Feasibility of Self-regulation of the Balance Between Salience and Executive Control Networks
Stress, the non-specific bodily response to any demand, is an important mechanism that aids organisms deal with threats in their environment. These changes profoundly affect various brain regions, that are organised in large-scale networks, such as the Default Mode (DMN), Salience (SN) and Executive Control (ECN) networks. It has been proposed that the latter two networks are activated in a reciprocal fashion in response to stressors, with the SN being more active in the initial stages of stress leading to a general scanning of the environment and heightened arousal, whereas ECN activity is suppressed. A subsequent reversal of these changes ensures a healthy adaptation to volatile environments. A flexible allocation of resources to these two networks would therefore enhance the adaptive value of the stress response. In this project, a real-time functional MRI (rt-fMRI) neurofeedback paradigm was used to determine whether participants were able to control the balance the SN and the ECN. Participants underwent three days of neurofeedback training, and concluded the study after a Transfer session, where their ability to self-regulate without feedback was tested. In addition, during the last session an acute stressor was introduced, namely mild electrical stimulation to the fingers. Participants were able to self-regulate the balance between the SN and the ECN, after receiving rt-fMRI neurofeedback training. It was also possible to self-regulate in the absence of feedback, as well as under the threat of mild electrical stimulation. Data also showed that pupil size was increased while under threat for most participants, confirming that the electrical stimulation was indeed perceived as a stressor. These preliminary data provide encouraging results, showing that it is possible to control the balance between large-scale networks, which could lead to a more flexible reaction to environmental demands.
Faculteit der Sociale Wetenschappen