How do you feel?

Few weeks ago I got lost on campus and somehow I ended up in this abandoned building. It was the creepiest and spookiest place I have even been into… by myself. It looked more-less like this…

 

I don’t want to get into details but I had to walk through the long hallway, and I must tell you, few times I have been more scared in my life. I was in alert mode. I was watching over my shoulders every few seconds to make sure nobody was following me because I could have sworn somebody was going to murder me or at least rape me right then and there.

 

Physically, my heart was pounding its way out of my chest, my legs were shaking more with each step, and my breathing became very rapid and heavy.

 

But how did I end up feeling that way? There are few different theories that explain how emotions are produced; however, what is the most logical sequence of events? What happens first? I felt afraid (emotion), then I got in that place (stimuli), then I my heart started to pound really fast (action), and then I realized that place was creepy and possibly dangerous (appraisal (cognition))? Or what?

Common sense told me that first I obviously got inside the building, then I realized it was very creepy, then I felt afraid, and then I started to express physical symptoms.

However, according to James-Lange theory of emotion I was wrong. They proved through a series of experiments that emotions are actually caused by physical arousal, and not the other way around. So the real sequence of events goes: Event, Appraisal, Action, and Emotional feeling.

 

That is: I got into that place, I identified it as threatening, I started to breath hard and my heart to beat fast, and then I identified it all as fear.

Yes, it does sound odd, but it makes sense. Have you ever heard that when you want to get in a better mood you can force a big awkward smile for 20 seconds and then you will feel a bit happier? No? Well I have and it actually works. No, it does not make you really happy in 20 seconds, but it makes a small difference. No, I am not crazy, James did and experiment in which he would deceive their participants to get them to smile while they rated comic strips in the newspaper according to their level of amusement. The results were that when people were forcing a smile they would rate the comics as funnier.

 

This theory therefore suggests that people who have no muscle movements or perceivable changes in any organ should feel no emotions. However, those people may still recognize the cognitive aspects of emotion. That is, they can identify a situation as sad, or frightening, or any other emotion.

So, does your mind control your body… or your body controls your mind?

Painless Life.

Complains. Sometimes it seems like life is all about complains. We focus more on the negative things than on the positive ones.

Pain. Pain is one of the principal sources of complains. Either emotional or physical, pain is popularly considered a burden. It exists to make us suffer, to make our lives more difficult.

Perspective.

What if it was possible to live a painless life?  How many of us would gladly stand in line for that? I would say quite a few. However, those people are not stopping to consider the possible consequences of not feeling pain.

Although pain is not pleasant at all, it exist for a reason. How could we know that we are healthy if we are not getting any feedback from our body? If I wouldn’t have felt that I stepped on a needle and cut myself, I may have ended up with a dangerous infection; if I weren’t feeling this pain in my side, I wouldn’t know that my appendix is about to break and I may die.

Unfortunately, a genetic condition that inactivates pain axons preventing people from feeling pain does exist. It is called Congenital Insensitivity of Pain with Anhidrosis (CIPA). Since this is a generic conditions people are obviously born with it. How can you explain a child the concept of danger when they do not know what pain is? It would be a little complicated to explain them that they should not chew on their fingers when they do not see anything wrong with it. Usually people with this condition do not live until adulthood because they die young due to some reckless activity or some illness which symptoms were not detected.

Here are two examples of what it is like to have CIPA. In the following video, although little Ashlyn suffered during her childhood adapting to her condition, nowadays she is way better and trying to make a difference for the future kids with her condition.

This other video shows the possible life-lasting consequences of the condition.

Alzheimer's Disease

Speech Problems?

Today we will talk about two different types of aphasia: Broca’s aphasia and Wernicke’s aphasia. Originally they were called that because they were the result of damage to the Broca’s area or Wernicke’s area.

However, today we use the terms to refer to the behavioral expressions of the damage regardless of its location.

Let’s begin with the Broca’s aphasia. this type of aphasia is characterized by the impairment in language production. That is, they have trouble expressing themselves not only verbally (speaking or writing), but also gesturing. They omit most pronouns, conjunctions, auxiliary verbs, quantifiers, prepositions. They do, however, understand pretty well other people’s speech, as long as the structure of the sentences is not very complex. Although their perception of grammar is affected, it is not completely lost. When presented a sentence with incorrect grammar, they realize there ir something wrong in it even though they cannot tell exactly what it is. In the following video we can observe a patient suffering from Broca’s aphasia caused by a stroke. This video was taken about a year after she had the stroke.

 

 

On the other hand, Wernicke’s aphasia is also known as fluent aphasia. This is because people with this condition preserve the ability to speak  fluently; however, they have trouble recalling many words, therefore they have to stop while talking. In addition, their understanding of speech is poor. They often cannot make sense of what other people is saying or what they are reading. In the following video we see an interview of someone with Wernicke’s aphasia.

 

 

 

I hope that now we all understand the differences between Broca’s and Wernicke’s aphasias better. If you didn’t, I invite you again to watch both videos they are really short and very informatives. Enjoy your spring break!
 

The Hindbrain

The brain is the most complex and mysterious part of the body. Despite the multiple research studies done, we are way far from completely understanding its functioning.
When we think about the brain, we usually think about the cerebral cortex. Few of us know that that, in fact, what most people believe is he brain (the cerebral cortex) is just a part of it. The brain is composed of many small parts that are very important.
First of all it is divided into three sections: the hindbrain, the midbrain, and the forebrain.

This time we are going to talk about the hindbrain.
The hindbrain is located in the posterior (towards the back of the head) part of the brain. It is composed of the medulla, pons, and cerebellum.

The medulla is like an extension of the spinal cord into the brain. the medulla controls some vital reflexes such as hearth rate, vomiting, sneezing, breathing, etc. As you may guess, damage to the medulla may be life threatening.

The pons is located anterior (towards the face) and ventral (towards the feet) to the medulla. This is very interesting because here is where the axons from the right side of the spinal cord cross to the left side of the brain and vice versa, making your left hemisphere able to control the right side of your body and your right hemisphere the left side of your body.

Last but not least we have the cerebellum. Before, we used to believe that the cerebellum's only function was for coordination and balance. However, our little friend is way more important. Research has proven that damage to the cerebellum affects the ability to alternate from visual to auditory stimuli. Besides, it also affects the sensory timing. Therefore, if your cerebellum has been injured/damaged/affected somehow, becoming a musician is probably not going to work for you.

Temporal Summation

Last semester I took a biology class. One day at the laboratory they had us doing some experiments on the reflexes (contraction of the pupil, etc.). I was then trying to perform the I’m sure very familiar procedure of the following picture to my partner.

 

 

It is a very easy procedure, so of course I was really pissed when I could not get it right. No matter how hard I hit her knee, it just would not lift. It was until few days ago that I realize what I was doing wrong.

When I was doing the experiment I was not told about temporal summation. Since I do not want you to make the same mistake whenever you find yourself in the necessity of performing the same procedure, I will explain the concept.

At the beginning of the 20^th century, the scientist Charles Scott Sherrington made an experiment with a dog. He would suspend the dog above the ground and pinch one of its feet. Then he observed its reactions which were to flex the pinched leg and extend the others. Seems easy and basic right? However, from this experiment, Sherrington discovered 3 things and won a novel prize.

He discovered (1)that reflexes are actually slower than conduction along an axon, (2)that few weak stimuli presented at short time intervals or slightly different locations produce a stronger reflex than a single stronger stimulus, and (3)that when a set of muscles becomes excited, another relaxes.

 

He observed that when he would pinch the dog’s foot several times really fast but not hard, he would cause a reflex. He assumed then that it was because the continuous stimuli must accumulate in a single axon causing it to reach its threshold and begin an action potential. He named this temporal summation. He also noticed that pinching in different spots close by in the dog’s foot would also cause a reflex, which means that stimuli in different spaces also accumulates. He named this spatial summation.

 

So, Why did my experiment not work? Because I was trying to produce the reflex in one single blow. I should have tried with a few continuous. Or maybe not. Maybe I am just very untalented for those kind of experiments. Try it yourself! Do the experiment and let me know what was easier: one strong blow, or few weaker hits.

The Purge And The Blood-Brain Barrier

The other day I was watching this movie called “The Purge.” In this movie, all kinds of crime are legal for one night a year. That night, either you go out to find a way to release your criminal instincts, or you install a very powerful security system to protect yourself and your family (since police and medical services are not available during that time).

 The following day, I was reading about the nervous system. In my reading, there was this one part about something called the blood-brain barrier and I thought “OMG this is just like the movie.”

In the movie, there is this one family perfectly locked up for the night, no one can get in. However, nobody knew that someone with no good intentions was inside the house before they locked up. Then this man appears on the street asking for help and the little boy decides to let him in without his parents’ permission. The situation here is that they cannot disable the security system again to get the strangers out because it could cause more bad people to come inside. Besides, there is also the problem that there is no police or anything to help them get through the night. That’s as far as the resemblance goes.

The blood-brain barrier has sort of the same situation. Since neurons are not very easy to replace once they have been damaged by a virus, they need to be particularly protected. That is why we have a barrier that separates the blood from brain cells. This barrier (as well as the security system in the movie) prevents many chemicals and bacteria from coming into the nervous system; however, it also keeps away may nutrients that cells need in order to function (which would be medical services, police, and fire fighters in the movie). The blood-barrier can only be trespassed by a few small, uncharged molecules such as O2 and CO2, in addition to certain fat-soluble molecules. Besides, active transport systems pump glucose and certain amino acids across the membrane. However, most large molecules and electrically charged molecules cannot cross from the blood to the brain.

 

Although the lack of nutrients is not a positive feature, our brain cells have adapted to it. The real problems is what happens once a virus does get pass the barrier. Just like in the movie, the virus will try (and possibly succeed) to kill you. If it can’t, at least it will stay inside your nervous system (your house) the rest of your life (the night). Besides, when the cells of the blood vessels that form your barrier shrink, harmful chemicals may get in and cause certain diseases such as Alzheimer’s.

 

The question here is: how can we treat Alzheimer’s or Parkinson’s disease, or some brain cancers if the chemicals used for the treatments are not able to cross the barrier? In the following video Devin Wiley explains his approach to this issue and his theory for overcoming the barrier.

http://www.youtube.com/watch?v=WLEPr3mz4qc

 

Solipsism

Have you ever heard that psychologists eventually go insane? I have, and up until now I thought it was just a stereotype. Today, I believe that as a future psychologist I may go mad one of these days. Believe me, if you were told that everything that you know is not actually true but instead it is just what your brain makes you think you know, you would be a little disturbed too.

Let’s start from the beginning. We acquire information about our surroundings through our senses. Let’s take the example of the hearing. Maybe many of you knew it a long time ago, but I just found out that sound in nonexistent. What we “hear” are just the vibrations of the air. Basically, the process works like this: let’s say your phone falls from your hand and hits the floor, the moment it hits the floor it shakes the air, the moving air will travel all the way to our ears and produce a vibration in your eardrum, this will translate into electrical energy, neurons will transport the signals to the brain, and finally your brain makes its best to make sense of the electrical signals and translate it into what we “hear.” It is a similar process for the other senses.

So, if what we are conscious of is not what is actually out there, but our brain’s interpretation of it, how do we know that what we know is actually accurate? How can we be sure that everything, anything, we know is actually true? What if our brain is making up the things we see, the things we hear, the people we know, or our “reality”? Yes, it does sound crazy, but how can you prove it is not true?

There is a condition called solipsism, which is based on the idea that your mental stages are the only mental stages. People that have this condition firmly believes that they are the only people that exists in the world. For them, other people as well as everything else is a product of their imagination.

The more you think about it, the more mind blowing it is. Why? Because you cannot prove it wrong. You can present a very powerful and convincing argument, but you cannot actually prove it. The conflict of proving that other people also has a consciousness is called the problem of other minds.

If you want to get your mind blown a little more, I totally recommend you to watch this video!