Dirk J. A. Smit


Genetic neuroscience in psychiatry

Focus of research

My focus of research lies in the intersection of two major scientific fields, neuroscience and genetics.


EEG is my main tool of investigation of how the brain works. Oscillatory activity (in rest or during task execution) is pervasively present in the signals that are recorded from the brain, both outside the skull and inside the brain (intracranial EEG). These oscillations are increasingly recognized as an important, perhaps even crucial element of the active brain. A large body of evidence shows that oscillations reflect synchronization of distant and not-so-distant brain areas, allowing them to synchronize neuronal spike activity and pass information.

I investigate the large scale properties of the brain network that show these interlocking oscillations. What brains show increased levels of synchrony, and is this predictive of behavior? What properties do the networks have that may reflect increased efficiency, measures that are based on graph theory? What are the intrinsic dynamics of the brain's activoty, and how do these predict behavior, ranigng from the most simple fingertapping task to creativity? How are intrancranial recordings of subcortical areas involved in reward processing and know to be affected in several mental health disorders, connected to cortical brain areas, mainly frontal cortical areas such as the Anterior Cingulate Cortex? 


My main focus here is to investigate whether the EEG measures based on oscillatory activity are genetic. Spoiler, some measures of brain function are one of the most heritable traits in humans. More recently, I have added investigations of the molecular genetics of brain activity. In addition, I am involved in investigations of the molecular genetics of mental health traits, including Obsessive-Compulsive disorders and substance use disorders. 

In addition, I am part of several genetic consortia: The Psychiatric Genomics consortium and ENIGMA. Specifically, I lead the ENIGMA-EEG consortium investigating the molecular genetics underlying brain activity, in order to relate these genetics to mental health disorders. I am further part of the OCD working group of the PGC, and co-leader of the OC symptom group and Hoarding group. These groups' aims is perfroming a Genome-Wide Association Study (GWAS) for their respective traits.