Kwantlen Polytechnic University

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Honours Theses

Student Scholarship

2008

Shifts in Colour Discrimination and Food Imagery
Preferences during the First Trimester
Levente L. Orbán
Kwantlen Polytechnic University

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Recommended Citation
Orbán, Levente L., "Shifts in Colour Discrimination and Food Imagery Preferences during the First Trimester" (2008). Honours Theses.
Paper 1.

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Running head: COLOUR DISCRIMINATION AND FOOD IMAGERY PREFERENCES

Shifts in Colour Discrimination and
Food Imagery Preferences during the First Trimester
Levente L. Orbán
Kwantlen University College

Submitted in fulfillment
of the requirements for the
PSYC 5010, Honours Thesis course

Abstract
The present study aims to test the adaptive theory of pregnancy sickness to limit
fetal exposure to teratogens, by investigating possible shifts in colour discrimination
and food imagery preferences in women during their first trimester of pregnancy.
We hypothesized that colour discrimination and food imagery preference shifts are
part of the changes that occur to the first trimester pregnant woman’s perceptual
shifts. The reason for this shift is to protect the embryo during its most vulnerable
phase of development. We recruited 6 pregnant women in their first trimesters and
9 nonpregnant women to participate in the study. Subjects completed the
Farnsworth-Munsell 100 hue test in which they were asked to order 85 coloured
caps in their order of hue. Next, subjects viewed a slideshow of 10 common food
exemplars. Each slide displayed a food at 6 different stages of its ripeness or
freshness and subjects were asked to rate how appetizing they found each food.
Preliminary results confirm our first prediction that first trimester subjects have
better chromatic discrimination when compared with non-pregnant subjects.

Shifts in Colour Discrimination and Food Imagery Preferences during the First
Trimester of Pregnancy
An estimated 10,000 infants were born with birth malformations and up to twice as
many self-induced abortions occurred over the period of 4 years from 1957 to 1961,
due to a drug, prescribed for treatment of morning sickness (Rajkumar, 2004). The
drug that swept in over 40 countries (mostly in Europe) was Thalidomide and today
this incident is known as the Thalidomide tragedy (Rajkumar; CAFMR, 1996; Lenz,
1988). Studies conducted after the tragedy confirmed that thalidomide is a powerful
teratogen, which if taken by pregnant women between days 35 and 49 after their
last menstrual period could have detrimental effects on the embryo, even with the
ingestion of a single pill (Rajkumar; Lenz). Approximately 40% of exposed infants
die within the first year of their life.
Morning sickness, from an evolutionary perspective, is not pathological; it is
hypothesized to be a useful adaptation that increases the individual’s chances of
survival. As such, a physician informed by evolutionary principles would be unlikely
to prescribe pharmacological therapy for the treatment of morning sickness
(excluding hyperemesis gravidarum (HG) and emesis due to non-pregnancy related
causes).
General Introduction
Several distinct changes characterize pregnancy, including changes in a woman’s
physiology, perception, hormonal profile, psychological state, and dietary
preferences (Flaxman & Sherman, 2000). This study explores whether changes in
visual perception, specifically shifts in visual discrimination and preferences also
accompany pregnancy. Earlier studies have documented shifts in olfactory
perception (e.g., increased generalized sensitivity) and taste perception (e.g.,
increased 1st trimester sensitivity to bitter taste) during pregnancy (Dastur, 2000;
Duffy, Bartoshuk, Striegel-Moore & Rodin, 1998). To date, no studies have examined
changes in visual perception.
The pregnancy sickness as embryo protection hypothesis proposes that the
mother experiences a variety of symptoms (e.g., nausea and vomiting, increased
disgust sensitivity and lethargy) in order to avoid ingestion of toxicogenic foods,
which could cause abnormalities, birth defects, or fatal malformations in the embryo
(Fessler, Eng, & Navarrete, 2005; Nesse & Williams, 1995; Profet, 1992). The
collection of these adaptive symptoms, which we view as defenses, occurs in the
mother’s body as a result of shifts in the physiological and psychological functioning
of systems that facilitate the selection of innocuous foods. The current study extends
on the pregnancy sickness as an adaptation hypothesis, also known as the embryo
protection hypothesis, by testing colour related visual changes in the mother during
their first trimester of pregnancy. Our research questions are: (1) Is a shift in
preference away from unripe and overripe foods associated with women in their
first trimester of pregnancy when compared with nonpregnant women and (2) is an

increase in colour discrimination ability associated with women in their first
trimester of pregnancy when compared with nonpregnant women.
It is important to distinguish pregnancy sickness from hyperemesis
gravidarum. Hyperemesis gravidarum (HG) is an extreme form of pregnancy
sickness that affects 0.3% to 2% of all pregnant women (Philip, 2003). HG is
characterized by excessive vomiting that leads to dehydration, electrolyte and
metabolic disturbances and nutritional deficiencies during the first trimester of
pregnancy (Broussard & Richter, 1998). This condition is most likely pathological
and needs to be treated.
A thorough literature review on the current state of knowledge about
pregnancy sickness will be followed by an evaluation of alternative theories and
hypotheses that attempt to explain pregnancy sickness.
Lines of Evidence
Historical
Modified diet and symptoms of nausea and vomiting during pregnancy have been
observed in cultures as long as 4000 years before present (BP) in the Pleistocene
period (Andrews & Whitehead, 1990; Profet, 1992). Profet proposed that there was
considerable selection pressure for the development of pregnancy sickness in the
Pleistocene era due to the high teratogenic content of wild plants compared to
modern domesticated plants. Additionally, dry seasons and drought years forced
hunter-gatherer societies to move from one region to another, exposing the
population, including women, to new kinds of toxins. For example, a study of
seasonal diet changes in hunter-gatherers in Eastern Paraguay has shown a great
variability in the species of plants consumed (Hill, Hawkes, Hurtado & Kaplan,
1984). Curiously, total calories of ingested food did not vary greatly. This variation
of exposure to toxins further amplified the selection pressure.
A more recently developed explanation for the high selective pressure on
pregnant females to develop pregnancy sickness is attributed to the ingestion of
pathogens found in meat (Fessler, 2002; Flaxman & Sherman, 2000). Two common
parasitic protozoas found in meat, Plasmodium and Toxoplasma gondii are
associated with congenital neurological birth defects (Fessler; Smith, 1999). Meat
was an important source of food for hunter-gatherer societies, but methods for
eliminating pathogens from meat were poor. Fessler suggested that the need to
avoid meat-borne pathogens provided sufficient selection pressure for the evolution
of pregnancy sickness.
Cross-Cultural
Cross-cultural prevalence of pregnancy sickness is also well established (Flaxman &
Sherman, 2000; Profet, 1992; Schmitt & Pilcher, 2000). Flaxman & Sherman
reviewed 56 studies related to pregnancy sickness and found that 62% of women
across 16 countries experienced the common symptoms of pregnancy sickness (i.e.,

nausea and vomiting). Frequencies varied greatly among countries from 84%
prevalence rate of symptoms in Japan to 34% in India.
Minturn & Weiher (1984) observed pregnancy sickness in 31 societies. In 23
(74%) of these societies, pregnancy sickness was clearly a pregnancy related
phenomenon. However, this study did not specify whether pregnancy sickness
symptoms concentrated around the first trimester, or the symptoms spread out
over the full period of pregnancy.
Profet (1992) noted that there is archaeological evidence showing that !Kung
women of the Kalahari Desert, and Australian Aboriginal women had vomiting and
food aversions during pregnancy. Further, pregnant women had clay-eating rituals
(kaolinic and montmorillonitic clays are most common) in the South American
Ottomac tribe along the Orinoco Valley and in tribes in East Africa and along the
Equator (Abrahams & Parsons, 1996; Profet, 1992; Wiley & Katz, 1998). Clay may
protect the embryo by preventing the absorption of toxins (e.g., potato alkaloids)
contained in plants (Abrahams & Parsons).
Heredity
Evidence of hereditary influence on pregnancy sickness is ambiguous. Research
does show that women were significantly more likely to experience pregnancy
sickness if their mother or sisters had also experienced the symptoms (Corey, Berg
& Nance, 1992; Gadsby, Barnie-Adshead & Jagger, 1997; Vellacott, Cooke & James,
1988; Whitehead, Andrews & Chamberlain, 1992). Corey et al., examined the
pregnancy history of 830 monozygotic and 902 dizygotic female twin pairs and
performed tetrachoric correlations to measure the contribution of genetic factors to
miscarriage, twinning, hypertension-toxemia and nausea and vomiting. They found
that monozygotic twin pairs were significantly more concordant in experiencing
pregnancy sickness than dizygotic twin pairs. A methodological drawback to this
and these kinds of studies is that daughters are being assessed currently whereas
mothers are being assessed by retrospective questionnaires. While currently there
are no studies that reported formal heritability estimates, the current state of
literature does suggest a genetic component to pregnancy sickness.
Psychological
Food aversions, one of the central symptoms of pregnancy sickness, are generally
defined as a strong desire to avoid certain kinds of foods or beverages (Pope,
Skinner & Carruth, 1992). In pregnancy, food aversions, measured by subjects'
attitude towards foods, are aimed at foods that were consumed by the female before
the pregnancy. Food aversions have shown to be so strong during pregnancy that
they can induce nausea and vomiting in the person.
A study showed that women in their first trimester mentioned food
aversions to coffee, tea, cocoa, vegetables, and meat and eggs the most (Dickens &
Trethowan, 1971). Cooksey (1995) has a more extended list of examples including
cooked vegetables, Italian foods and sauces, tea, cola drinks, milk, seafood, fried

foods, cola drinks, nonchocolate sweets, and juice. Dastur (2000) reports that the
top five pregnancy related food aversions were meats (16.8%), Italian food sauces
(9.6%), vegetables (9.2%), poultry (8.4%) and fried foods (7.2%).
Physiological
Fifty to ninety percent of all women experienced symptoms of pregnancy sickness
during the first trimester of pregnancy (Dastur, 2000; Gadsby, Barnie-Adshead &
Jagger, 1992; Klebanoff, Koslowe, Kaslow, & Rhoads, 1985; Lindseth, Buchner &
Gustafson, 1998). Further, the symptoms occurred with equal probability between 7
a.m. and 11 p.m. during the first trimester of pregnancy, which is in contrast to the
common belief that the symptoms occur mostly in the morning (see Figure 3).
Dastur (2000) investigated changes in olfactory sensitivity and perception in
pregnant women in their first trimester. Pregnant subjects were measured
longitudinally in each trimester of their pregnancy. A control group of non-pregnant
women were also measured at the same time intervals. None of the women in the
control group were taking oral contraceptives during the period of the study. The
results showed that subjects had (a) increased olfactory sensitivity during the first
trimester (i.e., threshold at which they were able to detect a smell was lower than
for non-pregnant women) and (b) the findings are consistent with Profet’s theory of
morning sickness.
Navarrete, Fessler, & Eng (2006) found that aversions during the first
trimester of pregnancy may not be exclusive to food. The study predicted that
pregnant women should be more withdrawn from outgroup members during the
first trimester of pregnancy because the embryo is most vulnerable to pathogens
that may be contracted through contact with outgroup members. Additionally, they
predicted that this withdrawal should lessen in second and third trimesters of
pregnancy. Two hundred and six pregnant subjects were asked to provide their
opinions on two essays; a critical essay of a foreigner about the U.S. and a positive
essay about U.S. values, written by an American author. Subjects’ ratings of disgust
were measured on a Likert scale using a variety of statements. The results of the
study showed that pregnant women in their first trimester were significantly more
likely to rate the foreigner more negatively and the resident more positively in
comparison to non-pregnant women. Further, this effect disappeared by the second
and third trimesters. These results are consistent with the idea that pregnant
women in their first trimester avoid outgroup members to protect themselves and
the embryo from diseases and pathogens, which may likely be carried by outgroup
members. A heavy criticism of this study is that there was no control group
therefore the results could indicate a decrease in ethnocentrism in the second and
third trimesters, as opposed to an increase in ethnocentrism in the first trimester.
The researchers counterargued using data from their pilot study, which was based
on nonpregnant women to affirm the validity of their hypothesis. Another criticism
of the study was the confound in the manipulation of the independent variables. The
researchers were actually manipulating two variables across conditions; the quality

of the statement and the ethnicity of the speaker. This weakness was not addressed
in the article.
Theories Explaining Pregnancy Sickness
Nonfuctional Theories
There is a line of research investigating various ways to eliminate the symptoms of
pregnancy sickness using herbal remedies such as ginger, peppermint and cannabis
(Westfall, Janssen, Lucas & Capler, 2006; Westfall, 2003). This research, however,
does not investigate the possible causes of pregnancy sickness; rather it assumes
that pregnancy sickness is a pathological condition. Westfall et al., found that
cannabis is an effective and supposedly safe way to control nausea and vomiting in
early pregnancy. The data showed that 92% of respondents reported cannabis as
“extremely effective” or “effective” in treating pregnancy sickness related
symptoms. While Westfall appears to argue that women with hyperemesis
gravidarum are the ones who need cannabis the most, her research sample consists
of women who have normal levels of nausea and vomiting. There are two
assumptions in Westfall’s research that would be important to clarify before
concluding that cannabis is useful for treating pregnancy sickness. First, it is unclear
whether cannabis is healthy for the embryo. Some studies provided suggest
evidence that women who smoked cannabis gave birth to infants who were, on an
average, 150 g lighter, 1.2 cm shorter, and had 0.2 cm smaller head circumference
than their nonsmoking counterparts (Balle, Olofsson & Hilden, 1999). However,
these studies are confounded with smoking and low social economic status, which is
why it is difficult to find conclusive evidence. Second, it is important to run the study
with a representative sample. Westfall appears to focus her interest on women with
hyperemesis gravidarum. However, the research sample must be representative of
the target population if she is to draw conclusions about women with extreme cases
of pregnancy sickness.
Some researchers have suggested that morning sickness, especially hyperemesis
gravidarum, is a result of a psychological dysfunction (Quinlan & Hill, 2003,
Fairweather, 1968). Fairweather administered the Cornell Medical Index (CMI) and
Minnesota Multiphasic Personality Inventory (MMPI) to pregnant and nonpregnant
women and found that those subjects with hyperemesis gravidarum are
significantly more likely to experience hysteria, excessive dependence on their
mothers, and infantile personalities. This theory is largely discredited today due the
lack of evidence to support the conclusions.
Finally, some researchers suggested that pregnancy sickness could be the result of a
gastrointestinal tract dysfunction (Broussard & Richter, 1998; Walsh, Hasler,
Nugent & Owyang, 1996). Walsh et al, postulated that higher progesterone levels
during early pregnancy may evoke abnormalities in the basal electrical rhythm of
gastric contractions causing slow-wave gastric dysrhythmias. However,
progesterone is not likely to be the culprit of pregnancy sickness because levels of
progesterone steadily increase after the first trimester (see Figure 4). According to

Profet, other hormones such as the human chorionic gonadotropin hormone (hCG)
and estradiol are much more likely candidates for triggering pregnancy sickness
because hCG peaks during the first trimester of pregnancy and estradiol is known to
cause nausea in nonpregnant women who have taken birth control pills (JarnfeltSamsioe, 1987; Morris, 1973; Profet, 1992).
Functional Theories
Forbes (2002) argues that spontaneous abortions during the first trimester and the
symptoms of pregnancy sickness are not the result of embryo protection
mechanisms, but are the result of a genetic conflict between the mother and the
embryo. The source of the conflict is that the mother attempts to expunge embryos
with intrinsic chromosomal defects by reducing the production of luteinizing
hormone (LH).
Embryos with chromosomal defects are associated with the production of
suboptimal levels of the hCG hormone, which is involved in maintenance of
pregnancy and the probable trigger of pregnancy sickness (Forbes, 2002; Homan,
Brown, Moran, Homan & Kerin, 2000). As such, pregnancy sickness has an indirect
adaptive value, not a direct one, as suggested by the embryo protection hypothesis.
Forbes presents 5 lines of evidence for the genetic conflict hypothesis. First,
pathogens and mutagens occur naturally in the diet and some foods have harmful
effects (Flaxman & Sherman, 2001, 2000; Schardein, 1996; Profet, 1995; Minturn &
Weiher, 1984). Second, pregnancy sickness is associated with food aversions, and
strong and pungent odors are often correlated with the presence of pathogens or
mutagens (Flaxman & Sherman, 2000; Profet, 1995). Third, pregnancy sickness
occurs during organogenesis, when the developing embryo is at greatest
susceptibility to mutagens (Profet, 1995). Fourth, the incidence of pregnancy
sickness correlates with diet; pregnancy sickness is absent from societies that
consume less harmful foods (Flaxman & Sherman, 2001, 2000). Finally, the 5th line
of evidence that is consistent with both embryo protection hypothesis and inferior
chromosome quality hypothesis is the correlation of pregnancy sickness with
pregnancy outcome; women without pregnancy sickness are more likely to
experience stillbirths, miscarriages, and spontaneous abortions (Weigel & Weigel,
1989). The evidence that Forbes presents to support the chromosomal defects
hypothesis is also consistent with the embryo protection hypothesis. Forbes’
argument for the inferior chromosome hypothesis is that the correlation between
diet across cultures and prevalence of pregnancy sickness is spurious. Low
prevalence of pregnancy sickness in some societies could be due to the poor
nutritional content of foods available to women; not the other way around as
suggested in the embryo protection hypothesis that women in some cultures choose
(non-consciously) to under-nourish themselves. Forbes also neglects to mention
shifts in olfactory and taste perception that also occurs in the first trimester, both of
which support the embryo protection hypothesis.
Profet (1992) was the first to articulate the embryo protection hypothesis using
multidisciplinary empirical evidence. The hypothesis built on Hook, Little and

Walker’s observations about food aversions to specific foods such as alcohol,
tobacco, meat, fish, coffee and fatty foods (Hook, 1978; Little & Hook, 1979; Walker,
1985). Profet proposed that pregnancy sickness is an evolved adaptation to limit
fetal exposure to toxins in the maternal diet. The core pieces of evidence that
support this hypothesis are that (a) the timing of pregnancy sickness coincides with
organogenesis, a period when the embryo is most vulnerable to developmental
defects; (b) women with pregnancy sickness experience food aversions especially
towards foods that are high in teratogenic content; (c) and olfactory sensitivity
becomes hyperacute during the period of pregnancy sickness, enabling better
detection of toxins in foods. Profet suggested that the mechanism of pregnancy
sickness is the result of the recalibration of the chemoreceptors of the
chemoreceptor trigger zone (CTZ), gastrointestinal region, and olfactory epithelium.
More recently, Flaxman and Sherman (2000) offered further support for the embryo
protection hypothesis by showing that pregnancy sickness is associated with the
avoidance of spoiled foods, burned meats, fish and eggs.
Visual Perception
According to Profet’s theory, we should see physiological and perceptual changes
during the first trimester in sensory systems that enable the pregnant woman to
select the least harmful foods. Changes in olfactory, visual and taste perception are
likely the sensory mechanisms by which these cues of toxicity are detected, typically
at thresholds lower than before the pregnancy. Evidence of lowered olfactory
thresholds during the first trimester has been documented along with shifts in taste
perception (Nordin, Broman, Olofsson & Wulff, 2004; Dastur, 2000; Duffy,
Bartoshuk, Striegel-Moore & Rodin, 1998; Gilbert & Wysocki, 1991). Beyond
olfactory and taste changes, we hypothesize that visual changes may also support
this defensive view of pregnancy sickness.
Pregnant women who can better discriminate between good and bad foods will
expose their developing embryos at lower risk than those who can not. However, we
have a great gap in our knowledge about the kinds of visual perceptual changes that
take place, if any, during the first trimester.
Present Study
The goal of this present study is to learn about what kinds of visual changes, if any,
may be happening to women during their first trimester of pregnancy. More
specifically, we are interested in examining whether there are any shifts in the
woman’s ability to discriminate between colours and whether there are any shifts in
preferences for foods at varying levels of ripeness or freshness.
Hypotheses & Predictions
The hypothesis of the objective component is that women in their first trimester of
pregnancy will exhibit increased colour discrimination ability compared with
nonpregnant women. Our prediction is that there will be a significant decrease of

error scores on the Farnsworth Munsell 100 hue test for all 4 hues. The hypothesis
of the subjective component is that women in their first trimester of pregnancy will
find unripe and overripe foods less appetizing compared with nonpregnant women.
Our prediction is that there will be a significant decrease in ratings of
appetizingness for unripe and overripe foods.
Methods
Subjects
Fifteen women served as subjects in the study. Six of these subjects were pregnant
women in their first trimester and another 9 subjects were non-pregnant women,
who served as a comparison group.
We recruited subjects from the Greater Vancouver Regional District (GVRD),
British Columbia, over a 3-month period. Recruitment methods included Google
Adwords Internet advertising, poster advertisements at Kwantlen University
College, medical clinic boards, midwifery offices, blood clinics (employees only), and
through word-of-mouth. The Google Adwords ads appeared in search results to over
150 search words related to pregnancy (for a list of keywords, see Appendix I) and
on content-network pages. Content-network pages are websites that display Google
advertising on their pages (for a list of content-network pages, see Appendix J).
Google Adwords was configured so that only visitors in the GVRD region were able
to see the advertisements. However, due to some inaccuracies, 5 participants from
Ontario, California and Vancouver island also signed up to participate. These women
were informed that the study is conducted on-site, and unless they can come to the
campus, we won’t be able to run the study with them.
Ethical Approval
The protocol, informed consent, and posters were submitted to the Kwantlen
Research Ethics Board (REB) for ethical approval. Informed, written consent was
obtained from every subject (see Appendix A) before participation in the study.
Main points of the informed consent were also reiterated to the subject including
the following elements: voluntary participation, confidentiality of collected data, and
withdrawal from study without penalty. Subjects were informed about the purpose
of the study, but not about specific hypotheses as they could serve as demand
characteristics and could bias the results of the study.
Risks & Benefits
Each subject received $15 cash for participating in the study and was entered into a
prize draw for a fruit juicer ($150 value). Participants were informed that they had a
1 in 60 chance to win. Additionally, subjects were educated about the purpose of
this study and were offered resources if they were interested in learning about the
phenomenon in more detail. There were no direct health benefits to completing this
study.

Subjects were not exposed to significant harm during the study. There was a chance
that the images of foods (e.g., spoiled broccoli) evoke nausea and possibly even
vomiting in a minority of pregnant subjects. This potential risk was explained to
women and they were reassured that such a response, while unlikely, is a normal
reaction to such images. Also, the testing room was situated close to a washroom to
be prepared for such an experience. The subjects, as always, were free to
discontinue the study at this or any point if they so choose.
Inclusionary Criteria
Confirmed First Trimester Pregnancy
Women were considered pregnant after a self-reported confirmation of a urinary or
blood test. The date of conception was also collected through self-report of the
women. Acceptable means for the determination of the date of conception date were
obtained from an ultrasound test in combination with the results of an ovulation
period test, or two weeks after the women’s last menstrual period (LMP), which
approximates the time of ovulation. The two methods produce results that do not
significantly deviate from each other (Olesen, Westergaard, Thomsen & Olsen,
2004). Women who were between 6-12 weeks post-conception and experienced at
least one symptom of pregnancy sickness were included in the study. Two subjects
were over the 12-week threshold (15 & 17 weeks), but were allowed to participate
due to the difficulty in recruiting first trimester participants.
Corrected to Normal Vision
Women who had normal or corrected to normal vision, such as women who wore
glasses, contact lenses, or have gone through laser corrective surgery were
permitted to participate in the study. One pregnant subject had a corneal transplant
recently that made her eyes sensitive to light. She was included in the analyses
because corneal transplants are not associated with chromatic discrimination
changes.
Age Restriction
Women who were between the ages of 20 and 39 were permitted to participate in
the study. The reason for the age restriction is twofold. First, colour-discrimination
ability is best between the ages of 20 to 39 (Kinnear & Sahraie, 2002; Mantyjarvi,
2001). Second, the optimal age of child bearing is between the ages of 18 and 40
(CDC, 2004; Dickinson, 2005). Additionally, an age restriction was essential for this
study because women above the age of 40 years have a significantly higher
proportion of miscarriages and genetic malformations.
Non-pregnant Women
Women with normal menstrual cycles (23 to 35 day long cycles) could participate in
the study. A menstrual cycle is defined as the period from the first day of menstrual
bleeding to the last day before the next menstrual period. Normal length of

menstrual cycle varies between 23 and 35 days with 28 days as the median length of
a menstrual period (Solomon, et. al., 2001; Wilcox, Baird, Dunson, McChesney, &
Weinberg, 2001). Further requirements for participation were that women had to
be in a non-lactating, non-menopausal phase of their lives. They could be in any
phase of their menstrual cycle, but they must not been taking hormonal
contraceptives for at least 6 months.
Exclusion Criteria
All criteria applied to both the pregnant and non-pregnant groups unless otherwise
specified under the subheading.
Nausea & Vomiting Interventions
Women taking pharmacological or non-pharmacological treatment for nausea and
vomiting were excluded. Artificial reduction in nausea and vomiting would
confound with the two conditions in the study.
Contraceptive Use
Women who use contraceptives that alter hormonal levels were not permitted to
participate in the study (condoms o.k.). Hormonal contraceptives such as ethinyl
estradiol, norgestrel, diethylstilbestrol, and norethindrone were excluded.
Hormonal contraceptives are associated with fluctuations in olfactory sensitivity,
which may affect food aversions and cravings, and symptoms of nausea and
vomiting (Doty, Snyder, Huggings, & Lowry, 1981).
Use of Drugs
There are drugs that are known to affect patients’ visual-perception (Eisner &
Incognito, 2006; Eisner, Burke & Toomey, 2004). Subjects that took such drugs were
excluded from the study.
Tamoxifen is a drug that is prescribed as adjuvant therapy for women who
have breast cancer. Subjects who took Tamoxifen for a period longer than 2 years
have been shown to have poorer colour-discrimination abilities. Subjects who have
taken drugs that are known to produce such effects will be excluded.
Medical Conditions
There are medical conditions that affect vision. Subjects that are diagnosed with any
of the following medical conditions were excluded from the study (see Appendix G).
Inexperience with Foods
Women with limited experience with a range of foods (e.g., vegans or wide-spread
food allergies) were excluded from the study. Women who do not eat foods that are
used in the study would be unable to accurately assess the food’s ripeness or
freshness, therefore making inaccurate assessments of appetizingness.

Procedure
Subjects completed the study in the psychology lab’s testing rooms at Kwantlen
University College, or in the offices of the Obstetricians and Gynecologists. Test
administration was scheduled between 10:00 A.M. and 6:00 P.M. to minimize the
interference of circadian rhythms on the subject’s wakefulness. However, some
subjects requested to be tested outside of this time interval. The testing rooms’
windows and doors were covered with a solid material to ensure that the only
source of light is from the full light spectrum viewer. The SpectraLight-3 (D50
bulbs) full-spectrum natural light booth produced the illumination in the testing
rooms.
The test was administered individually to ensure each subject understood
the instructions. Individual attention to subjects allowed for clarifying any
misunderstandings and confusions about the study or the instructions. This
configuration also allowed us to informally collect qualitative data about how
subjects behaved and responded to the stimuli and our methodology.
Test Administration
Subjects arrived in the testing rooms at a scheduled time. The research assistant
discussed the nature of the research, went over the informed consent documents
with the subject and asked the subject to sign the consent form if she agrees to
participate (see Appendix D). Confidentiality, voluntariness and privacy of their
participation were emphasized at this stage. After signing the informed consent,
subjects were given the $15 cash in an envelope. Subjects then completed the
demographic questionnaire. This was followed by the administration of the
Farnsworth-Munsell 100 (FM100) Hue test (the objective component) and the Food
Appetizingness Test (FAT) (the subjective component). At the end, subjects were
debriefed by informing them about the goals of the study (see Appendix E). They
were then given time to read the debriefing form and given a chance to ask
questions and make comments. Subjects were provided with our contact
information in case they wish to follow up with us at a later time. Subjects were not
told the hypothesis of the study because we wanted to ensure they do not
inadvertently tell another potential subject about it.
Instrument
Viewing Booth
We used the Judge IIS viewing booth with (D50) bulbs (produces full-spectrum
light) to administer both the objective component of the study.
Farnsworth-Munsell 100 Hue Test (FM100)
The FM100 test was used to measure subject’s colour discrimination ability. The
test consists of four trays containing 85 removable colour reference caps
(incremental hue variation) spanning the visible spectrum. Colour vision

abnormalities and aptitude are detected by the ability of the test subject to place the
colour caps in order of hue. Scoring of the colour caps is completed through a
Windows based scoring program. The test was administered in daylight conditions
that were established using the Judge IIS viewing booth.
Food Stimuli
We purchased a diverse variety of foods from a local grocery store (see Appendix
H). The foods were stored in the research lab at room temperature in low humidity.
The warm temperature stimulated the decaying process. Due to low humidity, most
foods shrank dramatically as their water content evaporated. We decided to put the
foods in a bag with a slice of apple to slow down the shrinking process and increase
the decaying process.
Meat Stimulus
An Australian studio produced time-lapse video of a piece of raw beef. The period of
the time-lapse was 1 week. The studio provided a steep discount for us in exchange
for displaying their logo in poster presentations.
Camera & Lighting
To take pictures of the stimuli, we used a FujiPix S20 Pro prosumer (i.e., high-end
consumer) camera on a tripod stand. We ensured that the camera was fixed in the
same position and location for the period we took photos of the fruits and
vegetables. The camera was configured in macro mode with shutter speed of
6/1000 second and aperture set to maximum (F11) in order to maximize depth of
field. As a result, more of the stimulus was in focus, which increased contrast around
the edges of the fruits and vegetables and minimized blurry areas. Further, manual
focus allowed us to focus the image more accurately in the low light environment.
The resolution of the image was set to highest (2832 x 2128 pixels, 6 Megapixel). We
placed the stimuli in the Judge IIS viewing booth to ensure standard full-spectrum
lighting. The room had two sources of external light; (a) one window, and (b) glass
portion of the door. Blinds on the window and aluminum foil on the glass portion of
the door minimized external light from entering the research room.
Time-Lapse Photography
We photographed the foods every 2 days for 20 days, at which point all foods had
decayed. We took photos of the broccoli and lettuce every day for 11 days because
of their faster decaying rate. The photographs were not manipulated or touched-up
in any way once transferred onto the computer. The only change we made to the
photos was to crop them in order to fit the photos on a slideshow.
Demographic Questionnaire
The demographic questionnaire collected general information about the subject
including the subject’s age, ethnic background as defined by the subject, medical

condition that might interfere with their vision, and use of glasses or contact lenses.
The data was collected through an electronic form at a computer workstation and
stored in a MySQL database.
Food Appetizingness Test (FAT)
The test was administered at a computer workstation in the testing room. The food
images were presented in a randomized manner. Each slide consisted of one food at
6 stages of its ripeness or freshness. The slide consisted of images that ranged (a)
from a completely unripe fruit to a completely ripe fruit and, or (b) from a
completely ripe fruit to completely overripe fruit (the unripe and overripe fruit
series were analyzed separately). In order to avoid order effects, the presentation of
the slides was also randomized. Each food was rated over 3 trials, which meant that
each slide was presented 3 times; randomization of the images ensured that the
order of the images on the slide were different across the 3 trials.
The subjects were asked to rate each photo on a Likert-like scale of 1 – 7
(anchors: 1-very unappetizing, 4-I would eat it, 7-very appetizing). The rating scale
was positioned below each image. Subjects were allowed to rate the fruits on the
screen in any order they wish because this mimicked a real-life situation more
closely. In a real-life situation, people are presented with a number of choices (e.g.,
fruits on a tree, vegetables in the market) from which they make a decision about
the most appetizing and least appetizing foods.
The Food Appetizing Test was built with PHP Hypertext Preprocessor (PHP)
and MySQL (SQL: Structured Query Language) database technology. The testing
computer was configured to run PHP and MySQL locally, avoiding the need to
connect to the Internet. This enabled us to collect the data securely using a flexible
and powerful platform.
Funding
Two $5,000 Kwantlen Minor Research Grants (MRG) were provided to Dr. Farhad
Dastur to fund this study.
Results
A total of fifteen subjects participated in the study (6 pregnant, 10 nonpregnant).
The mean age of the pregnant group was

and the mean age of the

nonpregnant group was
. The pregnant group included 4 Caucasian,
1 Indo-Canadian and 1 Fijian-Canadian subject. The nonpregnant group included 6
Caucasian, 2 Chinese-Canadian, 1 Indo-Canadian and 1 Filipino-Canadian subjects.
In the pregnant group, 5 subjects worked full time and 1 subject worked part-time.
In the nonpregnant group, 3 subjects worked full time, 3 worked part time, 2 were
full time students and another 2 were in the “other” category (e.g., unemployed).
Finally, the pregnant group had 3 subjects that had 1 to 4 years of post secondary
education and 3 subjects that had more than 5 years of post-secondary education.

The non-pregnant group had 7 subjects who had 1 to 4 years of post-secondary
education, 1 subject that had 5 or more years of post-secondary education and 2
subjects who had none.
(Insert Table 1 around here)
Objective Component
The FM 100 test score and time to complete was recorded for this part of the study.
The test score is reported in terms of total error scores (TES). In addition to the raw
TES score, we also reported the logarithmic TES values as described in FM 100
standardization studies (Kinnear & Sharaie, 2002; Mantyjarvi, 2001; Roy, Podgor,
Collier & Gunkel, 1990). We ran a one-factor ANOVA to test the difference in the
means of the Log TES scores in the pregnant and non-pregnant groups. The Log TES
means turned out to be significant (
, p<.05) (see Table 2).
(Insert Table 2 around here)
The assumptions of the ANOVA have been met. The Log TES charted on a histogram
displays a normal curve, and Levene’s test for equality of error variances was not
significant (
).
Subjective Component
For each food, we performed a one-way ANOVA’s resulting in 10 analyses.
Appetizing rating for each food image was the dependent variable in the mode, and
the status of the participant (pregnant or non-pregnant) was the independent
variable. The means for 10 food groups are displayed in Table 3.
(Insert Table 3 around here)
Ten one-way multivariate analyses of variance (MANOVA) were performed to
determine the effect of pregnancy on the 6 dependent variables, the 6 stages of food
images. No significant differences were found among the 6 stages on any of the food
images, Wilks’s
,
for the apple, Wilks’s
,
for the banana, Wilks’s
,
for the
broccoli, Wilks’s
,
for the lettuce, Wilks’s
,
for the mushroom, Wilks’s
,
for the
papaya, Wilks’s
,
for the pear, Wilks’s
,
for the raspberry, Wilks’s
,
for the
steak, and Wilks’s
,
for the tomato. ANOVA’s were not
necessary as follow up tests to the MANOVA.
Discussion
The objective component of the study supports our prediction that pregnant women
have a significantly increased ability of chromatic discrimination as shown by the

FM 100 hue test. The statistical analysis shows that women in their first trimester
have much better ability to discriminate between fine differences in colours. If we
were able to get participants who perfectly fit our criteria (within the first trimester,
no visual problem), it is likely that the significance of our findings would be further
amplified.
The subjective component of the study does not support our prediction that
pregnant women find foods significantly less appetizing when compared with
nonpregnant women. The findings show that pregnant and non-pregnant women
find the 10 categories of food images similar in terms of level of appetizingness. The
appetizing rating means show a very small tendency for pregnant women to rate
foods lower in appetizingness. The mean difference was largest on the fresh steak
image where most pregnant women rated the meat to be very unappetizing, while
non-pregnant women found the steak quite appetizing. Many pregnant subjects
made a note to tell me that the steak was so disgusting that they had to skip rating it.
None of the non-pregnant subjects had such an issue. This is consistent with the
evolutionary embryo protection hypothesis as meats are the most dangerous to the
embryo as meat carries the most dangerous pathogens (Flaxman & Sherman, 2001,
2000).
One reason for not finding significant differences among the two groups (pregnant
and nonpregnant) might be due to the increased variability introduced through
individual differences. The cross-sectional study design increased the noise in the
data greatly, reducing our chances of finding a significant difference. It may be
possible to overcome this obstacle by dramatically increasing the sample size, or by
designing a repeated measures study where subjects are tested while they are
pregnant and then tested again after they gave birth.
Overall, the result of the objective component serves as another test of the
hypothesis that pregnancy sickness has evolved to protect the embryo during the
first trimester of pregnancy. Previous research has shown that olfactory and taste
sensitivity goes through a physiological and perceptual change during the first
trimester of pregnancy, but this is the first study to provide preliminary evidence
that similar physiological and perceptual changes may be occurring on the visual
domain too (Nordin et. al, 2004; Dastur, 2000; Duffy et. al, 1998; Gilbert & Wysocki,
1991). We think that these physiological and perceptual changes occur together
because they are all involved in the selection of edible foods.
Selection of edible foods involves the integration of information about the food
coming from all of our senses. Depending on the stage of the food selection (e.g.,
attention, exploration, decision to eat), we rely on different senses to give us
information about the food in question. For example, imagine a situation our
ancestors may have likely faced. As they walked in a forest and spotted a berry in a
bush, they first relied on almost exclusively visual information. If there were many
berries around, they may have been able to smell the berries in which case they
would have received some olfactory information about the berries in the area. As
they walked up to the berry and picked a berry from the bush, they received tactile

information as they touched the food. Additionally, they had much more refined
visual information because they can position the berry close-up in the middle of
their visual field where their visual acuity is highest. If the berry passes this test,
they would put the berry in their mouth, where they would receive further
information about the berry; namely, taste and more refined olfactory information.
Future studies could explore further changes in the visual domain by setting up the
study with a longitudinal design. This allows increased experimental control and
would enable picking more subtle changes in pregnancy. Another area that could be
explored is whether or not there are any specific hues to which pregnant women
become more sensitive during the first trimester. It could be, perhaps that first
trimester women are more sensitive to yellows and reds, colours of ripeness. Or
conversely, it could be that first trimester women become more sensitive to bluish
colours that signify fungi and rotten food. We have also not analyzed the data to see
if there is differential discrimination for a specific hue in pregnant women, but it
would be a curious idea to explore this possibility in a future project.
The present study provides sufficient support to the idea that first trimester
pregnant women’s visual discrimination ability may become more sensitive at least
during the first trimester, but possibly even in the second and third trimesters. This
in turn provides further support that pregnancy sickness serves to protect the
embryo during its most vulnerable time of development.

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Appendix A

Consent Form
Colour-related perceptual shifts in first trimester pregnant women
Dr. Farhad Dastur, Chair, Pschology Dept. Kwantlen University College
Levente Orban, Honours Student, Psychology Dept. Kwantlen University College
Application #: [xxx xxx xxx]

The University College and those conducting this study subscribe to the ethical
conduct of research and to the protection at all times of the interests, comfort, and
safety of subjects. This form and the information it contains are given to you for
your own protection and full understanding of the procedures. Your signature on
this form will signify that you have received a document (please see attached form)
which describes the procedures and benefits of this research project, that you have
received an adequate opportunity to consider the information in the document, and
that you voluntarily agree to participate in the project.

Voluntary Participation
Your participation in this research project is completely voluntary. You have the
right to withdraw from the research study at any time without any penalties.

Confidentiality
The collected data will be held confidentially in a locked drawer at Kwantlen
University College. [more]

About This Study
The purpose of this fun, safe and stimulating research study is to learn about what
kind of perceptual changes occur, if any, during the first trimester of pregnancy. The
length of your participation would take approximately 1 hour. You will not be
followed up once you complete this study, however, you will have a chance to follow

up with us if you so choose. The study will be administered in a psychology lab or a
doctor’s office in full. You will not be asked to move to another location.
The study has two parts. The first part of the study consists of you viewing a series
of coloured caps and placing them in their proper order of hue. This portion of the
study takes approximately 25 minutes. The second part of the study consists of you
viewing a series of food images and rating each food on their level of appetizingness.
You will view about 300 images in total, which will take approximately 25 minutes
to complete.

The study will proceed at a pace that is comfortable for you. There are no time limits
and you can take a break at any point during the study.

Risk of harm, discomfort or inconvenience
Some of the images may evoke nausea in you. Be assured that this response, while
unlikely, is completely normal. Pease feel free to stop the study at any point you feel
you need to go to the washroom.

Benefits
Benefit to subject: You will receive $15 cash to help cover transportation costs to
participate in this study. Further, you will be entered for a chance to win a fruit
juicer ($100 value). You will have a 1 in 60 chance to win.
Benefit to society: Today, we know very little about what kind of perceptual changes
occur during pregnancy. This study will fill the vacuum that in this area of research.
Further, the results of this study may support the pregnancy sicknes as adaptation
hypothesis, which is an evolutionary theory that suggests that pregnancy sickness
developed as a defense mechanism to protect the embryo and avoid toxic
substances during the first trimester of pregnancy.

Funding
This study was funded by two Kwantlen Minor Research Grants.
Persons to Contact
If you want to talk to anyone about this research study because you think you have
not been treated fairly or think you have been hurt by joining the study, or you have
any other questions about the study, you should call the principal investigator, Dr.

Farhad Dastur at (604) 599-2170, or call the Kwantlen Office of Research and
Scholarship at (604) 599-2373.

Once you have read this document, or the document has been read and explained to
you, and you have been given the chance to ask any questions, please sign or make
your mark below if you agree to take part in the study.

Print Name of Subject: _____________________________________________
________________________________ ________________________________
Signature of Subject

Date

Signature of Witness

Date

________________________________________________
Witness to Consent if Subject Unable to Read or Write

Date

(Must be different than the person obtaining consent)
To receive a summary of the results, pease complete this section:
__ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
Email Address

Signed copies of this consent form must be 1) retained on file by the principal
investigator, 2) given to the subject and 3) placed on file in the Office of Research
and Scholarship at Kwantlen University College.

Appendix B

RESEARCH ETHICS BOARD
APPLICATION FOR ETHICS REVIEW
Cover Page
Application #
(For REB use only)
(Please submit your application via e-mail to research@kwantlen.ca)

Title of project
Shifts in Food-Related Colour Preferences in First Trimester Women
Principal Investigator
Dr. Farhad Dastur
Position
Chair
Department
Psychology
Contact telephone numbers
Office: (604) 599-2170, Cell: (778) 772-9428
Email
farhad.dastur@kwantlen.ca
Other contact methods (optional)
Fax

Pager

Preferred address to receive correspondence and/or approval if other than email

Co-investigator(s) (Name, Position, Department)
Levente Orban, honours student & research assistant, Psychology
Additional assistants and their roles
4 key words
pregnancy sickness, evolution, visual perception

Proposed Start Date: JAN 2008

Proposed End Date:MAY 2008

(Expect a minimum of 6 – 8 weeks for a response from the Research Ethics Board.)

Signature:

Principal Investigator:

FARHAD DASTUR

Date:

NOV 15, 2007

Full title of research
Shifts in Food-Related Colour Preferences in First Trimester Women
Describe the purpose of the research.
The purpose of this study is to investigate pregnancy-related changes in visual
perception.

Context
Pregnancy is characterized by several distinct changes including changes in a
woman’s physiology, perception, hormonal profile, psychological state, and dietary
preferences. This study explores whether changes in visual perception, specifically
shifts in visual discrimination and preferences also accompany pregnancy. Earlier
studies have documented shifts in olfactory perception (e.g., increased generalized
sensitivity) and taste perception (e.g., increased 1st trimester sensitivity to bitter
taste) during pregnancy (Dastur, 2000; Duffy, Bartoshuk, Striegel-Moore & Rodin,
1998; Gilbert & Wysocki, 1991). To date, no studies have examined changes in visual
perception.

Pregnancy Sickness as a Beneficial Adaptation
The first trimester (up to approx. 12 weeks post conception) is a time of significant
embryonic organogenesis: the development and differentiation of the embryo’s
major organ systems (Moore, 1982; Seeley, Stephens, & Tate, 1992). It is also the
time associated with the greatest number of miscarriages (Wilcox, Baird, &
Weinberg, 1999). Exposure to toxins during the first trimester is a risk factor for the
development of birth defects or miscarriages because the embryo and its developing
organs have few defenses against such toxins (Hodgson & Levi, 1987). Toxins are
found naturally in many foods, either as defenses against pests or as a result of
bacteria, fungi, or molds. The cues for these toxins are typically strong and bad
odours and bitter or sour tastes. Profet (1988; 1992) theorized that the symptoms
of pregnancy sickness—nausea, vomiting, and food aversions—are actually
defenses that the mother’s body uses to avoid food-related toxins. It is no
coincidence then, that first trimester is also the period most associated with both
sensory changes and symptoms of pregnancy sickness. Changes in olfactory and
taste perception are likely the sensory mechanisms by which these cues of toxicity
become detected, typically at thresholds lower than before the pregnancy. Evidence
of lowered olfactory thresholds during first trimester have been documented
(Dastur, 2000). Beyond olfactory and taste changes, we hypothesize that visual
changes may also support this defensive view of pregnancy sickness. Pregnant
women who can better discriminate between good and bad foods will put their
developing embryos at lower risk than those who can’t.

Relevance
The relevance of this line of research is twofold. First, if the predictions are
supported, it will provide empirical support for a theory that re-conceptualizes
pregnancy sickness in non-pathological terms and embeds the experience of
symptoms (e.g., food aversions) in an adaptive analysis of health and illness. Second,
the information from this research fills in the almost complete void in our
knowledge of whether changes in visual perception accompany early pregnancy and
what those changes are.

Describe the research question or hypothesis to be tested if known.
The theory that pregnancy sickness is an evolved adaptation to limit fetal exposure
to toxins in the maternal diet was used to generate two hypotheses: 1) that 1st
trimester women will have increased colour discrimination ability relative to
nonpregnant controls; and 2) that 1st trimester women will rate images of unripe,
overripe, or spoiled foods lower in preference than nonpregnant controls. For
example, we expect increased preferences for hues associated with ripeness in fruits

and vegetables (yellows, oranges, and reds) and decreased preferences for hues
associated with foods that are unripe, overripe, or spoiled (greens, blues, and
browns).
We hypothesize that these shifts in colour preference are one of the perceptual cues
that pregnant women use to make decisions that discriminate between foods of
varying levels of quality (e.g., ripeness, spoilage, etc). In this formulation, a shift in
visual perception is akin to a line of defense in a larger and integrated set of
defenses that serve to protect the developing embryo.

Describe the methodology of the research study/project.
Our first hypothesis will be tested with an objective test and our second hypothesis
will be tested with a subjective test.

I. Objective Discrimination Test
We use a quasi-experimental design with two levels of the quasi-independent
variable (1st trimester vs. nonpregnant). In our objective test of colour
discrimination we use the Farnsworth Munsell 100-Hue test (FM-100). This test is
an easy-to-administer, portable, and highly effective method for measuring an
individual’s colour vision. It has been used by ophthalmologists, optometrists, vision
researchers, government and industry for over 40 years to identify colour vision
ability and colour vision deficiencies.
The dependent measure is the number of errors on the FM-100 Hue test. We predict
that first trimester women will display fewer discrimination errors indicating better
discrimination ability.

II. Subjective Preference Test
We use a quasi-experimental, between-within groups design with 2 levels of a quasiindependent variable (1st trimester vs. nonpregnant) and 6 levels of an
independent variable (age of food). A series of high-resolution food images will be
displayed to the subjects using a data projector in a darkened room. Measures will
be taken to ensure consistency of stimuli presentation. Subjects will rate each food
image for “appetizingness” on a 1 -7 Likert-like scale: 1 = very unappetizing, 4 = I
would eat it, 7 = very appetizing. Several kinds of foods (fruits, meats, and
vegetables) will be presented at varying levels of the foods’ ripeness, freshness, or
spoilage. Examples of the foods include tomato, banana, steak, bread, broccoli, pear
and papaya. Six images of each food, corresponding to six ages, will be presented
simultaneously and in random sequence. The presentation of each different set of
food images will also be randomized. The subjects will rate each photo over three

trials. Subjects will have as much time as they need to complete the ratings and they
will be free to take breaks at any point during the study.
The dependent measures are the preference ratings for each food. We predict that
first trimester women will have lowered preferences across all ages of the foods,
especially those ages far from ripeness (unripe to overripe) or freshness (fresh to
spoiled).

Procedure
Subjects will be tested in a quiet and private testing room either at Kwantlen
University or in the office of an Obstetrician/Gynecologist. Testing will occur any
day of the week between 10 a.m. and 7 p.m. to avoid potential circadian rhythm
effects. Upon completion of the informed consent procedure, and the demographic
questionnaire (e.g., age, education level), subjects will complete the two tests of the
study, first the objective discrimination test followed by the subjective preference
test, and lastly the debriefing. We anticipate that this entire procedure will require 1
hour.

Describe the method(s) of recruiting participants.
We intend to test 60 participants in this study. We plan to use several methods to
recruit participants including newspaper ads, posters placed at universities,
hospitals, and community spaces, word-of-mouth, and ads on relevant internet sites
(e.g., the Psychology lab website). Obstetricians and gynecologists will be
approached for permission to advertise to their client/patients and, if conditions
permit, to test those subjects within their offices.

Describe the participant groups in this study.
Inclusionary Criteria:
All subjects will be healthy women between the ages of 20 and 40.
Pregnant women will be included for participation if they have confirmed
pregnancies and they have experienced any of the following symptoms within the
past month: nausea, vomiting, dry heaves, food aversions, noticeably increased
smell sensitivity.

First Trimester Group: First trimester will be defined as 6-12 weeks post conception
(from last menstrual cycle or ultrasound determination). Pregnancies will be
confirmed by a pregnancy test or ultrasound (as reported by the subject).

Nonpregnant Control Group: Women at any phase of their menstrual cycle, not in
menopause, and not taking hormone-based contraceptives (as these might influence
visual perception).

Exclusionary Criteria
Any subjects taking medications (e.g., the anti-epileptic drug phenytoin) or with a
medical condition (e.g., macular degeneration) known to alter visual perception will
be excluded.
Subjects with visual system problems such as severe astigmatism or uncorrected
myopia will also be excluded.
Subjects with greatly limited experience to a range of foods (e.g., vegans or wide
spread food allergies) will be excluded.
Pregnant women who conceived through interventions at a fertility clinic will be
excluded.

Will the study involve any potential risks to the participants? If so, please describe
the risks.

The images of some of the foods (e.g., spoiled broccoli) may evoke nausea and
possibly even vomiting in some of the pregnant subjects.

This potential risk will be explained to the women and they will be reassured that
such a response, while unlikely, is a normal reaction to such images. The testing
room will be situated close to a washroom in the event of such an experience. The
subjects, as always, will be free to discontinue the study at this or any point if they
so choose.

Describe your informed consent procedures where applicable. Where it is not
applicable, explain why it is not, e.g. where one is studying the public activities of
politicians who have agreed to publicity, consent is already given. (Be sure to
consider all of the elements of the Requirement for Free and Informed Consent in
the guidelines.)

Subjects will receive an informed consent form before participating in the study
which they will be free to take home in order to have information about the study,
the investigator’s name, and contact info. Subjects will be encouraged to read the
consent form thoroughly before deciding to participate. Additionally, the research
assistant will verbally explain the study and the procedures taken to protect the
rights and confidentiality of the subject and their data. Any questions the subjects
may have will be answered. Subjects will be told verbally and in the consent form
that they are free to withdraw from the study at any time without penalty. They will
also be told that their continued participation should be as informed as their initial
consent and they should feel free to ask for clarification or new information
throughout their participation.

The honour’s student / research assistant (Mr. Levente Orban) will be trained in
good ethical procedures surrounding confidentiality and respectful treatment of
human participants. He has also completed the TCPS Research Ethics Tutorial in
2007 and has completed a course in Professional and Ethical Issues (Psyc 4800).

Where deception is used, please include your rationale and debriefing procedures.
This study does not use deception. The specific and detailed hypotheses and
predictions of the study will not be shared with the subjects at the beginning of the
study in order to avoid response bias. Full disclosure of the hypotheses will occur at
the debriefing.

What provisions are made for informing participants, for follow-up with
participants?
Subjects will be given a chance to request a summary of the results of the study.

How do you plan to handle the requirement of confidentiality and/or anonymity
where applicable?
Subjects’ responses will be treated confidentially. Data for each subject will be
collected on a laptop computer in a database program (MySQL) that is password
protected. A backup of the data will be placed on a memory stick which will then be
placed in a locked filing cabinet in the Principal Investigator’s locked office at
Kwantlen.

Describe any potential conflict of interest of anyone involved in the research.

The principal investigator is the current chair of the research ethics board. To
address this conflict of interest, the principal investigator will not participate in the
ethical evaluation of this project. The results of that determination will be
communicated by another member of the research ethics board.

Describe any provisions for compensation of participants if applicable.
All subjects will be offered compensation for travel expenses of $15 cash. In
addition, all subjects will be eligible to win a juice maker (approximate value $100).
The odds of winning, which will be communicated to the subjects, are 1 in 60. We
believe that the value of this prize and the odds of winning represent a small
incentive and not an undue inducement to participate.

To what purposes will this research be put? Will it be published or presented to an
audience outside Kwantlen?
1. This project serves as a partial fulfillment of the requirements for the Honours
portion of the Bachelor of Applied Arts program degree in Psychology.
2. We intend to present the results of this research at the following research
conferences:
June 1 - 4, 2008: Human Behavior and Evolution Conference (HBES), Kyoto, Japan
July 17 - 20, 2008: International Society for Human Ecology (ISHE), Bologna, Italy
3. We intend to publish the results in a peer-reviewed academic journal (e.g.,
Evolution & Human Behavior Journal.

14.

Please notify the REB when your research is complete. Please submit an

annual succinct status report to let us know if there are any changes from what was
described in this application.

This form must be resubmitted after approval if there are major changes to your
study. See part C of the Kwantlen University College policy on post approval
monitoring. Major changes include changes in protocol, consent, risks, participant
groups, recruitment, compensation, deception, confidentiality, anonymity,
researchers involved, or other ethically sensitive matters. Please highlight changes
on the resubmitted form.

Date: Nov. 15, 2007

Signature:_____________________

Appendix C
Recruitment Protocol
There are three ways a subject may find out about the study:
Sign up sheets
The subject may read the sign up sheets located in the psychology lab for this study.
The sign up sheet is a standard form provided by the psychology lab. The only
customized area on the form will be the title of this pilot study.
Psychology Lab Assistant:
Psychology lab assistants will be on the lookout for potential subjects. They will
offer them to sign up to participate in various studies including this one. The
protocol for this process is defined by the psychology lab.
Research Assistant:
Potential subjects will be approached by the research assistant in the psychology
lab. The research assistant will say the following script:

Hello,

I would like to invite you to participate in a research study on women’s food
preferences. You may receive bonus marks from your psychology instructor if you
decide to participate. Would you like to participate?

If Yes: Excellent, come on in to the testing room and I will tell you more about the
study.

If Not right now: You may sign up at a time that is convenient for you on the sign up
sheet. Here is the sign up sheet, please write down your name and phone number in
the slot that you prefer.

If No: Thanks anyway, Good-bye.

Appendix D
Protocol
Step 1: Subject will arrive in the Cognition & Perception Lab as a result of either an
appointment made in advance, or a drop in.
Step 2: I will greet the subject: “Hello X, Thank you for coming here to participate in
the study. Have a seat and I’ll go over with you on what you will do in this study.”
Step 3: “Here’s the informed consent,” [hand informed consent form to subject], “I
will go over it with you emphasizing the important parts of this document. After
that, I will give you a few minutes to read the informed consent thoroughly. Once
you read it, please sign your name at the end of the document. Please sign both
copies of the document – one is for you, one is for me. ”
Step 4: Wait until the subject finishes reading and signing the consent form.
Step 5: “Here is the first questionnaire that I would like you to fill out. It is a
demographic questionnaire asking about a few basic details about you. Please let me
know when you’re finished.”
Step 6: Subject hands back questionnaire. At this point I will ask the participant to
move under the viewing booth and explain that this device produces daylight
conditions in order to ensure that the colour caps are under a standardized lighting
condition. I will then administer the FM 100 test.
Step 7. Once the FM 100 is complete, I will ask the participant to move to the iMac
computer where I start up the food rating application. I ask the participant to read
the questionnaire and offer to clarify anything that might be confusing. If the
participant is ready to start, I will tell them to use the left click mouse button to
proceed to the next page.
Step 8. Once the participant has completed the food appetizing test, I ask them what
they thought of the study and whether they can guess what we are investigating. As
the conversation progresses I try to hit all the points mentioned in the debriefing
form. I hand them the debriefing form during the conversation.

Appendix E
DEBRIEFING FORM
Colour Discrimination and Preferences for Food Imagery during
the First Trimester
Thank you for participating in this project.
Purpose of the Project:
This study explored changes in visual perception during the first-trimester of
pregnancy.
Context
Pregnancy is a time of change, including changes in a woman’s physiology,
perception, hormonal profile, psychological state, and dietary preferences. Our
study explored whether changes in visual perception, specifically shifts in visual
discrimination and preferences also accompany pregnancy. Earlier studies have
noted shifts in smell perception (e.g., increased generalized sensitivity) and taste
perception (e.g., increased 1st trimester sensitivity to bitter taste) during pregnancy
(Dastur, 2000; Duffy, Bartoshuk, Striegel-Moore & Rodin, 1998; Gilbert & Wysocki,
1991). To date, no studies have examined visual perception.

Pregnancy Sickness as a Beneficial Adaptation
The first trimester is a time of organ development in the embryo (Moore, 1982;
Seeley, Stephens, & Tate, 1992). It is also the time associated with the greatest
number of miscarriages (Wilcox, Baird, & Weinberg, 1999). Exposure to toxins
during the first trimester is a risk factor for birth defects or miscarriages because
the embryo and its developing organs have few defenses against such toxins
(Hodgson & Levi, 1987). Toxins are found naturally in many foods, either as
defenses against pests or as a result of bacteria, fungi, or molds. The cues for these
toxins are typically strong and bad odours and bitter or sour tastes. Profet (1988;
1992) theorized that the symptoms of pregnancy sickness—nausea, vomiting, and
food aversions—are actually defenses that the mother’s body uses to avoid foodrelated toxins. Interestingly, the first trimester is also the period most associated
with both sensory changes and symptoms of pregnancy sickness.

Changes in smell and taste perception are likely the sensory mechanisms by which
these cues of toxicity become detected, typically at levels lower than before the
pregnancy. Evidence of lowered smell thresholds during first trimester has been
documented (Dastur, 2000). Beyond smell and taste changes, we believe that visual

changes may also support this defensive view of pregnancy sickness. Pregnant
women who can better discriminate between good and bad foods will put their
developing embryos at lower risk than those who can’t.
Our Hypotheses and Predictions
The theory that pregnancy sickness may be an evolved adaptation to limit fetal
exposure to toxins in the maternal diet was used to generate two hypotheses: 1)
that 1st trimester women will have increased colour discrimination ability relative
to nonpregnant controls; and 2) that 1st trimester women will rate images of
unripe, overripe, or spoiled foods lower in preference than nonpregnant controls.
For example, we expect increased preferences for hues and other cues associated
with ripeness in fruits and vegetables (yellows, oranges, and reds) and decreased
preferences for hues associated with foods that are unripe, overripe, or spoiled
(greens, blues, and browns).
We hypothesize that these shifts in visual preference are one of the perceptual cues
that pregnant women use to make decisions that discriminate between foods of
varying levels of quality (e.g., ripeness, spoilage, etc). In this formulation, a shift in
visual perception is like a line of defense in a larger and integrated set of defenses
that serve to protect the developing embryo.

Visual Discrimination Test
In this test, known as the Farnsworth Munsell 100 hue test, you placed coloured
caps in sequence according to their hue. This is a widely used test of colour vision.

Rating Images of Foods Test
In this test, you rated how appetizing images of foods were that varied according to
ripeness or freshness.

Relevance
This research is relevant for two reasons. First, if the predictions are supported, it
will provide support for a theory that re-examines pregnancy sickness not as a
disorder but as a normal, healthy, and useful part of the experience of pregnancy.
Second, the information from this research fills in the almost complete absence in
our knowledge of whether changes in visual perception accompany early pregnancy.

If you have any further questions or if you would like a summary of our results
please contact the Principal Investigator:

Dr. Farhad Dastur
Dept. of Psychology,
Kwantlen University, Surrey, BC V3W 2M8
604.599.2170
farhad.dastur@kwantlen.ca
We thank you again for your participation.

Resources
Some Websites that provide information on Pregnancy and on Pregnancy Sickness:
General Information on Preconception, Pregnancy, Birth, and Post-Partum
http://www.pregnancy.org/
Ask the Experts, Get the Answers
http://www.pregnancy.org/experts.php
Pregnancy and Childbirth
http://pregnancy.about.com/
Ten Top Morning Sickness Tips
http://pregnancy.about.com/od/morningsickness/tp/tpmorningsick.htm
Pregnancy Info from the U.S. National Institutes of Health
http://www.nlm.nih.gov/medlineplus/pregnancy.html

Appendix F
Demographic Questionnaire

What is your age

____

What is your ethnicity ____
How many years of education have you received after completing high school?
____ none
Are you working:

____ 1-4 years

___ 5+ years

___ part time ____ full time ____ student

____ other

What week of your pregnancy are you currently in?

______

How was the date of your pregnancy determined?

_______________________

Please rate the intensity of the following symptoms (if experienced)

Very Weak

Very Strong

Food aversion

1

2

3

4

5

6

7

Smell Sensitivity

1

2

3

4

5

6

7

Nausea

1

2

3

4

5

6

7

Dry Heaves

1

2

3

4

5

6

7

Vomiting

1

2

3

4

5

6

7

Taste Sensitivity

1

2

3

4

5

6

7

Did you receive fertility drugs to help conception?

___ yes

Are you taking anti-nausea drugs?

___ no

___ yes

___ no

Appendix G
(a) Cataracts Conjunctivitis (i.e., pinkeye)
(b) Fuchs’ Dystrophy
(c) Retinitis Pigmentosa
(d) Colour Blindness

Appendix H
List of Purchased Foods

Fruits Status
Banana

used in pilot

Pear

used in pilot

Papaya

used in pilot

Apple

new

Strawberry

new

Vegetables
Broccoli

used in pilot

Tomato

used in pilot

Lettuce

new

Pepper

new

Mushrooms

new

Grains/Starches
White Bread

new

Potatoes

new

Steak

new

Chicken

new

Salmon

new

Meats

Appendix I
List of Google Adwords Keywords
1st trimester
1st trimester of
pregnancy
5 weeks pregnant
6 weeks pregnant
7 weeks pregnant
8 weeks pregnant
abdominal pain
during pregnancy
allergies pregnancy
** 1.20
become pregnant
being pregnant
belly during
pregnancy
calendar of
pregnancy
conceive
conceiving
conception
dizziness during
pregnancy
during pregnancy
during pregnancy
health
during pregnancy
vomiting ** 1.20
early pregnancy
early pregnancy
nausea
early pregnancy
symptoms
early pregnancy test
early signs of
pregnancy
exercising during
pregnancy
stage pregnancy
staying fit during
pregnancy
studies on
pregnancy
track pregnancy

first trimester
fitness during
pregnancy
food avoid
pregnancy
food cravings during
pregnancy
food during
pregnancy
food for pregnancy
food for pregnant
food for pregnant
woman
food for pregnant
women
food in pregnancy
food not to eat when
pregnant
food poisoning and
pregnancy
food poisoning
during pregnancy **
1.20
food poisoning in
pregnancy
food poisoning
pregnancy ** 1.20
food poisoning
pregnant
food poisoning while
pregnant
food to avoid during
pregnancy ** 1.20
food to avoid in
pregnancy
food to avoid when
pregnant
food to avoid while
pregnant
food to eat during
pregnancy
spicy food during
pregnancy

food to eat when
pregnant
food to eat while
pregnant
food when
pregnant
food while
pregnant
foods and
pregnancy
foods during
pregnancy
foods for
pregnancy
foods for pregnant
women
foods in pregnancy
foods not to eat
during pregnancy
foods not to eat
when pregnant
foods not to eat
while pregnant
foods to avoid
during pregnancy
foods to avoid in
pregnancy
foods to avoid
when pregnant
foods to avoid
while pregnant
foods to eat during
pregnancy
foods to eat when
pregnant
foods to eat while
pregnant
get pregnant
having a baby
healthy eating
during pregnancy
pregnant trimester
pregnant women

healthy pregnancy
hives during
pregnancy
insomnia during
pregnancy ** 1.20
maternity clothes
maternity fashion
maternity leave
migraines during
pregnancy
miscarriage
mommy to be
morning sickness
nausea during
pregnancy
ovulation calendar
pregnancy advice
pregnancy morning
sickness ** 1.20
pregnancy nausea
** 1.20
pregnancy nutrition
pregnancy questions
pregnancy sickness
pregnancy sign
pregnancy signs
pregnancy stages
pregnancy studies
pregnancy study
pregnancy support
pregnancy symptom
** 1.20
pregnancy
symptoms
pregnancy
symptoms trimester
pregnancy
symptoms week by
week
pregnancy test
pregnancy tests
pregnancy trimester
pregnancy website

trying to conceive
pregnancy websites
pregnant

spicy food
pregnancy
pregnant clothes
pregnant food
pregnant foods

food
spicy food and
pregnancy

Appendix J
List of Content-network Pages
411directoryassistance.ca

 womenshealthcaretopics.com

amazingpregnancy.com

 wrongdiagnosis.com

baby-gaga.com

 about.com

babycenter.com

 answers.com

babyzone.com

 are-you-pregnant.com

biology-online.org

 askdramy.com

diaperswappers.com

 babyandbump.com

exclusivelearning.com

 babyhopes.com

ezinearticles.com

 babyzone.com

families.com

 blinklist.com

fqnotebook.com

 cnn.com

freeovulationcalendar.info

 dailymail.co.uk

healthline.com

 ehealthforum.com

helium.com

 epigee.org

i-am-pregnant.com

 hd.org

imvu.com

 health-info.org

justmommies.com

 imdb.com

kidsinvictoria.com

 justmommies.com

manoramaonline.com

 laineygossip.com

medhelp.org

 mymonthlycycles.com

mymonthlycycles.com

 myspace.com

nationalledger.com

 ovulation-calendar.net

obgyn.net

 petplace.com

ovulation-calendar.net

 pregnancy-info.net

pregnancy-guidelines.com

 pregnancy-period.com

pregnancy-info.net

 suite101.com

pregnancy-period.com

 surebaby.com

pregnancy.org

 thecmr.com

pregnancyanalysis.org

 viseembryo.com

pregnancycheck.com
ratemds.com
revolutionhealth.com
skypedia.org
soaps.com
soulcysters.net
sparkpeople.com
thelaboroflove.com
tickerfactory.com
tvshark.com
urbanlegendsonline.com

 webmd.com

Figure Caption
Figure 1. Summary of One-Way ANOVA Analysis
Figure 2. F-tests and their significance for each food.
Figure 3. Number of Women experiencing pregnancy sickness throughout a day
Figure 4. Levels of Progesterone and Estrogen during Pregnancy

Figure 1. Summary of One-Way ANOVA Analysis
F

Power

2

3.40**

.884

.20


29.41***

1.00 

.68

Pear

2.77*

.796

.18

Papaya

11.48***

1.00

.47

Tomato

9.38***

1.00

.40

Banana
Broccoli



Note. *p<.05 **p<.01 ***p<.001

Figure 2. F-tests and their significance for each food.
F-value
Banana1

6.26*

Broccoli

106.63***

Pear1

31.90***

Papaya

17.28*

Tomato1

6.32*

Note. *p<.05 ***p<.001 1The comparison was made between the second and sixth
image

Figure 3. Proportion of women experiencing pregnancy sickness throughout the day

0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0

7am - 11am

11am - 3pm

3pm - 7pm

7pm - 11pm

11pm - 3am

3am - 7am

Figure 4. Levels of Progesterone and Estrogen during Pregnancy

QuickTime™ and a
decompressor
are needed to see this picture.

Table 1
Descriptive Statistics for demographic variables

Subject Variable

Age
Caucasian

Pregnant

Nonpregnant

34

26.4

4

6

East Asian
Ethnicity

South Asian

2
1

Filipino

1
1

Fijian

1

Full Time

5

3

Part Time

1

3

Work

Post-Secondary
Education

Students

2

Other

2

None

2

1-4 years

3

7

5+ years

3

1

Table 2
Significance test of FM 100 test

Pregnant

F value

Sig.

Effect Size

Power

4.756

0.047

.254

52.8%

Table 3
Appetizing rating means for the 10 food groups
Stage of Food
Apple

Mildly Unripe

Pregnant

5.56

5.44

4.83

4.39

4.17

3.89

Non-pregnant

5.03

5.10

4.97

4.88

4.60

2.77

Banana

Mildly Unripe

Pregnant

2.89

4.28

4.28

2.72

1.28

1.00

Non-pregnant

2.77

4.17

5.00

3.93

1.67

1.00

Broccoli

Completely Ripe

Pregnant

5.9

5.4

4.6

3.7

1.8

1.0

Non-pregnant

6.0

5.5

4.8

4.0

2.4

1.1

Lettuce

Completely Ripe

Pregnant

6.4

3.9

2.0

1.5

1.2

1.0

Non-pregnant

6.5

4.2

2.7

2.0

1.4

1.0

Mushroom

Completely Ripe

Pregnant

3.17

1.56

1.28

1.17

1.0

1.06

Non-pregnant

4.83

2.0

1.6

1.27

1.23

1.20

Papaya

Mildly Unripe

Pregnant

5.0

3.50

2.33

1.39

1.06

1.0

Non-pregnant

4.6

4.3

2.87

1.93

1.33

1.0

Pear

Mildly Unripe

Pregnant

5.9

5.4

4.8

3.8

2.4

1.1

Non-pregnant

5.2

5.3

4.8

4.4

3.5

1.1

Raspberry

Completely Ripe

Pregnant

6.1

5.9

3.9

1.6

1.6

1.3

Non-pregnant

6.70

5.30

3.30

1.40

1.40

1.00

Steak

Completely Fresh

Pregnant

2.80

2.80

2.50

1.70

1.88

1.00

Non-pregnant

4.80
4.40
Completely
Unripe
1.94
2.28

3.90

2.10

1.80

1.00

Tomato
Pregnant

Mildly Overripe

Completely Overripe

Completely Overripe

Completely Overripe

Completely Overripe

Completely Overripe

Mildly Overripe

Completely Overripe

Completely Decayed

Mildly Overripe
3.89

4.00

3.50

4.17

Non-pregnant

2.33

2.93

4.87

5.22

4.97

4.97