Experimental Psychology

THE EFFECT OF AROMATIC SCENT TO MEMORY RECALL

Submitted by: Jareen Caban Noreen Laserna

Submitted to: Prof.Leslie Gazzingan

I.

Title The Effect of Aromatic Scent on Memory Recall

II.

Introduction Aromatherapy can improve memory, recall and concentration. Researchers

have learned that memory recall doubles when a past event is associated with a recognizable smell. Psychologists refer to the experience of smell stimulating memory as the “Marcel Proust phenomenon.” One is the influence of aroma on the brain, especially the limbic system through the olfactory system. Since ancient times, the herb rosemary (Rosmarinus officinalis) was well used by different people. The small evergreen shrub and its oil were used by the Roman students to massage their foreheads before taking examinations. And in medieval times, rosemary was considered a love charm that would help a couple remember their wedding vows. Traditional uses of rosemary include: to energize, to ease tension, to relieve headaches, brighten mood and to improve mental clarity. III.

Hypothesis This experiment aimed to determine the effect of aromatic scent to memory recall. Specifically, it attempts to answer the question: 1. If aromatic scent really improves memory recall?

Hypothesis Aromatic scent impairs memory recall. I.

Variables Independent Variable Aromatic scent

has three levels which are with rosemary scent,

(Rosemary scent) scent

without rosemary scent and a placebo

Dependent Variable Memory recall

being measured if it will change after exposing the participants with the independent

variable Control Variables Smell acuity

participants should have no colds

IQ level

the experimenters chose participants with one

specific

IQ level; Poor IQ level

Educational level

participants are all freshmen students

Random Variables Course

participants came from different courses such as Legal Studies, Psychology and Computer

Science Gender

both males and females were included as

participants Age

participants ‘age ranges from 16 years old to 18

years II.

old

Definition of Terms Aromatic scent

refers to rosemary scent

Memory Recall

the ability of the participants to retrieve the words based on the list given by the experimenter

Free Recall

participants recall the words in the order that they wanted

Placebo

a mixture of 1 drop rosemary scent and 1 vial of

water III.

Experimental Design The experimental design used was multilevel experimental design. It is a single variable experiment presenting three or more levels of the independent variable. It is also called functional experiment by some investigators because it allows the experimenter to get some idea of the shape of the function relating the independent variable to the dependent variable. In demand characteristics, the experimenters used the placebo effect in control group 1. This was done by mixing 1 vial of water to 1 drop of rosemary scent.

IV.

Conduct of the Experiment Procedure •

The experimenters identified first who were the qualified participants.

•

Culture Fair Intelligence Test was administered to the possible participants.

•

Upon completion of the tests, the experimenters have chosen the students with poor IQ level based on the results of their test.

•

The qualified participants were divided into three groups namely the experimental group, control group 1 and control group 2. Random assignment was utilized to form different groups by the use of three different colors of sticks which were picked by each participants to determine which group they will be into.

•

When the subjects were ready, the experimenters presented a list of three letter words for them to memorize. Time of exposure to the list

was 30 seconds. After the presentation of the list, subjects were given 60 seconds to write all the words that they can remember in any order. •

The experimenters followed the same procedure to the other groups.

•

Three days after the participants were given the list of words, the experimental group was exposed to the rosemary scent for 15 minutes. The same procedure was done with control group 1 with their placebo scent. After 15 minutes, the experimental group and control group 1 were given the same list of words as their posttest. Control group 2 with no exposure to rosemary scent immediately received the list of words as their posttest.

•

Scores of the three groups were compared, computed and tabulated using the appropriate statistical treatment.

I.

Results with Computation t - test for correlated samples

t=DΣD2-ΣDn2n(n-1)

D = the difference between the pretest and post test ∑D²= sum of square of difference between pretest and post ∑D = summations of difference between pretest and post test N = sample size

t - test for independent samples t = X1 - X2_________ √ (SS1 + SS2) ( 1 + 1 ) N1 + N2– 2

N1

N2

t = the t-test X1= the mean of group 1 X2= the mean of group 2 SS1= the sum of squares of group 1 SS2= the sum of squares of group 2 N1 = the no. of observations in group 1 N2 = the no. of observations in group 2

Table 1 Results of the Experimental Group Experimental Group Participant 1 Participant 2 Participant 3 Total

Pretest

Post test

D

D2

4 6 5 15

6 7 7 20

-2 -1 -2 ΣD= -5

4 1 4 ΣD2= 9

t=DΣD2-ΣDn2n(n-1) t=-1.679--5323(3-1) t=-1.679-8.336 t=-1.670.676 t=-1.670.112

t = - 1,67 0.33

CV (-5.061) > tv (4.303) * reject Ho *

t = -5.061

There is a significant difference on the results of

df= n-1 = 3 – 1 = 2

the pretest and posttest on memory recall of

tabular value α .05 = 4.303

the participants in the experimental group. Table 2

Results of the Controlled Group 1 Controlled Group 1 Participant 1 Participant 2 Participant 3 Total

Pretest

Post test

D

D2

6 5 5 16

5 4 3 12

1 1 2 ΣD= 4

1 1 4 ΣD2= 6

t=DΣD2-ΣDn2n(n-1) t=-1.336-4323(3-1) t=-1.336-5.336 t=-1.330.676 t=-1.330.112

t = - 1,33 0.334

CV (-3.982) < tv (4.303) * accept Ho *

t = -3.982

There is no significant difference on the results

df= n-1 = 3 – 1 = 2

of the pretest and posttest on memory recall of

tabular value α .05 = 4.303

the participants in control group 1. Table 3 Results of the Controlled Group 2

Controlled Group 2 Participant 1 Participant 2 Participant 3 Total

Pretest

Post test

D

D2

5 4 4 13

3 4 3 10

2 0 1 ΣD= 3

4 0 1 ΣD2= 5

t=DΣD2-ΣDn2n(n-1) t=15-3323(3-1) t=15-36 t=126 t=10.333

t=1

df= n-1= 3 – 1 = 2

0.577 = 1.733

tabular value α .05 = 4.303

CV (1.733) < tv (4.303)

* accept Ho *

There is no significant difference on the results of the pretest and posttest on memory recall of the participants in control group 2. Table 4 Pretest Results of Experimental Group and Controlled Group 1 X12 16 36 25 ΣX12= 77

Pretest of EG 4 6 5 ΣX1= 15 X1 = ΣX1 N1

Pretest of CG1 6 5 5 ΣX2= 16

X2 = ΣX2 N2

= 15 / 3

= 16 / 3

=5

= 5.33

SS1 = ΣX12 – (ΣX1)2

SS2 = ΣX22 – (ΣX2)2

N1

N2

= 77 – (15)2

= 86 – (16)2

3

3

= 77 – 75

= 86 – 85.33

=2

= 0.67

t = X1 - X2_________ √ (SS1 + SS2) ( 1 + 1 ) N1 + N2– 2

N1

N2

= 5 – 5.33_____________ √ (2 + 0.67) ( 1 + 1 )

X22 36 25 25 ΣX22= 86

3+3–2

3

3

= -0.33____ √(2.67) (0.66) 4 = -0.33______ √(0.6675) (0.66) = -0.33_____ √0.44055 = -0.33_____ 0.664

df = N1 + N2 - 2 =3+3–2

=4

= -0.497

tabular value α .05 = 2.776

CV (-0.497) < tv (2.776)

* accept Ho *

There is no significant difference on the results of the pretest on memory recall of the participants in the experimental group and control group 1.

Table 5 Pretest Results of Experimental Group and Control Group 2 Pretest of EG 4 6 5 ΣX1= 15 X1 = ΣX1 N1 = 15 / 3

X12 16 36 25 ΣX12= 77 X2 = ΣX2 N2 = 13 / 3

Pretest of CG2 5 4 4 ΣX2= 13

X22 25 16 16 ΣX22= 57

=5

= 4.33

SS1 = ΣX12 – (ΣX1)2

SS2 = ΣX22 – (ΣX2)2

N1

N2

= 77 – (15)2

= 57 – (13)2

3

3

= 77 – 75

= 57 – 56.33

=2

= 0.67

t = X1 - X2_________ √ (SS1 + SS2) ( 1 + 1 ) N1 + N2– 2

N1

N2

= 5 – 4.33_____________ √ (2 + 0.67) ( 1 + 1 ) 3+3–2

3

3

= 0.67____ √(2.67) (0.66) 4 = 0.67______ √(0.6675) (0.66) = 0.67____ √0.44055 = 0.67_____ 0.664

df = N1 + N2 - 2 =3+3–2

=4

= 1.009

tabular value α .05 = 2.776

CV (1.009) < tv (2.776)

* accept Ho *

There is no significant difference on the results of the pretest on memory recall of the participants in the experimental group and control group 2.

Table 6 Pretest Results of Control Group1 and Control Group 2 X12 36 25 25 ΣX12= 86

Pretest of CG1 6 5 5 ΣX1= 16 X1 = ΣX1 N1

Pretest of CG2 5 4 4 ΣX2= 13

X2 = ΣX2 N2

= 16 / 3

= 13 / 3

= 5.33

= 4.33

SS1 = ΣX12 – (ΣX1)2

SS2 = ΣX22 – (ΣX2)2

N1

N2

= 86 – (16)2

= 57 – (13)2

3

3

= 86 – 85.33

= 57 – 56.33

= 0.67

= 0.67

t = X1 - X2_________ √ (SS1 + SS2) ( 1 + 1 ) N1 + N2– 2

N1

N2

= 5.33 – 4.33_____________ √ (0.67 + 0.67) ( 1 + 1 ) 3+3–2 = 1____ √(1.34) (0.66) 4 = 1______ √(0.335) (0.66)

3

3

X22 25 16 16 ΣX22= 57

= 1_____ √0.2211 = 1_____

df = N1 + N2 - 2

0.470

=3+3–2

=4

= 2.128

tabular value α .05 = 2.776

CV (2.128) < tv (2.776)

* accept Ho *

There is no significant difference on the results of the pretest on memory recall of the participants in control group 1 and control group 2. Table 7 Post test Results of Experimental Group and Control Group 1 Post test of EG 6 7 7 ΣX1= 20

X12 36 49 49 ΣX12= 134

X1 = ΣX1 N1

Post test of CG1 5 4 3 ΣX2= 12

X2 = ΣX2 N2

= 20 / 3

= 12 / 3

= 6.67

=4

SS1 = ΣX12 – (ΣX1)2

SS2 = ΣX22 – (ΣX2)2

N1 = 134 – (20)2

N2 = 50 – (12)2

3

3

= 134 – 133.33

= 50 – 48

= 0.67

=2

t = X1 - X2_________ √ (SS1 + SS2) ( 1 + 1 )

X22 25 16 9 ΣX22= 50

N1 + N2– 2

N1

N2

= 6.67 – 4____________ √ ( 0.67 + 2) ( 1 + 1 ) 3+3–2

3

3

= 2.67____ √(2.67) (0.66) 4 = 2.67______ √(0.6675) (0.66) = 2.67_____ √0.44055 = 2.67____ 0.664

df = N1 + N2 - 2 =3+3–2

=4

= 4.021

tabular value α .05 = 2.776

CV (4.021) > tv (2.776)

* reject Ho *

There is a significant difference on the results of the posttest on memory recall of the participants in the experimental group and control group 1.

Table 8 Post test Results of Experimental Group and Control Group 2 Post test of EG 6 7 7 ΣX1= 20

X12 36 49 49 ΣX12= 134

Post test of CG2 3 4 3 ΣX2= 10

X22 9 16 9 ΣX22= 34

X1 = ΣX1 N1

X2 = ΣX2 N2

= 20 / 3

= 10 / 3

= 6.67

= 3.33

SS1 = ΣX12 – (ΣX1)2

SS2 = ΣX22 – (ΣX2)2

N1

N2

= 134 – (20)2

= 34 – (10)2

3

3

= 134 – 133.33

= 34 – 33.33

= 0.67

= 0.67

t = X1 - X2_________ √ (SS1 + SS2) ( 1 + 1 ) N1 + N2– 2

N1

N2

= 6.67 – 3.33_____________ √ (0.67 + 0.67) ( 1 + 1 ) 3+3–2

3

3

= 3.34____ √(1.34) (0.66) 4 = 3.34______ √(0.335) (0.66) = 3.34_____ √0.2211 = 3.34_____ 0.470

df = N1 + N2 - 2 =3+3–2

=4

= 7.106

tabular value α .05 = 2.776

CV (7.106) > tv (2.776)

* reject Ho *

There is a significant difference on the results of the posttest on memory recall of the participants in the experimental group and control group 2. Table 9 Post test Results of Control Group1 and Control Group 2 X12 25 16 9 ΣX12= 50

Post test of CG1 5 4 3 ΣX1= 12 X1 = ΣX1 N1

Post test of CG2 3 4 3 ΣX2= 10

X2 = ΣX2 N2

= 12 / 3

= 10 / 3

=4

= 3.33

SS1 = ΣX12 – (ΣX1)2

SS2 = ΣX22 – (ΣX2)2

N1

N2

= 50 – (12)2

= 34 – (10)2

3

3

= 50 – 48

= 34 – 33.33

=2

= 0.67

t = X1 - X2_________ √ (SS1 + SS2) ( 1 + 1 ) N1 + N2– 2

N1

N2

= 4 – 3.33_____________ √ (2 + 0.67) ( 1 + 1 ) 3+3–2 = 0.67____ √(2.67) (0.66)

3

3

X22 9 16 9 ΣX22= 34

4 = 0.67______ √(0.6675) (0.66) = 0.67____ √0.44055 = 0.67_____ 0.664

df = N1 + N2 - 2 =3+3–2

=4

= 1.009

tabular value α .05 = 2.776

CV (1.009) < tv (2.776)

* accept Ho *

There is no significant difference on the results of the posttest on memory recall of the participants in control group 1 and control group 2.

II.

Implications of Results based on Research Literature Rosemary has recently been shown to help keep brain cells healthy. It has also

been shown to improve mental performance. In one study, “rosemary produced a significant enhancement of performance for overall quality of memory and secondary memory factors”. Aroma-memory associations tend to be powerful and enduring. A scent can actually improve one’s ability to recall information. One study compared participants’ performance on a cognitive assessment battery of tests while the subjects were exposed to diffuse a “relaxing” essential oil, lavender, a “stimulating” essential oil, rosemary, or no odor. Those in the lavender group showed a decrease in memory performance. The subjects who were exposed to rosemary showed enhanced memory performance as compared to the control group.

Sage (Salvia lavandulaefolia), traditionally known to help memory and brain function, was given to test subjects to take internally in the form of essential oil-filled capsules. The young adults participating in this study were given either sage essential oil capsules or placebo capsules. On word-recall tests, the participants who had received the sage capsules performed significantly better. In the cognition study using lavender and rosemary, mentioned above, it was reported that participants in the lavender group were significantly less alert than those in the rosemary group. This supports the traditional use of lavender as a more calming essential oil, and rosemary as a more invigorating essential oil. Lavender and rosemary were used in another study, where participants’ EEG activity, alertness, and mood were evaluated after three minutes of application by inhalation. Those in the lavender group felt less depressed and more relaxed, and had EEG activity suggestive of increased drowsiness. Those in the rosemary group had EEG activity which was suggestive of a more alert state. The participants who had rosemary aromatherapy also felt more relaxed and had lower anxiety scores. The participants in this study were given math computations before and after receiving aromatherapy. After aromatherapy, those in the lavender group did the math problems more quickly and more accurately, while those in the rosemary group did the problems more quickly but not more accurately. Another study seeks to test whether the scent of rosemary can actually improve short-term memory as measured by a number-recollection test. Subjects are read number sequences of increasing length and try to repeat the sequences from memory. Subjects are then given a sprig of rosemary, instructed to sniff it and are read a different set of sequences which they try to repeat. Tests results are compared.

To minimize the effect aging can have on memory, it was important that the subjects were all about the same age- in this case, all 12 year olds. Three were females and three were males. It was also important that subjects had not used a scent of any kind or consumed food in the past hour. Subjects were asked to wash their hands before the test. Since the ability to recall a number is influenced by the number’s position on the list, they factored in that the first and last numbers would be the most accurately remembered. Each subject was tested individually, out of sight and sound of other subjects, and subjects were allowed a 1-minute break between tests. When the subjects used rosemary, their recall seemed considerably improved. This was reflected in each subject’s recalling more numbers from the longer sequences in the first set- both with and without rosemary. However, without rosemary, only one subject could recall 8 numbers in sequence from the second set. After smelling the rosemary, five subjects correctly repeated 8 numbers in the second set and one recalled all 9 numbers. Subjects reported that they enjoyed the scent of the rosemary and that it helped relax them during the test. It may be that relaxation alone is enough for the brain to do its best remembering. Scent and Memory Scientists tell us that our memory retention is much stronger when linked to smell than to sight. A whiff of certain fragrances often brings to mind images and feeling that are associated with a particular event. Psychology professor Trygg Engen of Brown University in Providence, Rhode Island, and author of Odor Sensation and Memory and Perception of Odor found that the memory recall associated with scent is at least twice

as potent as that of visual recall. That’s why a whiff of a certain perfume or some other fragrance that you haven’t smelled for years will propped you back in time. With that scent comes everything associated with the original aromatic experience: sights, sounds and emotional impressions. Engen says that smells serve as “index keys” to quickly retrieve certain memories in our brain. He supports the “nurture” theory over “nature” argument, believing that all smells are initially perceived as neutral and that we each learn to regard scents as pleasant or unpleasant, then retain that information in our memories. Rosemary has a long history of increasing memory concentration, and even creativity. In the last act of Shakespeare’s Hamlet, the mad Ophelia declares, “There’s rosemary, that’s for remembrance.” In the seventeenth century, herbalist Nicholas Culpeper wrote that rosemary helps a weak memory, and quickens the senses. Modern research conducted in Japan confirms rosemary as a brain stimulant. As an antioxidant, it slows the breakdown of acetylcholine in the brain. This important neurotransmitter is found at low levels in Alzheimer’s patients. Aromatherapy Aromatherapy can improve memory, recall and concentration. Researchers have learned that memory recall doubles when a past event is associated with a recognizable smell. The essential oil from rosemary has a reputation for increasing memory, concentration and even creativity. Carnosol, a component of rosemary is a phenolic compound that has potent antioxidant and anti-inflammatory activities. A British study at the Human Cognitive Neuroscience at the University of Northumbria examined the cognitive performance of 144 participants by dividing them into three groups: 1) exposed to the essential oil lavender, 2) exposed to the essential

oil rosemary, 3) exposed to a placebo with no odor. Those in the rosemary group showed enhanced memory performance as compared to those in the lavender and placebo groups. III.

Figures and material used Pretest

Experimental Group: Treatment (with rosemary scent)

Pretest

Control Group 1:

Pretest

Control Group 2:

Placebo

Post test Post test

without treatment

Post test

Materials: Culture Fair Intelligence Test Rosemary essential oil

Burner

Dropper

Candle

Lighter

pencil/Ballpen

Data sheet

Stopwatch

Answer sheet

1 vial of Water

BIBLIOGRAPHY Books Huffman, Karen (2007). Psychology in Action. John Wiley & Sons, Inc. Vecchione,Glen (2005). Blue Ribbon Science Fair Projects. Sterling Publishing Company, Inc., page 54-55 Keville, K. & Green, M. (2009). Aromatherapy: A Complete Guide to the Healing Art 2nd Edition, The Crossing Press, Fredricks, Randi (2008). Healing and Wholeness: Complementary and Alternative Therapies for Mental Health. AuthorHouse, page 370

Martin, David (2004). Doing Psychology Experiments. Wadsworth/Thomson Learning Belmont CA

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