NEUROLOGIY

12/12/2016

Neurology
Dr. Jorge Efrain Salazar Ceballos
According to some authors made stone tools 1.5 million years ago in Koobi Fora, Kenya, by Homo habilis and Homo erectus evidence put on the table on this tendency to use the right hand. This indicates preference when born, but does not explain why he.
It is known that people famous for their abilities are or have been lefties as Leonardo Da Vinci, Michelangelo, Picasso, Chaplin, Beethoven and Newton, among others, but how many has been that are proficient?
The human body, like almost the entire set of forms of animal life, follows patterns of symmetry. We have two arms, two legs, two eyes and a nose on our central axis, and this is repeated in the disposition of almost all of our organs. We are adapted to receive and act much like both left and right
These same standards are reflected in the way our brain. We have two brain hemispheres, each left and right, which are like mirror images of each other at least at first glance. Actually both hemispheres are very different at the cellular level and, in fact, are responsible for different processes. It has traditionally been associated with the left hemisphere verbal, logical and sequential process of the mind. For its part, the right hemisphere is more intuitive, creative and more capable with spatial relationships.
important choice
These subtle variations make for certain tasks have one side of our body responds differently to the opposite way, since each of these halves is related to one of the two hemispheres of the brain. For example, almost all have a dominant hand and we consider skilled, and we use the right for almost everything. However, this does not mean we have one half of the body that is entirely dominant. Interestingly, it is possible that a person has a dominant right hand "Laterality" is the preference for reason of more frequent and effective use of a lateral half of the body to the other.
It is a fundamental for the child five to seven years aspect, since at this age school learning force you to face problems of spatiotemporal guidance related to learning reading and writing.
The consequences that often result from poor laterality are: reading and writing problems, dyslexia, stuttering, among others.
It is curious to note that in many cultures all that is left has a negative connotation in the same way that the left hand is usually the dirty hand that do not touch anything of significance. There are thousands of ways in various cultures in which the use of the left hand is exclusively dedicated to dirty or impure tasks.
One in ten people about is left-handed, of which the number of male lefties doubles the number of female lefties. And like all minorities, you have to emerge that the world is built for right-handed people, whether with respect to traffic, rather than buttons on clothing or building instruments. In some families this aversion reached extreme lefty prevent them usasen hand by nature preferred. In Japan, for example, left-handedness was enough for the husband could seek divorce reason.
There have been numerous theories to try to explain why 10% of the population is left-handed. Plato was the first who tried to explain it by saying that mothers and women caring for young children often take on the left arm to handle right hand freely.
Another theory says that in the past, in situations of life and death our ancestors had to quickly decide an instinctive response to survive and that the "lateralization" of this response prevented the brain lost time reflecting that hand to respond to that situation emergency. However, this theory does not explain why the preference of 90 of the population by the right hand.
More scientific is the theory that attempts to explain why the number of male to female doubles lefties. The hypothesis that testosterone circulating in the blood produces a developing fetus in growth elentecimiento left hemisphere, therefore the probability that the right hemisphere was dominant in the male fetus would be higher.
Today it is thought that left-handers are for genetic reasons being the preference for right or left hand because of a gene. Thus, some studies suggest that the possibility of having a left-handed child both parents being right-handed, is 9% increase this figure to 26% if both parents are left-handed. Other factors include; environmental influence (customs) or learning received.
In studies that have been done on the lateralization of functions in both hemispheres it has been used an anesthetic to sleep one cerebral hemisphere if the substance is injected the corresponding carotid. It has been shown in these studies that about 95% of right-handers have language in the left hemisphere and the same for 70% of lefties. The remaining 30% was divided between those with language in the right hemisphere and those who were ambidextrous.
Always it has been raised whether lefties are smarter than righties. So far there is no reliable evidence that intelligence is greater lefties than right-handed people.
Some studies with nuclear magnetic resonance lefties have shown that chess players there is a very high number of lefties, presumably with lateralized language in the left hemisphere so that the region responsible for visiuoespacialidad in the right hemisphere is free language function and can better engage visuospatial tasks involving the chess game.
Laterality is important in neurological assessment and even sometimes to make decisions regarding certain surgeries nervous to improve the quality of life of patients system.
neurologist