Thursday, March 8, 2018

Where am "I"?

Human beings have a remarkable capacity to project themselves into space.  Think about playing a video game.  Even though you and your physical body are sitting in a chair some distance from the screen, you can put yourself into the place of the avatar you have on the screen. 
In first-person games, that is pretty easy to do, because the view you get on the screen is the view from your eyes.  But, in third-person games, you are watching your character move in an environment.  Yet, you can quickly adapt your perspective to be focused on the location of your character on the screen.
Indeed, a study I did in collaboration with Miguel Brendl that was published in Psychological Science in 2005 showed how easy it is for people to take this kind of outside perspective. 
Previous research suggests that people like to pull positive things toward themselves and to push negative things away.  The question in this study is where the ‘self’ is located.
Participants sat at a computer screen and saw a corridor receding in depth.  Their name was placed in the middle of that corridor.  Participants were holding a lever that they could pull toward themselves or push away from themselves. 
Names of objects would appear on the screen.  Some of the objects were things most people think are positive (like flowers), while others were objects most people think of as negative (like spider).   On some blocks of trials, participants were told to move positive objects toward their name and on other blocks, they were told to move positive objects away from their name.
When the objects are far away in the corridor beyond where the participant’s name is, then the movements relative to the name and to the body are the same.  That is, pulling the object toward the name also pulls it toward the body and pushing it away from the name also pushes it away from the body.  In this case, it should be no surprise that people were faster to pull the lever when the word was positive and faster to push the lever when the word was negative.
The important condition was when the object was near to the participant in the corridor.  In this case, the object was in between the person’s physical body and their representation on the screen.  Now, if they pushed the lever, they were moving the object toward their name (which was their representation on the screen), but away from their physical body.  Likewise, if they pulled the lever, they were moving the object away from their name, but toward their physical body.
In this case, participants were faster to push positive objects toward their name (but away from their body), but faster to pull negative objects away from their name (but toward their physical body). 
This set of findings suggests that people are good at locating themselves at a point in space that is outside of their physical body.
But, an interesting study in the November, 2015 issue of Psychological Science by Elisa Ferre, Christophe Lopez, and Patrick Haggard suggests that the self is anchored into the body by the vestibular system.  The vestibular system is a mechanism in the inner ear that helps people maintain balance by recognizing where the body is relative to gravity.  The vestibular system is the one that you disrupt when you spin around in a circle several times.
The idea is that activating the vestibular system reminds the brain of where the body is located physically in space and causes representations of what is happening in the world to be interpreted based on the location of the body.
To explore this possibility, researchers used electrodes to gently activate the vestibular system.  When electrodes are placed near the ear, it is possible to deliver an electrical pulse that engages this system.  As a control condition, some other blocks in the study were done with the electrodes placed lower down on the neck where they do not engage the vestibular system.
The participant sat in a chair with their eyes closed and an experimenter sat in front of them.  While the stimulation was going on, the experimenter traced a letter on the participant’s forehead with a Q-tip.  The experimenter wrote the letter b, d, p, or q, and the participant had to say which letter they felt.
Notice, these letters are ambiguous.  Suppose the experimenter wrote the letter b.  If the participant is able to take the experimenter’s perspective, then the participant should respond that they felt a letter b being written.  But, if the participant takes their own perspective, then they should say that they felt a letter d being written.
When the vestibular system was being activated by the electrodes, participants were much more likely to take their own perspective on the letter than the experimenter’s perspective compared to the control stimulation on their neck. 
This finding suggests that engaging the vestibular system brings people’s perspective back into their physical body rather than allowing them to take someone else’s perspective.
This is interesting, but does it really matter? 
There are many situations in which it is valuable for us to be able to take an outside perspective on what is happening in the world.  Clearly, we do this with video games.  But, we make predictions about what people and objects in the world are going to do all the time.   This ability also helps us to give other people directions when they are trying to get somewhere. 
These results suggest that the more aware we are of our own physical bodies, the harder it is to take this outside perspective.  So, if we are going to be engaging in an activity where we need to take another person’s point-of-view, it would be useful to minimize the factors that remind us of our own physical body. 

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