lecture 20 from a college level introduction to psychology course taught Fall 2011 by Brian J. Piper, Ph.D. (psy391@gmail.com) at Willamette University, Loftus, eyewitness memory

1. Memory: Part I
Brian J. Piper, Ph.D.
1

2. Goals
• Overview (26)
• Encoding (27)
• Storage (28)
• Retrieval (29)
• Forgetting (30)
2

3. Memory
Memory is the basis for knowing your
friends, your neighbors, the English
language, the national anthem, and yourself.
If memory was nonexistent, everyone would be
a stranger to you; every language foreign; every
task new; and even you yourself would be a
stranger.
3

4. Definition
Memory is learning that has persisted over time.
It is our ability to store and retrieve information.
Cognitive Psychology & Cognitive Neuroscience
4

5. Which one is the real penny?
A B C D E
1
2
3
5

6. Impact of Lack of Memory
• Clive Wearing (0:10-7:00)
http://www.youtube.com/watch?v=WmzU47i2xgw&feature=related
Damage to the temporal cortex (herpes simplex
encephalitus)
Antereograde Amnesia
Some functions spared. Why?
6

7. Information Processing Models
of Memory (Simple)
Keyboard Disk Monitor
(Encoding) (Storage) (Retrieval)
Sequential Process 7

8. Information Processing Model
(Moderate)
1929-
1943-
• Atkinson-Schiffrin Model (1968)
Duration Size
Sensory Memory <1 second Infinite?
Short-Term Memory 1/2 minute ≈7
Long-Term Memory 1 lifetime Large 8

9. Modifications to the Three-Stage
Model
1. Some information skips the first two stages
and enters long-term memory automatically.
2. Since we cannot focus on all the sensory
information received, we select information
that is important to us and actively process it
into our working memory.
9

10. Information Processing (Complex)
10

11. Working Memory
Our ability to store and manipulate information for a
brief time
Corsi Block Tapping Test Tower of London
11

12. Working Memory Across the
Lifespan
• Spatial working
memory shows an
inverted-U shaped
relationship with age.
12
Piper et al. (2011) Physiology & Behavior, 103, 513-522.

13. Part II: Encoding: Getting Information In
 How We Encode
 What We Encode

14. Encoding: Getting Information In
How We Encode
1. Some information (route to your school) is
automatically processed.
2. However, new or unusual information
(friend’s new cell-phone number) requires
attention and effort.

15. Automatic Processing
We process an enormous amount of information
effortlessly, such as the following:
1. Space: While reading a textbook, you
automatically encode the place of a picture
on a page.
2. Time: We unintentionally note the events
that take place in a day.
3. Autobiographical: You effortlessly keep
track of things that happen to you.

16. Effortful Processing
Committing novel
information to memory
requires effort just like
learning a concept from a
textbook. Such processing
leads to durable and
accessible memories.

17. Rehearsal
Effortful learning
usually requires
rehearsal or conscious
repetition.
Ebbinghaus studied
rehearsal by using
nonsense syllables:
TUV YOF GEK XOZ
Hermann Ebbinghaus
(1850-1909)

18. Rehearsal
The more times the
nonsense syllables were
practiced on Day 1,
the fewer repetitions were
required to remember
them on Day 2.

19. Encoding Effects
1. Spacing Effect: We retain information
better when we rehearse over time.
2. Serial Position Effect: When your
recall is better for first and last items
on a list, but poor for middle items.

20. What We Encode
1. Encoding by meaning
2. Encoding by images
3. Encoding by organization

21. Encoding Meaning
Processing the meaning of verbal
information by associating it with what
we already know or imagine. Encoding
meaning (semantic encoding) results in
better recognition later than visual or
acoustic encoding.

22. Visual Encoding
Mental pictures (imagery) are a powerful aid to
effortful processing, especially when combined
with semantic encoding.
Showing adverse effects of tanning and smoking
in a picture may be more powerful than simply talking about it.

23. Mnemonics
Imagery is at the heart of many memory aids.
Mnemonic techniques use vivid imagery and
organizational devices in aiding memory.

24. Organizing Information for
Encoding
Break down complex information into broad
concepts and further subdivide them into
categories and subcategories.
1. Hierarchies
2. Chunking

25. Hierarchy
Complex information broken down into broad
concepts and further subdivided into categories
and subcategories.

26. Chunking I
Organizing items into a familiar, manageable
unit. Try to remember the numbers below.
1-7-7-6-1-4-9-2-1-8-1-2-1-9-4-1
If you are well versed with American history,
chunk the numbers together and see if you
can recall them better. 1776 1492 1812 1941.

27. Chunking II
Acronyms are another way of chunking
information to remember it.
King Phillup Came Over From Germany Singing: K P C O G S
Oh, Oh, Oh, To Touch And Feel Very Good' Velvet Aah Hah:
O O O TTAF V G V S H

28. Encoding Summarized in a Hierarchy

29. Part III: Storage: Retaining Information
 Sensory Memory
 Working (Short-Term) Memory
 Long-Term Memory
 Storing Memories in the Brain

30. Storage: Retaining Information
Storage is at the heart of memory. Three
stores of memory are shown below:
Sensory Working Long-term
Memory Memory Memory
Encoding
Events
Encoding Retrieval
Retrieval

31. Sensory Memory
Sensory Working Long-term
Memory Memory Memory
Encoding
Events
Encoding Retrieval
Retrieval

32. Whole Report
R G T “Recall”
F M Q RTMZ
(44% recall)
L Z S
50 ms
The exposure time for the stimulus is so small
that items cannot be rehearsed.
Sperling (1960) Psychological Monographs, 74 (498), 336.

33. Partial Report
S X T Low Tone
“Recall”
J R S Medium Tone JRS
(100% recall)
P K Y High Tone
50 ms
Sperling (1960) argued that sensory memory capacity
was larger than what was originally thought.

34. Time Delay
A D I Low Tone
“Recall”
Time
N L V Delay
Medium Tone N__
(33% recall)
O G H High Tone
50 ms

35. Sensory Memory
The longer the delay, the greater the memory loss.
Percent Recognized
80
60
40
20
0.15 0.30 0.50 1.00
Time (Seconds)

36. Sensory Memories
The duration of sensory memory varies for the
different senses.
Iconic
0.5 sec. long
Echoic
3-4 sec. long
Hepatic
< 1 sec. long

37. Working Memory
Sensory Working Long-term
Memory Memory Memory
Encoding
Events
Encoding Retrieval
Retrieval
Projector Off!!

38. Mini-Experiment
Size Stimuli
3 PXR
4 H G PA
5 ZCMIL
6 KHKSDE
7 VU JAZ IW
8 GOKYRXDN
9 SK JE Z FXYT
10 UNKMIHCQPF
11 RU JAZ IWTKD C
38

39. Working Memory Capacity
My problem is that I have been persecuted by an integer. For seven years this number has followed me
around, has intruded in my most private data, and has assaulted me from the pages of our most public
journals. This number assumes a variety of disguises, being sometimes a little larger and sometimes a
little smaller than usual, but never changing so much as to be unrecognizable. The persistence with which
this number plagues me is far more than a random accident. There is, to quote a famous senator, a design
behind it, some pattern governing its appearances. Either there really is something unusual about the
number or else I am suffering from delusions of persecution.
• Address to the Eastern Psychological Association, April 15, 1955 by
George A Miller & published in Psychological Review, 101, 343-352. 39

40. Working Memory Capacity
The Magical Number Seven, Plus or
Minus Two: Some Limits on Our
Capacity for Processing Information
(1956).
Ready?
MUTGIKTLRSYP
You should be able to
recall 7±2 letters.
George A. Miller
1920 -
http://www.psych.utoronto.ca/users/peterson/psy430s2001/Miller%20GA%20Magical%20Seven%20Psych%20Review%201955.pdf

41. Chunking
The capacity of the working memory may be
increased by “chunking.”
F-B-I-T-W-A-C-I-A-I-B-M
FBI TWA CIA IBM
4 chunks

42. Duration
Peterson and Peterson (1959) measured the
duration of working memory by manipulating
rehearsal.
CHJ
547
MKT
544 CH??
HIJ
541
547 …
The duration of the working memory is about
20 sec.

43. Working Memory Duration
Peterson & Peterson (1959). Journal of Experimental Psychology, 58, 193-198.

44. Long-Term Memory
Sensory Working Long-term
Memory Memory Memory
Encoding
Events
Encoding Retrieval
Retrieval

45. Memory Feats!!
http://www.recordholders.org/en/list/memory.html#pi

46. Summary: Memory Stores
Sensory Working
Feature LTM
Memory Memory
Encoding Copy Phonemic Semantic
Capacity Unlimited 7±2 Chunks Very Large
Duration 0.25 sec. 20 sec. Years