Author Archives: Ankita Gumaste

Musée du Parfum

Last week we visited Musée de la Parfumerie Fragonard, a museum created by the Fragonard Perfumery to expose visitors to their perfumes as well as the perfume-making process. As soon as we stepped into the museum we were met with a light flowery scent that filled the entire room. Being led through the museum by our bubbly and efficient tour guide, we learned about how scents are extracted from the oils of flowers, the ways in which these scents are diluted and packaged, and of course where on the body to wear perfume (your wrists and neck if anyone is wondering). At the end of our tour we were able to test a number of fragrances that were available for purchase. I remember instantly loving some of these scents (Etoile in particular, which means star in French) and also having quite a negative reaction to others.

I wondered what parts of my brain process odors as pleasant or unpleasant and if sensory stimuli other than scents can affect the perception of an odor. In a study done by Katata et al. (2009), adult human subjects, 27 females and 3 males, ranging from 18-35 years old were exposed to one of two different chemicals odors while their brains were being studied using an fMRI scanner. An fMRI scanner detects active areas of the brain through identifying an increase in blood flow. The subjects were told to pay close attention to the scent and after the scan they were told to rate the odor based on pleasantness. About half of the subjects were exposed to each odor and the odor was rated on a scale of -3 (strongly unpleasant) to +3 (strongly pleasant). The group found that those subjects which rated the odor as unpleasant had increased brain activation in their lateral orbitofrontal cortex (lateral OFC) and those who rated the odor as pleasant had increased brain activation in their anterior cingulate gyrus. The lateral OFC has been previously shown as one of the brain areas responsible for processing negative aspects of odor and facial appearance; this study provides further support for this claim. The cingulate gyrus has been shown to be involved in olfactory processing when attention to features of odors is needed; this study implies that perhaps the anterior, the front most part, of the cingulate gyrus is involved in specifically processing pleasant stimuli (possibly because we need to pay attention to the features of the odor in order to determine that it is pleasant). This study suggests that perhaps when I smelled a perfume that I considered pleasant, my anterior cingulate gyrus was activated, and when I smelled a perfume that I considered rather unpleasant (which was probably followed by a not-so discreet grimace) perhaps my lateral orbitofrontal cortex was activated. The findings of this study suggest that the activation of these brain areas are involved in olfactory perception, however the subjects were predominantly female and only 30 subjects were used, so these finding may not be universally applicable (although the study does provide further insight into the regions of the brain that may play a role in processing the pleasantness of odors).

Musée de la Parfumerie Fragonard (labeled as A)

As I stated before, upon leaving the museum, I also wondered if any other sensory input could affect an individual’s perception of smell (which could possibly be used as a tactic to sell perfumes). In a study done by Seo and Hummel (2010), the affects of auditory stimuli on olfactory perception were tested. Twenty-six human subjects (20 female and 6 male) between the ages of 20 and 40 were exposed to 1 of 4 auditory cues for five seconds and four seconds after the onset were presented with an odor. The auditory cues consisted of two pleasant sounds, baby laughing and jazz drum, and two unpleasant stimuli, a baby crying and a baby screaming. After auditory cue and odor exposure, the subject was told to rate the odor on a scale of 0 (extremely unpleasant) to 10 (extremely pleasant). The group found that subjects rated the odor as being more pleasant while listening to the “pleasant” auditory stimuli and less pleasant while listening to the “unpleasant” stimuli. This perhaps suggests that auditory cues can influence the way in which individuals perceive an odor. Like the first study, this study uses mostly female subjects which presents complications associated with the auditory cues used. The group chose auditory stimuli related to infant cries and laughing. These stimuli could have evoked a maternal behavior in women, putting the subjects in either a rewarding or fear-inducing state (which could lead them to rate odors as pleasant or unpleasant). Thus, these auditory cues may not be applicable to all individuals as “pleasant” and “unpleasant.” This study, however, does suggest that auditory cues in general may play a role in influencing whether individuals consider an odor pleasant or unpleasant. It would be interesting to see if by playing pleasant auditory stimuli, there is more activation in the anterior cingulate gyrus upon smelling an odor. Conversely, it would also be interesting to explore if by playing an unpleasant auditory cue, there is more activation on the lateral OFC upon smelling the same odor. It may be possible to alter the way that an individual perceives an odor by simultaneously presenting that individual with an auditory cue. Maybe perfume stores should start playing jazz drum recordings in the background while their customers shop. I wish I had remembered if the Musée de la Parfumerie Fragonard played music while having us test their scents. Judging by the amount of perfume one of my friends bought (shout out to Emily), perhaps they were one step ahead of all of us.

– Ankita Gumaste

Works Cited

Katata K, Sakai N, Doi K, Kawamitsu H, Fuji M, Sugimura K, Nibu K (2009) Functional MRI of regional brain responses to ‘pleasant’ and ‘unpleasant’ odors. Acta oto-laryngologica 129: 85-90.

Seo HS and Hummel T (2011) Auditory-olfactory integration: congruent or pleasant sounds amplify odor pleasantness. Chem. Senses 36: 301-309.

How Can You Tell I’m American?

One of the greatest challenges about being in Paris is being constantly exposed to a foreign language. I have found that fewer Parisians than expected speak English. Having studied French for a number of years, I am always eager to test my ability to communicate with native French speakers. I try to practice French in Paris as often as possible, whether it is through ordering food (obviously my most important application of the language), asking for directions, or even giving directions sometimes. Just a couple of days ago I asked a young lady for directions while on the metro and even though I knew that I had appropriately phrased my sentence in French, she responded in English. I knew that my accent had given away the fact that my native language is English, but I had expected her to respond in French. I have found myself in similar situations on many occasions. One time I was speaking French to an angry Cite Universitaire, the campus on which we are living, security guard after I had been locked out of my room and he responded in English, “I don’t speak English.” I was puzzled and in French let him know that I can speak French and he responded, “no you can’t.” I chose not to take this second encounter personally and instead began to wonder what about my speaking bothered him so much. It must have been my accent. Accent perception is such an interesting concept. We can tell what country a person is from, or even perhaps the city in which they were born not by listening to the words that they say, but by listening to the way that they say them.

Cite Universitaire (labeled as A)- where we have been living for the past 3 weeks.

In a study done by Adank et al. (2011), native monolingual Dutch speakers were played Dutch phrases in a Dutch accent and were also played the same Dutch phrases in an unfamiliar accent. While listening, the subjects’ brains were monitored using an fMRI scanner, a machine which uses magnetic imagining to monitor brain activity. The study showed that when the sound stimuli changed from the familiar to the unfamiliar accent, more of the subjects’ superior temporal gyrus (STG), a brain area involved in basic auditory language processing, became activated. The STG has also been shown to be associated with phonetic-analytic listening to speech. Perhaps this gives insight into as to why more of the STG is activated when listening to an unfamiliar accent; the brain is recruiting more cells to help analyze the phonetics of the speech because the speech is foreign. It is important to understand this because when French individuals hear me speaking French with an English accent, their STG becomes increasingly activated and they recognize that not only am I speaking in an accent, but then, through using other areas of the brain, may be able to understand what language I am speaking.

An exhibit in the Louvre Museum spelling out "love differences" in many different languages.

Whenever I’m on the metro and everyone around me is speaking French, it is difficult for me to decipher what they are saying unless they are speaking directly to me. I was curious as to the ways in which my brain would have responded to the sounds on the metro had I learned French at a younger age, but second to English. I wondered how the bilingual brain responds to language perception in general. In a study done by Archila-Suerte et al. (2012), a group of bilingual Spanish-English speaking children (whose native language is Spanish) and monolingual English speaking children were played the English syllables, “saf,” “sof,” and “suf,” while watching a silent film. These syllables were chosen because they are pronounced similarly in Spanish and would provide more insight into activation of the bilingual brain (perhaps because they may activate regions involved in perception of both languages). The subjects were told to focus on the silent film while the syllables were being played to them and simultaneously the group was analyzing the subjects’ brains using an fMRI scanner. The study was performed for young and older bilingual and monolingual children. The group found that the young monolingual and bilingual children had the STG activated (let’s call this area 1) while listening to the syllables. This data implies that the bilingual children when just beginning to learn the second language perhaps relates it to the first language and processes it in the same brain area. However, the older monolingual children still only had area 1 activated during the task whereas bilingual children had area 1 as well as other areas in the brain activated. This suggests that as bilingual children begin to master a second language more, their brain recruits other areas, other than area 1, to help distinguish between the two languages. Perhaps my brain is similar to the brain of the younger bilingual children, since I have not yet begun to master the French language. My brain may not be able to recruit other areas to help area 1 decipher a language other than English and this may be why I am unable to easily pick out French words and conversations while on the train. However, French individuals who are able to easily recognize my accent, process what my native language is, and then respond in my native language perhaps have activation of other brain areas which help the STG decipher the language. This is due to the idea that they are bilingual and no longer need to relate their second mastered language to their native language. It would be interesting to see what the combined results of the first and second study would be; to pursue a study that looked at monolingual and bilingual individuals’ brain activation to speaking their common language in an accent. I am curious to see if by being well versed in more than one language, bilingual children are able to recognize accents easier. Maybe one day I’ll master the French language enough to not have to constantly compare it to English! I guess I’ll just have to ensure that this isn’t my last trip to Paris…

–          Ankita Gumaste

Adank P, Noordzij ML, Hagoort P (2011) The role of planum temporal in processing accent variation in spoken language comprehension. Human brain mapping 33: 360-372.

Archila-Suerte P, Zevin J, Ramos AI, Hernandez AE (2012) The neural bases of non-native speech perception in bilingual children. NeuroImage 67: 51-63.

Les Pâtisseries à Paris

“The treasures of France; I love Patisseries!” one of my friends of French origin exclaimed when he discovered that I had been taking full advantage of the fact that nearly every street corner of Paris is occupied by a Boulangerie, or bakery. “Window shopping” in Paris is not limited to its boutiques; in fact, what really catches my eye when walking down the street are the rows of colorful macaroons, tartes and a number of other mouth-watering pastries. However, the real reason why I’m in France is not for the pastries, although they are a delightful perk to the trip, but is to study neuroscience through Emory University. With class from 9:30am to 1:30pm, the other students on my program and I take full advantage of our hour lunch break. We have made ourselves regulars at a nearby bakery and devour their enormous baguette-sandwiches nearly every day; but perhaps even more intriguing than their sandwiches are their desserts. A friend of mine and I, each having an extremely dedicated sweet tooth, have set out to try every pastry, cookie, cake, and dessert sold by our favorite bakery. Although this may seem like a daunting task, we are now four days into our endeavor and have already sampled about a quarter of the treats offered at our bakery.

Now, being an avidly interested neuroscience student, it wouldn’t be right to discuss such amazing sensory perceptions without giving credit to the nervous system. Endocannabinoids are chemical compounds produced by the human body that act in certain areas of the brain to stimulate appetite and food intake.  Yoshida et al. (2010) studied two different groups of mice, one normal group which had the receptor for endocannabinoids, and one which had been genetically altered to lack the receptor for endocannabinoids. The lack of receptor in the second group prevents the group from being able to experience the effects of endocannabinoids. The group of researchers administered cannabinoids, synthetically made endocannabinoids, to both groups of mice and found that in those mice with endocannabinoid receptors, behavioral responses to sweet compounds increased and the response of taste receptor cells on the back of their tongues to tasting sweet compounds increased as well. In the mice without endocannabinoid receptors, no increase in behavioral or cellular activity was observed in response to cannabinoid injection. In addition, in normal mice, with endocannabinoid receptors, if the endocannabinoid receptors are blocked using a drug, the mice show a decreased response to sweet compounds. This last portion of the experiment hints to the idea that endocannabinoids may be involved in allowing the animals to perceive a sweet taste.  These findings, in general, suggest that perhaps endocannabinoids play a role in the perception and enhancement of sweet tastes. Yoshida et al.’s normal mice which were administered a cannabinoid would have really loved the desserts that I have been delving into for the past few weeks. It may be possible that as I make my way through the treats at my regular bakery, my body releases endocannabinoids, which act on certain areas of my brain that eventually communicate with my taste buds and allow me to taste the sweet, delicious desserts. Perhaps a combination of my body’s release of endocannabinoids and my love for sweets is what is propelling me so quickly through my task. At this rate I’ll be onto my next bakery in a week; watch out Paris, I’m a little girl with a huge sweet tooth.

– Ankita Gumaste

Works Cited

Yoshida R, Ohkuri T, Jyotaki M, Yasuo T, Horio N, Yasumatsu K, Sanematsu K, Shigemura N, Yamamoto T, Margolskee RF, Ninomiya Y (2010) Endocannabinoids selectively enhance sweet taste. PNAS 107:935-939.