Other people are right-handed and other people are left-handed. “Handed-ness” or left-right asymmetry is prevalent throughout the animal kingdom, including in pigeons and zebrafish. But why do people and animals naturally favor one side over the other, and what does it teach us about the brain’s inner workings? Researchers explore these questions in a Review published April 19, 2017 in Neuron.
“Studying asymmetry can provide the most basic blueprints for how the brain is organized,” says lead author Onur Güntürkün, of the Institute of Cognitive Neuroscience at Ruhr-University Bochum, in Germany. “It gives us an unprecedented window into the wiring of the early, developing brain that ultimately determines the fate of the adult brain.” Because asymmetry is not limited to human brains, a number of animal models have emerged that can help unravel both the genetic and epigenetic foundations for the phenomenon of lateralization.
Güntürkün says that brain lateralization serves three purposes. The first of those is perceptual specialization: the more complex a task, the more it helps to have a specialized area for performing that task. The next area is motor specialization: “What you do with your hands is a miracle of biological evolution,” he says. “We are the master of our hands, and by funneling this training to one hemisphere of our brains, we can become more proficient at that kind of dexterity”. Natural selection likely provided an advantage that resulted in a proportion of the population (about 10%) favoring the opposite hand. The thing that connects the two is parallel processing, which enables us to do two things that use different parts of the brain at the same time.
Brain asymmetry is present in many vertebrates and invertebrates. “It is, in fact, an invention of nature, which evolved because many animals have the same needs for specialization that we do,” says Güntürkün.
Research on pigeons has shown that this specialization often is a function of environmental influences. When a pigeon chick develops in the shell, its right eye turns toward the outside, leaving its left eye to face its body. When the right eye is exposed to light coming through the shell, it triggers a series of neuronal changes that allow the two eyes to ultimately have different jobs. (1)
We need specialization.
But the greatest and most difficult specialization is generalization.
We believe that the environment feeds asymmetry.
But the environment in large scales is symmetric.
We may see asymmetry, but by simply changing perspective we can see the exact opposite. See a city from above. And you will see one small dot. Go into the small streets. And you will get lost in them. The same applies with thought, particles, society and so on. Yes, people are right handed or left handed. But seeing this from a “higher” perspective you could just say that “people write with their hands”.
Specialization comes from the need to dig into things. But the ultimate result of digging in is to learn that digging was useless.
There is no need to know with which hand people write. All you need to know is that they do. There is no need to get lost into the small roads. You can see the whole world from your home. There is not even a need to get out of your home. You can experience everything from your chair.
There is no left or right.
There is no right or wrong.
Not even “is” is. Just you.
When you are truly alive, when performing the one thing which makes you “be” (i.e. “being” without doing anything, just knowing that you “are” there and you are you), you do not use any hand. Or eye. Or ear. You just “exist”. There is no asymmetry in existence. Asymmetry is just a phenomenon materializing when you do not accept reality and want to “dig in” so as to “understand”. Your actions destroy reality and create a new one. Your decision to leave home destroys the dot and makes the city appear. You don’t have any hands. You just choose to write with the right one.
Abre los ojos!