30.01.2023UZH Postdoc Team Award

Silvia Maier and Marcus Grüschow met at the Department of Economics. “The department had a policy at the time that people who shared an office should be working on research questions in different fields,” says neuroeconomist Silvia Maier, who researches at the joint Translational Neuromodeling Unit at UZH and ETH Zurich. “The idea is that by talking to each other, people will come up with shared research ideas.” And this is precisely what happened with her and psychologist and neuroscientist Marcus Grüschow. Their research focuses on self-regulation and stress. It explores who is or isn’t good at handling stress, and how we can learn to control our response to stress.  

In a research project on dietary self-control, Silvia Maier was able to show how even moderate levels of stress negatively affected test subjects’ self-control – and not just acute stress, as was already known. For the project, she analyzed various regions of the brain using functional Magnetic Resonance Imaging (fMRI) to record the neural interactions between stress and self-control. Having established these data, she then teamed up with Marcus Grüschow, who specializes in pupillometry, the measurement of pupil size and reactivity.

“The size of pupils plays a key role when measuring the emotions of someone who is under stress,” says Marcus Grüschow. “Exposure to light isn’t the only factor that influences the size of our pupils. We can also observe changes when lighting stays the same.” A person’s eyes can reveal information about their emotional state, for example. When we’re happy or afraid, our pupils dilate. This is regulated by our autonomic nervous system and happens unconsciously.

Resilient to stress
The researchers observed test subjects using pupillometry and measured their response to unexpected strong stimuli. Scary images, for example, trigger a pupillary response that can be observed. This happens in mere milliseconds. Over the course of their project, the researchers were able to identify individuals who would respond to the stimuli but then also flexibly reappraise the situation. These individuals successfully used strategies to modulate emotional stress, and as a result of this their pupil constricted. “Some people even do this automatically. They use an emotional buffer or regulation strategy to mitigate the stress-inducing effects,” explains Grüschow. “People who can respond this flexibly are resilient to stress, while others experience stress for longer.” The latter may be at risk of diseases as a result of exposure to stressful situations.

Preventing stress overload
“It’s not trivial to measure whether individuals engage in regulating their emotions at any given moment, and most importantly, to predict how successful they will manage to do it.  These questions are paramount for both basic and applied research, because inflexibility or inability to adaptively regulate emotions through strategies that favor beneficial behavior in the long term is a hallmark of diseases such as depression, eating disorders, substance abuse and post-traumatic stress disorder,” says Silvia Maier.

Measuring the increase in pupil dilation could be used to help people who react strongly to stress, and emotional stimuli improve their resilience toward stress. This is one of the projects that Silvia Maier and Marcus Grüschow are currently pursuing