BIOLOGY RESEARCH PAPER

BIOLOGY RESEARCH
PAPER
Research question: To what extent does age and sexual orientation
influence one's olfactory fatigue and what sense of taste chemical
(espresso beans or lemon cuts) is more effective in curing one’s
olfactory weariness?
NAME: SHIVANI KHEMKA
WORD COUNT: 3718 WORDS

SHIVANI KHEMKA 001424-0065
1
ABSTRACT
The olfactory system gives humans their sense of smell by inhaling and detecting odorants in the
environment. Olfaction is physiologically related to gustation, the sense of taste in view of its
utilization of chemoreceptors to perceive data about substances. Humans can recognize an
extensive number of scents and utilize this data to interface effectively with their surroundings. The
olfactory system represents one of the most established tactile modalities in the phylogenetic
history of mammals. As a synthetic sensor, the olfactory framework distinguishes nourishment and
impacts social and sexual conduct.
In this essay, the effect of age and gender on olfactory fatigue was investigated through a
series of experiments. Here, subjects were divided into four groups based on their age and
gender, such as old, young, female and male. They were made to perform some tasks that
involved the usage of their olfactory system. Olfactory palate cleansers (coffee beans, lemon
slices) were used to cure the olfactory weariness that the subjects had developed. Then the
subjects were told to report the time at which they could not smell anything or could not distinguish
between odors.
The results of this experiment showed that (despite some inaccuracies or fluctuations)
women had better olfaction compared to men i.e. time for olfactory fatigue to occur was longer in
this case (women). When young people were compared to the older one’s the result showed that
younger people had better functioning olfactory system. Among the olfactory palate cleanser the
most effective was lemon slices as per the results obtained. Scientific studies are still being carried
out to prove the above reliable.

2
Table of Contents
INTRODUCTION:............................................................................................................................................3
AIM, RESEARCH QUESTION, HYPOTHESIS ........................................................................................5
VARIABLES:...................................................................................................................................................6
MATERIALS REQUIRED:.............................................................................................................................6
SAFETY PRECAUTIONS: ............................................................................................................................7
PRIOR TO START: ........................................................................................................................................7
PROCEDURE:.................................................................................................................................................7
DATA COLLECTION:....................................................................................................................................9
DATA ANALYSIS:....................................................................................................................................... 11
DISCUSSION................................................................................................................................................ 17
CONCLUSION: ............................................................................................................................................ 20
EVALUATION: ............................................................................................................................................. 21
WORKS CITED:........................................................................................................................................... 22
APPENDICES: ............................................................................................................................................. 22

3
INTRODUCTION:
There has been a drastic change in the multiplicity of organisms in this generation. The ones who
evolved, have led to the theory of survival of the fittest. Natural selection by the environment was
one of the key components that formed the basis of life. As the time passed by, our sense of smell
also evolved, we are now open to infinite number of odours. Sense of smell is evolutionarily very
significant. The most feasible way to survive this undulated topography of evolution is by using our
olfactory system. Olfaction has been one of the main components in making people compatible to
each other . The most critical part of olfactory signals in people, gives off an impression about
regulation of their conduct and interpersonal connections, of their association to specific
gatherings or social classes that has a major impact on their tastes and identity. This system is the
most important one which controls us sexually and mentally. Mating is also dependent on
olfaction, since the ancient period it hasn’t change a bit. Our sense perception plays with our
emotion and memory in a genuine manner. As an individual, olfaction personally interests me due
to the relative function sense perception has. Olfactory receptor gene family is the largest in the
mammalian genome.1 Many of the terrestrial vertebrates can identify a large number of odorants
due to the genetic radiation that occurred roughly 200 million years ago.
Every species has an olfactory repertoire unique to the hereditary makeup of that species. The
human olfactory collection is entirely assorted. As opposed to mistakenly reported assessments,
people can distinguish a huge number of airborne odorants (volatiles) in entirely little fixations. The
olfactory system consists of olfactory receptors and olfactory bulb. Olfactory receptors are situated
in the olfactory mucosa which makes up the olfactory epithelium. The second is olfactory bulb;
mainly a location in the brain where the nerves connect it to the olfactory epithelium. There is a
bone present in between the olfactory epithelium and the brain which separates the two, it is
known as cribriform plate. Above the cribriform plate lies the olfactory bulb which consists of
bundle of nerves, so it’s the cranial nerve that exits the brain and branches further. Whenever we
smell something, then its scent moves to our nasal cavity where it goes through different pathways
for us to analyse how good or bad an odour is. When we smell some air borne molecules, it enters
our nostrils as odorant molecules which follows the passage through the nasal cavity and hence
binds to the sticky mucosa that makes up the olfactory epithelium. The olfactory bulb which is
located right above the olfactory epithelium receives sensory information from them. Then the
odorant molecules will dissolve in the sticky mucosa where they come in contact with receptors on
cell which is very specific just like enzyme-substrate specificity. When the odorant molecules bind
to the receptors it triggers a cascade of events that causes the particular cell to fire in action
1 (Anthropol.)

4
potential to a specific location in the olfactory bulb, and this particular location is known as
glomerulus. Glomerulus is a destination point for various sensory olfactory cells that are sensitive
to the same molecules and they synapse to another cell type known as mitral which will project to
the brain. 2We show colossal variety in our genes that control the receptors in our olfactory
epithelium, and this might relate to variation in cross-cultural perception and inclination towards
scents. With age, people experience differential olfactory dysfunction, with a few smells staying
solid and others turning out to be progressively swoon. We have noticed that when we smell
something too strong, the odorant molecule acquires a prolonged life i.e. the temporary, normal
inability to distinguish a particular odour after a prolonged exposure to that airborne compound.
We can assume, olfactory fatigue to be as an adaptation of our sensory system for smell. To say
more specifically we have seen that whenever we go to a perfume shop, there are these little jars
full of coffee beans; this is mainly kept to revive our sense of smell. When we keep trying out
different perfumes or scents , a particular time comes when we feel all the perfumes to be
identical ;this is olfactory fatigue, at this point the shopkeeper tells us to sniff some coffee beans ,
the work of coffee bean is to act as an olfactory palate cleanser. Different types of olfactory
cleansers are available. Lemon slices can also be used to clear olfactory fatigue but is not used on
a regular basis. Long exposure to strong smells cause irrational functioning of the olfactory
system. Previously the ion channels that were active become dormant, so no odorant molecules
enter the nasal chamber for the receptors to detect and produce an electrical signal .This happens
because the cell membranes do not allow the entry of further odorant molecules, hence resulting
in a long lasting smell. But smelling an olfactory palate cleanser between each and every strong
scent open ups these ion channels causing the odorant molecules to bind to the receptors and
therefore works to generate an odour.
Illustration 1 :The diagram above shows the olfactory pathway discussed above.
2 (htt)

5
All of us have encountered a situation when we perceive a smell and suddenly get hold of a
memory which we had forgotten for years, this is how memory and physiology of olfaction tangle
each other. It has been recognised that when we smell something, the memory of that smell is
somehow always stored. Scientifically it is still unclear how this happens and what process lies
behind this, but some studies and researches have shown how these two correspond with each
other. What we incorporate through these studies may not even be applicable to humans, as most
of the experiments have been performed on animals. Above stated the pathway of olfaction, let’s
move on to how our brain perceives it and stores it as a memory. In the olfactory bulb, there are
some special cells when stimulated carry the impulses to the olfactory tubercle, which is then
forwarded to limbic system, thalamus and cortex. Limbic system consists of structures such as
hippocampus, amygdala, fornix and mammillary bodies. Most of the nerves terminate in front of
the cerebrum and are capable of interpreting thousands of smells. Memory of an odour is mainly
thought of a way used by animals to avoid preys, seek food, mating etc. Studies have classified
memory of odours to be a task of the limbic structures in the brain and the cortex. This shows the
significance of olfaction in our life. In this research paper, the investigation will be focussing on the
effect of age and gender on one’s olfactory fatigue and determine which olfactory palate cleanser
is the best to get rid of the fatigue.
Aim: This laboratory research work exhibits the correlation between olfactory fatigue, and age
and gender of the subjects and then finding which olfactory palate cleanser is the most suitable.
Researchquestion: To what extent does age and sexual orientation influence one's olfactory
fatigue and what sense of taste chemical (espresso beans or lemon cuts) is more effective in curing one’s
olfactory weariness?
Hypothesis:From the prior knowledge, this theory will be founded on the expectation that, solid
scents will bring about olfactory weakness all the more promptly when contrasted with weak
odours. Coffee bean as an olfactory palate cleanser clears the olfactory palate yet not with that
much adequacy as lemon slices. Water as a control will not affect any of the variables. It has
dependably been said that women have better sense discernment, hence without a doubt they
have preferably better olfaction than the men so the hypothesis would run with that certainty and
anticipate that it takes more time for women to secure olfactory fatigue contrasted with men. For
the most part it is seen that kids and moderately aged grown-ups have preferred comprehension
of aromas over the more seasoned ones. Again expressing that seniority gathering will have
sudden and quick olfactory weariness when contrasted with the other age bunches. So following
this trend I predict that women and young people will have better olfactory fatigue timing that is
they can resist more than men and old people.

6
Variables:
Independent variable - Dependent variable – Controlled variable –
 Garlic, Oil
 Aromatic balms
 Lemon
 Coffee
 Sample size (number of
individuals being
tested)
 Age
 Gender
 Water
Materials required:
 Coffee beans
 Lemon slices
 Garlic Cloves
• Aromatic balms –including five flavours:
1. Mangosteen
2. Coco Dean
3. Lemongrass
4. Orange(citrus)
5. Jasmine
 Coconut Oil
 Perfume
 Water
 Paper cups
 Tissue
 Stopwatch
 Stationary for recording
 Black cloth to be used as blindfold

7
Safety Precautions:
 Note that none of the subjects are allergic to any of the odorant materials used.
 Make sure that you keep any flammable liquids like perfume away from the burner.
 Make sure that the subjects wash their hands if they touch any sort of balms etc.
Prior to start:
 Firstly arranging different aromatic balms, coconut oil and perfumes in a tray large
enough to hold them.
 Make different concentration of odorant material. Diluted and concentrated will be most
preferable.
 Keep the coffee beans in an airtight jar.
 Lemon slices should be freshly cut at the start of the experiment.
Procedure:
1. Take a group of 56 individuals. Divide them into 2 small groups, each group consisting
of 28 individuals. Now we subdivide these two groups into 4 groups each, each
consisting of 7 members.
2. First group divided into four groups. This is the group which will be evaluating the effect
of coffee beans
Sample group A – 7 female members.
Sample group B – 7 male members.
Sample group C – 7 Young members aged between 5-30 years.
Sample group D – 7 Old members aged between 30 and above.
Now divide the second group into four more groups consisting of 7 members each:
Sample group E – 7 female members.
Sample group F – 7 male members.
Sample group G – 7 Young members aged between 5-30years.
Sample group H – 7 Old members aged between 30 and above.

8
3. Starting off we set up coconut oil followed by a clove of garlic, and then the 2 aromatic
balms. We then introduce water which acts as a control followed by the 3 other aromatic
balms.
Note: All the materials are kept in paper cups covered with the tissue having a small
hole, so that no misinterpretation of the data occurs as the subjects will not know what
they are smelling.
4. Then we set up the same things in the order mentioned but instead of water now we use
coffee beans.
5. Call out Sample A and make them smell all the materials kept in the order .Time keeper
should start the watch and note the time till the subject was no longer able to smell an
odour or distinguish between them. This is the time taken for the olfactory fatigue to
occur. Repeat this experiment on them with coffee bean. Hence, this gives you two
timings for each subject one with control that is water and another with coffee beans
which act as an olfactory palate cleanser.
6. Repeat this experiment with Sample groups B, C and D.
7. Now again set up the control experiment, and then again repeat the same by using
lemon slices instead of water.
8. Do this experiment with the Sample groups E, F, G and H. Again we generate two
different time values for each subject, hence giving us the olfactory fatigue timings.
9. Note down all the data obtained from the above steps.
Illustration 2- Setting of the experiment

9
DATA COLLECTION:
SAMPLE A (7 female members)
Subject no. Time taken for olfactory
fatigue to occur with water(
control experiment) (in
seconds)
Time taken for olfactory
fatigue to occur with coffee
beans(in seconds)
1 66.60 183.60
2 47.31 189.60
3 33.23 39.06
4 60.60 181.80
5 47.58 140.40
6 27.98 45.11
7 44.18 207.00
Table 1
Average time taken by control group A= (66.60+47.31+33.23+60.60+47.58+27.98+44.18)/7 = 46.78
Average time taken by for coffee bean group A=
(183.60+189.60+39.90+181.80+140.40+45.11+207.00)/7=141.06
SAMPLE B (7 male members)
seconds)
beans(in seconds)
8 13.18 14.73
9 11.30 11.46
10 94.80 72.00
11 32.37 35.43
12 150.00 213.60
13 127.20 150.60
14 150.60 211.20
Table 2
Average for control group B= (13.18+11.30+94.80+32.37+150.00+127.20+150.60)/7=82.77
Average for coffee bean group B= (14.73+11.46+72.00+35.43+213.60+150.60+211.20)/7=101.29
SAMPLE C (Young age)
seconds)
beans(in seconds)
15 32.87 45.90
16 121.93 109.81
17 223.45 239.46
18 112.30 167.87
19 59.12 124.32
20 43.20 21.45
21 74.65 98.65
Table 3
Average for control group C= (32.87+121.93+223.45+112.30+59.12+43.20+74.65)/7=95.36
Average for coffee bean group C= (45.90+109.81+239.46+167.87+124.32+21.45+98.65)/7=115.35

10
SAMPLE D (Old age)
seconds)
beans(in seconds)
22 51.12 54.90
23 39.47 69.00
24 14.98 12.30
25 23.89 31.56
26 16.54 35.67
27 41.90 56.78
28 12.31 19.87
Table 4
Average for control group D= (51.12+39.47+14.98+23.89+16.54+41.90+12.31)/7=28.60
Average for coffee bean group D= (54.90+69.00+12.30+31.56+35.67+56.78+19.87)/7=40.01
SAMPLE E (7 female members)
seconds)
fatigue to occur with lemon
slices(in seconds)
29 121.34 233.76
30 312.43 391.76
31 104.67 56.79
32 27.80 85.67
33 132.48 213.10
34 100.91 111.32
35 123.21 329.87
Table 5
Average for control group E=(121.34+312.43+104.67+27.80+132.48+100.91+123.21)/7=131.83
Average for lemon slice group E= (233.76+391.76+56.79+85.67+213.10+111.32+329.87)/7=203.18
SAMPLE F (7 male members)
seconds)
slices(in seconds)
36 12.00 45.60
37 120.80 163.45
38 31.45 76.04
39 42.68 121.50
40 95.02 98.76
41 153.23 218.09
42 162.30 190.23
Table 6
Average for control group F= (12.00+120.80+31.45+42.68+95.02+153.23+162.30)/7=88.21
Average for lemon slice group F= (45.60+163.45+76.04+121.50+98.76+218.09+190.23)/7=130.52

11
SAMPLE G (young age)
seconds)
slices(in seconds)
43 131.02 145.67
`44 167.50 193.45
45 112.54 154.89
46 114.56 231.67
47 62.04 93.30
48 244.93 396.00
49 117.82 84.30
Table 7
Average for control group G= (131.02+167.50+112.54+114.56+62.04+244.93+117.82)/7=135.77
Average for lemon slice group G= (145.67+193.45+154.89+231.67+93.30+396.00+84.30)/7=185.61
SAMPLE H (old age)
seconds)
slices(in seconds)
50 115.32 155.60
51 9.86 14.16
52 13.33 33.42
53 56.92 85.62
54 111.32 112.34
55 24.83 56.70
56 11.23 24.53
Table 8
Average for control group H= (115.32+9.86+13.33+56.92+111.32+24.83+11.23)/7=48.97
Average for lemon slice group H = (155.60+14.16+33.42+85.62+112.34+56.70+24.53)/7=68.91
Illustration 3- Subjects performing the experiment.

12
DATA ANALYSIS:
COMPARING BOTHTHE GRAPHS-
Graph 1
Graph 2
0
50
100
150
200
250
300
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
Time(inseconds)
Number of Subjects
The coffee bean group data analysis for Samples A,B,C
and D
Olfactory fatigue with
water
Olfactory fatigue with
coffee bean
Linear (Olfactory fatigue
with coffee bean)
0
50
100
150
200
250
300
350
400
450
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
Time(inseconds)
Number of Subjects
Lemon Slice group data analysis for Samples E,F,G and H
Olfactory fatigue
with water
Olfactory fatigue
with lemon slices
Linear (Olfactory
fatigue with lemon
slices)
(Legend) Graph 1 and Graph 2-The blue bar in the graph represents the olfactory
fatigue that would occur when water was used as control. Both the graphs above show
a general trend that is the olfactory fatigue timing for the control, the olfactory time is
less when water was used instead of coffee beans and lemon slices. Graph 1 has its
linear average value at 150 which is time taken for olfactory fatigue to occur when
coffee beans are used as an olfactory palate cleanser. Referring to Graph 2 we can
see that its linear average is at 200 which is again a longer time (in seconds) taken for
olfactory fatigue to occur when lemon slices were used instead of coffee beans.

13
THE GRAPH COMPARING THE TIME FOR OLFACTORY FATIGUE OF GROUP A, B, C, D
CONTROL AND COFFEE BEAN GROUP.
Henceforth, to evaluate to a precise point we find the average time taken by each sample group.
Average for control group
A
=
(66.60+47.31+33.23+60.6
0+47.58+27.98+44.18)/7
= 46.78
Average for coffee bean
group A
=
(183.60+189.60+39.90+1
81.80+140.40+45.11+207
.00)/7=141.06
B
=
(13.18+11.30+94.80+32.3
7+150.00+127.20+150.60)
/7=82.77
group B
=
(14.73+11.46+72.00+35.4
3+213.60+150.60+211.20)
/7=101.29
Average for control group C
=
(32.87+121.93+223.45+112
.30+59.12+43.20+74.65)/7=
95.36
group C
=
(45.90+109.81+239.46+167
.87+124.32+21.45+98.65)/7
=115.35
D
=
(51.12+39.47+14.98+23.
89+16.54+41.90+12.31)/
7=28.60
group D
=
(54.90+69.00+12.30+31.
56+35.67+56.78+19.87)/
7=40.0
Grouping the values and interpreting the average values we get the graph shown below.
Graph 3
0
20
40
60
80
100
120
140
160
A B C D
Time(inseconds)
Groups
AVERAGETIMEFOR OLFACTORYFATIGUEOF GROUP A, B, C, D
CONTROL AND COFFEEBEAN GROUP.
(control group) (coffee beans)
(Legend) Graph 3 shows the highest average value i.e. 140 seconds when coffee
beans were used is for the female sample group i.e. Sample A showing that they have
better sense of smell and olfaction. This highest value is followed by Sample C which
depicts the second highest value, suggesting that young people tend to generally smell
things for a longer period of time. Furthermore male group which is Sample B has its
average value slightly less than that of the other two groups mentioned above
suggesting their lower capacity of olfaction. The worst smelling power and the fastest
occurrence of olfactory weariness was found in the Sample group D i.e. the old age
(senior members). The blue bars in the graph depict the control experiment whose
variable was water. The trend is varying for the Sample A which gives the wrong idea
as the bar has to be higher because of the general trend considered above. However,
other Sample groups are abiding by the general trend.

14
THE GRAPH COMPARING THE TIME FOR OLFACTORY FATIGUE OF GROUP E, F, G, H
CONTROL AND LEMON SLICE GROUP.
Henceforth, to evaluate to a precise point we find the average time taken by each sample group.
E
=
(121.34+312.43+104.67+
27.80+132.48+100.91+12
3.21)/7=131.83
Average for lemon slice
group E
=
(233.76+391.76+56.79+8
5.67+213.10+111.32+329
.87)/7=203.18
F
=
(12.00+120.80+31.45+42.
68+95.02+153.23+162.30)
/7=88.21
group F
=
(45.60+163.45+76.04+121
.50+98.76+218.09+190.23
)/7=130.52
Average for control group G
=
(131.02+167.50+112.54+11
4.56+62.04+244.93+117.82
)/7=135.77
group G
=
(145.67+193.45+154.89+23
1.67+93.30+396.00+84.30)/
7=185.61
H
=
(115.32+9.86+13.33+56.
92+111.32+24.83+11.23)
/7=48.97
group H
=
(155.60+14.16+33.42+85
.62+112.34+56.70+24.53
)/7=68.91
Graph 4
NOTE: However, merely looking at the charts will not predict anything as both the charts ought to
give the same reflection. So, to get an accurate value for the complexity off the situation we
compare two groups of the same genre (such as age and gender) and see how the two differ
when two different olfactory palate cleansers are used.
0
50
100
150
200
250
E F G H
Time(inseconds)
Groups
TIME FOR OLFACTORY FATIGUEOF GROUP E, F, G, H CONTROL
AND LEMON SLICEGROUP
(control group) (lemon slice)
(Legend) Graph 4- Again, the highest average value for olfactory fatigue to occur when lemon
slices were used was for Sample E which was above 200 (in seconds) justifying that they have
better olfactory potential .Afterwards the same trend follows as it did in the coffee bean group.
However, the values are quite different as discussed in when comparing the Graph 1 and 2.
The blue bar depicts water which was a control, here the control sample values for Sample
Groups E and G is almost the same followed by Group F and then Group H.

15
Comparing groupsA and E:
Graph 5
Comparing groupsB and F:
Graph 6
0
50
100
150
200
250
300
350
400
450
1 2 3 4 5 6 7
Time(inseconds)
Number of subjects (combined for both groups)
Comparing A(coffeebean group) and E(lemon slice group) along
with thier mtual contolgroup (water)
A(control group) A(coffee beans) E(control group)
E(lemon slices) Linear (A(coffee beans)) Linear (E(lemon slices))
-100
0
100
200
300
1 2 3 4 5 6 7
Time(inseconds
Comparing B(coffeebean group) and F(lemon slice group) along with
thier mutual contolgroup (water)
P)
B (control group) B(coffee beans) F(control group)
F(lemon slices) Linear (B(coffee beans)) Linear (F(lemon slices))
(Legend) Graph 5-In the graph above we can see that the linear average line for lemon
slices are higher, hence proving that olfactory fatigue took time to occur for group E due to
the use of lemon slices as an olfactory palate cleanser.
6 (Legend) Graph 6-In the graph above we see that the linear line for group F is again
higher than the linear line of B for most of the part whereas there is a little dissociation at
the end. However, following the general trend we will consider that olfactory fatigue timing
due to lemon slices took longer.

16
Comparing C and G:
Graph 7
Comparing D and H:
Graph 8
0
50
100
150
200
250
300
350
400
450
1 2 3 4 5 6 7
Time(inseconds
Comparing C(coffeebean group) and G(lemon slice group) along with
thier mutual contolgroup (water)
C(control group) C(coffee beans) G(control group)
G(lemon slices) Linear (C(coffee beans)) Linear (G(lemon slices))
0
20
40
60
80
100
120
140
160
180
1 2 3 4 5 6 7
Time(inseconds
Comparing D(coffeebean group) and H(lemon slice group) along
with thier mutual contol group (water)
D(control group) D(coffee beans)
H(control group) H(lemon slices)
Linear (D(coffee beans)) Linear (H(lemon slices))
(Legend) Graph 7-In the graph above the two lines show a property of diversion. Again, the
result is the same as shown in another graphs. Olfactory fatigue timing was a little longer for
group G.
(Legend) Graph 8-In the graph above again we see the same general trend as discussed
in the graphs above.

17
DISCUSSION:
The Data collection and analysis proved that using this methodology for checking the effect of
gender and age on olfactory fatigue showed some variations which are in compliance with the
hypothesis stated above. Lemon slices proved to be better olfactory palate cleanser than coffee
beans. Research has not still been carried out to see how these cleansers clean the olfactory
palate, however experiments suggest that lemon slices, coffee bean and air are used to clean the
palate. Moreover, experiments (main and subsidiary) have shown that females have a better
olfaction i.e. their time for olfactory fatigue is prolonged as compared to men. In the experiment
with increasing age the ability to detect odour decreases as in a short span they get the olfactory
fatigue and no longer smell further or distinguish between the smell.
A study (1) was carried out in the Department of Anatomy, University of Health Sciences, Lahore.
Forty tissue samples were collected from cadavers of either sex, hence making it a total of eighty
ranging from 30 to 82 years of age. In early age group 30-39 had areas of respiratory epithelium
instead of olfactory epithelium. This change was observed in the superior region of the nasal
cavity. Age group 40-49 years showed morphological changes .The pure serous glands were
replaced with short epithelial invaginations and incidence of mucoserous gland. Disturbance of the
zonal distribution of the olfactory receptor cells and the 3Sustentacular cells was observed .For the
people aged 50-59 years the change observed was very significant. Reduction in the number of
nuclei was seen resulting in a decreased height of the epithelium .Zonal distribution was also
affected .Olfactory mucosa had changed position and elongated as a continuous sheet. Severe
number of respiratory. Olfactory mucosa had changed position and prolonged as a ceaseless
sheet. Serious number of respiratory epithelium was found in the olfactory area. Age related
changes in the epithelium in age group 60 years onwards was anticipated. The olfactory
epithelium was thinning with disturbance o the typical zonal dispersion. In some cases olfactory
epithelium without olfactory cells was seen. Olfactory receptors were rare in this gathering. At last,
in cutting edge organizes the decay and diminish in receptor cells prompted steady diminishing of
the olfactory epithelium. This study has greatly supported the experiment performed above. The
natural ageing process brings about some inevitable consequences, such as olfactory dysfunction.
An olfactory dysfunction has been pathologically connected to depression and personal
satisfaction issues, neurodegenerative disorders, adult and childhood obesity and diminished
nourishment in elderly females. Numerous age-related dementia, for example, Alzheimer's illness,
Vascular dementia, Parkinson's malady, and Frontotemporal Dementia is often seen as a result of
olfactory dysfunction. For example, recent studies from our gathering in transgenic mice over-
3
Sustentacularcells are barrel shaped;lyingopposite tothe surface,encompassingthe olfactoryreceptorcells.

18
communicating mutant human amyloid precursor protein, demonstrate that these mice show age-
subordinate olfactory dysfunction in comparison to age-coordinated control mice. These shortages
in olfaction, incorporate strange scent examination, smell habituation (transient memory) and
scent separation. Perceptual disorders are basic in neurodegenerative illnesses, incorporating
misfortunes in olfactory, visual and sound-related perceptual capacities .Perhaps owing to the
olfactory framework's nearby relationship with emotion and memory– two intellectual components
regularly affected in neurodegenerative ailment. In the experiment performed for this research
paper we see that older people get olfactory fatigue quickly as compared to young people, this
again proves the point mentioned above; with increasing age, effective olfaction decreases and
may even result in olfactory dysfunction.
However, there are some research studies which do not follow the pattern of the effect of age and
gender on olfactory fatigue. Such as the one where Clinical toxicologists performed assessments
and evaluation for patients with potential exposure to airborne toxicants: (2) this study contradicts
the experiment performed above, as this research states that with increasing age, odour detection
advances. Due to the clinical toxicology the reliability for the study was enhanced resulting in a
subjective deviation of results in the experiment that was conducted above. Facts even suggest
that some of the eccentricity could be due to the ethnic background, occupational background and
a person’s exposure to alcohol and smoking which might have affected there olfactory system and
how they perceive odours. Another research that might vary from the results obtained through the
experiment is the study of (3) olfactory acuity as a function of age and gender, here gender
showed the same outcome of women being more responsive, but some measures for olfaction
revealed that olfactory fatigue for older respondents did incline in a steep manner. This study even
shows that olfactory fatigue and olfaction are even affected by environmental factors such as the
indigenous background, as in this case they show the difference in olfaction between Americans
and Africans. This exhibited that African subjects were more responsive to odour, be it woman or
men. Hence this shows that many other factors could have brought about the deviation in the
results obtained. Another effect might be among the women as their senses are greatly influenced
by the level of oestrogen, so premenopausal and postmenopausal women will have different
lengths of olfactory fatigue as their handedness on olfaction differs. Some (4) studies on odour-
stimulated functional MR imaging showed that hormonal effects do not give much information as
how their might be earlier occurrence of olfactory fatigue for older people than for young ones. In
the above experiment women were shown to be superior to men when it comes to olfaction i.e.
they have an extended time for olfactory fatigue to occur. (5)Brazilian researchers found that
women have 40-50% larger area in the brain where the scents are processed. They used a
technique called the isotropic fractionators and measured the number of cells in a given brain

19
structure, in this case the the structure being olfactory bulb. The result showed that women have
43% more cells than men in this structure which concluded that since smells are linked to
experiences and emotions, the superior capability in women suggests they have developed
cognitive and emotional feature rather than just a perceptual one. Hence the studies compared
with the experiment performed suggests that many of the studies complement the experiment
above, however some research is still required as the experiment could have deviated from some
studies due to the inconsideration of some factors (discussed above) and the use of better
technology in the researches.
Future prospect in olfaction research might be socially and commercially viable. The consumer
product industries such as perfumes, food and beverages industries spend billions of dollars
every year in order to promote olfactory research with an end goal to upgrade their product design
and marketing. With such a large number of converging zones in research sector, anthropology
made an immense contribution towards developing assortment of work that crosses conventional
disciplinary lines and has a reasonable connected segment. Back in the antiquated times, scents
used to have impact in characterizing sexuality deliberately adding to the oblivious impact of
pheromone–like chemicals on the vomeronasal organ. Perfume shops can keep lemon slices
instead of coffee beans as it will be cheaper though it has to be replaced on a regular basis.
Specific people can be employed as perfumers so that perfumes can be made with distinct scents
resulting in greater accuracy and precision. For example young females can be assigned to make
perfumes such as Eau de Parfum, Eau de Toilette and Eau de Cologne due to the differing
concentration of aromatic compound hence making it distinguishable for perfumers. Humans can
differentiate between 10,000 different odours. Individuals (wine or perfume experts, for example)
can train their sense of smell to become expert in detecting subtle odours by practicing retrieving
smells from memory.
Additionally, human sciences could profit by considering the force of the olfactory framework in
memory, behavioural and meaningful gestures, developmental history, mate decision,
nourishment choices, and general well-being.

20
CONCLUSION:
To conclude, one could easily say that olfactory fatigue is a dependent variable which relies on
factors such as age and gender, majorly. However there are some other factors which might even
influence the olfaction which in turn influences the olfactory fatigue. When the control was
performed we got the same result as when lemon slices or coffee beans were introduced. The
results being; in women olfactory fatigue had taken a longer time to occur in all three cases of
control, lemon and coffee beans as compared to men. Methodically, the persistent prolonging of
olfactory fatigue to occur for young people were also observed. The experiment even concluded
that lemon slices are better olfactory palate cleanser than coffee beans. Hence the results
predicted in the hypothesis abide by the results obtained in the investigation.
Moreover some of the causes of little deviation that might have resulted might be due to the
exclusion of some variables such as ethnic background, community and hormones as discussed
above. Hence following the same pattern of gender and age as the only variables, the results
obtained might not be that compatible or reliable as the studies have proven to be. In future, more
research has to be performed to dive into the depth of the theory of older people having better
olfaction than younger individuals so that’s its reliability can be assured, as there are studies that
completely contradict each other. Furthermore, research into which olfactory palate cleanser is
better has not been proven scientifically hence cannot be that reliable so, further investigation
must take place to show its verity. Though the experiment was successful and proved the
hypothesis, there are still some limitations can could have brought about little deviation and effort
can be put towards its improvement.

21
EVALUATION:
LIMITATIONS:
 Many subjects did not give accurate reading due to the uncertainty that might have
occurred while reporting the time.
 Many subjects might have given inaccurate time due the experiment being long and time
consuming.
 Some of the aromatic balms were not as strong as the others resulting in variation in the
result.
 Some difference in result must have occurred due to the time gap between the time
reported and the time taken down.
IMPROVEMENTS:
 More people could have been appointed as subjects.
 The experiment could have been repeated to ensure its reliability.
 Monitor some factors that could have brought about a little deviation.
 Use the same concentrations of aromas.
 Be more accurate while recording the time with a stop watch.

22
Works Cited
Sfanta Maria" Clinical Hospital, ENT - HNS Department, 37-39, Ion Mihalache Bvd., District 1,
Bucharest, Romania. csarafoleanu@gmail.com. Apr-Jun 2009 . july-sept 2015
<http://www.ncbi.nlm.nih.gov/pubmed/20108540 >.
C Sarafoleanu, corresponding author C Mella, M Georgescu, and C Perederco. The importance of
the olfactory sense in the human behavior and evolution. 25 April 2009.
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3018978/>.
The Fragnance Shop. <http://www.thefragranceshop.co.uk/fragrance-guide.aspx#/panel-element-
516773>.
Boundless.com. <https://www.boundless.com/psychology/textbooks/boundless-psychology-
textbook/sensation-and-perception-5/sensory-processes-38/olfaction-the-nasal-cavity-and-smell-
164-12699/>.
Jorge Alves, Agavni Petrosyan, and Rosana Magalhães. Olfactory dysfunction in dementia. 16
November 2014. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4233420/>.
KC, Hoover. Smell with inspiration: the evolutionary significance of olfaction. 2010.
<http://www.ncbi.nlm.nih.gov/pubmed/21086527>.
Daniel W Wesson, corresponding author Donald A Wilson, and Ralph A Nixon. Should olfactory
dysfunction be used as a biomarker of Alzheimer's disease? 10 May 2010.
<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3629552/>.
Vokshoor, Amir. OLfactory System Anatomy. <http://emedicine.medscape.com/article/835585-
overview>.
EE guidelines. <http://www.andycrown.net/extended_essay_guidelines.htm>.
Smell with inspiration: The evolutionary significance of olfaction.
<https://www.researchgate.net/publication/47813782_Smell_with_inspiration_The_evolutionary_si
gnificance_of_olfaction>.
Svoboda, Elizabeth. Scents and Sensibility. 1 Jan 2008.
<https://www.psychologytoday.com/articles/200801/scents-and-sensibility>.
Function of olfactory epithelium.
Sensory Memory. <https://en.wikipedia.org/wiki/Sensory_memory>.
Dowdey, Sarah. How smell works. <http://health.howstuffworks.com/mental-health/human-
nature/perception/smell3.htm>.
M.L. Miller, A. Andringa, J.E. Evans, L. Hastings. Microvillar cells of the olfactory epithelium:
morphology and regeneration following exposure to toxic compounds .
<http://www.sciencedirect.com/science/article/pii/0006899394011447>.
Greenberg MI1, Curtis JA, Vearrier D. The perception of odor is not a surrogate marker for
chemical exposure: a review of factors influencing human odor perception. Feb 2013. june-dec
2015 <http://www.ncbi.nlm.nih.gov/pubmed/23387344>.

23
barber, Clifton E. Olfactory Acuity as a Function of Age and Gender: A Comparison of African and
American Samples.
<https://www.researchgate.net/publication/13940256_Olfactory_Acuity_as_a_Function_of_Age_a
nd_Gender_A_Comparison_of_African_and_American_Samples>.
David M. Yousema, Joseph A. Maldjiana, Thomas Hummela, David C. Alsopa, Rena J. Gecklea,
Michael A. Krauta and Richard L. Dotya +. The effect of age on Odor-stimulated functional MR
imaging. <http://www.ajnr.org/content/20/4/600.full>.
Ana V Oliveira-Pinto, Raquel M Santos, Renan A Coutinho, Lays M Oliveira, Gláucia B Santos,
Ana T L Alho, Renata E P Leite, José M Farfel, Claudia K Suemoto, Lea T Grinberg, Carlos A
Pasqualucci, Wilson Jacob-Filho, Roberto Lent. Sexual dimorphism in the human olfactory bulb:
females have more neurons and glial cells than males.
<http://www.jove.com/visualize/abstract/25372872/sexual-dimorphism-human-olfactory-bulb-
females-have-more-neurons>.
Jafari, Dr. Fahim Haider. A HISTOLOGICAL STUDY OF HUMAN OLFACTORY MUCOSA.
<www.uhs.edu.pk/downloads/dr_fahim_thesis.pd>.
Anthropol., Am J Phys. Smell with inspiration: the evolutionary significance of olfaction. 2010.
<http://www.ncbi.nlm.nih.gov/pubmed/21086527>.
<http://layoftheland.net/archive/ART4639-2012/weeks1-5/010411.pdf>.
Bibliography of the studies mentioned:
(1) (Jafari)
(2) (Greenberg MI1)
(3) (barber)
(4) (David M. Yousema)
(5) (Ana V Oliveira-Pinto)

24
Appendices:
(Subsidiaryexperiment 1)
To back the experiment up, a different experiment has been performed again to see the difference
in olfactory timing without using any olfactory palate cleanser or control but using the same
equipment’s to generate odour. It has been performed on 20 different individuals divided into four
groups each consisting of five individuals. Again, the olfactory fatigue timing are noted and
analysed.
Group A- Male members
Group B-Old members
Group C-Female members
Group D- Young members
Data collection:
Timing for olfactory fatigue
SAMPLE GROUP A
SUBJECT
NO.
TRAIL 1(
in
seconds)
TRIAL 2(
in
seconds)
TRIAL 3(
in
seconds)
1 26.73 26.80 16.55
2 20.60 18.59 10.41
3 18.50 19.60 10.50
4 21.33 17.90 14.70
5 25.10 11.50 13.90
SUBJEC
T NO.
TRIAL 1(
in
seconds)
TRIAL 2(
in
seconds)
TRIAL 3(
in
seconds)
6 14.78 7.21 7.54
7 14.15 13.67 7.60
8 10.45 9.16 8.21
9 16.37 10.15 8.18
10 12.10 9.12 6.90
SUBJECT
NO.
TRIAL 1(
in
seconds)
TRIAL 2(
in
seconds)
TRIAL 3(
in
seconds)
11 29.80 18.36 16.50
12 I24.50 86.80 40.50
13 113.40 78.94 69.76
14 54.91 39.89 19.00
15 9.44 7.68 15.42
SUBJECT
NO.
TRIAL 1(
in
seconds)
TRIAL 2(
in
seconds)
TRIAL 3(
in
seconds)
16 72.00 34.36 17.50
17 8.58 9.60 10.41
18 13.77 12.68` 11.78
19 55.99 12.25 11.02
20 11.20 12.54 9.67
SAMPLE GROUP B
SAMPLE GROUP C
SAMPLE GROUP D
Table 9 Table 10
Table 11 Table 12

25
DATA COLLECTION:
Mean evaluation of the time of olfactory fatigue for all the subjects:
Sample group A:
Table 13
Average olfactory fatigue time of GROUP A:
= (23.36+16.53+16.20+17.97+16.83) / 5
=18.17 seconds
Sample group B
Table 14
Average olfactory fatigue time of GROUP B:
= (9.84+11.80+9.27+11.56+9.37)/5
=10.38 seconds
SUBJECT NO. TRAIL 1( in seconds)+TRIAL 2( in seconds)
+TRIAL 3( in seconds)
Total/3 Mean time
(in seconds)
1 26.73 +26.80 +16.55 70.08/3 23.36
2 20.60+18.59+10.41 49.60/3 16.53
3 18.50+19.60+10.50 48.60/3 16.20
4 21.33+17.90+14.70 53.93/3 17.97
5 25.10+11.50+13.90 50.50/3 16.83
SUBJECT NO.
TRIAL 1( in seconds)+TRIAL 2( in
seconds)+TRIAL 3( in seconds)
Total/3 Mean time
( in seconds)
6 14.78+7.21+7.54 29.53/3 9.84
7 14.15+13.67+7.60 35.42/3 11.80
8 10.45+9.16+8.21 27.82/3 9.27
9 16.37+10.15+8.18 34.70/3 11.56
10 12.10+9.12+6.90 28.12/3 9.37

26
Sample Group C
Table 15
Average olfactory fatigue time of GROUP C:
= (21.55+83.93+87.36+37.93+10.84)/5
=48.32 seconds
Sample Group D
Table 16
Average olfactory fatigue time of GROUP D:
= (41.26+9.53+12.74+26.42+11.13)/5
=20.21 seconds
SUBJECT NO. TRIAL 1( in seconds)+TRIAL 2( in
seconds)+TRIAL 3( in seconds)
Total/3 Mean time
(in
seconds)
11 29.80 +18.36+16.50 64.66/3 21.55
12 124.50+86.80+40.50 251.80/3 83.93
13 113.40+78.94+69.76 262.10/3 87.36
14 54.91+39.89+19.00 113.80/3 37.93
15 9.44+7.68+15.42 32.54/3 10.84
SUBJECT NO. TRIAL 1( in seconds)+TRIAL 2( in seconds)+TRIAL 3(
in seconds)
Total/3 Mean
time(in
seconds)
16 72.00+34.36+17.50 123.86/3 41.26
17 8.58+9.60+10.41 28.59/3 9.53
18 13.77+12.68+11.78 38.23/3 12.74
19 55.99+12.25+11.02 79.26/3 26.42
20 11.20+12.54+9.67 33.41/3 11.13

27
DATA ANALYSIS:
Graph 9
(Legend) Graph 9-The Chart above shows that olfactory fatigue for Group C (48.32) was the
longest claiming that females have specified and powerful olfactory system which works better
than males. The second strongest olfaction was detected to be for the young people which is
20.21 which complies with the trend found in Experiment 1.
Reiteration of the graph above .
Chart 1
This shows the pie chart for the graph above again satisfying the results obtained in the first
experiment.
18.17
10.38
48.32
20.21
0
10
20
30
40
50
60
SAMPLE
GROUPA
SAMPLE
GROUP B
SAMPLE
GROUP C
SAMPLE
GROUP D
Time(inseconds)
GROUPS
TIME TAKEN FOR OLFACTORY FATIGUE TO OCCUR(
in seconds)
TIME TAKEN FOR OCFACTORY
FATIGUE TO OCCUR( in seconds)
18.17
10.38
48.32
20.21
Average time(in seconds) taken by each
sample group
GROUP A
GROUP B
GROUP C
GROUP D

28
(SUBSIDIARY EXPERIMENT-2)
Take any four of the aromatic balms, do this experiment with the 20 individuals in the four groups
used in the above experiment. Blindfold the subjects and hand them three of the four balms. Now
tell them to deeply recognize and remember the smell. Take the balms back and tell the subjects
to breathe in air, deeply. Now hand over all the four balms and tell them to recognize the new
odour when they are still blindfolded. Repeat this by introducing coffee beans and them lemon
slices instead of sir and check the results.
DATA COLLECTION:
40%
55%
75%75%
OLFACTORY TEST
OUTCOME
Coffee beans
Plain air
Lemon slices
Serial
no.
Coffee Air Lemon
1. ✓ ✓ ✓
2. ✓ ✖ ✓
3. ✖ ✓ ✓
4. ✓ ✓ ✓
5. ✖ ✓ ✓
6. ✓ ✖ ✖
7. ✓ ✖ ✓
8. ✖ ✓ ✓
9. ✖ ✖ ✖
10. ✖ ✓ ✓
11. ✖ ✓ ✓
12. ✖ ✖ ✖
13. ✖ ✖ ✓
14. ✓ ✓ ✓
15. ✖ ✓ ✓
16. ✓ ✖ ✖
17. ✓ ✖ ✓
18. ✖ ✓ ✓
20. ✖ ✓ ✓
Table 17– Identifying the odour using different olfactory
cleanser such as coffee, lemon and plain air.
Chart 2
In the pie chart we see
that the maximum
percentage of people
were clearly able to
identify the new odour
better in the presence
of lemon slices, than
coffee beans or plain
air. Hence proving that
lemon slices is the
most effective way of
cleaning our olfactory
palate.
DATA PROCESSING OF TABLE 17:
Correctly answered using coffee = 8 out of 20 =
(8/20)*100 = 40% answered correctly
Correctly answered using plain air = 11 out of 20=
(11/20)*100 = 55% answered correctly
Correctly answered using lemon slices= 15 out of
20 = (15/20)*100 = 75% answered correct

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