biological basis of individuality
I. P. Drobnitsa – Senior Researcher, Chelyabinsk state pedagogical university. E-mail: email@example.com
It is known, that there is considerable variation within typically developing individuals in the strength to which specific functions such as language or handedness are lateralized to the canonical side. Consequently, hemispheric specialization does not only vary in direction but is most likely a matter of degree (strong right-handed individuals vs. ambidextrous). It can mean, that each hemisphere has both kinds of mechanisms (synthesize/analyze), but in a different proportion. Although many investigations are confined to dichotomous measures (traditional laterality coefficient or individual laterality profiles), it is important to include factors associated with degree of lateralization in research model.
Large hemispheric specialization creates two strongly differing cognitive hemispheric products which are suitable for addition of one with another. It corresponds to rapid decision-making style. Otherwise, equipotential hemispheres create two not strongly differing cognitive products and they are compelled to compete (in case of absence of tonic hemispheric domination). Within this theoretical framework, variety of sensorimotor and morphological asymmetries could be interpreted as influence complementary/uncomplimentary interhemispheric information processing according to many factors: hemispheric specialization/equivalence, kind of tonic hemispheric domination, its degree and stability. In addition to this, factors associated with hemispheric specialization/equivalence should be shared according to two mechanisms (synthesize and analyze) because specialization on one mechanism and equivalence on other mechanism is possible. Cognitive approach to the treatment of sensorimotor and morphological asymmetries demands that these asymmetries as predictors of temperament traits should be used in the certain theoretically deduced combinations.
Data were provided by 200 adults (right- and mixed-handers). Subjects responded to Eysenck Personality Inventory, FPI, Cattell’s 16PF questionnaire, Keirsey's Type Inventory, Shmieshek Fragebogen, A. Zworykin’s questionnaire. Annett handedness questionnaire, clapping test, the myokinetique test by Emylio Mira y Lopez, Finger tapping test L-R inequality, Napoleon posture test, dominant eye test, dominant leg test and indicators morphologic asymmetries of the face were used to identify lateral factors. The cognitive model suggests that individuals with a different level of hemispheric specialization/ equipotentiality should have the different predictors of temperament traits. A corresponding finding was revealed by the multiple regression analysis.