Anxiety disorders are a major health problem. It is estimated that one fifth of the population will develop an anxiety disorder at some point in life. To enable better diagnosis and better care, it is necessary to understand how anxiety modulates our brain functions and modifies our behaviour in various situations, particularly social situations. Indeed, anxiety seems to be particularly detrimental to our social interactions. In my doctoral research, I sought to determine how anxiety modulates socio-cognitive mechanisms that are essential to our daily social interactions. Such investigations require a strong methods to elicit anxiety in a simple, consistent and sustained manner.
How can we study the impact of anxiety on our cognition?
Different approaches have been be used
1) A between-subject approach: previous studies on the impact of anxiety on human cognition have mainly addressed this question by comparing groups of anxious vs. healthy individuals.
2) A within-subject approach: instead, we can modulate the anxiety level of the same participant over time. Precisely, participants take part in cognitive tasks, which they performed either in a relaxed vs. anxiety-inducing contexts. Contexts are repeated and alternated. We can assess individual variations in anxiety, and the way it shapes cognitive functioning.
How to create contexts of anxiety in the laboratory?
The predictability of threat is a major determinant of anxiety-related bodily manifestations (e.g. changes in heart rate or fear-startle reflex). The Threat-of-Shock paradigm has been the gold-standard paradigm to induce anxiety. It consists in alternating blocks in which participants are explicitly told that they could receive an electric shock at any time (threat blocks) with blocks in which participants are explicitly told that no such shocks will occur (safe blocks). However, it can pose some ethical issues when testing vulnerable populations. Recently, an alternative solution has been proposed: replacing shocks by aversive screams presented at 95dB.
Our Study: can unpredictable aversive screams induce anxiety when delivered at low intensity?
One permanent issue is that the delivery of 95dB sounds can exceed tolerance (75dB) and danger (85dB) thresholds for audition. Ideally, sounds should not be deleterious for audition at all for anxiety-related reactions to be studied more properly, and to avoid contamination due to the high intensity of stimuli. We thus tested whether anxiety can be induced by unpredictable screams at 70dB. We considered that 70dB screams should be good candidates to induce anxiety as they are interpreted as an unpleasant (without being harmful) signal by communicating impending danger in the environment.
We observed in two different groups of participants (study plus replication) that threat blocks (with unpredictable screams) robustly elicited higher subjective reports of anxiety and higher skin conductance levels (the physiological marker used here to capture participants’ anxiety) for one hour. In addition, we observed a positive correlation between these measures of anxiety. Such coordinated changes across physiological and experiential anxiety responses clearly support the efficiency of our manipulation in inducing an anxiety episode.
Overall, our results provide new evidence that unpredictable delivery of low-intensity screams could become an essential part of a psychology toolkit to investigate the impact of anxiety on a diversity of cognitive functions and populations.
Morgan Beaurenaut (PSL Research University, Paris), Guillaume Dezecache (LAPSCO UCA CNRS, Clermont-Ferrand) & Julie Grèzes (PSL Research University, Paris)
Read the paper here:
Beaurenaut, M., Tokarski E., Dezecache G. & Grèzes J. (2020). The Threat of Scream paradigm: A tool for studying sustained physiological and subjective anxiety. Scientific Reports.
Human by emka angelina from the Noun Project & Morgan Beaurenaut