
How is information coded in STM?

52. Coding in STM Clues about coding in STM:
# of items stored in STM depends on rate of speech

53. Coding in STM Clues about coding in STM:
# of items stored in STM depends on rate of speech
phonological similarity effect: similar sounding words are harder to store/recall than different sounding words

54. Coding in STM Clues about coding in STM:
# of items stored in STM depends on rate of speech
phonological similarity effect: similar sounding words are harder to store/recall than different sounding words
What does this suggest about the nature of information in STM?

55. Coding in STM
It seems that information can be stored in a linguistic or phonological form

56. Coding in STM
It seems that information can be stored in a linguistic or phonological form
Must it be stored this way?

57. Are there two different STM systems?
Coding in STM
It is also possible to “keep in mind” non-verbal information, such as a map
Are there two different STM systems?

58. A Modular Approach to STM
Central Executive
Articulatory Loop
Visuospatial Sketchpad
Experiment 1 in the article by Lee Brooks demonstrates a double dissociation between Articulatory Loop and Visuospatial Sketchpad

59. Working Memory “Modules”
Lee Brooks: interference between different representations in STM (Experiment 1)
Memory Representation
verbal task: categorize words in a sentence
spatial task: categorize corners in a block letter
Response Modality
verbal response: say “yes” or “no”
spatial response: point to “yes” or “no”

60. Working Memory “Modules”
result:
Verbal Representation
(categorize words)
Performance
Spatial Representation
(categorize corners)
Verbal
Spatial
Response Modality

61. Working Memory “Modules”
Interpretation:
supports notion of modularity in Working Memory (visuospatial sketchpad / articulatory loop)