Posts Tagged ‘rubber hand illusion’

Keep Track of Your Body in Space

January 15, 2017

HM works from his iPAD.  This is the print title of an article by Anil Ananthaswamy in the October 1 issue of the New Scientist.  The healthy memory blog has stressed the importance of the unconscious mind and provided suggestions as to how to make use of your unconscious mind.  This and the previous blog posts taken from this issue of the New Scientist elaborate on these ideas.

Proprioception is a much under-rated ability.  It is the result of unconscious processing and results from a constant conversation between the body and the brain, allowing us to know where our limbs are and what they are doing, and adds up to an unerring sense of a unified, physical “me.”

Proprioception predicts the cases of the various sensory inputs it receives — from nerves and muscles inside the body, and from the senses detecting what’s going on outside the body.  What we are aware of is the brain’s best guess of were the body ends and where the external environment begins.

In the famous rubber-hand illusions a volunteer puts one hand on the table in front of him, and a rubber hand is put in front of him.  A second person they strokes the real and rubber hands simultaneously with a paintbrush.  Within minutes many people start to feel the touches on the rubber hand and even claim it as part of their body.  The brain makes its best guess as to where the sensation is coming from and the most obvious option is the rubber hand.

Newer research suggests that this sixth sense extends to the space immediately surrounding the body.  Arvid Gutersam of the Karolinska Institute in Stockholm and his colleagues repeated the rubber-hand experiment, stroking the real hand but keeping the brush 30 centimeters above the rubber hand.  Participants still sensed the brush stokes above the rubber hand, implying that as well as unconsciously monitoring our body we keep track of an invisible “force field” around us.  Gutersam suggests this might have evolved to help us pick up objects and move through the environment without injury.