Memory Tasks with Variations and Distractions: Implications of experiments in PowerPoint with respect to systems of the Model Human Processor By: Neel.

Memory Tasks with Memory Tasks with Variations and Variations and Distractions:Distractions:

Implications of experiments in Implications of experiments in PowerPoint with respect to PowerPoint with respect to

systems of the Model Human systems of the Model Human ProcessorProcessor

By: Neel Gehani and Alex Thorn

Advisor: Professor Alain Kornhauser

PSY / ORF 322: Final Project

Date: Thursday May 5, 2005

BackgroundBackground

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 objectivesOur 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 objectivesOur 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 TechnologyChoice of Technology

Why we chose PowerPoint1. User-friendly features (color, visual appeal)2. Accurate / flexible timing controls3. Ability to handle sound files4. Compatibility with most students’ computers

Limitations of PowerPoint1. Inability to easily switch assigned data sets around2. Difficulty of electronic response (paper-based)

Experiment DesignExperiment 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 Specific things trying to be testedto be tested

Effect of the amount of time that users Effect of the amount of time that users see the data to be memorizedsee the data to be memorized

Effect of memory decay by forcing users Effect of memory decay by forcing users to wait between seeing the data and to wait between seeing the data and recording the datarecording the data

Effect of chunking on ability to Effect of chunking on ability to memorizememorize

Specific things trying Specific things trying to be testedto be tested Effect of harmonically similar data Effect of harmonically similar data

on perceptual and cognitive on perceptual and cognitive memory systemsmemory systems

Effect of different distractions and Effect of different distractions and different levels of interaction with different levels of interaction with the same distraction (this was the same distraction (this was accomplished by using two accomplished by using two versions of the experiment)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

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.

Please read the following story out loud at a normal pace.

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 AResults from Version A

Experiment AVERAGEADJUSTED 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

Letter distraction – no repeat 7.4 8.5

Story distraction – read out loud 8.05 8.5

Song distraction 7.6 8.17

Given verbally 7.45 7.92

Results from Version BResults from Version B

Experiment AVERAGEADJUSTED AVERAGE

1.5-second - no delay 6.05 6.08

1.5-second - no delay, harmonic 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

Chunking 9 9

Letter distraction - repeat 8.1 8.67

Story distraction - silent 8.45 8.75

Song distraction 8 8.58

Given verbally 7.1 7.08

Examination of ResultsExamination 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 ResultsExamination 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 ResultsExamination 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 ResultsExamination 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 Changes to make experiments betterexperiments better More participantsMore participants Better quasi-random sets of lettersBetter quasi-random sets of letters Perhaps switch sets of letters between Perhaps switch sets of letters between

peoplepeople Different time lengths rather than just Different time lengths rather than just

1.5, 10 and 30 seconds1.5, 10 and 30 seconds Vary tests againVary tests again Test same participants again to see Test same participants again to see

effects of practiceeffects of practice Vary order of experimentsVary order of experiments

Implications on Implications on Memory (and Daily Memory (and Daily Life?)Life?)

Our experiments show the importance Our experiments show the importance of the joint functionality of the of the joint functionality of the perceptual and cognitive systems of the perceptual and cognitive systems of the Model Human Processor. Though these Model Human Processor. Though these were simple memory tests, it is evident were simple memory tests, it is evident that memory accuracy can be easily that memory accuracy can be easily weakened in the presence of weakened in the presence of distractions, particularly by distractions distractions, particularly by distractions of similar nature to what is being of similar nature to what is being memorized.memorized.

THE END!

We’ll see you at this guy’s house for the picnic!

Neel Gehaniand

Alex Thorn