The theme of the left has always been a problem of general interest. The left-wing people, of course, have suffered or felt it especially because in some of them it has been a source of many problems (older or younger), especially when this trend has been repressed in childhood, when the child was forced to use the right hand, to write and in other activities of his childhood life (eat, use the knife, etc. ). ).
The left have existed in all ages, and studies carried out in the stone instruments of the Neolite era show that in those times the number of left and right was quite equal.
Subsequently, the invention and use of weapons caused a division of labor between both hands. Therefore, one hand was used for the attack (right) and another for the defense of the chest cardiac environment (left).
The proportion of left is variable in the general population according to age. For example, in research at the University of Winipeg in Canada.
The most famous left can be Leonardo da Vinci. Everything he wrote did with the left hand, with the name of mirror writing. Other illustrious characters were left: Michel Angelo, Goethe, Nietzsche, Holbein, Beethoven, Schuman, ...
Throughout history, in the traditions of the peoples, there is already a social lateralization related to the sunrise and entrance.
In the common language (at least in Spanish, French and English, in Basque it is not so obvious), the right indicates GOOD, CORRECT, ADEQUATE. The left, however, is synonymous with clumsy, of certain clumsiness, of little ability.
It is a functional asymmetry that manifests in hands, feet, eyes, and other double organs. What is it expressed in? A certain difference predominates, even in directed activities.
Being left is not a bad habit, but something already biologically predetermined.
The laterality of a person appears in body and facial asymmetry. For example, right manual laterality is often accompanied by laterality of the feet and eyes, being at the base of all the left laterality of the brain.
The left hemisphere of the brain is imposed on most people, which makes these people right. On the left, on the contrary, the right hemisphere predominates. This domain of one hemisphere in the other is hereditary and is transmitted within the family. In his favor are the conclusions of the investigations carried out in the twins unibitelinos and bibitelinos. But, on the other hand, the fact of being left also appears as a personal and individual variable.
There is also a manual laterality acquired due to brain alterations during childbirth or encephalitis. In these people you can see other neurological signs and this type of left has been responsible and guilty of all the “bad fame” of the left.
In the growth of the fetus, the beginning of the largest volume of the cerebral left hemisphere has already been observed. Cerebral asymmetry is already observed in week 29 of pregnancy.
Manual laterality has different levels, so the left level is different: from the almost mere left (which barely serves them at all right) to the one used by the two hands of the other end.
The development of language is almost parallel to laterality.
The human being has until the seventh month two POSSIBLE language centers, and from now on the lateralization of the right (especially that of the hand) supposes a greater development of the left part of the brain, while the center of the right remains as “asleep” (if the circumstances demanded it, it largely recovers and would reinforce).
The functional domain of a hand is seen at the beginning of the 2nd year.
A delay in language acquisition may indicate that there has been a delay in the acquisition of laterality: this delay represents an increase in waist, starting from language.
Relations that may have the left and stuttering have always been the subject of debate, but today there is no consequence. Apparently, not only being left, but being the left of confirmation (or laterality not yet defined) would be the cause of the different language alterations (according to SOVÁK).
The obligatory primitive forms of education, which forced the own tendencies (in this case those of the use of the left), and the nervous impulses coming from both hemispheres to dance and to compete with each other, could produce alterations in the language, writing and manual skill. Today, by respecting this natural tendency of the child to use his right hand, the frequency of these errors and the sensations of inferiority and complexity that occurred at the same time has been reduced.
When does the problem appear? For the first acts of his life (games, meals, etc.) When the child begins to pick things up and is more important to write or draw when the child is forced to use one of the two hands (before in school he started at 5-7 years, but now quite earlier in the parvular).
Before diagnosis, the child must be left with complete freedom, on his own, observing and studying in detail. When its leftist condition has been diagnosed, it is necessary to promote, strengthen and reinforce this laterality, as has been indicated above, since the re-education that is carried out at the right hand will cause alterations in reading, language, writing and manual skill.
To write, we must teach him the most beneficial attitudes or positions for him.
His laterality, once consolidated, is convenient to train both right and left in his “bad” hand.
There are some children who tend to the right left (to ambidextrism), but it seems proven that it is not an ideal situation, let alone. It seems that with this education, problems can arise in language, writing and reading.
The left can act in almost all professions or trades, provided they have capacity for it. However, users of machines designed and adapted for the right should have special care and care.
Wegener found more left among students of the upper classes, but also among backward students, who could be treated as normally developed.
As for the tachygraphy, there is currently a special tachygraphy for the left, which is written from right to left (using the left hand).
1. constancy through the REY test.
In the image, all circles located to the right of short and quite vertical lines must be crossed.
Number of circles correctly labeled in the first session and then in the second. (1 minute per circle)
2. PIAGET test.
The one who performs the test is sitting in front of the child at the same table and asks:
Now cross your hands on the table, as you do at school. Very good. I will put before you three objects (things): the inkwell, the keys, the clock (about 15 cm). Now you also have to answer my questions as soon as possible without moving your arms or hands.
If you respond “in the middle”, the child is forced to respond to the right or left.
* KRAEMER tests
Once these tests are done, the tendency to displacement is measured:
0 = nothing 1 = very weak 2 = weak 3 = average level 4 = strong 5 = very strong (very strong)
It must be taken into account that there are new lefts that mean they are very skilled with the right hand, or pretend to do so (especially when they know the scope and meaning of their study). Therefore, we must use different tests. Paying attention to the child and asking the parents if getting used to using the right hand cost him a lot (long time or effort).
If all these works are done with the same eye, no other study is necessary. If not, after a small distraction, it should be repeated along with other tests.
2 Duck/rabbit test PERRETA
This test is suitable for the smallest (and not very clear). Question from the examiner: “What animal is that?”, looking at about 60 cm.
Replies: Responses: Duck: right (right) Rabbit: left (left of eyes) The medium see two animals
3 Noise problems
It is worth mentioning the number of leftovers that have been found in patients with strabismus (but later they have become true again).
Strabismus, therefore, is an alarm for the pedagogue when there are errors in language, reading and spelling.
It should be sent to the oculista.
Below will be the most used tests. According to Kramer:
Emil Froschels, a research researcher in New York, discovers over 400 people: The 70% does so on the same side in which it predominates its manual laterality by clicking the language and more easily.
To see which is the main ear, on which side it predominates.
The SOVÁK test can be performed. On a table is placed a clock that works, along with other things and everything is covered with a cloth, in which the person has to look for the clock through the ear. The main ear is the one that approaches the fabric.
It is advisable to repeat this test.
The main ear, almost 50% of people, is in the opposite part of the main hand, according to data from Sovák.
Saioa hasi iruzkinak uzteko.