Now that the end of my time in Paris is right around the corner, I have realized that I would no longer be able to enjoy the beautiful and mouthwatering pastries that are sold all over the city.
Even if I stayed here for a longer period of time, I don’t think that I would ever say that I have had enough of the French pastries since I fell in love with them from day one (French food is great too, but I LOVEEE the pastries!!!). After reflecting on all the beautiful foods (mainly pastries) that I have tried with the aims of getting a last bite of the most delicious ones before I depart, I began to wonder about the way in which their pleasant appearance is reflected in my brain.
I have always liked to try different foods, yet there have been times when I have found myself disliking some based on their appearance (I know that we should not judge a book by its cover, but for the eyes of my stomach that is an important feature).
Based on all my experiences about pleasant and unpleasant appearance of foods, I decided to look into the literature of neuroscience to learn if food appearance had any impact on brain activity. I came across an interesting study on the activation of the orbitofrontal cortex (OFC) and the ventral pallidum (VP) from the presentation of food items to human participants. These areas were particularly studied since previous research observed their activation during food reward studies on animals like mice and monkeys (Smith et al., 2005; Izquierdo et al., 2004). You can see their location in the brain in the images below .
The study I found, conducted by Simmons et al. (2014), looked for the activation of the OFC and VP through fMRI imaging testing, where a machine scans and records brain activity by detecting changes in blood flow, of 22 participants while they completed a task (described below). The participants were all right-handed, native English-speaking healthy volunteers (12 males and 10 females between the ages of 21-39). The task that they completed while undergoing the fMRI scan consisted of rating the pleasantness of 144 food images that were presented on a screen inside the scanner. The rating was based on the question they were asked: “If given the opportunity right now, how pleasant would it be to eat this food?”
The way in which the participants provided their responses was by using a scroll wheel (similar to a regular computer mouse) to select the values outlined in a scale presented next to each of the food images. The participants were presented with a total of 144 high-resolution photographs of a variety of foods (from highly processed to natural fruits and vegetables) for 5 seconds each. In between each image, participants were asked to stare at a cross (+) that was presented on the screen for distinct amounts of time. In addition, to control for factors like hungriness, all of participants were scanned at the same time (6pm) and were monitored and fed a controlled meal 4.5 hours prior to the scan. The image below shows a representation of the task described and the scale for rating the foods that was used in this study.
The data collected from the study showed that both the left and right VP of the male and female participants had a positive correlation with the ratings of food pleasantness. This basically means that the higher the participant rated the image, the higher the activity of the VP was observed. In addition, the researchers also confirmed that the OFC region was also activated in a positive manner according to the ratings as it was previously described in animal studies (Izquierdo et al., 2004).
I think that the data obtained from this study means that the activation of the OFC and VP human brain areas in the presence of pleasant foods (like the beautiful pastries I have been eating here in Paris) plays an important role on directing our food choices since we tend to pick the food we find pleasant over unpleasant ones. Maybe that’s why I keep recurring to the beautiful and yummy French pastries since my OFC and VP are most likely activated by their pleasant looks. It would be interesting to see the extent to which the activation of these areas directs food choices or see if these areas respond any differently when the same images are presented to people with eating disorders like anorexia nervosa, bulimia nervosa, and binge-eating. It would be really cool if by performing such studies, new treatments could be developed for those eating disorders.
Well that’s all I have to share for now. Thanks for reading, I hope you enjoyed the post! Now go treat your self (and your brain) with beautiful foods that you find appealing since that is exactly what I am going to do for the next couple of days. Bon appétit!
-Maria G. Vazquez
Izquierdo A, Suda RK, Murray EA.(2004) Bilateral orbital prefrontal cortex lesions in rhesus monkeys disrupt choices guided by both reward value and reward contingency. J Neurosci. Aug 25;24(34):7540-8
Smith KS, Berridge KC. (2005) The ventral pallidum and hedonic reward: neurochemical maps of sucrose “liking” and food intake. J Neurosci. 25(38):8637-49
Simmons WK, Rapuano KM, Ingeholm JE, Avery J, Kallman S, Hall KD, Martin A. (2014) The ventral pallidum and orbitofrontal cortex support food pleasantness inferences. Brain Struct Funct. 219(2):473-83.