Fig. 2

Experimental design for each of the tasks residing in four domains of stress regulation (implicit-exogenous, explicit-exogenous, implicit-endogenous, and explicit-endogenous) with example stimuli. A An image of a room is shown on the screen as the context. Shortly after, a shape (e.g. circle or square) is shown within the room providing information on how likely it is to receive an electrical stimulation on the hand. During the conditioning phase, electrical stimulations are administered at the end of 35% of trials depicting one of the shapes. The other shape is never paired with an electrical stimulation. In the remaining phases of the task the same stimuli are shown but electrical stimulations are never administered. B Participants select the emotion depicted on a face (happy or scared) while ignoring the word describing an emotion (happy or scared; “blij” or “bang” in Dutch) superimposed on top of the face. The word can either match the emotion on the face (congruent trial) or not (incongruent trial). Depicted stimuli [61] are examples; actual stimuli will be taken from Ekman and Friesen. C Participants fixate their gaze on a fixation cross for 5 min during a resting state scan. A stress induction procedure follows, including a socially evaluated cold pressor test and a mental arithmetic task. Another 5-min resting state scan is acquired after the stress induction procedure. D Participants are asked to make the grey disk larger or smaller using only mental strategies. After a short rest they see the size of the disk change, reflecting their brain activity during their regulation period. This serves as feedback which can be used to learn and improve one’s strategies to control their brain activity