Tag Archives: five senses

Synesthesia: Can You Hear Colors?

What is it like to hear colors and see sounds – people who have synesthesia might be able to give a little insight into that. Imagine the world full of new possibilities, sounds, images, and tastes. The way you are able to perceive and sense nature is so different from everybody else. You can say that the sky tastes like plums. When you hear Vivaldi’s four seasons on the piano, vibrant colors appear from every possible direction, representing spring, summer, fall, and winter. You are able to differentiate months of the year by colors and different smells by taste. Some of these are just examples. If you are able to relate to any of them, you might have synesthesia.

What is synesthesia?

Synesthesia

Scientists consider synesthesia to be a neurological and perceptual condition. It comes from Greek words that represent ‘togetherness and sensation’.  It is quite extraordinary and brings a whole different understanding to what surrounds us. In fact, people who have synesthesia most often than not, embrace it. They do not want to ‘cure’ the condition, per say. To them, the world is full of tastes and colors and sounds, depending on their particular type of synesthesia, of course. That’s how they’ve always experienced the world. They understand that Monday to have a green color, but Saturday more of a purple one and it makes sense to them.

Imagine looking at the sun each and every day and seeing that it’s yellow and one day wakes up and realize it’s a bland gray. That’s what it would be like for a synesthetic to lose their sense and understanding of the world. They would not only be very confused for a long period of time. No, despite that, they’d probably also feel sadness and grief for the loss of all of the beautiful imagery, sounds smell and touch that they will never experience again.

It’s quite difficult to understand synesthesia without experiencing it. A sky that tastes like blueberries or colors appearing when you hear music? That sounds crazy to anybody who has not experienced it themselves. Synesthesia, however, is not limited to just these people though. A lot of researchers looked into synesthetic occurrences in the regular population. These studies found that many are actually able to experience synesthesia. Sometimes they don’t even realize they are doing it.

Perhaps, in order to understand it better, you should experience a little touch of what synesthesia can be. This is what scientists call the McGurk effect

The McGurk effect

For a very long time, researchers understood speech as an auditory perception only. Now know the McGurk effect where there is an interplay between auditory and visual stimuli in the perception of speech. It is somewhat an illusion. Scientists, Harry McGurk and John Macdonald coined the effect in their 1976 study. It seems to be that when speech is paired with visual stimuli, a very extraordinary multi-sensory illusion happens.

They achieved this surprising effect by making a recording of a person voicing a consonant. After that they put the recording with a face, however, that face was expressing a different consonant. When the voice recording was heard by itself, the participants recognized it for what it was. However, when McGurk and Macdonald paired the voice recording along with a face expressing an incongruent sound – the participants heard a different sound. That sound ended up being the combination of the voice recording and the visual face articulation. The McGurk effect shows an absolutely astounding example of multisensory integration and how both, visual and auditory information can integrate and result in a unified experience.

If you can imagine, a lot of researchers found the illusion quite interesting and attempted to replicate it with different populations and conditions. What they found was quite astounding. Summerfield & McGrath found in their 1984 study that the effect happens with the use of vowels and not just consonants. The McGurk effect is present in pre linguistic infants according to the 1997 study by Rosenblum, Schmuckler & Johnson. Astonishingly enough, the effect even worked across a variety of languages which Massaro, Cohen, Gesi and Heredia showed in their 1992 study.

Synesthesia and the McGurk effect

It seems that even people who do not have the condition fall for the McGurk effect. The effect is very strong. Even when you know what to expect from it, you still cannot change it. When you think about it, it makes sense. The world we live in is full of senses and a variety of experiences. We do not just perceive sound by itself, or cannot look at something in a complete silence. There is always an ongoing integration of senses that happens all around us. It is no wonder that sometimes in our lives we are able to experience a synesthetic episode.

Types of Synesthesia

Synesthesia can appear in a variety of forms and types. In fact, researchers have been able to find over seventy types of synesthesia. We characterize the different varieties by what type of sensation they are able to cause and where that sensation came from. Here are some of the more common ones:

  • Number-Form Synesthesia: those who have this type of synesthesia are able to perceive numbers as mental maps. That means that these people will put the numbers in certain positions in space that will form a mental map. Whenever a person thinks of a number, a mental map will appear in their mind. Francis Galton introduced this type in his ‘The visions of sane persons’ work.
  • Lexical-Gustatory Synesthesia: people with this type will experience different tastes that correspond to specific words or phonemes. Badminton could taste like mashed potatoes but suitcase will taste like a chocolate cake. Quite a fun type, this one!
  • Grapheme Synesthesia: this one emerges with perceiving numbers and letters as different colors. This is one of the most common types of synesthesia. Interestingly enough, different people experience different colors in association with numbers and letters. Some commonalities occur. Letter ‘A’ often appears red for some reason.
  • Personification: A variety of ordered sequences will show up as different personalities. For example, Friday can be a happy go-lucky girl who enjoys dancing while Monday is an angry and bitter old man. Do you see any connection with real life?
  • Chromesthesia: people perceive sounds as a variety of colors. There is a variety of different experiences within this type with some people only perceiving colors during spoken speech and others seeing them during musical pieces. This type is quite common among musicians.
  • Misophonia: this one is not a particularly nice type of synesthesia. People who have this type experience very negative emotions when it comes to sounds. Examples of experienced emotions can be anger, disgust, sadness etc. Fortunately, this is one of the rarer types and it happens due to a disturbance between the limbic system and the auditory cortex.
  • Mirror-touch-pain Synesthesia: these people will experience a sensation of touch when they see somebody else being touched. The pain type can experience pain in a similar way when they see somebody else in pain. Researchers have linked this particular type of synesthesia with mirror neurons and regions responsible for empathy in the brain.

There are many other types of synesthesia. If you think you might be experiencing synesthesia but did not find your specific type above, you can type in your symptoms into google search, and sure enough, there will be somebody else with similar symptoms.

Synesthesia: Diagnostic Criteria

Synesthesia

Up to this date, there is no clear cut method for diagnosing synesthesia. Certain criteria exist that specialists adopt in order to help with the diagnosis. Keep in mind, however, that some of the leading scientists and researchers do not follow these criteria. Despite that, it gives at least a little bit of guidance in diagnosing synesthesia.

Symptoms

  • Projection: people will see the sensations outside of their body (hearing sounds outside during a musical piece)
  • Memory: associations that the synesthetic has will stick with him and will often overpower new associations that he or she might experience in the course of a lifetime.
  • Involuntary: sensations happen without the control of these people
  • Emotion: sensations can be perceived either positively or negatively.
  • Duration: the perceptions have to be stable and unchangeable.

Synesthesia and the Brain

Synesthesia

The original cause for synesthesia is still unknown. Due to such a variation in types of synesthesia, it is quite difficult to generalize brain studies to all of the different types. The brain uses different parts of the brain for the processing of different senses, therefore, with such a large variety of synesthesia types, an involvement of different brain parts happens. Researchers have to study each type separately and see whether there are some similarities between them. Some studies reported the activity in the superior posterior parietal cortex in relation with the grapheme-color synesthesia. Both visual cortex and the auditory cortex are activated during the McGurk effect because we are both listening and seeing at the same time.

The consensus among scientists is that depending on the type of synesthesia, the brain regions responsible for that sense will activate. What we speculate is that the uniqueness of synesthesia comes from a different way of network connections within the brain. Baron-Cohen and colleagues mention the excessive quantity of neuronal connections in the brain of synesthetics. According to him, during normal perceptual experiences, we have different brain areas for different senses and a different perception. The connection between those areas is present but is restricted. However, when you have synesthesia, your brain develops more connections between different neurons. This makes the restrictions between the areas to disappear and leads to synesthesia.

Peter Grossenbacher, on the other hand, says that the feedback communications are not subdued in a way that it happens in normal perception. The information that is processed from areas responsible for high-level of processing is not able to come back to each signified area. Instead of different senses going back to areas responsible for single senses, they mix together, allowing synesthesia.

Ramachandran and Hubbard support the increase in neural connection theory, but they also add that it happens due to the fact that the pruning between different sensory modalities is decreased.

Pruning is the removal process of the synaptic connections and more neurons in order to enhance the work of already existing neural transmissions.

Synesthesia and Genetics

Some studies have found a genetic link with the development of synesthesia. Asher and colleagues claim there is a link between auditory-visual synesthesia and certain chromosomes. Due to previous research suggesting a familial trend and a genetic factor helping in the development of synesthesia, they decided to look at 43 different families who had it. They found four different types of loci that could cause the variation in brain development in the brain of those who have the condition. What is interesting is that one of the genes that they identified, might be important for pruning.

Thomsen and colleagues focused on different genetic components. This leads to a variety of scientists to believe that synesthesia occurs due to a combination of a variety of genes.

Famous people throughout history with Synesthesia

Synesthesia is more common than some people believe. In fact, a variety of famous people are believed to have had this condition.

  • Vincent Van Gogh: chromesthesia
  • Lorde: music –> color
  • Vladimir Nabokov: grapheme -> color
  • Pharrell Williams: chromesthesia
  • Stevie Wonder: chromesthesia
  • Billy Joel: chromesthesia, grapheme-> color
  • Duke Ellington: chromesthesia

Prevalence

As mentioned before, diagnosis synesthesia is quite difficult so knowing its prevalence can bring some challenges as well. Before people used to think that the condition is quite rare, however, nowadays we know that it is a lot more common. Simner and colleagues in their 2006 study investigated the overall population. They found that around 1% of the population have the grapheme-color type. Around 5% have some sort of type of synesthesia. Due to the difficulty of diagnosis, this could be a very low account of the overall numbers, however.

Synesthesia is very common and a lot of people might have it. Family members, friends, co-workers, and classmates. Even you might have some sort of type of synesthesia and not know about it!

What is MSG: Everything you need to know about this flavor enhancer

What is MSG and what is it used for? What is the relationship between MSG and the fifth flavor or umami? Should we avoid this flavor enhancer? In this article we explain everything about monosodium glutamate: With what other names this food additive is known, what foods contain it, its relationship with obesity, the Chinese restaurant syndrome, and we give you some advice.

What is MSG

You may have heard the word glutamate somewhere, but do not know very well what it is, or what it means. Sometimes we even get information of how bad it is but have no idea why. For example, we hear about the effects of foods with glutamate in our body. In this article, we will develop what you need to know about this amino acid.

What is MSG or monosodium glutamate? This substance, also known as MSG or sodium glutamate, is the sodium salt of glutamic acid (one of the most abundant essential amino acids in nature). MSG is a food additive, which provides the same “umami” flavor that we can find naturally in some foods. Chemically, they are the same. The food industry uses and commercializes monosodium glutamate as a food additive or “seasoning” to enhance the flavor of some foods.

MSG, by itself, does not have a pleasant taste. It is necessary to complement this substance with other foods so that it can enhance, harmonize, and balance the flavor of certain dishes, making them more appetizing.

What is MSG in foods? Monosodium glutamate combines very well with different foods: Meats, fish, vegetables, soups, sauces and contributes for these to have a more pleasant taste.

This additive has been considered non-toxic and safe if consumed in normal quantities. However, there seems to be a group of people who manifest symptoms, such as vomiting, nausea or diarrhea, when they consume foods prepared with MSG.

What is MSG and its relationship with “umami” or fifth flavor?

We all know the basic flavors of taste (sweet, bitter, salty and acidic). Well, in addition to these, we have to include the umami, the taste of monosodium glutamate. For many it may sound like something new or strange, however, it was identified as a flavor by Kikunae Ikeda in 1908.

This scientist investigated algae rich in umami and managed to isolate one of the components of these algae, MSG or Monosodium Glutamate.

“Umami” in Japanese, means “delicious” or “deep flavor” because, after eating it, the flavor remains in your mouth. In fact, it has such a pleasant taste that it encourages to continue eating more of that product.

  • We can learn to identify MSG taste by concentrating on the center of our tongue. The biologist Charles Zuker, determined in 2001 that the largest number of taste receptors specific for this taste are there, in the center of the tongue.

Surely, you have eaten foods that had this characteristic flavor, but since we do not have this word in our vocabulary, we simply describe it with either a “mmmm” or  “wow this is so tasty!” You may even have tried some pre-cooked food or bag snacks and commented, “I don’t know why but I can not stop eating it!”.

Even if you stop to think about it, there are various commercials, which indirectly allude to the properties of Monosodium Glutamate (MSG). They bet that “you won’t resist just eating one” or they warn you, suggestively, that “once you pop open the bag, you won’t be able to stop”.

What is MSG and what other names does it have?

Monosodium Glutamate is a flavor enhancer that appears on food labels in different ways. This amino acid receives different names, such as:

  • E-621
  • Hydrolyzed vegetable protein
  • Self-leavening yeast
  • Hydrolyzed casein
  • Hydrolyzed corn
  • Hydrolyzed Wheat Gluten
  • Proteins
  • Whey protein concentrate
  • Citric acid
  • Partially hydrolyzed whey
  • Hydrolyzed milk protein

What is MSG and what food contains it?

There are many other foods that contain monosodium glutamate added to generate this flavor and increase its consumption. We could consider it a sort of “trick” of the food industry to raise its income, increasing the demand for these “succulent snacks”:

  • Appetizers, fried foods, snacks
  • Cold meats and sausages
  • Pâtes
  • Olives, pickles, pickles …
  • Pre-cooked food
  • Instant soup
  • Frozen food
  • Prepared sauces and soy sauce
  • Junk Food (frozen pizzas, kebabs, hamburgers …)

What is MSG ?- MSG effects?  Relationship between MSG and obesity

Should you avoid MSG? After reading this article, the next time you go to the supermarket you will start reading the labels and you will find that MSG is everywhere in its E621 form.

Glutamate can affect us negatively when we exceed a certain intake. However, this is like with everything. If you exceed in eating fruit it can be negative for your health as well. Nothing is good in excess, therefore it is advisable to limit consumption.

Try not to get too caught up on this. It’s true that there is a relationship between MSG and overweight, but it doesn’t mean that monosodium glutamate is directly fattening. MSG’s relationship with obesity is as follows:

Consume high processed foods like snacks, junk food, pre-cooked food, etc:

  • One of the main characteristics of this type of food is that it is loaded with sugars and trans fats, which in turn make us feel not satisfied nor full. Apart from these additions, we might guess that MSG is also added to the mix, to make it more flavorful and increase our intake of the product. Thus, Monosodium Glutamate contributes indirectly to weight gain, but it isn’t alone. What really fattens us is the consumption of hypercaloric foods, especially if it is part of our regular diet.
  • Lack of self-control: There are people who are more controlled at mealtimes than others. As much as a food carries MSG and your brain asks you for more, we are owners of our actions. Therefore, it is up to us, and only us, to decide to eat only a portion or less. This is highly related to impulsive behaviors and the immediate gratification of a desire or need.

What is MSG and its relationship with Chinese food?- Chinese Restaurant Syndrome

What is MSG- Chinese Restaurant Syndrome

You may have heard about how Chinese food or products used can be detrimental to your health. Some things you have heard will be rumors or speculations. However, there is something that is real.

These restaurants have become common to produce certain symptoms that have been labeled part of the “Chinese Restaurant Syndrome”.

Something I want to clarify before is that these symptoms are a consequence of free-form amino acids.

  • Origin: It was first described by Dr. Kwok
  • Beginning: Appearance around 15-20 minutes of starting a meal prepared with MSG.
  • Duration: 2 hours
  • Symptoms:
    • Cervical hardening with pain radiating to both arms and back.
    • General weakness
    • Palpitations
    • Headache
    • Sickness

Dr. Taliaferro undertook an analysis of the situation in the Journal of Environmental Health, stating: “All competent international agencies agree that the normal and controlled use of Monosodium Glutamate does not pose a health hazard”.

The Committee of Experts on Food Additives of the World Health Organization,  Joint FAO/WHO Expert Committee on Food Additives (JECFA), the Scientific Committee for Food of the European Community, and the American Medical Association have expressed this on different occasions. Even the demanding US FDA has classified Glutamate as generally recognized as safe or GRAS substance in the same group as salt, pepper or sugar.

“There is no scientific evidence establishing that glutamate causes, in particular, severe adverse reactions or that  reactions from low concentrations pose a threat “- US FDA

What does this all say? There are people who are more vulnerable or sensitive to MSG. The best thing is to do is to control consumption and not eat large quantities of food containing this product.

What is MSG-Recommendations

Health seems to be the key to the survival human beings. We aim for stability, good habits, superb cognitive skills, physical and brain training routines and a balanced diet. With MSG it’s the same, to be healthy just try to consume it with moderation and always within a balanced diet.
On the other hand, knowledge is power and, with food, it is very important to know what you are eating. We have already seen what other names MSG has on labels, therefore, it is your decision if you want to ingest it or not.

Anyway, these are our conclusions. You can contribute more information if you like. What do you think? Have you suffered any of the Chinese restaurant syndrome symptoms? Have you ever heard of Monosodium Glutamate? Do you know any myths or truths about this amino acid? Just remember are what we eat.

As always, I invite you to comment below!

This article is originally in Spanish written by Patricia Sanchez Seisdedos, translated by Alejandra Salazar.