Subjective Stress.
State Anxiety. State anxiety will be evaluated using the
state scale of the State Trait Anxiety Questionnaire (STAI; Spielberger,
1983, French version: Gauthier & Bouchard, 1993).
It includes 20 items concerning the current emotional intensity at that
moment, using a 4-point Likert scale ranging from 1 (not at all) to 4
(very much). A score is computed by summing the items. Scores range from
20 to 80, with higher values indicating greater anxiety. The scale shows
good internal consistency and test-retest reliability in different
samples (Barnes et al., 2002).
Stress Item. Based on previous research (Becker et al.,
2019; Lesage et al., 2012; Luettgau et al., 2018; Paszkiel et al.,
2020), the perceived stress item (“Right now, how stressed do you
feel?”) will be measured along a visual analog scale ranging from 0
(“not stressed at all”) to 10 (“extremely stressed”).
Stress Appraisal. We will administer the Primary and
Secondary Appraisal Scale (PASA, Gaab et al., 2005). The wording of the
items will be modified to match the context of the MAST (e.g., replacing
“jury” with “experimenter”). The scale is composed of 16 items on a
scale from 1 (totally disagree) to 6 (totally agree). It measures threat
(e.g., “This situation scares me”), challenge (e.g., This task
challenges me”), self-efficacy (e.g., “In this situation I know what I
can do”), and control expectancy (e.g., “It mainly depends on me
whether the experimenter judges me positively”). We will obtain primary
and secondary appraisal scores by combining the scores from the first
two and last two, respectively. The four factors have shown good
internal consistency (e.g., from .60 to .83; Wirtz et al., 2006).
Repetitive Thinking Processing Modes. The State
Repetitive Thinking Questionnaire (SRTQ; Philippot, 2019) will capture
state negative repetitive thinking. Individuals will rate the extent to
which they are having 10 specific thoughts in the preceding minutes, on
a scale from 0 (“totally disagree”) to 4 (“totally agree”). We will
focus on the Concrete-Experiential (3 items, e.g., “I am focused on
what I am concretely experiencing now”) and Abstract Evaluative (4
items, e.g., “I wonder why I react like this”) processing modes.
Emotion Regulation. The Emotion Regulation Questionnaire
(ERQ; Gross & John, 2003, French version: Christophe et al., 2009) will
measure participants’ tendencies for reappraisal (six items, e.g.,
“When I was faced with the stressful situation, I made myself think
about it in a way that helped me stay calm”) and suppression (four
items, e.g., “I controlled my emotions by not expressing them”). The
wording was modified to evaluate the strategies implemented during the
stressor, ranging from 1 (not at all) to 7 (completely). Previous
studies demonstrated adequate internal consistency (reappraisal, α =
.76, and suppression, α = .72, Christophe et al., 2009).
Physiological Stress. The Mindware Mobile Recorder (Mindware
Technologies, LTD) will be used to measure heart rate, skin conductance,
and respiration at a sampling rate of 500 samples per second. Three
Electrocardiogram electrodes (45mm, Ag/AgCl, liquid gel, MedCat) will be
placed according to Mindware Technologies protocols (seehttps://support.mindwaretech.com/training/):
one on the right collarbone and two on the last two ribs on both sides.
Respiration will also be measured using a belt. In line with the Society
for Psychophysiological Research Ad Hoc Committee on Electrodermal
Measures (SPRAHCEM, (2012), electrodermal activity will be measured
using disposable finger electrode strips (Ag/AgCl, MedCat) placed on the
distal phalanges of the left major and index fingers and filled with
Isotonic Electrode Gel (0.05 molar NaCl paste, Biopac).
These physiological measures will be collected using the BioLab
Acquisition Software (V3.4.1). Systolic and diastolic blood pressure
will be event-based, measured using the oscillometer method with the
Omron M6 Comfort (HEM-7360-E, Omron Healthcare Co., Ltd; for more
information see Topouchian et al., 2014) in sitting position (Shapiro et
al., 1996). The M6 Comfort takes three consecutive 30-second readings.
Procedure
General Procedure
The study will be divided into three successive parts. It will begin
with the signing of an informed consent form and the completion of
online questionnaires before one’s visit to the laboratory. These will
include sociodemographic items, as well as validated questionnaires
evaluating chronic stress (PSS-10; Cohen et al., 1983).
Then, participants will come into the lab for a two-hour visit composed
of cognitive testing followed by an acute stress induction. Participants
will take a 10-minute break between the two sessions to allow for
acclimatization (Shapiro et al., 1996). They will be able to hydrate,
use the restroom, and complete a HRV screening checklist (Laborde et
al., 2017). This questionnaire will help ensure that participants have
avoided alcohol and strenuous physical activity for the previous 24
hours, as well as caffeine, food, and smoking for the last two hours
(Jennings et al., 1981; Shapiro et al., 1996). They will provide their
sleep and wake times and confirm whether they adhered to their usual
sleep routine (Labuschagne et al., 2019).
Participants’ weight and height will be measured before the stress
induction. The lab will be windowless, temperature-controlled, and
electrically shielded to minimize any influences on psychophysiology
measures (Shapiro et al., 1996, SPRAHCEM, 2012).
Acute Stress Induction
Acute stress will be induced using the validated Maastricht Acute Stress
Test (MAST; Smeets et al., 2012; see Figure 1 for the overall
procedure). Participants will first relax for five minutes, while heart
rate, skin conductance, and respiration are continuously measured. Blood
pressure will then be obtained, while participants complete the state
items of the STAI (Spielberger, 1983) and a perceived stress level item
(Becker et al., 2019).
The MAST procedure includes an anticipation, stress, and recovery phase.
During the anticipation phase, participants will read through the MAST
instructions using PowerPoint 2016 (provided by Tom Smeets, Smeets et
al., 2012) and ask any questions. Then, they will complete the stress
item, as well as questionnaires evaluating primary appraisal, emotion
regulation, and repetitive thinking mode. During the stressphase, participants will alternate immersing their right hand in
ice-cold water and performing a mental arithmetic task (serially
subtracting 17 from 2043). Water and arithmetic trials will be exactly
90 and 45 seconds, respectively. The experimenter will be dressed in a
white lab coat and will maintain a neutral attitude. A video camera will
also be placed in front of the participant to record their facial
expressions. Participants will be informed that their facial expressions
throughout the MAST will be analyzed by a research team. Following the
initial 12 minutes of the MAST, participants will complete the
questionnaires again (see Figure 1), and blood pressure will be measured
once more.
Upon completing the scales, participants will be informed that the task
is finished and will be given a 10-minute recovery phase to relax. They
will then complete the STAI and stress items, and we will measure their
blood pressure. Participants will be fully debriefed about the study and
financially compensated with 20 euros.
For a manipulation check, a control group will take part in a modified
version of the MAST (Placebo-MAST, Smeets et al., 2012). Participants
will place their hand in lukewarm water and perform a simple counting
task at their own pace. All elements of evaluation (white lab coat,
camera, or negative feedback for errors in calculations) will be
removed.