Tuesday, February 17, 2015

7 messages sent by your pupils

In the past people believed that the eyes were the mirror of the soul. In fact, even today many people try to uncover a lie asking the others to look directly into their eyes. However, is it just a popular myth or definitely our eyes can speak for us?

Science discovered that our pupils send many signals to our interlocutor, we only need to know how to scrutinize those messages.

1. You’re thinking something complicated

In 1964, psychologists at the University of Chicago recruited a group of people and asked them to solve different problems. The key was that problems were organized according to an increasing level of complexity. While people were solving the problems, the researchers analyzed their pupils. They found that the more difficult is the task we face, more our pupils dilate.

2. Your brain is saturated

In 1973, some psychologists at the University of California asked themselves whether pupils could indicate when we’re reaching the limits of our cognition. So on that, they recruited a group of volunteers and asked them to resolve as quickly as possible a problem that appeared on a computer screen. They just had to choose one answer among four options. The catch was that the problems went faster and faster, until it reached a point where people felt overcrowded and could not continue. Thus appreciated that when our brain is overloaded pupils reduce significantly its size.

3. They caught your attention

In 1977, several psychologists at the University of California conducted a very interesting experiment: they recruited a group of people and asked them to listen a reading of an erotic book, a story about a mutilation and some neutral content that doesn’t generate any emotions in particular. The funny thing was that pupils dilated at the beginning of each story but only remained dilated during the stories of erotic and violent dyes, but quickly returned to normal listening with the neutral stories. Therefore, when someone really captures our attention pupils dilate and remain that way.

4. You feel disgusted

In 1960 a group of psychologists from the University of Chicago prepared a series of images that could trigger different reactions. As volunteers saw them, a camera was recording their pupils. So it was observed that when people watched violent images, of mutilation or about persons harming children, they reacted with a deep disgust. The funny thing is that at first their pupils were dilated but immediately decreased considerably in size in an unconscious attempt to avoid images that aroused disgust.

5. You’re feeling pain

In 1999, psychologists at the University of Washington recruited a group of people to participate in a painful experiment for a good cause: science. These people were applied electric shocks in the fingertips, while they undergo the experiment their pupils were recorded . This way was possible to see that when we feel pain our pupils are much dilated, which is a response of the autonomic nervous system that prepares us to flee from danger and obviously demand that our view be 100% sharp to detect any potential threat in the environment.

6. Uncover your political position

In 1969 was produced one of the most curious studies about what our pupils are communicating. In that case, some psychologists at the Louisiana State University recruited some people who had very distinct political positions and were quite sure of them. Then, they showed them pictures of traditionally liberal and conservative personalities. At this point the researchers noted that our pupils dilate when we see people who share our political ideas and contract when they belong to opposing parties.

7. Discover some traits of your personality

This is not about contracted or dilated pupils but the lines of the iris. According to researchers at the Karolinska Institute, if you look close enough in the eyes of someone, you can discover some features of his personality. When the crypts found in the iris (wavy filaments) are radiating from the pupil out, people tend to be more sensitive, honest, friendly and experience more positive emotions. When appear concentric folds around the iris, people are more nervous and impulsive. The key lies in the Pax6 gene, which is not only involved in the growth of the eye tissue but also in the development of the anterior cingulate cortex, which is involved in the regulation of mood and self-control.

Changes too small to be noticed?

At this point you're probably thinking that these details are too small to notice. However, according to a study at Dartmouth College probably we’re not noticing many of these changes consciously but they won’t remain unnoticed by the unconscious.

These neuroscientists analyzed the brain activity of dozens of people while were watching others, with dilated, normal or constricted pupil. They were able to see that our brain reacts differently, especially the amygdala, which is our emotional sentry. In fact, when the pupils of another person dilate, the amygdala increases its activity, perhaps to indicate that we must be alert.

Demos, K. E. et. Al. (2008) Human Amygdala Sensitivity to the Pupil Size of Others. Cerebral Cortex; 18 (12): 2729-2734.
Larsson, M. et. . Al (2007) Associations Between iris características and personality in adulthood, Biological Psychology; 75 (2): 165-175.
Chapman, C. R. et. . Al (1999) Phasic pupil dilation response to noxious stimulation in Normal Volunteers: Relationship to brain evoked potentials and pain report. Psychophysiology; 36 (1): 44-52.
White, GL & Maltzman, I. (1977) Pupillary activity while listening to verbal passages. Journal of Research in Personality; 12: 361-369.
Poock, G. (1973) Information processing vs. pupil diameter. Perceptual and Motor Skills; 37: 1000-1002.
Barlow, JD (1969) Pupillary size as an index of preference in political candidates. Perceptual and Motor Skills; 28: 587-590.
Hess, EH & Polt, JM (1964) Pupil Size in Relation to Mental Activity During Simple Problem-Solving. Science; 143 (3611): 1190-1192.
Hess, EH & Polt, JM (1960) Pupil Size as Related to Interest Value of Visual Stimuli. Science; 132 (3423): 349-350.


Keep feeding your neurons

7 messages sent by your pupils
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Jennifer Delgado Suárez

Psicologist by profession and passion, dedicated to to string words together. Discover my Books


Psychology as you never heard about...

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