HUL211 (Object Perception and Memory)

Course Project

IIT ROPAR

“EFFECT OF LAUGHING ON SHORT TERM VERBAL MEMORY”

Submitted by: Abhishek Ghosh P2009ME1074 Submitted to: Dr. Snehlata Jaswal 4th April, 2012

Abstract “Laughing is considered to be the best medicine”; this experiment goes on to gather facts regarding the validity of this statement. The main emphasis of this experiment has been to study the effect of laughing on short term verbal memory, but the end effects could be well felt in our daily lives. “Whether a simple dose of laughter makes your mind more resistant to memory decay?”, this is one of the questions that this report tries to answer. Another part of the experiment deals with the effect of laughing on memory for the so called happy words (which induce happiness). The experiment assumes the accuracy of response to be a measure of memory. Final results show that laughing reduces memory decay by 50% for a subject as compared to a neutral behaviour. On the contrary, memory for happy words decline faster after a good laugh. In broader terms, laughing does add a boost to our short term verbal memory.

Aim To study the effect of laughing on short term verbal memory for neutral and happy words.

Introduction The experiment tries to find out the effect of laughing on short term verbal memory. The memory of individuals will be determined based on their score in memory tests. In addition, the experiment also examines whether happy words are preferred by individuals when they remember word lists and whether seeing a funny video would affect this preference.

Hypotheses

1. Laughing increases short term verbal memory 2. Laughing increases short term verbal memory for happy words

Method Participants Number: 24 Age group: 18-21 Gender: Male IIT Ropar students Tests / Apparatus and stimuli / Tools Material used: pen, paper, laptop. Tests used: Verbal memory test Type of computer: Laptop Software: Microsoft Power Point, VLC media player The stimuli given to the subjects include videos and power point presentations.

Design and procedure The experiment involves testing the memory of subjects and find out the effects of laughing on their performance. The memory test consists of a grid of 12 words which is shown to the subjects for 20 seconds. A sample grid looks like this: Range Lollipop Beam

Storm Worm Puppies

Flower Actor Music

Jelly Sparkle Jewel

After the time elapses the subjects are required to write down as many words as they can remember on a piece of paper (provided to them at the beginning). This count is taken as a measure of their short term verbal memory.

In addition to the normal words the list also includes 6 happy words. The happy words can be defined as those which invoke happiness in the reader. For the sample word list above the happy words are marked in red below. Range Lollipop Beam

Storm Worm Puppies

Flower Actor Music

Jelly Sparkle Jewel

The happy words that are reported by the subjects from the list of all word that they report becomes the measure for selective remembrance of happy words. To promote laughter, a funny video in which “babies are laughing” is shown to the subjects. The time duration of this video is 3 minutes. Experiment set happy consists of the following procedure:

1. Take memory test 2. Show happy video 3. Take memory test again

In this way it’s possible to compare the performance of individuals before and after they laugh. COUNTER-BALANCING This method was prone to defects and several counterbalancing strategies were developed to make the experiment unbiased.

1. Any improvement that the subject shows in the second test could be a cumulative result of laughing as well as video watching. To remove such kind of bias another video was selected (neutral content) which doesn’t evoke any emotions and the above experiment was repeated on the same subjects with this video replacing the earlier one, this being called Experiment Set neutral.

2. In order to avoid any bias that may result from following a particular sequence, half of the subjects went through Set happy on first day and Set neutral on the second day while the remaining half did Set neutral first followed by Set happy on the following day.

3. A total of 4 word lists have been prepared for the whole experimental cycle. These can be marked as list A,B,C and D. The order in which these tests were presented to the subjects was also permuted to avoid any bias die to a particular sequence. For example subjec1 was given the order: ABCD, the next one: BCDA and so on.

4. The position of happy words in the word list could also make an impact on the results. Hence, they were positioned in a random fashion through all the lists.

In a nutshell the experiment is spread over two days, one set on the first day and a counter set on the next day. The response of the subjects which is used for analysis can be divided in two parts: (X identifies the word list used for the test, e.g. A)

1. Total score X- The total number of words remembered 2. Happy score X- The total number of happy words remembered

These two scores for all the individuals were recorded in an excel sheet. To analyze the data two factors were devised, namely

1. Coefficient of Improvement total(%) = total score (X+1) – total score (X) - ----------------------------------------- Total score(X) Where, X - memory test before showing video in either of the two experiment sets X+1 - memory test after showing video This is a measure of improvement that the subject makes after viewing the video on the memory test. 2. Coefficient of Improvement happy(%) = happy score (X+1) – happy score (X) ---------------------------------------------- happy score(X) Where, X - memory test before showing video in either of the two experiment sets X+1 - memory test after showing video This is a measure of improvement for remembering happy words that the subject makes after viewing the video on the memory test.

Results The main aim of the experiment is to demonstrate that laughing has a positive effect on short term memory. A subsidiary aim is to find any specific attention of subjects towards happy words after laughing out. COI (coefficient of improvement) for neutral experimental set (Table 1) and happy experimental set (Table 2) are presented below:

Neutral Video Serial COI(total) COI(happy)

1 -44.444444 -252 -14.285714 03 -14.285714 504 -33.333333 -255 0 -206 -22.222222 07 -20 08 20 33.33333339 -40 -25

10 0 33.333333311 -44.444444 -4012 -57.142857 -33.33333313 28.571429 10014 0 33.333333315 -42.857143 -8016 -22.222222 -2517 0 33.333333318 25 019 20 020 -28.571429 021 -14.285714 -20

average COI -14.501134 -0.4761905

Table 1

Happy Video Serial COI(total) COI(happy)

1 -40 -33.3333332 0 1003 16.66666667 504 0 05 0 -33.3333336 -11.11111111 07 0 -258 -33.33333333 -409 0 -50

10 -14.28571429 011 50 012 -12.5 -5013 25 2014 -42.85714286 -6015 42.85714286 10016 -11.11111111 -2017 -45.45454545 -6018 -50 019 -11.11111111 0

average COI -7.223171565 -5.3508772

Table 2 The first hypothesis is supported however the second hypothesis is not supported by the results.

Discussion The main aim of the experiment is to demonstrate that laughing has a positive effect on short term memory. A subsidiary aim is to find any specific attention of subjects towards happy words after laughing out. The study looks at the improvement people make in verbal memory tests after watching a funny video. As seen from table 1, the average COI is -14.5% for neutral video watchers. This implies that in general performance decreases in the second trial. Compared to this value, the average COI for happy video watchers comes out to be -7% (table 2), a reduction of almost 50%. Hence, laughing considerably reduced the memory decay of individuals and boosted it up by 50%. This works in support of the first hypothesis. For the happy word case, neutral video watchers seem to stick to happy words more as its average COI is -0.5% (table 1) as compared to an overall average of -14.5%. This implies that people in general prefer happy words to be remembered. However in contrast to the expected result that happy word will be on top for funny video watchers the COI goes down to -5.3% (table 2). It seems that after watching the funny video and having a laugh, happy words loose their earlier significance and the subjects do not show any indifferent behaviour towards them. CONCLUSION The results show a 50% reduction in memory decay after laughing for general verbal memory. Therefore laughing certainly boosts short term memory. Happy words are preferred by individuals for memorizing purposes after watching the neutral video. Laughing out removes the preference for happy words.

Appendices Tests used: Memory Test A Range Lollipop Beam

Storm Worm Puppies

Flower Actor Music

Jelly Sparkle Jewel

Memory Test B Honey Sunshine Belt

Steam Wheat Rose

Tree Balloon Chocolate

Song Chalk Jail

Memory Test C Cherry Virus Belly

Mouse Ice-Cream Angel

Truck Family Whale

Baby Sunlight Judge

Memory Test D Butterfly Venom Beam

Glove Stars Garden

Tiger Holiday Review

Rainbow Clock Vanilla

Instructions:

• This experiment is designed to test how well you process memory. This file contains the material for the experiment.

• During this session you will be shown 12 words for 20 seconds • After the session you will be required to recall and write down as many words as

you can remember. • Please pay close attention to each word. • Good luck!

After showing word list, --Now write the words on the paper given to you. Stimuli: Funny video: “Babies – youtube.com”; link: http://www.youtube.com/watch?v=UjXi6X-moxE Neutral video: “shadow art – youtube.com”