National American University
Secrets of the Mind
This summary is based on a video series, found on YouTube, depicting the findings of neurologist, Dr. V.S. Ramachandran. Ramachandran is noted for his use of experimental methods that rely relatively little on complex technologies such as neuroimaging. According to Ramachandran, "too much of the Victorian sense of adventure [in science] has been lost."
In the case of Derek Steen, who is suffering from Phantom Limb Syndrome, Dr. Ramachandran evaluated the levels of feelings on both sides of the patient’s body by touching certain parts of the patient with a q-tip. When the Dr. stroked the q-tip across the left side of the patients face, the patient felt that same movement sensation on the missing right hand. Dr. Ramachandran theorizes that the left side of the body is mapped to the right side of the brain through a strip of cortex called the somatosensory cortex. When there is a missing limb, the part of the brain the corresponds to that limb no longer gets any input.
The Dr. has learned that sensory signals that, normally, only activate facial senses, are now invading the vacated territory that corresponds to the missing hand and activates the same sensations in the hand that are felt on the face. This research has shown that there has been a massive reorganization of sensory pathways in the brain, confirming neurogenesis.
Patient, Graham Young, suffers from a paradoxical condition called Blind Sight. He is totally blind, but, he is able to sense movement with both eyes in his left field of vision and not his right. Dr. Ramachandran has determined that vision is not necessarily seeing and that blind sight is our ability to detect things, but not to be aware of them. He has discovered that there are two separate vision pathways- a newer pathway that goes to the visual cortex and an older pathway that is connected to the brain stem. Each pathway observes...
References: Ref.: Phantoms in the Brain: Probing the Mysteries of the Human Mind, coauthor Sandra Blakeslee, 1998, ISBN 0-688-17217-2
[ 1 ]. Part 1 - Phantoms In The Brain (Episode 1)
[ 2 ]. Phantoms in the Brain: Probing the Mysteries of the Human Mind, coauthor Sandra Blakeslee, 1998, ISBN 0-688-17217-2
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