Neural correlates of children's theory of mind development

Essential to our human ability to interact and communicate with others is an appreciation of mental states. An understanding of concepts such as beliefs, desires, and emotions, and their causal connections to actions is often referred to as having a "theory of mind" (Wellman, 1990). The uniquely human nature of theory of mind and its impairment in the neurodevelopmental disorder of autism have resulted in great interest in understanding the brain basis of theory of mind. However, a fundamental gap in research on and theorizing about the brain basis of theory of mind is the absence of developmental data and the neglect of developmental issues. However, theory of mind is a developmental phenomenon, and without developmental neuroscience data, brain research is unable to provide complete insight into how theory of mind develops. The current research examines the functional relationship between theory of mind development and brain development.;Included in this dissertation are two main studies of the neurophysiological underpinnings of theory of mind and its development. Both studies were conducted with the human event-related brain potential (ERP) methodology. A multi-trial belief-reasoning task was specifically developed to be compatible with the ERP methodology. In the first ERP study with adult participants, the results showed a left-frontal negative late slow wave associated with judgments about beliefs in contrast to judgments about reality. The second ERP study is the first to examine the brain basis of theory of mind in children and is the first to examine possible links between functional brain development and theory of mind development. The results from the second ERP study, with a new sample of adults, confirmed the findings in the first ERP study. Furthermore, the results from the second ERP study, with a sample of 5- and 6-year-olds with false-belief understanding, found a more bilaterally diffused frontal negative late slow wave associated with judgments about beliefs. A negative late slow wave was not found in a group of 5- and 6-year-olds without false-belief understanding. These findings demonstrate a developmental pattern of increasing localization and left lateralization of the frontal negative late slow wave in association with theory of mind development.