Author Archives: Reema Panjwani

The Good, the Bad, and the Smelly: Which Odor Will You Notice?

On any given day in Paris, I’m hit with so many different odors. The wet grass smell mixed with morning breeze greets me as I exit my dormitory. The man standing outside the door however snatches this pleasant nature aroma from my nose, masking it with copious layers of cologne. As I make my way to the RER, the stench of urine overpowers my senses forcing me to run down the stairs to catch the train even faster. And once on the train, I realize that perhaps the French sweat more than the average human being, because boy, oh boy, is that body odor game strong (I merely postulate – no scientific data supports such an outrageous presumption). As I step out of the Metro and onto the stairs rising up towards Bastille, the stench of last night’s garbage quickly hits me in the face.

Figure 1: The debris on the steps of the Opera Bastille on a Monday Morning.

Figure 1: The debris on the steps of the Opera Bastille on a Monday Morning.

The odor of the musty water thrown on the stairs by the sanitation department clashes with the spills of beer along those stairs underneath the Opera Bastille.

As I continue to make my way onto Rue de Faubourg Saint-Antoine, I realize that no matter the time of day, a good number of Parisians will always be smoking a cigarette somewhere. Fortunately, the aromas of baguettes and café au laits begin to swirl around me as I step into a local boulangerie (bakery). My nose feels at ease even if it’s just for a moment.

Figure 2: A local boulangerie near the Opera Bastille.

Figure 2: A local boulangerie near the Opera Bastille.

But let’s say I woke up at 9:06AM and class begins at 10:00AM, and not only does Dr. Shreckengost start on time, but he forces us tardy ones to pay penance by bringing French goodies the next day – aka, I want to get to class on time.

I leave my room at 9:20AM (should have left ten minutes ago), and of course this is the one-day that the tram’s ETA is 7 minutes (instead of in it’s normal 2 minute intervals), the RER is especially slow today, and all of the escalators at Chatel-Les Halles have broken down. Anything that could have gone wrong has and I emerge from the Bastille Metro stop at 9:55AM. The normal walking time from Bastille to class takes a solid 7-8 minutes. Like any other normal human being, I bolt across Rue de Faubourg Saint-Antoine sporting sandals and a bouncing backpack. I arrive panting and sweating at 9:59AM. That’s pretty clutch, I’d say.

Figure 3: Rue de Faubourg Saint-Antoine.

Figure 3: Rue de Faubourg Saint-Antoine.

So what’s the point? You’re probably thinking, “Well that’s cool Reema, nobody cares if you got to class on time (except for maybe you and Dr. Shreckengost)”. Hold your horses – there’s always a point to Reema Stories!

The difference is that when I was stressed and pressed to get to class on time, I did not notice the morning breeze or the aromas of the boulangerie (probably because I didn’t actually go inside one). What I did smell was the smoke from all the cigarettes people were smoking that morning. All I could think about was the detrimental effects of the smoke in my lungs and how these effects would slow my running speed down (not that the immediate inhalation of cigarette smoke was going to immediately affect my respiration at the time, but I didn’t think about the logistics while I was running). The only smells amplified that late morning included harmful or fear inducing odors(I don’t want to die from second-hand cigarette smoke).

I wonder why that it is…

Turns out, I’m not the only one who is extra sensitive to particular odors when I’m under stress. In fact, in some extreme cases of anxiety-related disorder, people are super-sensitive to smells associated with traumatic events in their lives.

In a recent study, Cortese et al. lookeds at the different sensitivity of odors in patients with post-traumatic stress disorder (PTSD). PTSD is a mental health condition triggered by terrifying events, whether those events were experienced or witnessed. Patients with PTSD may experience flashbacks, nightmares, and anxiety from thinking about those traumatic experiences. Many PTSD patients report trauma-related odors are particularly potent reminders of these events. A trauma-related odor might mean the smell of burning to a house fire victim or the smell of bombshells in Iraq or Afghanistan to a war veteran. There’s been increasing evidence and research that odors elicit psychological arousal and retrieval of autobiographical memories PTSD patients (Chu and Downes, 2002). Differential Odor Sensitivity in PTSD: Implications for treatment and future research is one of the first sets of studies of a long-term research plan by Cortese et al. where they looked at the behavioral responses to a range of odors with different qualities (traumatic and non-traumatic) in combat veterans with PTSD, veterans without PTSD, and healthy controls. Particularly, they examined the difference in proportion of individuals reporting distress to different categories of odors, specific individual odors, and the specific hedonic (pleasant vs. unpleasant) valence of such odors.

Figure 4: Buzz words to PTSD.

Figure 4: Buzz words to PTSD.

Cortese et al. found that the olfactory system plays a significant role in the identification of biological threats. The researchers saw that combat veterans, as compared to control subjects, had decreased responses to a large number of odors across various categories and hedonic valence. Cortese et al. believe that hyposmia (a decreased ability to detect and smell odors) may explain some of the decrease in susceptibility of positive valence odors. More so, the experimenters found that combat veterans learned to ignore non-life-threatening “distractor” odors (i.e., garbage, feces, raw sewage) and concentrate on life-threatening odors. Previous studies have shown there to be an association between stress-related disorders and attentional bias toward threat (Bryant and Harvey, 1995; Cisler and Koster, 2010).

Cortese et al.’s study is very important to the field of olfaction, to the field of psychology in which PTSD is studied, and to our country’s veterans. Experimenters analyze a detailed list of odors that affect combat veterans – a type of experimentation that had previously never been done before. However, the researchers don’t actively study this “attention bias” that they claim combat veterans may be exhibiting. The experimenters don’t actively conduct any attentional bias surveying and although data may seem to support previous research on attentional bias, it’s a bit of stretch to predict that there’s a correlation.

While my stressful sprints to class do not closely relate in magnitude to the severity of PTSD that troops go through, I find it interesting to know what odors I detect and what odors I ignore depending on what I’m doing and the mood I’m in.

Maybe I’ll notice every odor on my relaxed plane ride home? Only one way to find out!


Work Cited:

Bryant RA, Harvey AG (1995) Processing threatening information in posttraumatic stress disorder. J Abnorm Psychol 104:537-541.

Cisler JM, Koster EH (2010) Mechanisms of attentional biases towards threat in anxiety disorders: an integrative review. Clin Psychol Rev 30:203-216.

Chu S, Downes JJ (2002) Proust nose best: odors are better cues of autobiographical memory. Mem Cognit 30:511-518.

Cortese BM, Leslie K, Uhde T (2015) Differential odor sensitivity in PTSD: Implications for treatment and future research. J Affective Disorders 179:23-30.


Running on Parisian Time

Bonjour family, friends, and strangers of the virtual world!

I would be lying if I said I was always on time to things back in the states, but somehow, in some odd fourth-dimensional way, “Parisian Time” has hit me hard. I’m always fifteen minutes late everywhere, unless I’m going to class (in which case I’m only a minute late), and if I’m on time it’s because I ran for my life to catch the train.

Jokes on me aside, people go about things real slowly here in Paris (even Monday mornings on the Metro). At the local boulangerie (bakery) I could be the only person in the store but the barista will still take nine minutes (yes – I’ve counted) to make my café au lait (espresso with milk).

Café au lait

Café au lait

Why is that? Why do I want to function so much faster back at home than I do in Paris? Why are some Parisians gallivanting about their day without concern for the time? What causes the difference in how we perceive time? Why can’t people just give me my coffee already!

Interval time, the type of time that we use to perceive, estimate, and discriminate how long something has been going on for (the kind of time we use to estimate how long it’s going to take to get to class), is controlled by parts of our brain known as the striatum and cerebellum (Coull et al., 2011). The striatum is a region of the brain responsible for producing dopamine, a neurotransmitter that’s associated with one of our brain’s reward pathway (the striatum is what gets activated when I feel like I’ve done something great – like the satisfaction that comes from being on time). The cerebellum has many functions, but is most commonly known for playing a role in motor control and cognitive functions that also influence time (i.e., consciousness, self-awareness, and emotion). Science aside, what does interval time have to do with why my midtown Starbucks barista makes my low-fat, sugar-free iced caramel macchiato faster then the lady at the boulangerie making my simple café au lait?


Striatum and Cerebellum

Interestingly enough, there’s been a recent study by Pollatos et al. on how interoceptive processes affect our perception of time. Interoceptive processes are the systems in our bodies that allow us to sense and perceive the physiological conditions that are occurring within our bodies. An example of an interoceptive process is someone paying attention to how quickly his or her own heart is beating.

The study wanted to particularly explore how one’s perspective of their physiological responses during an emotional state (like how you stop breathing for a second when you kiss that special someone on the top of the Eiffel Tower – nope, haven’t done it yet, still waiting to meet that perfect Parisian guy who also speaks English) affected their perception of time.


Eiffel Tower


The study hypothesized that time contraction (perceiving less duration of time than has actually passed) and time dilation (perceiving more time than has actually passed) will be more pronounced in groups that were focused on their internal bodily processes as opposed to those focused on external stimuli.

It’s believed that when you’re experiencing emotions related to fear, you experience time dilation, whereas experiences that make you laugh lead to perceived time contraction (Buhusi and Meck 2005). Pollatos et al. took 254 participants, showed them a documentary (served as a control that wouldn’t elicit emotions), a German horror movie (to elicit prolonged fear), and Ice Age III (for comical effects), and separated the subjects into two groups. One was asked to focus on their bodily processes while watching the films (the interoceptive focus group) and the other was asked to focus on the film so they could answer a questionnaire on the content of the films (the exteroceptive focus group). All participants were subsequently asked to answer the same survey to which Pollatos et al. used the retrospective time paradigm, a way to measure a subject’s judgment of time without them knowing about it (sneaky…).

They ended up finding that subjects who focused on their internal physiological responses experienced an accentuated subjective time perception. Subjects who focused on their bodily functions while watching scared watching the horror film, exhibited greater time dilation to those subjects who did not pay attention to their bodily functions. Similarly, subjects who focused on their interoceptive processes while watching the comedy exhibited greater time contraction to those subjections who focused extrospectively. Because the hypothesis was supported, Pollatos et al. concluded that the more aware a person is of ongoing bodily functions, the more influential an emotional experience is on a subjective time experience.

Perhaps, Parisians are having a great time. Why wouldn’t they be? The wine is great, the baguette’s are fresh, the architecture is phenomenal, and the paintings in some of the museums are breathtaking! So, the feeling of joy may elicit time contraction, and they’re always walking everywhere making it seem like they’re at least slightly aware of their bodily functions, exacerbating their time contraction. With them thinking that time is passing slowly, of course they’re bound to take their time and be late to things! I exaggerate in my analogy, but it’s a thought!



Art at Musée d’histoire de la médecine

Lastly, the study addresses that one of the things they want to focus on in the future is what factor age plays in subjective time distortion. Ironically, now that I think about it, the 20-something year old barista at the Le Pain Quotidien around the corner made my cappuccino a lot faster than the 40-something year old lady at the local boulangerie.

Or maybe the 40-something year old lady has more to worry about or more on her mind that causes stress and induces fear making her less aware of her bodily functions, which would cause time dilation. This might explain why it takes her 9 minutes to make my café au lait instead of the normal three. Or, she could just not like me.




Work Cited.

Buhusi CV, Meck WH (2005) What makes us tick? Functional and neural mechanisms of interval timing. Nat Rev Neurosci 6: 755–765.

Coull JT, Cheng R, Meck WH (2011) Neuroanatomical and neurochemical substrates of timing: a review. Neuropsychopharmacology. 36, 3-25.

Kreibig SD (2010) Autonomic nervous system activity in emotion: a review. Biol Psychol 84: 394–421.

Pollatos O, Laubrock J, Wittmann M (2013) Introceptive Focus Shapes the Perception of Time. PLOS One. 9: 86934