Thomas Z. Ramsøy

Stress and the Brain: A Network Connection

In the heart of Copenhagen, my team at Neurons Inc. and I embarked on a fascinating journey. Our mission? To unravel the mysteries of the human brain under stress. Our tools? Electroencephalograms, or EEGs, are capable of capturing the electrical symphony that plays out in our minds every second of every day.

My team, including Farzad Saffari, Kian Norouzi, Sahar Zarei, and our collaborator Luis E. Bruni from Aalborg University, set out to explore a simple yet profound question: How does our brain react to varying levels of stress? And more importantly, how does this impact our decision-making processes?

How we tested stress in the brain

The experiment was as intriguing as the question itself. We invited forty-one volunteers to our lab. Each participant was fitted with an EEG cap, a device that would allow us to monitor the electrical activity in their brain. They were then exposed to three levels of mental stress, each designed to push them out of their comfort zone just a little bit more.

Flow Diagram of the study

As the participants navigated through these stress-inducing tasks, the EEGs recorded the electrical activity in their brains. But we didn’t just look at the raw EEG data. We used advanced methods like Inter-Trial Phase Coherence (ITPC) and Phase Lag Index (PLI) to analyze the synchrony and connectivity between different regions of the brain. These methods go beyond classical EEG analyses and open new possibilities in understanding how our brains function.

The general procedure of the experiment shows the flow of the tasks (A), the order of tasks (B), and the stimuli (C).

What did we find?

What we discovered was startling. As the level of stress increased, the synchronization and connectivity between different regions of the brain decreased. It was as if the orchestra of the brain was falling out of tune, each section playing its melody, no longer in harmony with the others.

The distribution of the ITPC values
Brain connectivity drops dramatically when going from relaxed states to high levels of stress.

But what does this mean in a broader sense, such as for businesses and consumer behavior? As the brain’s harmony falters under stress, so does our decision-making process. A stressed consumer may make impulsive decisions, or they may avoid making decisions altogether. Understanding this can help businesses tailor their strategies, whether it’s simplifying choices for stressed consumers or creating a calming environment to help them make better decisions.

Moreover, our research, which was part of the RHUMBO EU project, has opened up a new frontier in predicting consumer behavior. We found that a Random Forest classifier could predict three levels of stress with 83.78% accuracy based on EEG data. This suggests that EEG features could serve as a novel neurometric for quantifying in vivo stress levels. Imagine a future where businesses can use this technology to better understand their customers, to create experiences that are not just engaging, but also cognizant of their mental state.

Our journey into the human brain has only just begun. As we continue to explore this fascinating organ, we hope to uncover more insights that can help businesses better understand their customers. After all, the brain is the seat of all our decisions, and understanding it is the key to predicting consumer behavior.