The human body, like that of almost all bodies that inhabit all forms of animal life, follows certain symmetry patterns.
We have two arms, two legs, two eyes and a nose in our central axis, and the same logic is repeated available to almost all of our organs. We are adapted to perceive and act in a very similar fashion on both the left and the right.
What are laterality and transversality?
As you might expect, these same rules are embodied in the shape of our brains. We have two cerebral hemispheres, each left and right, Which are sort of mirror images of each other … at least at first glance. In reality, the two hemispheres are very different at the cellular level and, in fact, are in charge of different processes. We all know this idea that the right hemisphere is rational and analytical, while the right is emotional and responds in a particular way to music.
These subtle variations mean that for some tasks we have a band of our body that responds differently to its opposite side, because each of these halves it is linked to one of the two hemispheres of the brain. For example, almost all of us have a dominant hand and consider ourselves skillful because we use the right for almost everything. However, this fact does not mean that we have one half of the body that is fully dominant. Interestingly, it is possible for a person to have a dominant right hand, but the opposite happens with their eyes or legs. These are the cases of cross-laterality.
Cross laterality, homogeneous laterality and dominance
We generally speak of homogeneous laterality, because people whose dominant hand is on one side tend to have aligned in this half the dominances of the rest of their members and their senses. So when we talk about laterality we are referring to the different dominances that exist in a person, And the set of these dominances will be the one that defines whether a cross or homogeneous laterality occurs.
In any case, transversality is one more form of laterality, and the existence of one or the other type is a consequence of the functioning of our nervous system. This means that it is in the interconnections of our different parts of the body from the nerves that the causes of one or the other type of laterality must be sought, and this can also be defined by the areas of the body in the that affects. In this sense, there are different dominance classes which serve as criteria to define the type of laterality:
- manual dominance: Defined by the dominance of either hand when gripping objects, writing, touching, etc.
- The domain has been handed over: Defined by the domination of either foot to kick, kick a ball, stand on one leg, etc.
- auditory dominance: Tendency to use either direction for listening, putting on headphones, etc.
- Ocular or visual dominance: Defined by the dominant eye when aiming with gaze.
Why is there a cross laterality?
The nervous mechanisms by which one or the other type of laterality occurs are not very well understood., Or why there are sometimes cases of transversality being that the majority is that there is homogeneity. In any case, transversality would be proof that there is no major planning center responsible for coordinating the different dominances or that, if it exists, its function is or is essential.
However, it is currently believed that transversality could cause problems when the coordination of dominance of body parts is jarring, such as when writing. Research is lacking in this regard, but it is considered cautious consider transversality as a risk factor for the onset of learning disabilities in children.
However, since the system of connections between neurons on which dominance relies is highly plastic (i.e. adaptable according to our learnings and experiences), laterality is not only determined by genetics, but also learned behavior influence, Culture, habits, etc.
Cross laterality is no exception to this rule, and so you can learn to mitigate the effects of very extreme dominance by also using the homologous part of the body in the other half, in this case speaking of forced laterality.