Right or left handed?

27/03/2019

Right or left handed?

Being right-handed or left-handed is the result of the way the brain organizes and distributes its workloads. The most recent explanation of why a left-handed brain exists was elaborated by three experts in evolutionary biology at the University of Durham, England (Diana Widermann, Robert A. Barton and Russel A. Hill).

They say that normally the left hemisphere of the brain adopts two different functions that require a lot of energy expenditure: the fine movement of the hands and the fine movement that is required in the throat, tongue and mouth to articulate the language. In most cases the brain decides to unite the two functions in the left hemisphere because it makes a more efficient expenditure of energy and that is why there are more people who are right-handed.

However, there are cases in which the brain first installs the functions related to the fine movements of the hands in the right hemisphere of the brain, in a stage prior to the appearance of language, so that when the need arises to speak and do the fine movements that are needed to pronounce words, the left hemisphere creates circuits and processes only specialized in language, while the right conserves the circuits and processes that had previously woven for the movement of hands, fingers and feet.

The construction of movement circuits in hands and fingers, say evolutionary biologists, begins from the child's first attempt to throw objects.

Studies conducted in 2010 by the Imperial College of London, identified that the lack of a clear division of labor between the hemispheres of the brain causes that children who are ambidextrous and those who have crossed laterality have more learning and language development problems than those who are only right-handed or are only left-handed.