Title: Article summary
1Article summary
- You will summarize and critique one research
article from recent cognitive psychology
literature (since 1998). - The length should be no less than two and a half,
double-spaced typed pages. - Use Times New Roman 10-12 point font with 1-inch
margins. - The required length does not include spacing from
the title. - Turn in a copy of the first page (i.e. title page
with abstract, authors, etc.) of the actual
article with your summary. - I will find the article online and do not want a
big pile of papers. - Summaries turned in late will receive one full
letter grade deduction for each week they are
turned in late. - For example, papers turned in up to one week late
will receive a B grade at best.
2Article Summary Grading
- I will evaluate your ability to clearly
- (a) identify the research question,
- (b) identify the independent and dependent
variables, - (c) summarize the results
- (d) summarize the researcher(s) conclusions.
- (e) your evaluation of the method
- (f) your evaluation of the authors conclusion
- (g) larger implications of the research.
- Do not simply answer each of the above in a list
of bullet points. Try to write the summary as if
you are verbally telling someone about the
article (because you are). - I will take off points for poor grammar and
spelling. - I am willing to look at drafts of your summary
before it is due (until Sunday evening).
3Short-Term Working Memory
- March 2, 2005
- Brandon Beltz
4What is Memory?
- The process of acquiring and retaining
information for later retrieval - The mental storage system involved in these
processes.
5Why is memory important?
6Memory The Big Picture
W. W. Norton
7Synonyms for Short Term Memory
- Working Memory
- Immediate Memory
- Elementary Memory
- Short-term Store
- Temporary Memory
- Primary Memory
8Short Term versus Working Memory
- Short Term Memory (STM)
- Older term emphasizing input and storage of new
information. - Example Remembering a phone number
- Working Memory (WM)
- Newer term emphasizing processing (work) and
storage. - The mental workbench.
- Example Solving an arithmetic problem in your
head - However, there are no clear distinctions between
the two terms.
9Aspects of STM and WM
- Where active mental effort is expended.
- Where comprehension takes place.
- Often associated with attention and
consciousness. - Can eventually lead to long-term memory.
10Short Term Memory Limitations
- Amount of information storage
- Limited capacity bottleneck
- Duration (time) of information storage
- Interference and decay
11Limited Capacity Bottleneck
- There is a limit to the amount of input that can
be stored. - Hmmm, this theme sounds familiar. Remember
attentional resources? - The Magical Number Seven (plus or minus two).
The bottle can only allow in as much fluid as its
neck allows.
Example of a dam controls the flow of water
downstream.
12Seven Plus or Minus Two
13Check your answers
- three
- four
- five
- six
- seven
- eight
- nine
- ten
- eleven
P X R H G P A Z C M I L K H K S D E V U J A Z I
W G O K Y R X D N S K J E Z F X Y T U N K M I H C
Q P F R U J A Z I W T K F C
Was your memory capacity for letters close to
seven (plus or minus two)?
14Overcoming STM limitations
15Chunking
- The process of reducing complex information into
smaller parts (chunks) to aid in memory storage
and retrieval. - Going from larger to smaller
- e.g. Remembering phone numbers.
- (703) 993-1207 compared to 7039931207
- Chunks can vary in size from single letters to
entire words -
- BYGROUPINGSIMILARITEMSINTOUNITSWEREMMBERTHEMBETTE
R
16Recoding
- Grouping smaller items together and remembering
the newly formed groups. - You recode some items into a different form
- Going from smaller to larger
- Example Remembering items on a grocery list
- Mnemonic devices (next weeks class)
17Addressing the duration of STM storage
- Influences of decay and interference on duration.
18The Brown-Peterson Task (1958)
- Goal Determine how long non-rehearsed
information stays in STM. - On each trial, the subject sees three letters,
followed by three numbers. - Subjects must remember the letters while counting
backward by 3s from the number. - Plot recall accuracy by time spent counting.
19Brown-Petersen Example (3 sec)
count backwards
What are the three letters?
20Brown-Petersen Example (9 sec)
count backwards
What are the three letters?
21Recall Accuracy in the Brown-Peterson Task
22Brown-Petersons Interpretation.
- The data represent a simple decay function.
- Decay Loss of a memory trace due simply to the
passage of time. - Assumed no interference due to difference between
letters and numbers
23Challenge to decay only explanation in STM
- Interference (loss of a memory trace due to
competition from other events) plays little or no
part in this task. - Waugh and Norman (1965)
- Subjects heard a list of digits read at either 1
or 4 digits per second. (total time span in both
cases is 4 seconds) - Last digit was a repeat of an earlier one.
Subject had to remember which digit came after it
in the list. - Example 7, 4, 6, 9.4 last digit is 4, recall
the digit 6.
24Waugh and Normans Task
8
1
5
7
1
Recall
Time (always 4 seconds)
25Waugh and Normans Task
6
2
8
1
2
26Waugh and Normans Task
3
5
6
8
7
6
4
2
8
9
2
1
7
27Waugh and Normans Results
- Recall was better when fewer digits were
presented in the 4 second time span.
28Interference or Decay?
- How do Waugh and Normans results demonstrate
that interference rather than decay is the loss
mechanism in STM? - Other evidence for interference (Keppel and
Underwood, 1962) - Performance on the Brown-Peterson Task is
relatively good early on (and nearly perfect on
Trial 1). - Performance gets much worse on later trials.
- Proactive interference of previous information
29Proactive Interference
- Previous information interferes with new learning
- example. Today, I walk to where I parked my car
yesterday.
Present Information
Previous Information
Time
30Retroactive Interference
- More recent information interferes with older
learning. (interruptions) - Example. I hear a busy signal when calling
someone and it interferes with the memory of the
phone number I called.
Present Information
Previous Information
Time
31Release from Proactive Interference
- When the stimuli are switched in the
Brown-Peterson task, proactive interference goes
away. - Wickens (1972)
32Brown-PetersenTask
PI ReleaseVariation
- M N P, 309
- Y P O, 316
- I K N , 218
- Q X P, 870
- etc
-
- M N P, 309
- Y P O, 316
- I K N , 218
- 4 5 8 , 870
- etc
-
Accuracy gets worse in later trials (proactive
Interference)
On the 4th trial letters switched to numbers
Recall accuracy on the 4th trial matched
accuracy on the 1st trial
33Why do we rehearse information?
- Keeps information in STM.
- Increases probability information will be
transferred to long-term memory.
34How do we retrieve the contents of memory?
35Short-Term Memory Recall
- Free recall recall the items in any order
- Exact order of list not necessarily important
- Example, a grocery list
- Serial recall recall the items in exact order of
presentation - Order is important
- Example, a phone number
36Effects of item order on serial recall
- Primacy Better memory for the first items in a
list. - Recency Better memory for the last items in a
list. - Imagine a 5 year old reciting the alphabet.
37Explanations of Serial Order Effects
- Primacy
- First items get the most rehearsal.
- A long-term memory effect.
- Recency
- Last items still in STM at time of recall.
- A short-term memory effect.
- Middle items
- Not as much time for rehearsal
- Already decayed from STM at time of recall.
38Recognition
Study Phase
39Recognition
Test Phase
Test Phase
- Did you see any of these faces earlier?
- What are some other real life examples of
recognition?
40How do we search the contents of STM?
- Sternbergs (1966) STM Scanning Task
- On each trial, subjects saw a memory set,
consisting of between 2 and 5 numbers. - After the memory set disappeared, a single, probe
digit appeared. - Yes or No, was the probe digit a member of the
memory set?
41Sample Sternberg Task
42Process Model of the Sternberg Task
43How Might People Scan STM?
- Parallel Search (e.g., yes, or no, are my car
keys on the table?). - Serial Self Terminating Search (e.g., my keys
could be on the sofa, the kitchen table, or in
the car. I find them on the sofa, and stop my
search). - Serial Exhaustive (e.g., a police line up).
44Sternbergs Results
45Summary of Sternberg
- People scan STM in a serial exhaustive fashion
(dont stop even if a match is found). - The scan rate is about 38 msec per item
(Sternbergs slope). - The intercept represents the time it takes for
all other stages in Sternbergs model.
46Working Memory
47Working Memory(Baddeley, 1974)
- Executive and two slave systems.
- All share resources.
Baddeley, A., and Hitch, G., Working Memory, in
Bower, G.H. (Ed.), The Psychology of Learning and
Motivation, Vol. 8. New York, Academic Press,
1974, pp. 4789. Adapted by permission of the
publisher.
48Components of Working Memory
- Central Executive
- Planning future actions
- Initiating retrieval and decision processes
- Integrating information coming into the system.
- Transfer information to long term memory via
rehearsal
49Components of Working Memory
- Visuo-Spatial Sketch Pad
- Visual and spatial information
- e.g. visual, spatial search
- Example Is the doorknob for your bedroom door on
the left or right side? - Drains executives resources if visual task is
demanding.
50Components of Working Memory
- Phonological Loop
- Rehearsal of verbal information
- Phonological (auditory) processing
- Drains executives resources if verbal task is
demanding.
51Measuring Working Memory Capacity- Individual
Differences
- Memory Span Tasks (dual-task methods)
- Reading-Span
- Subjects must process the sentences and words
- some sentences WORD1
- more sentences WORD2
- Arithmetic Operations-Span
- Subjects must process the arithmetic problems and
words - Is (6 x 2) - 2 10? WORD1
- Is (3 x 4) - 4 9? WORD2
- Subjects are scored on
- ability to process the sentences and arithmetic
problems. - the of words they can recall.
52Measuring Working Memory Capacity- Individual
Differences
- People classified into low and high WM spans
based upon scores. - Performance on these tasks correlate strongly
with higherorder tasks. Also correlate with
aptitude and achievement tests.
53An alternative approach toworking memory
(Engle, 2002)
- Working memory not directly about memory
- Focus less on subjects accuracy for word recall
in dual task procedures (which measures memory
capacity). - Contrasts with general approaches to STM.
- Working memory more about directing attention and
avoiding proactive interference. - Actively maintaining a task goal is important for
performance - Proactive interference causes task goals to be
forgotten and performance suffers
54Experiments to support alternative approach to
working memory
- Antisaccade Task
- Shadowing Task
55Antisaccade task
This is the fixation point
This is the target cue It always appears on the
opposite side of the target And predicts where
it will be!
This is the target
56Antisaccade Results
- Low WM spans slower reaction times in finding
the target - High WM spans faster reaction times in finding
the target
57What does having a low ability to recall words in
the memory span tasks have to do with remembering
that the target cues predict the target location
in the antisaccade task?
- In both tasks, the maintenance of the task goals
requires work. - People with high WM able to reduce effects of
interference and focus on task - People with low WM memory more easily distracted
by interference -
58Further support for alternative view of working
memory
- In the shadowing task
- Subjects with low WM span will detect their name
in unattended ear. - Subjects with high WM span will detect their name
less often.
Shadowing Task
- Again, WM associated with ones ability to direct
attention and focus on task goal while reducing
interference.
59Short Term, Working Memory- Lecture Outline
- Short Term Memory (STM)
- Short term memory limitations
- Limited capacity bottleneck
- Overcoming the bottleneck
- Duration
- Decay
- The Brown Peterson task
- Interference
- Accessing contents of memory
- Recall
- Free versus serial recall
- Serial position effects
- Recognition
- Searching the contents of STM
- Serial exhaustive search
- Sternberg
- Working Memory (WM)
- The components of working memory (Baddely)