Tag Archives: perception

I don’t like the taste of this anymore!!

Posted on June 27, 2019 by | 2 comments

In class, we discussed gustation and the different mechanisms associated with taste processing. Later, we participated in an amusing activity. We taste tested different snacks! In this activity, we were given chips of different flavors and had to taste and guess the flavor. The first chip smelled like barbeque, but I thought that was too easy of a guess. After tasting it, I was left uncertain of the flavor because it wasn’t particularly gross or tasty. Upon receiving a suggestion card that revealed the flavor as “mustard,” I still was not convinced I knew the flavor. When the options of pickle, cheeseburger, and mustard were given to me, I immediately thought it could be cheeseburger because it distinctly tasted like the aftertaste of a McDonald’s cheeseburger (the one in the kid’s meal). The next two flavor of chips were easy to guess because they both tasted exactly like their said flavors, cheese and ketchup.

After the chip taste test, Dr. O’toole gave us a supplement, and the effect of that supplement was that we had a harder time tasting sweet. To test how well it worked, we tried a piece of chocolate, and I do not enjoy the taste chocolate. However, it was not as bad as I expected because the sweetness of chocolate that I hate was not perceived by me. Instead, I really just felt the texture more than usual, but maybe that was due to that specific type of chocolate.

Anyway, during this activity, it occurred to me that the flavors we tasted were savored by some and despised by others, and some people started to enjoy certain chips. This observation triggered an intriguing thought. In what situation does one change taste preference? When I thought of this idea, I dove into scientific literature to find an answer to my question, and I stumbled upon a pilot study that investigated changes in taste and food preferences in breast cancer patients.

Breast cancer is the most common cancer in women, and the prevalence is increasing (DeSantis et al., 2015). To decrease the fatality and to remove cancerous tumors from individuals, treatments such as surgery, chemotherapy, radiation, and/or targeted hormone therapy are administered (Andre et al., 2006). Moreover, patients who underwent chemotherapy have reported changes in taste preference before treatment (Mattes et al., 1987). Different interactions between learned food aversion and basic side effects of chemotherapeutic drugs can limit what a person wants to eat and can alter taste (Mattes et al., 1987).

5 basic tastes

Based on previous research, Kim et al. (2019) decided to investigate how cancer treatment plays a role in appetite reduction and change in taste preference. In order to test this question, the authors administered taste detection thresholds and recognition thresholds and compared the results between breast cancer patients and healthy subjects (control group) for sweet, salty, bitter, and sour solutions. The taste detection threshold is the lowest point at which one can distinguish the solution from water, and the recognition threshold is the lowest concentration that one can recognize and correctly identify the solution (Keast and Roper, 2007). If one has high sensitivity to a specific taste, then there will be reduced detection thresholds and recognition thresholds of that taste, and vice versa. The changes in taste thresholds and food preferences were monitored before and during treatment in the breast cancer patient group.

Both detection and recognition thresholds were measured in both the experimental and control group at baseline. The baseline data showed that the experimental group had lower sweet and salty detection and recognition thresholds and higher sour recognition threshold compared to the control group. The bitter thresholds (detection and recognition) were similar between both groups. The results of this study showed that as treatment progressed, the detection thresholds and recognition thresholds in breast cancer patients for sweet declined significantly compared to the threshold at baseline. The other tastes’ thresholds (detection and recognition) were not affected. For food preference, at baseline and during treatment, the patients had a consistent preference for mild and soft dishes (Kim et al., 2019).

Taking these results, Kim et al. (2019) concluded that at baseline, sensitivities to sweet, salty and sour were different in breast cancer patients compared to healthy individuals. Furthermore, as cancer treatment progressed, sensitivity to sweet increased and the other tastes were unaffected when compared to baseline. The results provide useful information to better understand what cancer patients can be sensitive to in regards to food. Overall, this information can be used to accommodate them so that their food intake can increase even during treatment to lower malnutrition rates commonly seen in cancer patients.(Kim et al., 2019).

I found this paper quite intriguing because it showed how certain conditions in life can impact what you do or don’t want to consume, therefore changing one’s taste preference. I never took the time to think about how changes in taste preference can impact health in several ways. There are so many other fields to explore preferential changes in taste anywhere spanning from general aging to food neophobia in autism spectrum disorders. Wow, who would have that a simple activity would unravel such a deep avenue of thought?!

 

References

Andre, F., Mazouni, C., Hortobagyi, G. N., & Pusztai, L. (2006). DNA arrays as predictors of efficacy of adjuvant/neoadjuvant chemotherapy in breast cancer patients: Current data and issues on study design. Biochimica et Biophysica Acta (BBA) – Reviews on Cancer, 1766(2), 197–204. https://doi.org/10.1016/j.bbcan.2006.08.002

DeSantis CE, Bray F, Ferlay J, Lortet-Tieulent J, Anderson BO, Jemal A (2015) Cumulative     logistic regression with food preference score as an ordinal variable was used to         compare the preference of BC patients and CTRLs. The analyses were adjusted for        age.1.International Variation in Female Breast Cancer Incidence and Mortality RatesCancer Epidemiology, Biomarkers & Prevention 24 (10):1495–1506

Keast, R. S. J., & Roper, J. (2007). A Complex Relationship among Chemical Concentration,       Detection Threshold, and Suprathreshold Intensity of Bitter Compounds. Chemical      Senses,32(3), 245–253. https://doi.org/10.1093/chemse/bjl052

Kim, Y., Kim, G. M., Son, S., Song, M., Park, S., Chung, H. C., & Lee, S.-M. (2019). Changes in taste and food preferences in breast cancer patients receiving chemotherapy: A pilot study. Supportive Care in Cancer. https://doi.org/10.1007/s00520-019-04924-9

Mattes, R. D., Arnold, C., & Boraas, M. (1987). Learned food aversions among cancer     chemotherapy patients. Incidence, nature, and clinical implications. Cancer, 60(10),2576–2580. https://doi.org/10.1002/10970142(19871115)60:10<2576::AID           CNCR2820601038>3.0.CO;2-5

Images

https://www.france-export-fv.com/Chips-Ketchup-Lays/en

https://www.france-export-fv.com/epages/6449c484-4b17-11e1-a012-000d609a287c.sf/en_US/?ObjectPath=/Shops/6449c484-4b17-11e1-a012-000d609a287c/Products/LP1269%5B2%5D

https://www.france-export-fv.com/epages/6449c484-4b17-11e1-a012-000d609a287c.sf/en_US/?ObjectPath=/Shops/6449c484-4b17-11e1-a012-000d609a287c/Products/LP1269%5B8%5D

https://www.yummylixlollipops.com/food-for-thought-the-5-basic-taste-categories/

https://en.wikipedia.org/wiki/Pinkwashing_(breast_cancer)

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the sky is more than blue

Posted on June 10, 2019 by | 2 comments

“Why is the sky blue?” The question that children love to ask. Frankly, I want to know the answer too. Before tackling this question, we need to answer the question, “What color is the sky?” To me, the sky’s the limit (pun intended). Today on this beautiful and sunny day, the sky is blue, but when it is cloudy and gloomy, the sky is grey. At night the sky is black with the presence of stars that are spread throughout the galaxy. The sky can present itself as a spectrum of colors. During sunrise it is a refreshing mixture of yellow, orange, and blue. During sunset, the sky is a gorgeous blend of the rainbow from royal purples to warm, sultry reds. The colors of the sky can vary depending on your location on Earth. For example, during the northern lights, it is an array or colors that light up the sky. There are numerous answers to what the color of the sky actually is, but these are just examples of how I see the sky.


However, the perception of color is really at the core of this question. When we think about how we perceive the color of the sky, the answer to this simple question becomes quite complicated. There are many different ways that people see different ranges of color. This is quite special because these experiences and qualities allow for us to experience the world quite differently. People with “normal vision” will perceive the sky differently than others with something such as synesthesia.

Based on my thought process to answer this question, I really dove into different ways people with synesthesia are different in terms of how they perceive the world. Synesthesia is a phenomenon in which people experience unusual percepts elicited by the activation of a sensory modality that is unrelated or a cognitive process (Safran and Sanda, 2014). It is truly fascinating that people experience the world in such a distinct and unique way.

The literature provides great resources to better understand how people with synesthesia process many different stimuli in the world. In a study by Itoh et al. (2019), the experimenters performed a Stroop-like test in individual with synesthesia. The Stroop test is a neuropsychological test to test the ability to inhibit cognitive interference that happens when the processing of a specific feature of a stimulus disrupts the simultaneous processing of a different stimulus (Scarpina and Tagini, 2017).  For example, one must say the color of a word and not the actual word itself. When the color of the word and the word itself differ, this task seems to become increasingly difficult. The authors did this with people with synesthesia, except with an auditory stimulus because some people with synesthesia relate a color and sound together. This was done to test the automaticity of pitch class with relation to color. They did this by presenting pitch class names (e.g., do, re, and mi) in font colors that lined up with their color sensations. These results showed that people with synesthesia had decreased time in identifying font color when the color was incongruent with their associated pitch class names, concluding that pitch-class synesthesia is a genuine type of synesthesia (Itoh et al., 2019).

Stroop Test

 

Synesthetes have been implicated to have a cross activation of visual areas that processes shape and color, supporting how visual stimuli lead to their unique perceptions of the world (Amsel et al., 2017). A review by Safran and Sanda (2014) took a look into how people with color synesthesia have varying associations in regards to perceptions, emotions, and consciousness. For example, synesthetes showed improved digit identification because each number is represented by a color, making a specific digit stand out. Some synesthetes experience their emotions and understanding through color, as shown in the review. An example that was shown was how a painting called “Vision” showed how the synesthetic painter drew out the visual experience of a needle puncture during an acupuncture session (Safran and Sanda, 2014).

“Vision” (Safran and Sanda, 2014)

 

To me, I would interpret it as a red splotch that could be blood. Clearly, my interpretation is far less poetic and meaningful when compared to the synesthete’s perception. Even within this review, the authors explored and reviewed many different ways that people with synesthesia navigate the world around them.

It is genuinely mind-blowing how the person on my right can interpret the world completely differently than the person on my left. I never would have imagined how a simple question like, “What color is the sky,” could be such an intriguing conversation starter.

 

References

Amsel, B. D., Kutas, M., & Coulson, S. (2017). Projectors, associators, visual imagery, and the time course of visual processing in grapheme-color synesthesia. Cognitive Neuroscience, 8(4), 206–223. https://doi.org/10.1080/17588928.2017.1353492

Itoh, K., Sakata, H., Igarashi, H., & Nakada, T. (2019). Automaticity of pitch class-color synesthesia as revealed by a Stroop-like effect. Consciousness and Cognition, 71, 86–91. https://doi.org/10.1016/j.concog.2019.04.001

Safran, A. B., & Sanda, N. (2015). Color synesthesia. Insight into perception, emotion, and consciousness: Current Opinion in Neurology, 28(1), 36–44. https://doi.org/10.1097/WCO.0000000000000169

Scarpina, F., & Tagini, S. (2017). The Stroop Color and Word Test. Frontiers in Psychology, 8.   https://doi.org/10.3389/fpsyg.2017.00557

Images

Media Library

https://study.com/academy/lesson/the-stroop-effect-in-psychology-definition-test-experiment.html

 

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Do we see as well as we think we see?

Posted on June 10, 2019 by | 2 comments

Picture of the sky over Pont du Gard

On the first day of Arts on the Brain, we were told to write freely about the prompt “What color is the sky?” I immediately remembered a podcast about a man, Guy Deutscher, who asked his daughter every day what color the sky is, and she didn’t answer blue. The podcast by Jad Abumrad and Jim Gleick starts off by talking about Homer and his lack of the word blue in his texts. It then goes onto talking about other old texts that don’t mention blue. It then goes into talking about the order that colors enter languages and says that blue is always the last one and that the theory was that it had to do with having the ability to make the color. They then talked about another person who brought a test to a group of people without the word for blue and that they had trouble identifying the blue box from green boxes. This seemed like proof that language impacts perception. They then got to Deutscher’s experiment with his daughter. They made sure that no one told her the sky was blue but made sure she did know the color blue. At first, she refused to answer the question about what color it was until one day she answered white and eventually she said blue. This seemed to answer why languages wouldn’t find it incredibly important to add a word for the color blue.

This made me wonder, how much does language impact perception? Do French people experience the world differently than I do? So many people speak more than one language here, unlike in America, and would that impact your perception as well?

Photo from https://theophthalmologist.com/fileadmin/_processed_/0/a/csm_0614-201-brain_b506a2a191.png

Broca’s and Wernike’s areas, outlined above, are two of the major regions associated with speech. The visual cortex at the back of the brain is where the majority of visual processing happens. At first, it appears that the visual cortex is so far away from the rest of the sensory processing and anything involving language. However, everything in the brain travels through multiple areas in the brain. Here is the path that light takes after entering the eye:

Photo from http://brainmind.com/images/VisualCortexOptic.jpg

Once the sight has been processed by the visual cortex, it then projects out to other regions of the brain.


Photo from https://nba.uth.tmc.edu/neuroscience/m/s2/images/html5/s2_15_10.jpg

Language and speech also move around to different regions like in the picture below.

Photo from https://michellepetersen76.files.wordpress.com/2015/06/redrawing-language-map-of-brain-neuroinnovations.png

With all of this and other information moving through the brain, it doesn’t seem super farfetched to me that language could impact our perception. Bhatara et al. (2015) showed that learning a second language would impact rhythm perception in native French speakers. Work by Ardila et al. (2015) shows that one region of the brain has to do with both recognition and adding a word to what you see. They also showed that this region connects with regions that play roles in thinking, categorization, and memory.

More recent research by He et al. (2019) compared color perception between Mongolian and Mandarin speakers. According to the study, both languages only have one word for light versus dark green. However, Mongolian divides light and dark blue into two different words while Mandarin only has one word for light and dark blue. They showed the subjects greens and blues and asked them to divide them into one of the 2 or 3 categories. They were then asked to sort the colors so that similar ones were together. The Mongolian speakers grouped the colors more closely together than the Mandarin speakers did. They also did an experiment where they timed how long it took the participants to find which color was different than the rest and found differences between the two groups. These experiments further show that language does have an impact on how we perceive color.

It would be interesting to find out if language or culture plays more of an impact on color perception. However, because the two heavily influence each other and are nearly impossible to completely separate, it would be impossible to know which plays a larger role. I would also be interested to know if language’s impact on color perception means that I would see artwork differently than a native speaker of a different language. Did all of the artists that we’re learning about in Arts on the Brain see their paintings differently than I do?  Would a bilingual person categorize colors according to their first language or the language they speak with the most color terms? Would common terms like light blue vs dark blue play a role or would they both be considered blue? I think the impact that language can have on perception is fascinating and will definitely keep it in mind the next time I’m looking at paintings in a museum.

Works Cited

Ardila, A., Bernal, B., & Rosselli, M. (2015). Language and visual perception associations: meta-analytic connectivity modeling of Brodmann area 37. Behavioural neurology, 2015, 565871. doi:10.1155/2015/565871

Bhatara, A., Yeung, H. H., & Nazzi, T. (2015). Foreign language learning in French speakers is associated with rhythm perception, but not with melody perception. [Abstract]. Journal of Experimental Psychology: Human Perception and Performance, 41(2), 277-282. doi:10.1037/a0038736

He, H., Li, J., Xiao, Q., Jiang, S., Yang, Y., & Zhi, S. (2019). Language and Color Perception: Evidence From Mongolian and Chinese Speakers. Frontiers in psychology, 10, 551. doi:10.3389/fpsyg.2019.00551

Radiolab – Why Isn’t the Sky Blue? [Jules Davidoff and Guy Deutscher] [Audio blog review]. (2018, January 2). Retrieved June 9, 2019, from https://www.youtube.com/watch?v=um6j_WRDggs

 

Pictures:

https://theophthalmologist.com/fileadmin/_processed_/0/a/csm_0614-201-brain_b506a2a191.png

http://brainmind.com/images/VisualCortexOptic.jpg

https://nba.uth.tmc.edu/neuroscience/m/s2/images/html5/s2_15_10.jpg

https://michellepetersen76.files.wordpress.com/2015/06/redrawing-language-map-of-brain-neuroinnovations.png

 

 

 

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Louis XIV’s Crib Was Cool, But Those Flowers Though

Posted on June 4, 2019 by | 4 comments

Now coming up on two weeks into my stay in Paris, I’m amazed at how much art seeing (and walking!) opportunities there are across the city. I went to the Palace of Versailles  this past weekend and learned a little bit more about myself in the process. The overall aesthetics of some of the rooms, like the Hall of Mirrors, were breathtaking. Throughout my time in France, the distinct architecture of everything still astonishes me. The fact that people could see a vision that combined order and beauty is a testament of the human ability. However, even though the palace exemplified all of these things with the added adventure of getting around, I still found myself more at peace and grounded in the presence of flowers. In a larger than life palace with years of French history intertwined in it, it was nothing compared to the gardens, random buildings’ intricate flower arrangements across town, and especially the unique paintings of gorgeous flower bouquet and sceneries that truly made me stop and smell the roses.

A random but greatly appreciated restaurant I came across while walking the Shakespeare and Company bookstore in the 5th Arrondissement of Paris.

I couldn’t imagine why the Palace didn’t resonance with me as much as moving through a museum did; it was kind of a museum in some respects. My sister was shocked to learn I didn’t have plans to go to the Palace before this past weekend. It had been one of her favorite places in France, and she expected me to have the same experience. Surprisingly, I didn’t get that overwhelming feeling of wonder and disbelief at the magnitude  that she and some of the people at the palace had. So, I started to research why do people have different aspects artistic expression that resonances with them more than others and came across the world of neuroaesthetics.

A map of the extensive grounds in the Palace of Versailles.

Neuroaesthetics is this field in neuroscience where researchers are trying to figure out what neural connections activate and interact while someone is having an aesthetic experience that causes joy or disgust (Belfi et al., 2019). The greater question of this field is exactly the question I was trying to answer: what makes something more appealing to one person opposed to another? The field has a large reach with questions like why humans  chose the mates that we do, why we decide on one consumer product over the other, and perception’s effect on how we communicate (Chatterjee and Vartanian, 2014).

Neuroaesthetics continues to shine light on subjects such as what neural networks are involved when we view visual art. One study did this looking at how perception paintings as aesthetically pleasing or not affected what brain networks and structures were activate or deactivated (Belfi et al., 2019). Previous research found that the default mode network (DMN) was active when the person viewed artwork they thought was more moving, so the study recorded the DMN with fMRI processing as participants examined 90 paintings at various time lengths (Vessel et al., 2012) (Belfi et al., 2019). They found more DMN activation while the participants viewed a painting they thought was aesthetically pleasing compared to non-aesthetically pleasing works (Belfi et al., 2019). More DMN activation could lead brain system to associate a pleasing reward to the stimulus leading to a strong emotional response (Belfi et al., 2019).

So, while the Palace was objectively amazing to witness in real life, my perception of the art was not as high as the ones in the Musee D’Orsay leading me to some conclusions that my DMN could have been less active.

The Hall of Mirrors at the Palace of Versailles. My favorite part of the entire experience with the sunlight glittering on the chandeliers.

The museum experience is also a big determinate when viewing art as well. One study had a group of people examine art in a museum in Vienna and in a computer program to see if the way in which people received art would change their perception of it and their memory of the art (Brieber, Nadal, and Leder, 2015). Those that experienced the art through the museum had better recall of the art they saw and found the art to be more “arousing and pleasing” (Briber, Nadal, and Leder, 2015). So, there is the possibility that, in addition to a pretty weak DMN response, actually being in a museum where I expected to see this great art colored my perception of the paintings there compared to the palace’s paintings. The palace’s paintings I saw was great, but the palace did not support the type of art enjoying experience that a museum did. The participants in the study could stop and absorb a work as much as they wanted to much like my experience in the Musee D’Orsay: wandering around not knowing which work would capture me (Briber, Nadal, and Leder, 2015). This might have made the difference in my perception of the Palace as a whole.

It is pretty cool that even though we have the same brain systems activated with the aesthetically pleasuring figures, our internal states as well as the manner in which we consume art affects what we consider to be life changing pieces of art. I didn’t expect to stumble upon a whole section of neuroscience that I never encountered before to understand why Louis XVI’s chambers did not stimulate my DMN as much as Monet’s 1878 Chrysanthemums painting could.

Monet’s Chrysanthemums painting done in 1878. One of my many favorites by my favorite artist.

If you want to learn more about the neuroaesthetics, Anjan Chatterjee is a cognitive neuroscientist that specializes in neuroaesthetics with research on how “certain configurations of line, color, and form” affect what humans consider to be beautiful (“Anjan Chatterjee: How your brain decides what is beautiful | TED Talk,” n.d.) . He talks all about his study in this 2016 Ted Talk.

From what I’ve learned in my research, your surroundings have just as much to do how you perceive the beauty as your brain networks do. Appreciation of art is never linear, so even if something doesn’t elicit a strong DMN engagement, it’s can still be a great experience, nonetheless.

Next stop, fingers crossed, the Catacombs!

References

Anjan Chatterjee: How your brain decides what is beautiful | TED Talk. (n.d.). Retrieved June 4, 2019, from https://www.ted.com/talks/anjan_chatterjee_how_your_brain_decides_what_is_beautiful

Belfi, A. M., Vessel, E. A., Brielmann, A., Isik, A. I., Chatterjee, A., Leder, H., … Starr, G. G. (2019). Dynamics of aesthetic experience are reflected in the default-mode network. NeuroImage, 188, 584–597. https://doi.org/10.1016/j.neuroimage.2018.12.017

Brieber, D., Nadal, M., & Leder, H. (2015). In the white cube: Museum context enhances the valuation and memory of art. Acta Psychologica, 154, 36–42. https://doi.org/10.1016/j.actpsy.2014.11.004

Chatterjee, A., & Vartanian, O. (2014). Neuroaesthetics. Trends in Cognitive Sciences, 18(7), 370–375. https://doi.org/10.1016/j.tics.2014.03.003

Vessel, E. A., Starr, G. G., & Rubin, N. (2012). The brain on art: intense aesthetic experience activates the default mode network. Frontiers in Human Neuroscience, 6. https://doi.org/10.3389/fnhum.2012.00066

Image #2: [Screenshot of the grounds at the Palace of Versailles]. Retrieved from https://www.google.com/maps/place/Palace+of+Versailles/@48.8047375,2.1106368,15z/data=!4m5!3m4!1s0x0:0x538fcc15f59ce8f!8m2!3d48.8048649!4d2.1203554

Image #1, #3, and #4 were taken by me

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Watch your step!

Posted on June 8, 2015 by | 4 comments

Dear Friend,

The phrase “Attention à la marche en descendant du train” echoed through the platform as I grabbed my bag and stepped from the train. Ready to explore the beautiful, world-renowned city of Paris, I proudly raised my head and firmly stepped forward with intent. However, I couldn’t help but ask two very important questions. Where am I, and where can I find the delicious food?

Thoughts of savory crepes, warm baguettes, and chocolate-filled croissants distracted me during my voyage, somehow causing me to step off at the wrong station. I stopped and unfolded my pocket metro map, promptly realizing my disorientation landed me somewhere in the center of the complex Parisian underground maze. I wondered how I lost track of time so fast by simply staring through the window of the train. I was practically blinded by my quest for French desserts, but just about ready to go back home to Cité Universitaire.

map

In the two subsequent weeks that zoomed by, I paid much closer attention to my surroundings. Though I indulged in wonderful Parisian delicacies, and adapted to the city life, I also started perceiving my environment with more respect for sensory information. Doing so kept me from getting lost and allowed me to focus more. This habit greatly coincided with our neurosciences classes that started focusing on the brains interaction with bodily functions like motion, vision, and hearing.

With my senses primed, I took note of Paris’ every little detail, and learned how to travel as an expert tourist and passenger, exploring what Paris has to offer both above and below ground.

Above ground, I saw beautiful gardens and remarkable architecture. I experienced the jostling waves of the Seine while on a boat tour, and got dizzy staring up at the Eifel tower. I also heard countless sirens, and noticed pedestrians don’t care about traffic lights.

Below ground, I listed to musicians perform inside metro hallways and I watched entertainers dance in moving trains, all accompanied by the hum of bustling crowds and the sound of screeching metal pressing together to slow down trains. In this wild sub-terrain, I also noticed that closing automatic doors don’t care about rushing passengers, and warnings of “attention à la marche” exist for a reason.

train1Some things however literally caught my eye. As I stared outside of a train window one day, I caught a short glimpse of a nearby pole while we zoomed by. This was strange considering how slow and peaceful the buildings and scenery in the background passed by. I looked more closely, noticing the tracks below the train and the platform steps to the side of the train, moved incredibly fast while the landscape a few hundred meters out barely seemed to move at all. At this speed, the steps were actually dangerous!

 

I realized my mind must be playing tricks on me since the train was moving at the same speed compared to the ground, shared by both the tracks and the landscape. A few days later, I noticed this effect again at the roundabout circling the Colonne de Juillet at the Place de la Bastille (a great monument, see link 1)where cars near me seemed to move faster than those furthest away. I wanted to know more so, like any student investigator, I decided to search and see if neuroscience could provide and answer to this puzzling question.

Bastille

Screenshot at Bastille from GoogleMaps

The above process, called motion parallax. is a visual cue that signals depth where objects that are closer appear as if they move further across the visual field, while those that are farther away move less (Kim et al., 2015)

 

A recent study by Kim et al. (2015) looks at the neuroscience behind this cue and explores a specific area of the brain called the middle temporal (MT) area that could be responsible for the perception of depth from motion parallax. Although another study by Nadler et al. (2008) found that this part of the brain carries information about depth, it was not necessarily clear what kind of information was transmitted. The data from Kim et al. (2015) fill this gap by hypothesizing that the MT specifically carries information about the perception of depth.

The experimenters take two male monkeys, trained to respond to dots they see on a screen, and set them up with recording devices for their eyes. Researchers then fix the monkeys with electrodes in their MT areas, located by the use of MRI imaging. Finally, testing involves placing monkeys on a motion platform where the monkeys’ eye movements and brain signals provide computer-collected data.

The results from Kim et al. (2015) show that the MT will actually predict a monkey’s decision regarding its perception about depth. This paper gives a lot of support to the field of neuroscience because it reveals more information about the MT with sound methods.

The study finds that the MT further contributes to the perception of depth but it does not show that the area is entirely responsible perception. Although very recent, this article comprises one train-cart in a long train of studies on the MT. It lacks particular novelty and demonstrates that there is still much to learn about vision and the brain. Research in animals should definitely continue, but it would find it very interesting blend more than one study to find bigger applications. For example, Nawrot and Stroyan (2012) show that humans require about 30ms to detect depth from motion parallax. What if scientists could use deep brain stimulation (DBS) in the MT to provide brain enhancement for car accident prevention? I am incredibly excited for this research to continue.

Through my city travels, I hope to walk down the beautiful streets of Paris and remember that neuroscience allows me to navigate safely and effectively. My time in Paris is showing me that even though life has twists and turns, senses are needed to make “sense” of them (pun intended). I hope one day, a breakthrough in research and technology will allow us to better watch our steps!

References:

Kim HR, Angelaki DE, DeAngelis GC (2015) A functional link between MT neurons and depth perception based on motion parallax. J Neurosci 35:2766–2777 Available at: http://www.ncbi.nlm.nih.gov/pubmed/25673864 [Accessed June 8, 2015].

Nadler JW, Angelaki DE, DeAngelis GC (2008) A neural representation of depth from motion parallax in macaque visual cortex. Nature 452:642–645 Available at: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2422877&tool=pmcentrez&rendertype=abstract [Accessed June 8, 2015].

Nawrot M, Stroyan K (2012) Integration time for the perception of depth from motion parallax. Vision Res 59:64–71 Available at: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3349336&tool=pmcentrez&rendertype=abstract [Accessed June 8, 2015].

 

link 1 http://www.discoverfrance.net/France/Paris/Monuments-Paris/Bastille6.shtml

link2 http://psych.hanover.edu/Krantz/MotionParallax/MotionParallax.html

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Put on Your Dancing Shoes

Posted on June 25, 2013 by | 1 comment

Last Friday, we had the incredible opportunity to be a part of Paris’ Fête de la Musique, a celebration of music in all its forms. Starting in the evening and lasting well into the next morning, the festival brings thousands of musicians to hundreds of bars, clubs, courtyards, and street corners in all twenty of the arrondissements of the city. Everyone crowds the streets to celebrate, and there is music wherever you turn; oftentimes musicians are so close that you can actually hear multiple performances simultaneously. As the night went on, we found ourselves immersed in an environment filled with new friends, loud music, and lots of dancing. We danced alongside the Parisians to club electronica, gritty rock, solo vocals, drum circles, and even American pop. The instinct to move in synchrony with the music was not only consistent across genres, but also ubiquitous among individuals. This final post of our trip aims to explore the profound and fascinating link between dancing and music.

Venues for Fête de la Musique 2013. A better question: where isn't there music?

One prominent theory to explain movement coordinated with music suggests that this type of synchronized movement simulates music production itself, which may have evolved as a method of social bonding (Levitin and Tirovolas, 2009). The importance of music as a type of honest, yet generalized, form of communication may have lead to activation of reward systems in the brain upon not only personal production of music, but imitating the production of music present in the environment. I personally tend to disagree with this hypothesis. Though I find actual production of music to be the most enjoyable of all, I do not necessarily feel that fingering along accurately to a piano lick is any more rewarding than flailing my entire body to the beat. Though my own personal experiences prove nothing, this theory of pleasure being derived from musical imitation tends to draw skepticism in literature on the topic, as it is not even clear that music is an evolutionary adaptation in the first place.

One of the festival's larger venues.

More recent research, however, takes a different approach to the question. Testing of both musicians and non-musicians suggests that moving to a beat actually enhances perception of the metrical structure (Su and Pöppel, 2012). The experiment that demonstrated this was actually fairly straightforward. Test subjects listened to rhythmic excerpts that maintained a constant tempo throughout and were instructed either to move to the music (e.g. foot-tapping, head-nodding, or body-swaying) or were told to sit still while they listened. Participants were also told to indicate what they felt to be the beat of the music by tapping their finger on the table in front of them. Once the music began, the researchers would occasionally silence the music at random on key beats, though subjects were instructed to continue tapping during these “dropped” beats. The accuracy of the placement of the dropped beat and overall consistency of tapping throughout the sequence were measured and compared between test groups, and researchers found significant improvements in both measures when the subjects were moving versus remaining still. Interestingly, this finding held true regardless of what the consistent tempo was. Whether at 60 beats per minute (the tempo of a very slow ballad) or at 210 bpm (well above the vast majority of music), synchronized movement enhanced understanding of the rhythmic structure.

Further characterization of movement-induced enhancement of beat perception found that this effect is only true of auditory stimuli, and in fact, movement impairs timing extraction in equivalent visual tasks (Iordanescu et al., 2013). This finding implies that synchronized movement may somehow bear a particularly special connection to our interpretation of sound. Could the fun of dancing arise from its ability to increase our sensitivity to rhythmic patterns? That may be what the research suggests. From soon after birth, humans have an innate desire for information and, quickly thereafter, an insatiable need to categorize (Perlovsky, 2010). This ability and, in fact, craving to classify our world has been referred to as the “knowledge instinct,” and this may explain why we so readily appreciate a more intensified and obvious pattern in our aural environment.

All of the rhetorical questions, personal musings, and references to psychological theory in this post are a testament to the real conclusion to this discussion: nobody actually knows why we like dancing so much. Indirect experiments and conveniently intuitive theories of selective pressure can only provide so much insight into the issue; so while science works on solving this highly urgent question, just enjoy the music and keep on dancing.

Dancing (if you can call it that) in Homo sapiens.

 

-Max Farina

 

References:

Iordanescu L, Grabowecky M, Suzuki S (2013) Action enhances auditory but not visual temporal sensitivity. Psychonomic Bulletin & Review 20: 108-114.

Levitin DJ, Tirovolas AK (2009) Current advances in the cognitive neuroscience of music. Annals of the New York Academy of Sciences 1156: 211-231.

Perlovsky L (2010) Musical emotions: functions, origins, evolution. Physics of Life Reviews 7: 2-27.

Su YH, Pöppel E (2012) Body movement enhances the extraction of temporal structures in auditory sequences. Psychological Research 76: 373-382.

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Musée du Louvre

Posted on June 11, 2013 by | 14 comments

The overwhelming feeling landing in Paris just a few short weeks ago can only be described as a combined wave of nervousness, anxiety and excitement.  I didn’t expect to feel that sensation again so soon, but walking into the Louvre brought the same, overwhelming rush. I was amazed by the architecture of the building and its’ perimeter and tried not to look like a typical tourist stopping to take pictures along every step of the way. After attempting to blend in with the crowd by buying some “French” coffee, we grabbed a map of the museum and (blindly) picked a starting point.

Musée du Louvre

We started with the Ancient Egyptian exhibit, which was confusing given the French descriptions mounted by all of the pieces. The intricacies of the hieroglyphics, artwork and tools, however, transcended the language barrier. After walking through, we were tired (we had climbed the Eiffel Tower earlier that day) and decided to head to one more piece before completing our day—the famous Mona Lisa.

Ancient Egyptian Art

Following the crowd, we made our way to the other side of the museum and quickly saw the international amalgamation surrounding this infamous painting. How is it that this one painting can draw so much attention from so many different people? Part of the interest in this picture lies in the mystery behind its creation—why did Leonardo da Vinci paint this picture? Who is the woman depicted here? Is she real? These questions are unanswered and add to the mystery associated with this artwork. One of the elements of this painting that interests people from across disciplines and countries is the ambiguity in Mona Lisa’s smile.  When we look at this infamous smile in the context of neuroscience, we should consider the role of visual perception. Visual perception in itself is a bridge between art and science, as this is the type of information processing that takes different visual stimuli from our environment and processes them into a “single”, interpretable unit. Visual perception is broken down into different elements such as visual closure, memory, form constancy, spatial skills and more (Chakravarty 2011). All of these factors contribute to how we perceive the outside world via our vision.

Scientists have taken this described cognitive approach to vision and have applied it to different areas of the brain. They have found that vision and interpretation of what we see relies on multiple brain areas. The primary visual area is referred to as V1, and next to this area are different, specialized regions such as V3 (recognizes the shape and size of an object), V4 (color perception) and V5 (essential in identifying object motion) (Chakravarty 2011).

The Mona Lisa

Taking a step back, it is clear that there are multiple parts of the brain with their own specific, intricate mechanisms that can affect the way faces and objects, for example the Mona Lisa, can be perceived and processed across any given population. The human visual system has allowed us to, over time, develop specific visual skills that correspond to face perception (Haxby et al., 2000). For example, individuals with brain damage in the ventral occipitotemporal cortex (an area in the brain associated with visual perception) have difficulty in recognizing faces—but can recognize objects with ease (Haxby et al., 2000). This condition, prosopagnosia, is one that supports the claim that there are very specific areas in the brain associated with face perception—perhaps providing a neurological reasoning behind the fascination with the Mona Lisa. The fact that this is a portrait of a mysterious face might be driving the worldwide fascination.

When actually getting a better look at the Mona Lisa after pushing through the crowds of people, the neuroscience student in me couldn’t help but wonder how many different neurobiological systems were working in order for me to appreciate this piece of art. I had to focus on the picture, discern the face from the background, take in account of the colors, recognize that this was a portrait, and attempt to make associations and recall what I had learned about this piece in my high school art class. Aesthetic preference is yet another factor that has significant neurological underpinnings. Cela-Conde (2011) found, through various neuroimaging studies, that certain areas in the brain (the hippocampus, parahippocampal gyrus and the amygdala) are all actively engaged when individuals are aesthetically pleased with a piece of artwork. When patients with neurological conditions (in which these areas degenerate) are presented with previously “pleasing” pieces of artwork, the patients show a completely altered taste and preference. This supports that these areas of the brain have some influence over the cognitive perception and appreciation of artwork. Similarly, studies have reported that damaging the amygdala (an area of the brain primarily associated with emotion) can alter artistic, visual preference. Individuals with amygdala damage generally expressed a liking for “…geometrical shapes, landscapes and color arrangements” when compared to the healthy, control groups (Cela-Conde et al., 2011).

Mona Lisa Selfies...

Perhaps the fascination with the Mona Lisa is brought about by the evolutionarily driven sensitivity to faces. Or, maybe there is a genetic predisposition in some of our brain’s visual areas to appreciate certain types of artwork. Some scientists even suggest that the ambiguity in her smile activates area V5, an area of the brain involved in perceiving movement, which enhances aesthetic appeal (Chakravarty 2010). Regardless of the reasoning, there are complex neurological mechanisms by which we process not only the Mona Lisa, but also every other sculpture, painting or realistically anything in our visual field. Visual perception in itself relies on cognitive theories and activation of various brain areas to yield some form of appreciation of art—now try not to think about that next time you go to a museum.

Written by: Noareen Ahmed

References:

Cela-Conde C, Agnati L, Huston J, Mora F, Nadal M (2011) The neural foundations of aesthetic appreciation. Progress in Neurobiology 94: 39-48.

Chakravarty A (2010) Mona Lisa’s smile: A hypothesis based on a new principle of art neuroscience. Medical Hypotheses 75: 69-72.

Haxby J, Hoffman E, Gobinni M (2000) The distributed human neural system for face perception. Trends in Cognitive Sciences 4: 223-233.

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