The article below suggests that the lateralization of speech and communication is genetic in origin. I was thinking earlier in the day before seeing this article that the brain structures somehow had to mirror the function. I have no idea really what does what and how. I am unclear on what plasticity there is the brain. I can unequivocally say I did not differentiate the left and right sublingual musclature previously along with not 'seeing' the left side of others faces. I still see the persona represented in the right half of someone else face with my right eye being the lead dominant eye in normal day to day activities. There is a postural adjustment of the head and spine that goes along with the right eye dominant movement. When I make the deliberate effort to connect with my left eye to left eye in order to integrate the movement more fully, a switch feels to be needed with the deep postural musculature of my head and spine.
In the human brain, from early in development through to adulthood, the superior temporal sulcus is deeper in the right than the left cerebral hemisphere in the area ventral of Heschl’s gyrus. Irrespective of gender, handedness, and language lateralization, and present in several pathologies, this asymmetry is widely shared among the human population. Its appearance early in life suggests strong genetic control over this part of the brain. In contrast, the asymmetry is barely visible in chimpanzees. Thus this asymmetry probably is a key locus to look for variations in gene expression among the primate lineage that have favored the evolution of crucial cognitive abilities sustained by this sulcus in our species, namely communication and social cognition.
The depth asymmetry of superior temporal sulcus