Abstract

Executive Functions and Prefrontal Cortex: Genetic and Neurochemical Influences, Gender Differences, and Novel Methods to Help Children Become Masters of their Own Behavior Adele Diamond Canada Research Chair Professor of Developmental Cognitive Neuroscience, Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada adele.diamond@ubc.ca

Unusual properties of the dopamine neurons that project to prefrontal cortex (PFC) cause PFC to be vulnerable to environmental and genetic variations that have little effect elsewhere. For example, because PFC has a paucity of dopamine transporter protein, it is more dependent on secondary mechanisms for clearing released dopamine, such as the COMT enzyme. Hence variations in the COMT gene selectively impact PFC . It has long been known that some of the brightest people also have the most fragile personalities and are highly reactive to stress. The COMT gene provides a possible mechanism for why the two might go together. Children with one COMT genotype are probably more resilient in the face of stress; children with another COMT genotype, who are vulnerable in adverse, stressful circumstances, probably have extraordinary potential if only the right fit of circumstances can be found. Since estrogen down-regulates COMT transcription, there are gender (and menstrual phase) differences in effects of variations in the COMT gene—and, apparently, gender (and menstrual phase) differences in the effect of stress on executive functions (EFs). Nowhere is the importance of social, emotional, and physical health for cognitive health more evident than with PFC and control functions that depend on it (the executive functions [EFs]). PFC and EFs are the first to suffer, and suffer disproportionately, if anyone is lonely, sad, stressed, sleep-deprived, or not physically fit. For our children to be able to think clearly and creatively and to exercise optimal self-control and discipline (optimal EFs), we need to nurture the whole child: Our children need to feel joyful and that they are in a supportive community they can count on and their bodies need to be strong and healthy. While it may seem logical that if you want to improve academic outcomes you should concentrate on academic outcomes alone, not everything that seems logical is correct.