Research Projects

Brain network to classify personality [disorders]

The mass-univariate approach to study the brain basis of psychiatric disorders is not working. So we have to try something else. The brain is a network, and network analyses seem like a natural way to approach brain imaging data. By combining network analyses with machine learning we are studying the predictive power of node centrality to predict personality and personality disorders.

Statistical Power in fMRI

The great Jacob Cohen has long addressed statistical power and its consequences.

"... there is the irony that the "sophisticates" who use procedures to adjust [their alpha error] for multiple tests [ā€¦] are adjusting for a nonexistent alpha error, thus reduce their power, and, if lucky enough to get a significant result, only end up grossly overestimating the population effect size!ā€
Cohen, J. (1994). The earth is round (pā€‚< .05). American Psychologist, 49(12), 997ā€“1003.

Yet despite his warnings, few things have changed. In brain imaging research the combination of small samples and many variables make the power problem more prominent, and the consequences more troublesome. We have created a simulation and analyzed data to illustrate the problem of low statistical power in fMRI research.

Behavioral control and stress

Being able to control events make them less stressful. At least that is the intuition, the relation between control and stress is actually fairly complicated, for instance illustrated by Suzanne Thompson. Yet once these theoretical issues are tackled, behavioral control is one of the few psychological processes that has a well described neural mechanism which involves the vmPFC and connections to subcortical areas, such as the PAG and amygdala. We have developed a paradigm to study this process in humans, combined with a proposed data-analytic methodology to investigate the role of the vmPFC.

The neurobiology of Social Anxiety

Social anxiety is characterized by a persistent and excessive fear of social or performance situations. Like many other psychiatric disorders, social anxiety is highly co-morbid, but there are a few symptoms that can be considered specific to social anxiety. We have developed some paradigms that aim to tackle these processes.