Freezing for better performance part 1!

Did you know that “freezing” is actually very important for performing well and making good decisions under high pressure? I did not. Did you know that what we often mean by freeze is not freeze but ‘fright’? And that as first responder trainers we should better speak about choking under pressure instead of freezing! I did not know about the difference between a ‘good’ and a ‘bad’ freeze and how the autonomic nervous system acts different in both cases? And we only learn to perform better under pressure if we bring participant in a state of pressure where there is stress and it is linked to action and decision-making. And to my suprise: that you don’t need realistic VR simulations for this at all.

Their research shows that low heart rate (HR) and high HRV under threat is associated with better perception (Lojowska ea 2016; de voogd ea 2022) faster acute shooting decisions (Hashemi ea 2019) better cost-benefit analysis in approach-avoidance decisions (Klaassen in prep). However it is not only linked to better acute performance but also predictive of better stress-resilience in a longitudinal study in 400 police officers (Jaswetz in prep).

Finally, did you know that there is a game developed by Prof. Karin Roelofs and her team @ Radboud University that trains all this for police officers!

I spoke with Karin Roelofs , a Professor of Experimental Psychopathology at the Behavioural Science Institute (BSI) and chair of the Affective Neuroscience group at the Donders Institute for Brain Cognition and Behaviour (DI), Radboud University Nijmegen (RU). She studies and follows police officers on the topic of dealing with acute and chronic stress and the relation with performance and mental health outcomes. 

Topics in the video part one:


Police paradox (staying calm in stressful situations)

What is Freezing and why is it important for better performance?

A simple representation of defensive behavior from Roelofs, K. (2017). Freeze for Action. Neurobiological mechanisms in animal and human freezing. Philos Trans R Soc Lond B Biol Sci. 372(1718).

Important for acute situations but also for long term mental health

Voluntary freezing (low heart rate and so on)

Is Freezing good or bad?

The autonomous nervous systems in freezing are optimal with parasympatic as a break

The metaphor of a car race, release the break

The fright state and the difference with freezing

How people behave while in fright

Choking under pressure as a better term for ‘bad freeze aka fright

Long term stress resilience

Longitudinal police study on acute stressors

Who is susceptible to mental health problems

Predictors of resilience (control autonomic responses)

Physiological mechanisms of the stress reaction

VR game based on biofeedback

VR game forces officers to recognize their state and to regulate their ANS

How important is realism in a VR game?

Ecological validity is important, not the visuals

Action and DM under stress are key elements

Using set shifting

What mental skills are taught

The importance of breathing for self-regulation

Officers choose their own strategy

How does this training transfer to the real world?

How to use this technology on the street (giving reminders)

Developing triggers/ habits to apply skills in practice

Is biofeedback material required for this training?

Register – Regulate – Reflect

Personalized que

Sniper study and the importance of personalized approach



  1. Roelofs, K. (2017). Freeze for Action. Neurobiological mechanisms in animal and human freezing. Philos Trans R Soc Lond B Biol Sci. 372(1718). pii: 20160206. doi: 10.1098/rstb.2016.0206..
  2. Michela A, van Peer JM, Brammer JC, Nies A, van Rooij MMJW, Oostenveld R, Dorrestijn W, Smit AS, Roelofs K, Klumpers F, Granic I. 2022. Deep-Breathing Biofeedback Trainability in a Virtual-Reality Action Game: A Single-Case Design Study With Police Trainers. Frontiers in Psychology, 13:806163. doi: (a follow-up in 50 police trainers is currently under review)
  1. Hashemi MM, Gladwin TE, de Valk NM, Zhang W, Kaldewaij R, van Ast V, Koch SBJ, Klumpers F, Roelofs K. (2019). Neural Dynamics of Shooting Decisions and the Switch from Freeze to Fight. Nature Sci Rep. 9(1):4240. doi: 10.1038/s41598-019-40917-8.

And for the die hearts interested in neural and autonomic interactions during freezing:

  1. Roelofs K, Dayan P (2022) Freezing revisited: coordinated autonomic and central optimization of threat coping. Nature Reviews Neuroscience. 23, 568–580 Perspective DOI: 10.1038/s41583-022-00608-2