New Paper - Testing the validity of a novel passive stress task

Our recent paper tests if a novel passive stress task (watching yourself completing an active speech task) elicits a pattern of cardiovascular responding indicative of passive coping. The final paper published in Psychophysiology can be viewed here, or the preprint is available here. Here is just a brief synopsis of the main findings!

Background

But first, just a bit on what we mean by cardiovascular responses to stress. When we talk about cardiovascular responses to stress, we are looking at how our bodies respond when under stress. For example, when faced with a stressful situation our blood pressure might increase, our heart rate increases, oxygen is pumped to our muscles, and we prepare for action (sometimes you might hear this referred to as the “fight-or-flight” response).

How our bodies respond to stress is predictive of future disease, especially cardiovascular disease. Simply, people who show the greatest increases in blood pressure during stress (exaggerated cardiovascular responses to stress) tend to be at greatest risk of heart disease later in life [1]. In stress reactivity research we look at what factors influence our physiological stress response, and how we can modify these factors to help protect against the negative effects of stress, e.g., personality traits, coping styles.

But what actually happens in the laboratory to test this?

Well, researchers use a range of methods to elicit a “stress response” in participants. Essentially we invite people into the lab, stress them out, and see how much their blood pressure increases. This either sounds horrific or fun depending on your viewpoint!

Types of stress tasks

The tasks we use to elicit this stress response vary, and can be generally divided into active and passive stress tasks [2]. Active tasks are tasks that require active engagement (in terms of cognitive engagement), where participants actively participate in the task and have some control over their performance on the task – examples include a speech task or a mental arithmetic task (or both)! Often participants are recorded and are given feedback on their performance during the task - just to make it more stressful (social evaluation). These tasks have been shown to result in increased blood pressure, heart rate (HR), and cardiac output (CO); that is blood pressure responses to active tasks are driven by more cardiac mechanisms, or a myocardial response[3].

Passive tasks, on the other hand, are those that do not require active engagement. Really you just sit there and “put up with” the stress task, you can’t really engage with it or alter your performance. A well-known passive stress task is the cold pressor task; where participants are asked to put their hand in ice-cold water and keep it there for as long as possible. Another task is to show participants really exciting, or sad, or scary video-clips (or negative images) to elicit a “stress” response. These tasks generally elicit a physiological response thought to indicate passive coping; changes in blood pressure are driven by vascular mechanisms, i.e., driven by changes in total peripheral resistance (TPR) [4]. While these tasks do appear to elicit changes in blood pressure, they have a few issues!

Take the cold pressor task for example; this is believed to be a passive stress task and reliably produces increases in TPR (i.e. a more vascular response). However, this task is used in pain research – to elicit pain! Furthermore, if you think about it … if we put our hand in ice-cold water, what will happen to our blood vessels? More than likely our vessels will constrict; which may (or may not) be responsible for the vascular response typically observed. Likewise, watching a sad video-clip might be stressful for someone – but for someone else this might not be the case (in particular if they have seen that clip before)!

Our Study

Therefore, this paper reports on the validity of a novel passive stress task. Does it elicit a physiological response driven by vascular mechanism?

The task we used required participants to attend the laboratory twice; and on each visit complete a stress task. On the first visit participants completed a speech task (an active task) that was video-recorded. A year later, on the second visit, participants were asked to watch the video-clip of themselves completing the speech task (the passive task). At each visit participants completed a 20-minute acclimatization and a 10-minute resting baseline prior the 5-minute task (see Figure 1).

This type of task has been used in previous research, and elicits increases in blood pressure [5,6,7]. However, no research had examined if this passive task elicited changes in blood pressure driven by vascular mechanisms – indicative of passive coping.

Figure 1. Outline of laboratory paradigm employed

We expected everyone to show a physiological stress response; but we expected the active task to produce blood pressure increases driven by cardiac mechanisms (e.g. increased CO) and the passive task to produce blood pressure increases driven by vascular mechanism (e.g., increased TPR). Indeed, this is what we found!

Both tasks elicited a cardiovascular stress response. The active task (speech task) led to increases in systolic blood pressure (SBP), diastolic blood pressure (DBP), HR, and CO (with no change in TPR). While the passive task led to increases in SBP, DBP, and TPR (with no changes in HR or CO). This pattern of responding is consistent with that observed during more traditional passive stress tasks, such as the cold pressor task and film-clips.

The results suggest the validity of this task as a way of inducing passive coping mechanisms in a laboratory setting, and overcomes the limitations with the passive tasks that have been used to date (e.g., the cold pressure task, negative imagery/film-clips). It can even be used within the same laboratory setting as in previous research[7]; and subsequently in my own research...stay tuned for that paper!

Note: This research was supported by an Irish Research Council New Horizons Research Project Award awarded to Dr Siobhán Howard (REPRO/2015/39)

Full paper: Griffin, S. M. & Howard, S. (2020). Establishing the validity of a novel passive stress task. Psychophysiology, 57, e13555. https://doi.org/10.1111/psyp.13555

Key References

[1] Chida, Y., & Steptoe, A. (2010). Greater cardiovascular responses to laboratory mental stress are associated with poor subsequent cardiovascular risk status: a meta-analysis of prospective evidence. Hypertension, 55(4), 1026-1032. https://doi.org/10.1161/HYPERTENSIONAHA.109.146621

[2] Obrist, P. A. (1981). Cardiovascular psychophysiology: A perspective. New York, NY: Plenum Press.

[3] Winzer, A., Ring, C., Carroll, D., Willemsen, G., Drayson, M., & Kendall, M. (1999). Secretory immunoglobulin A and cardiovascular reactions to mental arithmetic, cold pressor, and exercise: Effects of beta-adrenergic blockade. Psychophysiology, 36(5), 591–601. https://doi.org/10.1111/1469-8986.3650591

[4] Sherwood, A., Allen, M. T., Obrist, P. A., & Langer, A. W. (1986). Evaluation of beta-adrenergic influences on cardiovascular and metabolic adjustments to physical and psychological stress. Psychophysiology, 23(1), 89–104. https://doi.org/10.1111/j.1469-8986.1986.tb006 02.x

[5] Schwerdtfeger, A., & Rosenkaimer, A. K. (2011). Depressive symptoms and attenuated physiological reactivity to laboratory stressors. Biological Psychology, 87(3), 430–438. https://doi.org/10.1016/j.biops ycho.2011.05.009

[6] Hartley, T. R., Ginsburg, G. P., & Heffner, K. (1999). Self presentation and cardiovascular reactivity. International Journal of Psychophysiology, 32(1), 75–88. https://doi.org/10.1016/S0167-8760(99)00003 -3

[7] Soye, A., & O'Suilleabhain, P. S. (2019). Facets of openness to experience are associated with cardiovascular reactivity and adaptation across both active and passive stress exposures. International Journal of Psychophysiology, 140, 26–32. https://doi.org/10.1016/j.ijpsy cho.2019.03.016