Several research projects aim to investigate the neurobiological mechanisms underlying (mal)adaptive behaviour, by combining hormone interventions with behavioural and/or neural (EEG or fMRI) assessments in healthy and clinical samples.
In several studies, we have investigated the effects of the stress hormone cortisol on approach-and avoidance behaviour and attention to threat. The results of these studies showed a direct link between increased cortisol stress-responsiveness and social avoidance behaviour in patients with SAD (Roelofs et al., 2009). Furthermore, studies using oral administration of a small dose of cortisol showed that cortisol facilitated relative avoidance, as well as early processing of angry faces in high anxious participants (van Peer et al., 2007;2009). Modulation of these effects by individual differences in (social) anxiety and task factors (van Peer et al., 2010; Putman & Roelofs, 2011) suggest that the effects of cortisol are context-dependent and facilitate behaviour/processing that is most relevant to the situation.
“The psychoneuroendocrinology of social anxiety. An emotion regulation approach.” is a research program that was funded by the Netherlands Organisation of Scientific Research (NWO) by means of a VIDI grant. The project aimed to investigate the neural and endocrine mechanisms underlying social motivational behavior in humans. In specific, the project explored the effects of testosterone administration on social motivational behavior in healthy participants and in patients with social anxiety disorder. The results of this project have shown that patients with social anxiety disorder have reduced testosterone levels and that oral administration of a small dose of testosterone promotes social approach in healthy participants (Enter et al., 2014) and alleviates social avoidance in these patients (Enter et al., 2015; 2016). We have also shown that testosterone plays an important role in how the brain regulates fight-flight tendencies in healthy individuals and in aggressive samples (Radke et al., 2014; Volman et al., 2016).
Neurodefense is a research program that is funded by the European Research Council (ERC) by means of an ERC starting grant. The project aims to investigate defensive freeze-fight-flight reactions in humans. In specific, the project focuses on the neural and endocrine mechanisms underlying these defensive reactions. We explore the influence of hormones –such as cortisol and testosterone- on the control of defensive freeze-fight-flight reactions.
In addition, the project aims to investigate the role of defensive freeze-fight-flight responses in the development of internalizing and externalising symptoms. Therefore, adolescents will be tested at a critical transition stage in their lives (between age 14 and age 17), when most symptoms develop. We have shown that testosterone plays an important role in puberty related shift form subcortical to frontal control over emotional action (Tyborowska ea, 2016). We have also shown that testosterone plays an important role in how the brain regulates fight-flight tendencies in healthy individuals and in aggressive samples (Radke et al., 2014; Volman et al., 2016):
In another project, we investigate how administered testosterone causally affects the psychological mechanisms underlying different types of value-based decision making and choice behaviour. The data-collection of this project is finished , the data-analyses plan will soon be registered on the Open Science Framework (Isa Woyke, Iris Iklink and Bernd Figner).