From the heart to the brain – or the other way around? Interview with Dr. Julian Koenig

From the heart to the brain – or the other way around? Interview with Dr. Julian Koenig about his recent paper in Psychophysiology

A few weeks ago, PD Dr. Julian Koenig (University of Heidelberg, Germany & University of Bern, Switzerland) was the lead author on a remarkable publication in Psychophysiology. It is remarkable because it’s rare to see such an extensive collaboration in our area, with scores of researchers from more than 60 different institutions. And this large-scale collaboration wasn’t a gimmick: it was necessary to achieve a sample size that can reliably find effects which have eluded earlier studies. As a result, Julian and his colleagues were able to describe the fascinating interconnections between cortical thickness and cardiac activity, which helps clarify inconsistent prior results and furthers our understanding regarding cardiac health and aging.

For the SPR website, we spoke with Julian to find out more about the background of this interesting study.

The Origin Story

 What got you interested in this type of research?

We and others previously investigated the brain morphological concomitants of heart rate and its variability in a variety of smaller samples. Although we were able to reproduce core findings - showing a consistent pattern concerning the brain regions associated with autonomic activity - it was striking to see considerable heterogeneity in effects sizes and variability in the regions of interest, alongside of the usual suspects, showing meaningful correlations.

“Someone had to raise this treasure for our field of psychophysiological research!”

What evidence lead you to believe that the current study was something worth pursuing?

In recent years, several studies discussed the limitations of small sample sizes in mono-centric neuroimaging studies. Simultaneously, we learned from studies on the reliability and validity of photoplethysmography based measures indexing cardiac activity even at lower sample-rates. We came to realize that neuroimaging data obtained on MR scanners from a certain vendor, include puls-oxy signals recorded with on-board equipment. While these data are used to correct for physiological noise in the neuroimaging field - someone had to raise this treasure for our field of psychophysiological research! I chatted back with close colleagues in the field to see who would be able to contribute data. The resonance was quite good and the core team to lift this soon established. Following a pre-print, outlining the principal idea and methodological approach, we started a social media initiative to find additional labs outside of our established networks. From thereon it was all about actually getting this done and wrapping it up – we didn’t think it should take another 3 years from thereon…

The Discovery

 Describe the day / what you felt when you discovered the current study’s findings?

 Honestly, I consider the aspect that multi-lab projects in psychophysiology are possibly the most significant finding of this study – outside of the actual results. There wasn’t a particular day on which we realized the momentum we had created.

 What result of this project did you find most exciting and what results were most unexpected?

 Dan (Quintana) and I chatted back and forth to decide on when to stop data collection; I think once the numbers hit n = 1000 and the author list wouldn’t fit a single page anymore, including researchers form all around the world, is when we got really excited about what this initial idea had grown to be. On a personal note, although I expected this to somehow work out given the great collegiality I experienced over the years in the field of psychophysiological research, I was proud to see what we are able to achieve, when we work together.

“Communication involving more than 80 scientists was certainly challenging.”

The Challenge

 What were some of the challenges you had to overcome to make this discovery? Or What was the most memorable challenge you had to overcome?

 I think setting up a transparent process of data management and analyses, co-working and (most importantly) communication involving more than 80 scientists was certainly challenging. However, as noted earlier, the community was very supportive, kind and patient along the way. The most memorable challenge was to realize that the editorial system hosting our societies journal (and many others) is not equipped for the submission of manuscripts with that many authors. Without the fantastic support by the editorial team and Monica (Fabiani) this would not have been possible. I think that’s one very pragmatic aspect we need to address to support future collaborations that are scalable. It is ridiculous how limitations by the technical infrastructure and culture we have set up to be more productive, have turned out to compromise actual progress and influence the way research is conducted. Or do you remember your password for manuscript central?

Looking Ahead

 Do you have plans to follow-up on these results? If so, what will you do next?

It’s been in the making for a while, but this current project encouraged me once more to follow-up on an old idea: a repository for heart rate (variability) data collected under a standardized recording protocol – the HRV repository. I think providing the technological infrastructure, enabling data sharing in adherence with methodological standards, ethical regulations, while simultaneously balancing personal interest by different labs is the bottle neck we have to solve to see more large-scale research like this published in the future. Further, we have also made arrangements with the UK BioBank to conduct HRV analyses on the rich existing ECG data set they have. These data will later be made available to researchers worldwide. This project has experienced some delay due to the ongoing COVID-pandemic but I’m very exited about these opportunities.

“I hope to see more multi-lab projects and replication attempts in the field of psychophysiology.”

If we speak again in a year, how do you think this discovery will have changed research or the field? How will things in your area of research have changed?
Generally speaking, I hope to see more multi-lab projects and replication attempts in the field of psychophysiology. I think we have great opportunities to work together as physiological signals don’t face the extent of limitations we see in other disciplines or those associated with other measurement modalities when it comes to data sharing. I hope that we as a society can embrace these ideas in the future and support each other by providing the tools and expertise to realize multi-lab projects and joint grant applications on the basis of international exchange and collaboration.

 Thank you very much for this interview!

(This interview was conducted and edited by Jens Foell)