Kоrelacija lateralizacije ruke sa fenotipskim i kognitivnim karakteristikama dece

Abstract

The lateralization of upper limbs, i.e. the tendency to use one arm more often in comparison to the other one while performing unimanual actions is the most obvious example of cerebral lateralization and it represents a characteristic of human population. The percentage representation of right-handed persons in comparison to the left-handed is approximately 90%-10% on the global level. The representation of left-handed persons is significantly lower than the right-handed, which was taken as the basis of a lateralization phenomenon research. For the sake of this research, lateralization is defined through seven unimanual skills, the performance of which requires precision. Based on the data analysis, both direction and degree of lateralization, as well as ipsilateral correlation with other organs (leg, eye and ear) were defined. The aim of this research was also to determine the potential correlation of hand lateralization with the observed phenotypic and cognitive characteristics of examinees, as well as to predictability of hand lateralization in relation to observed characteristics. It was concluded that the lateralization degree is more expressed with the right-handed, as well as with females. What was also observed was that this characteristic is stabilized later in life, meaning it is more expressed with older examinees in comparison to the younger ones. In addition to that, the higher lateralization degree indicates a more expressed ipsilateral correlation with the legs, eyes and ears. Hand lateralization is not a predictor of cognitive process speed, but can be correlated to learning and thinking styles. The representation of handedness direction in examinees’ families was observed through three generations of relatives and it indicates a genetic basis, especially in the cases of a left-handed mother or left-handedness in the mother’s family. Among the observed phenotypic characteristics of the examinees (hair and eye color, ear lobe shape, Darwin’s tubercle, finger overlapping, irregular articulation of the sound R, diastema), finger overlapping is the only characteristic that can be correlated to the hand lateralization.