1 of 9 Spanish Neuroscientist Nazareth Castellanos, Researcher at NirakaraLab Laboratory and Professor at Complutense University of Madrid, Spain — Photo: Personal Archive via BBC Spanish Neuroscientist Nazareth Castellanos, Researcher at NirakaraLab Laboratory and Professor at Complutense University from Madrid, in Spain — Photo: Personal archive via BBC
How is your body as you read this report? Upright or curved? And your face, is it relaxed? Or are you frowning?
Our posture and face send important signals to the brain, and it’s information that our brain responds to, explains Spanish neuroscientist Nazareth Castellanos, a researcher at the NirakaraLab Laboratory and a professor at the Complutense University of Madrid in Spain.
“If I make an angry face, the brain interprets this face as typical of anger and thus activates the anger mechanisms,” says Castellanos.
Likewise, “when the body is in a posture typical of sadness, the brain begins to activate neural mechanisms typical of sadness.”
Our brain interacts with the rest of the body in many more ways than previously thought.
Because “we don’t just have five senses we have seven,” says the scientist. And the five bestknown senses — smell, sight, hearing, touch, and taste — “are least important to the brain.”
Nazareth Castellanos spoke to BBC News Mundo, the BBC’s Spanish service, about how posture and facial expressions affect the brain, the power of a smile and what we can do to learn to listen to “the whispers of the body”.
BBC News Mundo: How did you start studying the relationship between posture and the brain?
Nazareth Castellanos: After 20 years of just studying the brain, I started rethinking neuroscience.
It struck me as odd that human behavior relied on only one organ, and that was the head.
Before that he had started to study the influence of organs such as the intestine on the brain. And he said, “For the brain, it can’t be the same whether my body is bent or whether my body is upright.”
So I started researching to see what the scientific literature says. I discovered things that seemed absolutely amazing to me, and I thought, ‘Everybody needs to know this.’
BBC: Then can you explain to us why posture is important and how it affects the brain?
Castellanos: It is important to understand that neuroscience already recognizes that we have seven senses.
We were always taught in school that we have five senses smell, sight, hearing, touch and taste which are the senses of exteroception.
And that’s very symbolic, because until now science has been more interested in studying the relationship between people and the outside world.
Now, for about five years, neuroscience has been saying that this needs to be expanded.
We don’t just have five senses, we have seven. And it turns out that the five senses of exteroception hearing, etc. are least important. Number one, the most important sense, is interoception.
2 of 9 The two most important senses for the brain are interoception and proprioception — Photo: Getty Images via BBC The two most important senses for the brain are interoception and proprioception — Photo: Getty Images via BBC
BBC: What does interoception mean?
Castellanos: It is the information that reaches the brain about what is happening in the body. What is happening in the organs.
We talk about the heart, the breath, the stomach, the intestines. It’s purpose number one, because of all things that happen, it’s what the brain gives the most importance to, it’s a priority for the brain.
And second is the sense of proprioception, the information the brain receives about how my body is externally, what postures, gestures and sensations I have throughout my body.
For example, the sensations in your stomach when you are nervous, or a lump in your throat or heavy eyes when you are tired. Proprioception is the second most important sense. And then come the other five.
BBC: What does it mean to say that interoception and proprioception are the first and second senses (in order of priority) for the brain?
Castellanos: It was already known that the brain needs to know how the whole body is doing, but before thinking it was passive information, the change now is that it’s a sense. That is, a sense is the information that the brain receives and has to act on.
Depending on what’s going on, the brain has to act one way or another, and that’s the big change.
3 of 9 Woman frowning: “When I frown, I activate my amygdala,” says Nazareth Castellanos — Photo: Getty Images via BBC Woman frowning: “When I frown, I activate my amygdala,” says Nazareth Castellanos — Photo : Getty Images via BBC
BBC: In what part of the brain do we perceive our posture or gestures?
Castellanos: There is an area in our brain that is like a tiara, like the one you wear in your hair. It’s called the somatosensory cortex, and that’s where my body is represented.
It was discovered in 1952 and it was thought that the larger areas in our body had more neurons in the brain. So it was thought that the brain allocates a lot more neurons to the back, which is very large, than to my little finger, for example.
But it turns out that’s not the case, the brain gives more importance to some parts of the body than others, and the parts that the brain gives more importance to in the body are the face, the hands, and the curve of the body.
So my little finger has about a hundred times more neurons dedicated to it than the whole back, than the whole leg, because the hands are so important to us. Notice that when we speak, we use our hands, we activate these areas of the brain.
BBC: How do facial gestures affect the brain?
Castellanos: The brain attaches enormous importance to what happens in the face.
Things were observed here that are very important. On the one hand, it has been observed that when people frown and we often do this with smallscreen cellphones an area related to the amygdala is activated.
It is a part of the brain that resides in deep zones and is more involved with emotions.
When I frown, I activate my amygdala, so I’m more stimulated and responsive in a stressful situation because I already have that area ready.
The amygdala, which is like an almond, is an area that becomes more active when a stressful situation occurs.
So it’s an area that’s best kept quiet.
But if it’s already activated when a stressful situation occurs, it will hyperactivate, and this will provoke a hyperreaction.
Trying to relax that part, the frown, deactivates our amygdala a bit, it relaxes.
BBC: In a lecture you mentioned a fascinating study with pens showing how frowning or smiling changes the way we interpret the world. Can you explain this study to us?
Castellanos: Next to the muscles around the eyes, the mouth is the second most important part of the face for the brain. We have no idea the power she has, it’s impressive.
So what the studies did to test the facial feedback hypothesis is they took a group of people and put a pen in their mouths.
First they had to hold (the pen) between their teeth they simulated a smile but didn’t smile, which was the most important thing. And they were shown a series of pictures and had to say how beautiful they looked. When they had the pen in their mouth and simulated a smile, the pictures seemed more likeable to them.
4 of 9 study image Strack et al. 1988 shows that when they had the pen in their mouth to simulate a smile, the images appeared more likeable to viewers — Photo: Courtesy Nazareth Castellanos via BBC Image from the Strack et al study. 1988 shows that when they had the pen in their mouth to simulate a smile, the images appeared more likeable to viewers — Photo: Courtesy Nazareth Castellanos via BBC
But when they had the pen between their lips and simulated an angry face, the same pictures didn’t look as nice anymore. This is a study from the 1980s, but many, many studies have been done since then.
For example, it has been observed that when we see smiling people, we are more creative, our cognitive capacity increases, the neural response in front of a smiling face is much stronger than in front of a face that is not smiling or frowning.
The insula, one of the areas of the brain most involved in identity, is activated when we see someone smile or when we smile ourselves. Smiling isn’t laughing, it’s different. So we see the power that a smile has on us because, as we said, the brain devotes a large number of neurons to the face.
BBC: How does the brain react when we smile or frown?
Castellanos: As I said, proprioception the information that reaches the brain about how my body and especially my face is doing is information that the brain has to react to.
When I’m sad, when I’m angry, when I’m happy, my face reflects that, but also vice versa. When I have an angry face, the brain interprets “this face is characteristic of anger, so it activates anger mechanisms” or “this face is characteristic of calm, and therefore activates calming mechanisms”.
5 of 9 Image of a smiling woman: “The neural response to a smiling face is much stronger than to a nonsmiling or grumpy face,” says neuroscientist Nazareth Castellanos — Photo: Getty Images via BBC Image of a smiling woman: “The Die neural Response to a smiling face is much stronger than to a face that doesn’t smile or frown,” says neuroscientist Nazareth Castellanos — Photo: Getty Images via BBC
That is, the brain is always looking for what is called mindbody congruence.
And that’s interesting because what happens when I’m sad or angry or stressed and I start to put on a relaxed face? First the brain says “that doesn’t add up, she’s nervous but her face is relaxed”.
And then it starts to create something called mood migration. The brain says, “Okay, so I’ll try to match the mood with the face.”
In other words, look what resources we have.
BBC: You also talked about another aspect of proprioception, the curvature of the body. Nowadays we often lean forward with cellphones, how does it affect the brain?
Castellanos: The brain and this is a discovery of three months ago has an area dedicated solely to “reading” my posture.
It has been observed that there are postures that the brain associates with an emotional state. For example, if I wave my arms up and down, the brain doesn’t have a record that raising my hand is emotional because we don’t normally do that, right?
However, being stooped is characteristic of sadness, because when we are bad, we stoop. We’ve all been hunched over lately because, among other things, we spend eight hours a day in front of the computer.
“When the body is in a posture characteristic of sadness, the brain begins to activate the neural mechanisms characteristic of sadness,” says neuroscientist Nazareth Castellanos — Photo: Getty Images via BBC Woman “When the body is in a posture characteristic of sadness, the brain begins to activate the neural mechanisms characteristic of sadness,” says neuroscientist Nazareth Castellanos — Photo: Getty Images via BBC
BBC: Does that refer to a famous study that you mention in your lectures, the one on the computer?
Castellanos: A relaxed attitude affects our emotional perception of the world and our memory.
This is where a famous experiment came into play, in which a laptop was placed at the participants’ eye level and a series of words appeared one after the other.
At the end, the computer was closed and participants were asked how many words they remembered. (The researchers) did the same thing by placing the computer on the floor in such a way that it forced people to bend down.
What was observed? That people in the huncheddown position remembered fewer words, that is, they lost their memory capacity and remembered more negative words than positive ones.
That is, just like when we are sad, when we are not as cognitively agile and focus more on the negative side, when the body is in a posture characteristic of sadness, the brain begins to activate the neuronal mechanisms typical of sadness.
What does science tell us? Well, it’s not like you have to be one way or the other, but throughout the day, pay more attention to your own body and correct the postures we’ve adopted.
For example, I observe myself a lot and every now and then I find myself hunched over again. You correct it and over time you gradually pick less of the habit.
But if you don’t have the ability to observe your own body, you can stay like this for hours and not realize that you are like this.
BBC: So how do we train ourselves to listen to our bodies more? Usually they say that the body doesn’t scream, it whispers, but we don’t know how to listen to it.
Castellanos: I think the first thing to know about how our body is doing is learn to observe it. And studies tell us that a large part of the population has very low body awareness.
For example, whenever we feel an emotion, we feel it somewhere in the body; Emotions without the body would just be an intellectual idea.
There are studies that ask people: When you are nervous, where would you find that feeling in your body? Most don’t know how to answer because they’ve never stopped observing their own bodies.
The first thing I have to do is stop throughout the day and see how my body is doing. And when we feel an emotion, we stop for a moment and say: where do I find it? How does my body feel now? That said, do a lot more body watching.
7 out of 9 Nazareth Castellanos: “Antonio Damasio conducted many experiments observing that people with greater body awareness make better decisions” — Photo: Courtesy Nazareth Castellanos via BBC Nazareth Castellanos: “Antonio Damasio conducted many experiments observing that this was the case It has been observed that more bodyconscious people make better decisions” — Photo: Courtesy Nazareth Castellanos via BBC
BBC: And does this body awareness help with difficult emotions?
Castellanos: For example, when I get nervous, I feel something in my stomach or a lump in my throat. All of this is felt by my brain, it absorbs it. When I am aware of these sensations, the information reaching the brain is clearer and therefore the brain has a better ability to distinguish one emotion from another.
That said, one thing is those almost unconscious whispers, and another thing is turning them into words.
And we do so with conscience, which is also an ally in dealing with emotions. Because when we’re caught up in an emotion, whatever it is, stopping in that moment and bringing our attention to the sensations of the body gives us a lot of relief.
It’s one of the ways to relax to stop that whirlwind we get into when we have an emotion. This is called body awareness.
As early as the 1990s, Antonio Damasio, the great neuroscientist of our time, spoke of the benefits of this somatic marker. He has conducted many experiments observing that people with greater body awareness make better decisions.
I think that’s because the body doesn’t tell you where to go it tells you where you are. And when we’re in a complex situation and emotions are involved and even I don’t know where I am or what emotions I have, it’s harder for me to know where to go.
Emotions are very complex and mostly mixed. Being able to identify an emotion with just a mental analysis is harder than observing my own body.
But of course for that we have to train ourselves, observing the sensations of the body throughout the day, when I’m tired, when I’m happy, when I’m more neutral, when I’m angry, when I’m overwhelmed. Where do I feel it? It helps us a lot to get to know each other.
8 of 9 Man with hand on chest and eyes closed taking a deep breath — Photo: Getty Images via BBC Man with hand on chest and eyes closed taking a deep breath — Photo: Getty Images via BBC
BBC: The hunched posture makes it harder for us to breathe, could you talk about breathing and the brain?
Castellanos: Breathing is an ally that we have completely in our hands, but we do not know how to breathe.
Posture and breathing are closely related. If you take care of your posture, take care of your breathing. What has been observed in the neuroanatomy of breathing is that breathing affects memory, attention, and the management of emotions. But be careful if (breathing) is nasal when inspiration is through the nose
When we breathe through our mouths, and a large proportion of the population breathes through our mouths, we don’t have as much capacity to activate the brain.
The brain needs rhythms for this, and breathing is one of the pacemakers that our brain has so that the neurons create their rhythms, their electrical discharges. When we breathe through our mouth it is a muted pacemaker. It must be inhaled through the nose.
The moment we have the most memory is the moment we breathe in through the nose, at that moment the hippocampus is activated.
If something, a word, was said to you at the moment it coincided with inspiration, it has a better chance of being remembered than if it was said to you when you exhaled, after the expiration.
Which brings us to something very interesting, which is slow breathing. Normally we breathe very quickly.
9 of 9 Woman with eyes closed and a calm expression with yellow lights in the background — Photo: Getty Images via BBC Woman with eyes closed and a calm expression with yellow lights in the background — Photo: Getty Images via BBC
BBC: How important is slow breathing?
Castellanos: We just published a scientific study on the power of slow breathing as an analgesic for chronic pain due to disc disease (deterioration of the discs between the vertebrae).
And for emotions it is important that the time to exhale, to take a breath, is longer than the time to inhale. See how important, how many things we can do with our own bodies.
Our body is the instrument through which our life sounds, but it is an instrument we do not know how to play.
We have to get to know it first and then touch it.