Tag Archives: Metro

Rodents on My Mind, Rodents on the Metro

What does this look like to you?

The RATP logo (Image from Creads.fr)

To me it looks like a female face tilted back to take a big whiff of something—presumably, the fresh, pleasant-smelling air of Paris’s underground metro system (of course I’m being entirely facetious; it is often quite the opposite).

Why is this relevant? Let me explain.

One day on the way to class, out of boredom I was perusing the exciting advertisements plastering the walls of the metro car. My eyes landed upon this intriguing logo, accompanied by the letters, “RATP,” and I found it to be one of the most unintentionally amusing things that I have ever seen.

Standard interpretation of the RATP symbolism (Image from Creads.fr)

You see, in class we have been discussing many experiments that use mice. Mice are really good at being the subjects of neuroscience experiments, it turns out. So the first thing that came to my mind was this sort of double entendre: this poster was advertising the Paris metro system while highlighting the scent of rat urine that may often accompany it.

Lab rat (Image from Shutterstock.com)

The symbol and acronym actually represent Régie Autonome des Transports Parisiens, the group that operates much of the public transportation in the region. And according to one website, the logo is supposed to be an artistic representation of  Paris.  I never would have guessed this, but perhaps my interpretation is unique, influenced by my recent experiences in class.

In fact, I’ve been thinking so much about rodents that I’ve been dreaming about them! So I wanted to know: Why was I dreaming about mice? Is it possible that these dreams impacted my interpretation of the RATP symbol?
My theory was that mice have been so prevalent in my thoughts during the day (due to all the neuroscience research that I have been reading about) that they infiltrated my dreams at night. Maybe this is what led me to interpret the logo in such a humorous way! Neuroscience can provide some answers as to what likely occurred here.

The neuroscience of sleep and dreaming isn’t fully understood. But, scientists know that the brain isn’t inactive when we’re asleep: contrary to the idea of “resting” during sleep, the brain actually doesn’t shut down at all (Debunking Sleep)! It fluctuates through different stages of activity  throughout the night, meaning the cells are active in different patterns (Brain Basics).

During one type of brain activity called slow-wave sleep (SWS), our brains “replay” certain memories from the day and put them into long-term storage (Hasselmo, 1999). This is termed “memory consolidation,” and it is as if these experiences were being packaged into neat little containers for protection and easy access in the future. During “slow-wave sleep,” cells are sending signals in slow bursts, and this likely had a role in making my memory of the mice stronger and easier to recall! This strong memory of mice seems to be why I interpreted the RATP symbol in such a way. But what does dreaming have to do with it?
Dreams are created by the brain’s activity while we sleep. Scientists also know that their content—the scenes and emotions that get incorporated into them–is pulled from our recent thoughts and experiences while we’re awake (Stickgold et al., 2001). This explains why I was dreaming about mice!

But, my question isn’t fully answered yet: Was dreaming about mice what caused the memory consolidation that led to my humorous interpretation?

Neuroscientists actually don’t yet understand the relationship between dreaming and memory consolidation. But, some current research can help to shed some light on the subject.

A recent study by Siclari et al. (2017) identified a certain part of the brain they called a “hot spot” for dreaming. Whenever a certain type of activity is detected in this area—the back half of the brain, lying directly behind your ears—you are likely dreaming!

In order to do this, researchers used a machine called an electroencephalogram (EEG) to measure people’s brain activity while they were sleeping. Using sensors placed all over each subject’s head, this machine detects changes in electrical activity, telling researchers the patterns in which brain cells are firing (Britton et al., 2016).

Electroencephalogram (Image from Michigan Advanced Neurology Center)

In this study, people wearing EEG sensors (shown in the picture above) were awakened at random points during a night’s sleep and asked to report if they had been dreaming. By looking at the EEG data, the researchers were able to determine that high frequency activity—meaning that brain cells were sending signals very quickly—was associated with dreaming when it occurred in the back half of the brain. This means that they were able to predict whether someone was having a dream or not (Siclari et al., 2017)!

So what does that mean for me? The conclusions of this study suggest that dreams are actually less likely to occur during SWS, which is associated with low-frequency activity. Since this activity signals when memory consolidation occurs, it is not clear if dreaming about mice helped my brain consolidate the memory.

Dreams of neuroscience experiments (Image from ScienceABC.com)

But, it’s still not clear if dreams have a role in consolidating memories. In the realm of neuroscience research, these findings are important, but they don’t exactly align with what has been suggested in the past. Some researchers have found that dreaming about an experience enhances one’s ability to recall it (Fiss et al., 1977; De Koninck et al., 1990; Wamsley 2014). Still, this is an essential step in understanding the mechanisms of memory consolidation in sleep: dreams likely have some functions that we haven’t fully uncovered yet!

In conclusion, it is still amusing to me how my daily experiences—solidified into my memory during sleep—shaped my interpretation of this advertisement in such an entertaining way! Certainly my experiences in class contributed a lot about rodents to my memory bank, and I’m grateful for it: If nothing else, it gives me an extra opportunity to chuckle to myself every day on an otherwise monotonous metro ride!


Brain Basics: Understanding Sleep. (n.d.). Retrieved from https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Understanding-Sleep

Britton J.W., Frey L.C., Hopp J.L., et al. (2016). Electroencephalography (EEG): An Introductory Text and Atlas of Normal and Abnormal Findings in Adults, Children, and Infants. American Epilepsy Society. Available from: https://www.ncbi.nlm.nih.gov/books/NBK390346/

De Koninck, J., Christ, G., Hébert, G., Rinfret, N. (1990) Language learning efficiency, dreams and REM sleep. Psychiatr J Univ Ott. 15:91-92.


Debunking Sleep Myths: Does Your Brain Shut Down When You Sleep? (n.d.). Retrieved from https://www.sleepfoundation.org/articles/debunking-sleep-myths-does-your-brain-shut-down-when-you-sleep.


Fiss H, Kremer E, Litchman J. (1977).The mnemonic function of dreaming. Sleep Res. 6:122

Hasselmo, M. E. (1999) Trends Cogn. Sci. 3:351-359.pmid:10461198

Que signifie le logo RATP ? Creads décrypte ! Design Tribe. 06 May 2019. 17 June 2019 <https://www.creads.fr/blog/logos/ratp-logo-signification>.

Siclari, F., Baird, B., Perogamvros, L., Bernardi, G., LaRocque, J. J., Riedner, B., … Tononi, G. (2017). The neural correlates of dreaming. Nature neuroscience, 20(6), 872–878. doi:10.1038/nn.4545.

Wamsley, E.J. (2014) Dreaming and offline memory consolidation. Curr Neurol Neurosci Rep.14:433. doi:10.1007/s11910-013-0433-5.








Hyperlinked sites and videos:





The Art (and Science) of People Watching

After my weekend exploring the Musee du Louvre, going to the Women’s World Cup, and riding my umpteenth trip on the metro, I noticed that my go to activity while I explore is people watching. People watching, in its purest form, is the idea of observing other people in a public setting. We all do it, whether we are aware of it or not, and it has a variety of results from my own experience as a seasoned player.

Location of where the Louvre right next to the Seine River

People watching takes on a different form where you are; you can get away with more than a glance at a sporting event  like the Women’s World Cup than you can in a cramped metro where everyone is trying, and sometimes not trying at all, to look at everything but the five different people close enough to count eyelashes. Even in those situations, you cannot help but take a millisecond scan of your surroundings just in case in you miss out on something compelling.

This is a part of everyday life and a hobby that I do almost daily. We’re doing the opposite of what we usually do when we people watch; instead of blocking out majority of the stimuli we encounter on a daily basis we take the time to take in every detail as it crosses our path. I started to wonder how people watching is so enjoyable despite the cacophony of stimuli we take in when we do this activity.

Main entrance to the Louvre: Prime location for art appreciation and people watching!

It turns out that people watching requires activation in three different brain networks to during people watching (Quadflieg & Koldewyn, 2017). For example, the person perception network (PPN) is a brain network of brain structures that examine a person’s individual appearance and the way they move which is important to decipher an overall person to person encounter (Quadflieg & Koldewyn, 2017). One specific brain area in the PPN that supports the PPN’s overall function is the posterior superior temporal sulcus (pSTS), but it was not explicitly seen that the pSTS was active while observing social interactions until one 2018 study (Walbrin, Downing, & Koldewyn, 2018).

To test the pSTS activation, the researchers asked fifty-five participants to view human like figures in two 8-second scenarios for multiple trials: one scenario had two figures socially interacting and the second scenario had the two figures doing independent activities (Walbrin, Downing, & Koldewyn, 2018). The researchers used fMRIs to compare pSTS activity when the participants viewed social interactions verse when the participants viewed individual actions. After testing, the researchers found that the right pSTS had a significantly higher activation as the participants viewed the figures interacting with each other compared to when the participants viewed figures doing individual activities (Walbrin, Downing, & Koldewyn, 2018).

Graph showing a significant change in percentage signal activation of the pSTS once shown social interactions verse independent actions

It’s great that the researchers recorded pSTS activation from people seeing direct social interaction because it helps focus further directions into how social patterns change when people have conditions that affect the pSTS. The researchers even looked at other brain areas thought to assist in people watching but in a different capacity than just surface level observations of the interaction. The researchers added a control where they examined the temporoparietal junction (TPJ). The TPJ helps in assigning people’s intentions with one another from what we observe, but it does not work on a board scale in analyzing social interactions verse individual interactions like the researchers predicted the pSTS to do (Quadflieg & Koldewyn, 2017).

While this control helped the researchers determine if pSTS functions specifically while viewing social interactions, an experiment looking into nonhuman subjects’ that have areas similar to the pSTS inhibited or lesioned with provide more concrete evidence to the pSTS functioning examining social interactions or people watching.

Nevertheless, it is still interesting how we have multiple brain networks and brain structures involved to help us understand what we are looking at as we scan our surroundings and the people within it.

In my opinion, people watching is a great skill to have especially in places you’ve never been to before. By watching the people around interacting with each other and their surroundings, I’m able to pick up on what’s acceptable and what’s not. Especially in Paris, I’m trying to do everything I can to blend in and not expose myself as the Lost American, a title I still haven’t been able to shake off.

USA vs. Chile Women’s World Cup. The BEST place to people watch: screaming Chilean grandparents, babies decked out in USA memorabilia, cursing in three different languages, and an indescribable energy you have to love

Even so, everyone still has instances where social cues fall through the cracks. It is those times when you realize that you haven’t moved quickly enough when there is a bike riding on the sidewalk as you walked to the Musee du Louvre or you  you’re taking your sweet time trying to get a glimpse of Hope Solo while someone waits patiently to get their new profile picture during half-time, or the numerous other fish out of water experiences that I have encountered in France. Thankfully, I’ve stopped being embarrassed in these situations and tried to do better for the future by sticking my faithful ally in people watching.

Because we have various brain networks like the PPN with brain structures like the pSTS present to determine most beneficial actions to blend in any situation or find most entertaining of scenarios, it’s not hard see why we continue to people watching at the most inopportune times. We have the wiring to help us bounce back from the mistakes we make.

Without the spatial and social awareness that comes from people watching, I would not have the same peculiar but truly fascinating experiences I’ve had throughout Paris. So, I’m keeping my eyes peeled for the next exciting exploration or the next cue that comes my way.


Children’s Healthcare of Atlanta. (n.d.). fMRI. Retrieved from https://www.youtube.com/watch?v=3fNf8KX1AlQ

Quadflieg, S., & Koldewyn, K. (2017). The neuroscience of people watching: how the human brain makes sense of other people’s encounters. Annals of the New York Academy of Sciences,1396(1), 166–182. https://doi.org/10.1111/nyas.13331

Walbrin, J., Downing, P., & Koldewyn, K. (2018). Neural responses to visually observed social interactions. Neuropsychologia,112, 31–39. https://doi.org/10.1016/j.neuropsychologia.2018.02.023

Image #1: [Screenshot of the Musee du Louvre]. Retrieved from https://www.google.com/maps/place/Louvre+Museum/@48.8606111,2.3354607,17z/data=!3m1!4b1!4m5!3m4!1s0x47e671d877937b0f:0xb975fcfa192f84d4!8m2!3d48.8606111!4d2.337644

Image #3: [Screenshot of the Figure 2]. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5899757/

Image #2 and #4 were taken by me

The Music of the Metro

Paris is a unique city experience unlike any other I’ve partaken in. So many sites to visit, places to eat, districts to explore…how can one possibly get to them all? Simple: the Metro! Paris has an extensive metro system that covers any point you could ever want to visit. Atlanta may be fantastic in other respects, but the MARTA is definitely not set up for the burdens of massive public transportation. Riding the Metro daily to and from class was an entirely new process for me to get used to, from the rapidly closing doors to complete lack of personal space. Attached here is a picture of me in front of the station for the Balard train at the ACCENT center stop, Ledru Rollin.

Pictured above: the Balard Metro station as I wait for the next upcoming train three minutes away.

One of the first things I noticed about Metro riding was the efficiency; the doors closed so quickly after each person, I was shocked no one got stuck! As I got used to the train, I observed a noise that is played in front of every door right before it closes to alerts passengers that the door is closing. This noise is poignant and cutting, eliciting a harsh auditory reaction that informs passengers to stay clear of the area. As you hear it, you register that it is loud and unpleasant. What interested me so much is how this closing noise utilizes tonal dissonance to be more brash and effective. Attached below is an audio recording of the noise, taken during my morning commute (it may not open in Chrome, but it works in other web browsers).


This simple use of two tones causes such a visceral reaction for a reason; the frequencies of pitch and how they travel to the brain. Two pitches that are half or eight steps apart affect the same area of the basilar membrane, a structure located in the cochlea that is responsible for converting sound waves into nerve impulses that head to the brain. This joint stimulation results in beating (roughness in the basilar membrane) at a frequency that is determined by the difference between the two frequencies of the initial pitches (Johnson-Laird 2012). The clash between these almost-identical frequencies interact with one another to make a warbling, distorted sound.

This can be defined as a harmonically incongruous combination of notes, which is one that does not conform to the rules of harmony. The response to this in the brain is called the early right anterior negativity (ERAN); this event-related potential component occurs at an early latency, is prominent over anterior regions of the scalp, and tends to be lateralized to the right side. The amplitude of this response is modulated directly by attention and is more prominent in those with a familiarity towards music. An experiment was done observing harmonically incongruous chords in the context of a melodic sequence of chords and is shown in the figure below. Harmonically incongruous chords result in an attenuated response of neuronal firing when the tonal discord is in different positions (Positions 3, 5, 7) in the melodic phrase (Leino 2007). The hemispheric lateralization of the ERAN response is visible in the Position 3 example. In Position 7, the incongruous chord occurs at the end and elicits the strongest response and the greatest difference in neuronal firing rates.

Shows the difference in neuronal firing rates in specific areas of the brain during harmonically congruous and incongruous chords,

Of course, every individual has a different level of pitch identification. Absolute pitch refers to the phenomenon of identifying any pitch without given an external reference. Even during our pitch identification process, we activate the auditory cortex, prefrontal cortex, and certain parietal regions of the brain (Brauchli 2019); yet, we are not all as heavily invested in pitch as a musical function. Why is the ability to identify harmonic versus dissonant sounds in everyday life even important? Besides the tones used in music, language lends itself to a variety of colorful tones and variations in pitch. We use pitch in everyday conversation with specific inflection; for example, a rising pitch at the end of a sentence is often used to indicate a question. On the Metro, this understanding is important because it allows us to register a harmonically incongruous sound like the door closing and turn that into information: the train will soon close the doors. A small part of the everyday Parisian experience, yet an important one nonetheless. Maybe this is something you have yet to notice about the Metro experience, but it is fascinating regardless!

Aliyah Auerbach

Brauchli, C., Leipold, S., & Jäncke, L. (2019). Univariate and multivariate analyses of functional networks in absolute pitch. NeuroImage, 189, 241-247. doi:10.1016/j.neuroimage.2019.01.021

Jonhson-Laird, P. N., Kang, O. E., & Long, Y. C. (2012). On Musical Dissonance. Music Perception: An Interdisciplinary Journal, 30(1), 19-35.

Leino, S., Brattico, E., Tervaniemi, M., & Vuust, P. (2007). Representation of harmony rules in the human brain: Further evidence from event-related potentials. Brain Research, 1142, 169-177. doi:10.1016/j.brainres.2007.01.049

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.