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Image: Jann Billker

Katharina Wulff Group

Research group Human responses to natural daylight in physiology and mental health.

Daylight provides energy and information on direction of time for the ecosphere. I am fascinated by the biological mechanisms that organisms developed to anticipate climate variations to occupy diverse geophysical spaces. Studying human individuals in our Daylight Laboratory at subarctic conditions and in their homes, we will better understand how our brain and behaviour adapt under quickly changing natural light and which conditions have the biggest impact on mental health.

Working closely with urban architects, engineers and lighting designers, I hope one day, we will no longer be deprived of daylight because buildings taking advantage of daylight glazing and plain facades are substituted with greenery.

My favourite research matter

I want to introduce you to my favourite research matter – the photon. The photon is the smallest quantum of energy that produces nothing less important than - daylight. Without photons of daylight we would not exist.

And it is no accident that human eyes can absorb photons. Because the detection of daylight is a very powerful tool to orientate in space and time. The sun emits continuous spectrum of wavelengths to which our eyes have developed specialised photoreceptors to signal changes in light intensity.

In my studies I recruit children, women and men for behavioural studies. Studies that look at how natural daylight impacts on our eyes and - in fact - our entire physiology. Because, our bodies are reliant on daylight to tell time, it affects our mood, brain chemistry and it works closely with our body clocks to tell us when it is time to be awake and to sleep. When and for how long to be awake and sleep varies from person to person.

Today – we miss out on natural daylight to a large degree because we expose ourselves heavily to artificial lighting. But this lighting is crude because it does not account for, or maintain, the natural variation that we get from the daylight composition.

So the questions we need to be asking are:

· What is it, what we are doing with our lifestyles that causes our physiology to change?

· And, what is it what we are losing out when we are depriving ourselves of daylight?

Read more on Katlab.org


Open positions in the lab

For questions regarding future positions, or questions regarding master thesis projects, please contact Katharina Wulff (katharina.wulff@umu.se)

Head of research

Katharina Wulff
Associate professor, research fellow, other position


Participating departments and units at Umeå University

Department of Molecular Biology, Department of Radiation Sciences
Latest update: 2023-01-23