Risk taking during decision-making under stress:
The effects of psychological stress on risk taking in feedback-based decision making

This protocol describes three separate studies which together aim to provide
novel insights in the underlying (neural) workings of the effects of stress on
the neural underpinnings of risk taking in feedback-based decision making.

Rationale:
Feedback-based decision-making is a frequently occurring process in our
everyday lives, which is often performed under a certain amount of stress.
Also, because by far the most of our decisions contain a level of uncertainty
regarding the outcome, risk is an important aspect of this decision-making. It
is known that under stress males tend to increase their risk-taking whereas as
females tend do decrease their risk-taking. The neural underpinnings hereof are
not yet fully elucidated. It is also not yet clear if the processing of
positive and negative feedback is a mediator of this effect stress has on risk
taking. We aim to gain insight in the neural workings during feedback-based
decision-making under stress by using EEG and fMRI during both decision-making
and feedback processing in a suited decision-making task, the BART task.

Study 1
To determine if and to what extent it is possible to manipulate physiological
stress responses (heart rate, systolic and diastolic blood pressure and
electrodermal response) using our developed set-up. To this end we will look at
the correlation between predicted physiological stress response by the set-up
and the actual measured stress response, including the measured cortisol levels.

Study 2
1. Determine the effects of stress on feedback processing in a feedback-based
decision-
making task. To this end we establish the effect of stress (aforementioned
physiological stress responses) on the amplitude of FRN and P300 EEG components
in response to positive and negative feedback during the BART task, and the
differences between sex.
2. Determine if this processing of feedback is a mediator of the effect of
stress on risk-taking.

Study 3
1. Gain insight in the structures involved in decision-making during stress. To
this end we will establish the effect of aforementioned physiological stress
responses on the BOLD response in the limbic system during decision-making in
BART trials, and the potential differences between sex.
2. To gain insight in the structures involved in feedback processing in a
feedback-based decision-making task during stress. To this end we will
establish the effect of aforementioned physiological stress responses on the
BOLD response in the limbic system in response to positive and negative
feedback in BART trials, and the potential differences between sex.

Studies 1 and 2 are interventional EEG studies three groups (two experimental
and one control group), study 3 is an interventional 3T fMRI study with one
experimental group.

Stress induced through a transient psychological stressor in the form of a
digital game.

The total duration of the experimental session in study 1 and 2 is around two
hours, in study 3 the session is around one hour, all completed in one session.
During this experimental session physiological measurements and either EEG or
fMRI measurements are performed. Subjects perform computerized tasks during
which stressful stimuli can be presented. There are no known risks associated
with either the measurements or the presented stimuli in this research. Besides
financial remuneration, no immediate benefits are to be expected from
participation in this study for the subjects.