Genes and experience shape brain networks of conscious control.
Review
Overview
abstract
One aspect of consciousness involves voluntary control over thoughts and feelings, often called will. Progress in neuroimaging and in sequencing the human genome makes it possible to think about voluntary control in terms of a specific neural network that includes midline and lateral frontal areas. A number of cognitive tasks involving conflict as well as the control of emotions have been shown to activate these brain areas. Studies have traced the development of this network in the ability to regulate cognition and emotion from about 2.5 to 7 years of age. Individual differences in this network have been related to parental reports of the ability of children to regulate their behavior, to delay reward and to develop a conscience. In adolescents these individual differences predict the propensity for antisocial behavior. Differences in specific genes are related to individual efficiency in performance of the network, and by neuroimaging, to the strength of its activation of this network. Future animal studies may make it possible to learn in detail how genes influence the common pattern of development of self-regulation made possible by this network. Moreover, a number of neurological and psychiatric pathologies involving difficulties in awareness and volition show deficits in parts of this network. We are now studying whether specific training experiences can influence the development of this network in 4-year-old children and if so, for whom it is most effective. Voluntary control is also important for the regulation of conscious input from the sensory environment. It seems likely that the same network involved in self-regulation is also crucial for focal attention to the sensory world.