The nature of individual differences in EEG parameters during homogeneous visual field in 5- and 6-year-old twins: a pilot study.

Objective: To assess the genetic and environmental influences on the inter-individual variability of spectral EEG parameters under two conditions of reduced visual input in preschoolers.

Methods: EEG was recorded in 21 monozygotic and 20 same-sex dizygotic twin pairs aged 5-6 years under the Closed eyes and Darkness conditions. The contributions of genetic and environmental influences to individual EEG parameters were estimated using structural equation modeling.

Longitudinal genetic analysis of childhood IQ in 6- and 7-year-old Russian twins.

Using a longitudinal twin study of Moscow children, we have studied the development of psychometric intelligence during the transition from preschool (age 6) to school (age 7). Children were tested using the Wechsler Intelligence Scale for Children (WISC). Simplex models were applied to explore the relationship of different sources of phenotypic variance.

On the application of queuing theory for analysis of twin data.

A mathematical model based on queuing theory is used to study the dynamics of environmental influence on twin pairs. The model takes into consideration genetic factors and effects of nonshared environment. Histograms are exploited as base analysed characteristics, with the method of minimum chi-square yielding estimated characteristics.