Halika, Kain Tayo!

For the great finale of this funny, wonderful, totally amazing blog, we decided to do a legitimate study on one of the five senses in the body: taste.

A lot of research goes into food. This is typical, as food is one of the basic human necessities. From childhood, the four basic tastes taught by the basic education system is: sweet, sour, salty, and bitter. There’s a new taste in town however, and it’s called umami. It’s still a little bit controversial, in the sense that some people still refuse to recognize it as a basic taste. Umami is a Japanese word, meaning savory.

Through these four basic tastes, a lot has been discovered. The chemicals that can provide these tastes, the taste receptors that recognize these tastes, and from which specific cortex the tastes are recognized in the brain. Perception psychology has contributed a lot to data regarding taste.

As psychology majors, it’s our job to be able to think up of new ways of researching for more data on food, like figuring out which factors or social constructs are able to affect the way we perceive food. After all, we Filipinos take pleasure in eating with others, even when all we have are two hands and one big banana leaf in front of us. Food just seems so much tastier with great company, which is why we never hesitate to go to the next fiesta spread or to go try new restaurants with the barkada. Eating with friends is a way to celebrate our ups and downs in life as well, whether it’s pigging out after passing a hard exam or comfort eating together after a bad breakup. Since previous research indicates that moods always affect your perception of things, we decided to research on the effect of mood and relationship closeness on taste perception, namely for the sweet taste in cookies.

A well-timed study, considering that Christmas feasts will be starting soon.

In our environment where everything happens, any event that catches our attention might influence and change our moods. Mood is a "general and pervasive feeling state that is not directed toward a specific target” (Wood, Saltzberg, and Goldstampt, 1990) which occurs as a response to situations that happen in the environment (Isen, 1984). On the other hand, relationship closeness is pretty similar to our concept of kapwa. It’s when our representation of the self or ‘me’ as being a part of our representation of others. So the higher the relationship closeness, the greater the overlap between the ‘self’ and ‘others’(Aron & Fraley, 1999).

Previous research has already shown that we tend to eat more when we’re around other people, especially if it’s people that we know (Hetherington, Anderson, Norton, & Newson, 2006). While that doesn’t necessarily mean that we taste differently when we’re around other people, research has also found that eating chocolate together with someone else enhances how much we like or dislike the chocolate (Boothby, Clark, & Bargh, 2014). As for mood, depressed people tend to taste sweetness and bitterness more intensely after feeling a positive or negative mood (Platte, Herbert, Pauli, & Breslin, 2013). But is this true even for the non-depressed?

For our experiment, we looked for 120 volunteers from the Psych 101 subject pool. Days before our actual data gathering schedule, we posted several sign-up sheets for an experiment entitled COOKIE MONSTER (we even drew a cute Cookie Monster on it) on a bulletin board near the classrooms hoping that the students would be interested in participating. Luckily, throughout our data collection we did not have any problems looking for participants (in fact the challenge was how to accommodate all the students who wanted to walk-in). In the end we only had time and research participation credits for 124 participants but at least it's 4 more than our initial intended number.

Cookie says Hi!

For our experiment, we looked for 120 volunteers from the Psych 101 subject pool. Days before our actual data gathering schedule, we posted several sign-up sheets for an experiment entitled COOKIE MONSTER (we even drew a cute Cookie Monster on it) on a bulletin board near the classrooms hoping that the students would be interested in participating. Luckily, throughout our data collection we did not have any problems looking for participants (in fact the challenge was how to accommodate all the students who wanted to walk-in). In the end we only had time and research participation credits for 124 participants but at least it's 4 more than our initial intended number.

Upon arrival outside the experiment room, we asked the participants if they came with a friend or if they signed-up for a solo/stranger slot. Of course, being the sigurista experimenters that we were, we re-checked and quantified the relationship levels of the participants using both a qualitative (small talk while waiting for their turn) and a quantitative method (Person Scale & Interpersonal Solidarity Scale which was administered in the middle of the experiment).

Our actual experiment involved 8 phases that would take about 20-30 minutes in total. A pretty good cover-up story was also used to divert the attention of the participants from guessing our real research objective and to justify the fact that they had to eat the cookies provided while inside the room. Don’t worry; we debriefed our participants before letting them go so there was no harm done besides that of the minimal deception.

We told our participants that we wanted to see how a shared experience, like watching a video, affected their perceived closeness to each other. The mood scales were there, we said, just so that we could check if they were feeling any extreme emotions that could affect the results. As for the cookies, they were told that they were actually free cookies provided by our sponsors!

Anyways, going back to the experiment procedures, the first thing we did upon the arrival of the participants was to give them a consent form and to instruct them about what they would do. Once they agreed to participate, we administered the PANAS-X test to determine a baseline of their moods. Since in this research we are looking at the effects of mood and relationship closeness on taste perception, after they have answered the aforementioned scale, we presented them with either a happy video or a sad video to alter their moods. For the happy condition, we used one of the impossible challenges try not to laugh videos you can find in YouTube. In the same way, we used 2 Thai insurance commercials (those that make the ninjas inside the room cut onions…) from YouTube to induce the sad mood. Ok, so now the question is whether the videos worked. Statistical analysis showed that the videos were effective, so effective in fact that during the experiment the participants were either laughing their hearts out or trying to stifle their tears.

Impossible Challenge

My Dad is a Liar

Silence of Love

      
So now comes the cookie. Each participant was given one cookie to eat while they watch the video. The cookies provided were homemade and baked the day before the experiment. We altered a cookie recipe readily available online to make them taste less sweet and we removed the chocolate chips and nuts so as to make the cookies as simple as possible. You can find the actual recipe we used to for the cookies before the references part of this blog. You guys should try it sometime especially if you are fond of not too sweet desserts.

PANAS v. 1

Once the participants have finished watching the videos (and ideally eating the cookie), they were given the Interpersonal Solidarity Scale and the “Person Scale” to quantitatively measure the participant’s closeness. Then the participants were asked to answer the PANAS scale again but in a different presentation so as not to make them realize that they are answering a form identical to the one given previously. Finally they were asked for feedback on the video and the cookie.

PANAS v. 2
*Would you believe that these two are actually identical?

The Person Scale

When we searched the vast ocean of research, we found several studies that stated being happy increased the perception of sweetness (Boothby, Clark, & Bargh, 2014;Platte, Herbert, Pauli, & Breslin 2013). Unfortunately, it was not to be. There are, after all, other studies that did not obtain a significant perception of sweetness (Dichter et al., 2010), and ours happened to be one of them. Perhaps Filipinos are just so accustomed to sweet cuisine, that it affected our perception of sweetness.

We did find some pretty interesting (and sometimes unexpected) results though. In fact, there was a positive effect of mood induction and relationship closeness on bitterness. This means that those who felt happy and were with a friend actually sensed bitter tastes more accurately. As unusual as it may seem, we also found out that individuals who are with their friends perceived sourness when the positive mood is induced. This might be because an enhanced state of arousal when mood was induced. A similar case happened in Platte, Herbert, Pauli, & Breslin’s (2013) study, wherein they obtained significant sourness scores for both happy and sad conditions! We postulate that while arousal does happen when one is happy or sad, one may become more aroused when happy as compared to sad. There was also an significant interaction between relationship closeness and mood, which affected sour scores. In a way, this wasn’t all that surprising. We do tend to experience greater feelings of excitement when other people are around, especially when they’re people we know.

There still seems to be a long road ahead. Sometimes sweetness doesn’t significantly increase when we’re happy. Maybe we tend to be more sensitive to bitterness when we’re with a friend. Either way, we must continue to search for the tasty truth.

Cookie Recipe

Ingredients:
  2 ¼ cups all purpose flour
  ½ teaspoon baking soda
  ½ teaspoon salt
  1 cup softened butter
  ¾ cups granulated sugar
  ¾ cups packed brown sugar
  1teaspoon vanilla extract
  2 large eggs

Combine flour, baking soda and salt in a small bowl. Beat butter, granulated sugar, brown sugar and vanilla extract in a large mixing bowl until creamy. Add eggs, one at a time, beating well after each addition. Gradually beat in flour mixture.  Drop by rounded tablespoon onto ungreased baking sheets. Finally bake for 9 minutes or until golden brown.

References:

Aron, A., & Fraley, B. (1999). Relationship closeness as including other in the self: Cognitive
underpinnings and measures. Social Cognition, 17(2), 140–160.
doi:10.1521/soco.1999.17.2.140

Boothby, E. J., Clark, M. S., & Bargh, J. A. (2014). Shared experiences are amplified.
Psychological science, 25(12), 2209-2216.

Hetherington, M. M., Anderson, A. S., Norton, G. N. M., & Newson, L. (2006). Situational effects on meal intake: A comparison of eating alone and eating with others. Physiology & Behavior, 88(4-5), 498–505. http://doi.org/10.1016/j.physbeh.2006.04.025

Isen, A. M. (1984). Toward understanding the role of affect in cognition. In Sedikides, C. (1992). Changes in the Valence of the Self as a Function of Mood. Personality and Social Psychology Review, pp. 271-311

Platte, P., Herbert, C., Pauli, P., Breslin, P. A. S. (2013) Oral perceptions of fat and taste stimuli are modulated by affect and mood induction. PLoS ONE, 8(6):e65006. doi: 10.1371/journal.pone.0065006

Wood, J.V., Saltzberg, J.A., & Goldstampt, L.A (1990). Does affect induce self-focused attention? In Sedikides, C. (1992). Changes in the Valence of the Self as a Function of Mood. Personality and Social Psychology Review, pp. 271-311

Photo Credits:

[Photo of a painting of a Filipino family having dinner]. Retrieved from http://static.squarespace.com/static/5411d80ae4b02fc94fefce4a/5457e7a5e4b06c364300fd00/5457e901e4b06c3643013042/1291127341000/G00003.jpg?format=original

Personality and the Senses

When people think of Psychology, one of the first words that usually pop-out is the term personality. In this case, why not connect this concept with sensory perception? Luckily that is exactly what Ilona Croy and her team did in their 2010 paper entitled "Agreeable Smellers and Sensitive Neurotics - Correlations among Personality Traits and Sensory Thresholds". In their research they investigated on several of the more common senses such as smell, touch, and taste and one other less common, which is trigeminal (I would expound on these later). Generally, their study showed that agreeable people tend to have a better sense of smell, significantly enhanced trigeminal sensitivity in neurotic people, and an enhanced pain tolerance in highly conscientious people.

The personality dimensions of NEO-PI were used to determine the correlations between personality traits and sensory thresholds. It is a scale crafted by Paul Costa and Robert McCrae back in the 1970s when they were researching on how personality changes with age (Burger, 2011). The NEO-FFI that was used in the research conducted by Croy and her coworkers is an updated, shortened version of the original NEO-PI. It still consists of the five dimensions - Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism and their respective facets.

OCEAN and Facets

As for the senses studied by the researchers, they focused on chemosensory perception like olfactory, gustatory, and trigeminal. Olfactory is the sense of see while gustatory is for taste perception. Trigeminal, on the other hand, is a less common chemosensory channel that is closely associated with the perception of pain and temperature information in the skin (Purves, Augustine, Fitzpatrick, Hall, La Mantia, & White, 2012). More generally, it is responsible for the burning/stinging sensation typically felt when eating spicy foods or when detecting fires.

In the actual experiment, the researchers initially asked each participant to answer the NEO-FFI questionnaire before subjecting them to threshold testing. In order to prevent visual cues from prompting responses, each participant was blindfolded before starting the chemosensory testing procedure. Stimuli used for the tests include Carbon Dioxide for trigeminal, Phenyl Ethyl Alcohol for the olfactory, Citric Acid and Salt (NaCl) for the sour and salty tastes of the gustatory, and a small, continuous electrical signal for the pain perception.

After all the number crunching of the data collected from a total of 126 healthy subjects (41 men, and 85 women), and the necessary corrections the researchers found out that there is a small, but significant positive correlation between agreeableness (people perceived as kind, sympathetic, cooperative, warm, and considerate (Burger, 2011)), and orzo detection sensitivity. This means that although the effect is small, people who score higher in that dimension or the personality test tend to have more sensitive noses as compared to people who scored low in agreeableness. In addition to this, the same trend is found in neuroticism (characterised by anxiety, fear, moodiness, worry, envy, frustration, jealousy, and loneliness (Burger, 2011) and trigeminal chemosensory detection sensitivity. Conversely, there are no significant patterns found between extraversion, and openness to any of the perception taste used in the experiment.

Image Sources:

NEO-FFI

- http://www.psihoterapeutul.ro/wp-content/gallery/neo-ffi/neoffi2.jpg

5 Dimensions

- http://2012books.lardbucket.org/books/psychology-research-methods-core-skills-and-concepts/section_09/ef2ea72504412c1ca95aadcd08ca6c14.jpg

References:

Burger, J. M. (2011). Personality (8th Edition ed.). Belmont, California, United States of America: Cengage Learning.

Croy, I., Springborn, M., Lotsch, J., Johnston, A. N., & Hummel, T. (2011). Agreeable Smellers and Sensitive Neurotics - Correlations among Personality Traits and Sensory Threshold. (H. Matsunami, Ed.) PLoS ONE , 6 (4).

Purves, D., Augustine, G., Fitzpatrick, D., Hall, W., La Mantia, A.-S., & White, L. (2012). Neuroscience (5th Edition ed.). Sunderland, MA, United States of America: Sinauer Associates, Inc.

Tactile Illusion: An Explanation

Before anything else, check out this BuzzFeed video about how to trick your sense of touch:

Coolbeans, yeah? But the question is, how is it possible that we’re able to feel all these illusions even though we know we’re being tricked? Here are the scientific and psychological answers to those questions.

1.     1. Sound and Touch – the first illusion

In this first trick, the guy in the video is writing something on the chalkboard while hearing the scraping of the chalk on the board. Afterwards, he is asked to wear earplugs so he wouldn't hear anything. He reported to have felt like the texture was smoother than before. How is this possible?

This is actually possible due to the connections in our brain. We don’t feel the senses separately, we actually integrate the senses together in our brain. In our auditory cortex in the brain, which is right about here:

There is a belt surrounding the auditory cortex, wherein the integration of the senses of touch and hearing can occur. Hearing something and touching something at the same time is more likely to be associated with one another as well. The integration of senses happens in the brain. (Kayser, et. al, 2005)

However, it seems that the texture of the surface (whether rough or smooth) is an exception (Lederman, 1979). Other studies showed that haptic sense (or touching the object) actually overpowers the auditory senses in other characteristics but surface texture is more affected by auditory than haptic cues (Lederman, et. al, 2002)

2.     Imaginary String – Suggestion and Sense of Touch

Amazingly enough, this one can be explained with fatigue. The muscles on your fingers aren’t meant to stay that way, so once you start relaxing your finger muscles, they come back together. However, suggestion and sense of touch do come hand in hand.

In one research, it was found that a request made by the “toucher” to the “touchee” was more likely to be granted than if the “touchee” wasn’t being touched. This was in a restaurant setting, wherein the touchers were the customer service crew and the touches were the customers. The customers gave higher ratings to the service crew and gave bigger tips if they were touched than if they weren’t. The service crew would lightly touch the customer’s forearm. Unfortunately, it’s still unknown as to why this is the case today. All that’s known is that there’s a correlation between suggestion and touch in consumer behaviour research (Gueguen, Jacob, & Boulbry, 2007)

3.     Hot and Cold – Thermal Grill Illusion

For this trick, the woman puts her hands in hot and cold and then puts her hands in lukewarm water and describes the feeling as strange and confusing as to what the actual temperature of the warm water would be. Pushed further, it is something called the thermal grill illusion.

The thermal grill illusion is when you switch from hot to cold and cold to hot quickly and your brain gets confused about what sense to feel. Research shows that it’s actually more uncomfortable than feeling normal hot and cold (Bach, et al, 2011).

Why exactly do we feel this way? According to a recent research study which recorded the fMRI of people experiencing the Thermal Grill Illusion, the biggest influence in our brain (aka, the one most active during the experience) is actually the thalamus (Lindstedt, et al, 2011). The thalamus’ job is to regulate the senses and the body.

So why exactly is it important to study the reasoning behind the illusion? Well, there is this certain disorder called the cold allodynia, which makes a person feel like the normal cold is more painful than normal. Research has been conducted on the pain receptors before, but it’s much more data enriching and useful to know which parts of the brain are activated in healthy human beings in order to identify what could be going wrong in people with these disorders and what to prescribe or do with them.

4.     Dead man’s Finger – All in the Brain 

In this illusion, stroking the finger of another person managed to make your finger feel numb. Surprisingly, the answer for this question is more biological than psychological. According to research, it was found that the key to getting the “Numbness Illusion” to your brain is not the visual or the motor senses alone but rather is influenced by the tactile inputs in the primary somatosensory cortex (Dieguez, et al, 2009), thus making it a top down processing rather than a bottom up.

References:

Bach, P., Becker, S., Kleinböhl, D., & Hölzl, R. (2011). The thermal grill illusion and what is painful about it. Neuroscience letters, 505(1), 31-35.

Dieguez, S., Mercier, M. R., Newby, N., & Blanke, O. (2009). Feeling numbness for someone else's finger. Current Biology, 19(24), R1108-R1109.

Guéguen, N., Jacob, C., & Boulbry, G. (2007). The effect of touch on compliance with a restaurant's employee suggestion. International Journal of Hospitality Management, 26(4), 1019-1023.

Kayser, C., Petkov, C. I., Augath, M., & Logothetis, N. K. (2005). Integration of touch and sound in auditory cortex. Neuron, 48(2), 373-384.

Lederman, S. J. (1979). Auditory texture perception. Perception, 8(1), 93-103.

Lederman, S. J., Klatzky, R. L., Morgan, T., & Hamilton, C. (2002). Integrating multimodal information about surface texture via a probe: relative contributions of haptic and touch-produced sound sources. In Haptic Interfaces for Virtual Environment and Teleoperator Systems, 2002. HAPTICS 2002. Proceedings. 10th Symposium on (pp. 97-104). IEEE.

Lindstedt, F., Johansson, B., Martinsen, S., Kosek, E., Fransson, P., & Ingvar, M. (2011). Evidence for thalamic involvement in the thermal grill illusion: an FMRI study.

Ratatouille: That Sounds Sweet!

Whenever I watch Pixar’s Ratatouille, one of the most fascinating scenes was seeing Emile consume a grape and a piece of cheese while Remy describes the experience. While Remy describes a “creamy, salty, sweet” and “oaky nuttiness”, what I think is a low bass guitar plays softly in the background. As he describes “smooth, crisp, slight tang on the finish”, sweet percussion instruments create an ethereal sound. When Emile eats the two together, an explosion of color and an amalgam of sound occurs. While it may seem like the director Brad Bird used creative license here, he actually wasn’t off the mark. Contrary to popular belief, taste is a multimodal experience. This means that we recruit all 5 senses- hearing, taste, touch, smell, and sight- when we savor our food. In fact, the color (for example, red) can enhance the sweetness of let’s say, strawberries. It’s easy to see how vision or smell might influence taste, but what does hearing have to do with it?

Researchers have already established that we tend to use the same adjectives to describe music and our taste experience (Knöferle and Spence, 2012; as cited by Kontukoski, et al., 2015). For example, “sweet” ,”dry”, “light”, “soft”, and “crisp” are all words I’d use to describe an introductory Disney movie song and a good bag of potato chips. People also take these associations a step further. When musicians were asked to improvise musical theme from basic taste words like “sweet”, “salty”, “bitter”, and “sour”, certain words corresponded to certain musical patterns (Mesz, Trevisan, & Sigman, 2011, as cited by Kontukoski, et al., 2015). Take a look at the song Edeilwess, as sung by Captain Georg Von Trapp (Theodore Bikel) in Rodger and Hammerstein’s Sound of Music.

The flow of the song is consistent, slow, and soft. This was similar to the patterns created by the taste word “sweet”. On the other hand, take a look at the song Your Fault from Into the Woods (2014).

It seems erratic or dissonant as the different characters chirp in with often high-pitched voices. These sort of musical patterns were improvised under the “sour” category. Lastly, “bitter” improvisations were both low-pitched and legato, much like the Gregorian chanting seen at the beginning of The Hunchback of Notre Dame’s Hellfire.

People also link music to other words related to the basic tastes. For example, in Kontukoski, et al.’s (2015) study, people often used the words like “chocolate”, “tasty”, “dessert”, “velvety”, and “creamy” to describe a “sweet” musical piece- all words I’d associate with having a great experience savoring a decadent piece of chocolate cake. On the other hand, people used more “unpleasant” taste sensations when describing “sour” music, like “hard”, “pungent”, “strong”, and “burning”, among others.

Listening to certain kinds of music not only influence associations, but how we choose to act.   Kontukoski, et al. (2015) also asked their participants to mix a drink after listening to a piece of music. When people listened to “sweet” music, their drink had higher sugar content (including honey, mango juice, and pineapple juice). The reverse was found after listening to “sour” music; the drink had more sour ingredients with higher acidity (lemon and pineapple juice).

Dr. Frankenstein was probably listening to some weird music when he made his monster...

While all these things seem to occur in the vacuum of an experiment, these effects are also evident in a world where Top 40 songs are constantly blaring on as we eat at fast food joints. Music may seem like background noise as you concentrate on that juicy piece of chicken in front of you, but it may play a much more important role than many realize. For example, one study (Wang  & Spence, 2015) was set up in a wine tasting event with live classical music. When a high-pitched and fast Debussy piece was played, the wine was given significantly high acidity and low fruitiness ratings. However, the slower Rachmaninoff piece was given the opposite (low acidity, high fruitiness). This was true whether a person was given red wine, which tends to be sweeter, or white wine, which was made to be more sour and citrusy. Looking back on word-associations, this actually makes sense (you’ll have your explanation later, but I don’t want to spoil it for you …try figuring it out). 

They also tried seeing how music influences our experience of an all-time favorite of mine, chocolate (Carvalho, et al., 2015). This time, they used a Brazilian song- a song that wasn’t deliberately manipulated to modulate taste like in previous experiments. They found out that when the participants were told that the chef used the music as his source of inspiration for creating the chocolate, they significantly liked the chocolate more as compared to other conditions wherein they were not told as such. In fact, they enjoyed it so much that they were also the most willing to pay for it! It didn’t matter that the participants didn’t know who the chef was or were unfamiliar with the music, they nevertheless still enjoyed it. This honestly seems like an interesting marketing strategy. Could this be the end of an era where famous

Inspired by Cool for the Summer by Demi Lovato

people create fragrances with their name slapped on it, and the start of a new craze where chefs create mints dedicated to 5 Seconds of Summer’s new album? While it is an interesting proposal, the problem here is that by simply creating an air of likeability for the chocolate (“Wow! The chef handcrafted this chocolate because he was inspired by the music? This is special!”), this may have contributed to the participants’ tasting experience.

But what could be the reason behind these associations and preferences? One fascinating explanation is through the cognitive priming theory. Let us use the aforementioned Debussy piece to argue this case. Because we derive symbolic meaning (a fast pace and high-pitch is related to “sourness”) from the music we hear, we also activate information related to these terms (“sourness” strongly relates to “acidity”). When this happens, it becomes easier to access these ideas when we think about something.  So these associations ("Man, this drink sure has high acidity!") are what we retrieve as we taste and evaluate the wine.

I must end this post with a small word of caution: as with many crossmodal studies, we have yet to truly establish how the relationship between music and taste perception works. But while we can’t definitely say that food tastes better when accompanied by the right music (thanks to priming), it definitely wouldn’t hurt to try eating some French food while listening to the Ratatouille soundtrack.

Carvalho, F. R., Van Ee, R., Rychtarikova, M., Touhafi, A., Steenhaut, K., Persoone, D., & Spence, C. (2015). Using sound-taste correspondences to enhance the subjective value of tasting experiences. Frontiers in psychology,6.

Knöferle, K. and Spence, C. (2012), “Crossmodal correspondences between sounds and tastes”, Psychonomic Bulletin & Review, Vol. 19, pp. 992-1006

Kontukoski, M., Luomala, H., Mesz, B., Sigman, M., Trevisan, M., Rotola-Pukkila, M., & Hopia, A. I. (2015). Sweet and sour: music and taste associations. Nutrition & Food Science, 45(3), 357-376.

Mesz, B., Trevisan, M.A. and Sigman, M. (2011), “Taste of music”, Perception, Vol. 40 No. 2, pp.209-219.

Wang, Q. J., & Spence, C. (2015). Assessing the Effect of Musical Congruency on Wine Tasting in a Live Performance Setting. i-Perception, 6(3), 2041669515593027.