Transcript Final Project Presentation 322

Memory Tasks with
Variations and Distractions:
Implications of experiments in
PowerPoint with respect to systems
of the Model Human Processor
By: Neel Gehani and Alex Thorn
Advisor: Professor Alain Kornhauser
PSY / ORF 322: Final Project
Date: Thursday May 5, 2005
Background
The Model Human Processor- 3 Subsystems

The perceptual system
– buffer memories—Visual Image Store, Audio Image Store
– stores input while it is being transferred to working memory
– stores an image, rather than a symbolic representation

The cognitive system
– obtains information for perceptual stores, places this in working memory
in the form of an encoded symbolic representation, uses working
memory along with long term memory
– use of these two memory systems results in some sort of decision

The motor system
– completes the cycle, decision is carried out
Our objectives
1.
To isolate the functions of the perceptual system from
the cognitive system and to analyze their operation
- sought to determine subjects’ performance in situations
where they were forced to rely primarily on perceptual
system
- sought to compare this performance with similarly
devised tests where subjects were able to rely upon their
working memory
Our objectives
2.
To examine the effects of a variety of
distractions/complications on the functionality of the
perceptual and cognitive systems
-
acoustic similarities in assigned data
forced delays before allowing response
varying the length of time allotted for initial perception
musical distraction
distraction with visual tasks
distraction with auditory tasks
Choice of Technology
Why we chose PowerPoint
1.
2.
3.
4.
User-friendly features (color, visual appeal)
Accurate / flexible timing controls
Ability to handle sound files
Compatibility with most students’ computers
Limitations of PowerPoint
1.
Inability to easily switch assigned data sets around
2.
Difficulty of electronic response (paper-based)
Experiment Design



In each of eleven (11) experiments, subjects were
presented with a set of directions instructing them to
memorize nine (9) letters under varying conditions.
Twenty (20) subjects were used. We used ten (10) subjects
for each of two versions (A and B). For each version, five
(5) males and five (5) females were tested.
At the end of each experiment, subjects were told to write
down, to the best of their ability, the original letters they
had been shown. In some cases, they were asked to do so
immediately, in other cases they were made to wait 30
seconds, and in some cases they were asked to perform
tasks during this 30 second interim period.
Specific things trying to
be tested



Effect of the amount of time that users see
the data to be memorized
Effect of memory decay by forcing users to
wait between seeing the data and recording
the data
Effect of chunking on ability to memorize
Specific things trying to
be tested


Effect of harmonically similar data on
perceptual and cognitive memory
systems
Effect of different distractions and
different levels of interaction with the
same distraction (this was
accomplished by using two versions of
the experiment)
Experiment # 1
On the next slide, you will be presented
with some letters. Try to focus and pay
attention to what you are shown during the
1.5 SECONDS during which the letters are
on the screen. You will be asked to recall
these letters afterward.
Experiment # 1
C E p
r
y
Q a
W B
Experiment # 1
ITEM #1: Write down what the letters were.
ITEM #2: Write down which letters were
capitalized.
Click on the screen ONCE when you are
done.
Experiment #8
On the next slide, you will be presented
with some letters. Try to focus and pay
attention to what you are shown during the
TEN SECONDS during which the letters
are shown. You will be asked to recall this
data after a THIRTY SECOND break
during which you will hear a series of
letters. Simply listen to the letters.
Experiment #8
G
U
A
I
C
D
F
R
K
Experiment #8
Please listen.
Experiment #8
Item #9:
Write down the letters you were shown
before the audio.
Click this screen ONCE when you are done.
Experiment #9
On the next slide, you will be presented
with some letters. Try to focus and pay
attention to what you are shown during the
TEN SECONDS during which the letters
are shown. You will be asked to recall this
data after a THIRTY SECOND break
during which you will be shown a short
story. Please read it out loud at normal
pace for thirty seconds.
Experiment #9
J
R
C
A
O
L
Y
N
G
Experiment #9
Please read the following story out loud at a normal pace.
Once upon a time there was a hare who, boasting how he could run faster than anyone else, was forever
teasing tortoise for its slowness. Then one day, the irate tortoise answered back: "Who do you think you are?
There's no denying you're swift, but even you can be beaten!" The hare squealed with laughter.
"Beaten in a race? By whom? Not you, surely! I bet there's nobody in the world that can win against me, I'm
so speedy. Now, why don't you try?"
Annoyed by such bragging, the tortoise accepted the challenge. A course was planned, and the next day at
dawn they stood at the starting line. The hare yawned sleepily as the meek tortoise trudged slowly off. When
the hare saw how painfully slow his rival was, he decided, half asleep on his feet, to have a quick nap. "Take
your time!" he said. "I'll have forty winks and catch up with you in a minute."
The hare woke with a start from a fitful sleep and gazed round, looking for the tortoise. But the creature was
only a short distance away, having barely covered a third of the course. Breathing a sigh of relief, the hare
decided he might as well have breakfast too, and off he went to munch some cabbages he had noticed in a
nearby field. But the heavy meal and the hot sun made his eyelids droop. With a careless glance at the
tortoise, now halfway along the course, he decided to have another snooze before flashing past the winning
post. And smiling at the thought of the look on the tortoise's face when it saw the hare speed by, he fell fast
asleep and was soon snoring happily. The sun started to sink, below the horizon, and the tortoise, who had
been plodding towards the winning post since morning, was scarcely a yard from the finish. At that very point,
the hare woke with a jolt. He could see the tortoise a speck in the distance and away he dashed. He leapt
and bounded at a great rate, his tongue lolling, and gasping for breath. Just a little more and he'd be first at
the finish. But the hare's last leap was just too late, for the tortoise had beaten him to the winning post. Poor
hare! Tired and in disgrace, he slumped down beside the tortoise who was silently smiling at him.
"Slowly does it every time!" he said.
Experiment #9
Item #10: Write down the letters you were
shown before you began to read the story.
Click this screen ONCE when you are done.
Results from Version A
Experiment
AVERAGE
ADJUSTED AVERAGE
1.5-second - no delay
6.2
6
Capitals
2.55
2.42
1.5-second - no delay, harmonic
5.65
5.42
10-second - 30 second delay
8.2
8.67
10-second - 30 second delay, harmonic
7.25
7.25
1.5-second - 30 second delay
7.1
7.67
10-second - no delay
8
8.08
Chunking
9
9
7.4
8.5
8.05
8.5
Song distraction
7.6
8.17
Given verbally
7.45
7.92
Letter distraction – no repeat
Story distraction – read out loud
Results from Version B
Experiment
AVERAGE
ADJUSTED AVERAGE
6.05
6.08
5
4.67
10-second - 30 second delay
8.6
9
Capitals
2.8
2.75
10-second - 30 second delay, harmonic
7.95
8.17
1.5-second - 30 second delay
6.7
6.5
10-second - no delay
8.2
8.5
9
9
Letter distraction - repeat
8.1
8.67
Story distraction - silent
8.45
8.75
8
8.58
7.1
7.08
1.5-second - no delay
1.5-second - no delay, harmonic
Chunking
Song distraction
Given verbally
Examination of Results

Chunking:
– Very effective, all 20 participants scored perfectly…confirms beliefs
about chunking

Visual Image Store:
– Capitalization Recall: Participants actually had better recall in
10sec/30sec delay experiment as compared to 1.5sec/no delay
experiment…contrary to expectations regarding encoding

Reading as a Distraction:
– Worse performance when reading out loud as compared to reading
silently
– Worse performance on both than in 10sec/30sec delay experiment
without distraction
Examination of Results

Auditory Distractions:
– Expected to eliminate ability to rehearse assigned data and thus
weaken accuracy of recall…surprisingly, not worse when participants
had to repeat letters (anomaly?)
– Definitely a noticeable distraction, more so than reading
– Letter repeating was poor, probably because the assigned memory
task conflicted with it directly
– Could have been more distracting, but GUAICDFRK easily grouped
into “Guai” “Cd” “Frk” – unintentional chunking possibility
– Musical Distraction…similar results as letter distraction, but letters
were not as easy to chunk...RKOFAEIMC
Examination of Results

Acoustically similar data
– With exact same directions, and harmonically similar data
(BGVCPZEDT as opposed to CEPRYQAWB), performance was much
worse.
– We expected this as similarly sounding letters are more easily
confused when rehearsed.
– We expected this performance weakening to be felt more so in the
10sec/30sec delay stage since rehearsal during the delay provided
more time for confusion…less image based, more working memory
based, which in most cases, probably relied on the repeated silent
recitation of the data to oneself
– Actual differences between harmonic and non-harmonic in 1.5/0
and 10/30 conditions turned out to be similar…more participants
needed to show this effect
Examination of Results

Auditory presentation of assigned data:
– Performance worse than in tests visual presentation of data
– Participant only has one chance to ‘observe’ each letter…can’t go
back and read the data set again
– Would have a better basis for comparison had we done a test in
which letters were presented visually 1 by 1 by 1

This has been a short summary of our results. In our
paper we will more thoroughly analyze features of
each experiment.
Changes to make
experiments better







More participants
Better quasi-random sets of letters
Perhaps switch sets of letters between
people
Different time lengths rather than just 1.5,
10 and 30 seconds
Vary tests again
Test same participants again to see effects
of practice
Vary order of experiments
Implications on Memory
(and Daily Life?)
Our experiments show the importance of
the joint functionality of the perceptual and
cognitive systems of the Model Human
Processor. Though these were simple
memory tests, it is evident that memory
accuracy can be easily weakened in the
presence of distractions, particularly by
distractions of similar nature to what is
being memorized.
THE END!
We’ll see you at this
guy’s house for the
picnic!
Neel Gehani
and
Alex Thorn