Roman Kessler
PostDoctoral Researcher · Cognitive Neuroscience & Data Science
News
Publication
September 2025
Our new paper is out in Developmental Cognitive Neurosciences. We demonstrated using EEG and decoding the neural time course of face categorization in 6-12 month old infants, showing an early time window where faces of different species are processed distinctly. We also showed, that face individuation, e.g. decoding the face identity from the EEG signal, is not easily possible. This could indicate a lack of automated and fast-paced individuation of unfamiliar faces in that age, but at the same time could similarly be a result of lack of power combined with the challenging data quality in infants.
Publication
August 2025
I am especially proud of my recent EEG multiverse paper, which got accepted in Nature Communications Biology. Here I systematically evaluate, how standard EEG preprocessing steps influence the accuracy of downstream machine learning models. It particularly demonstrates, how artifacts correlated with the stimulation condition drive decoding performance. Many thanks also to my co-author and friend Alex Enge, who motivated me conducting these analyses and provided many helpful insights during this project.
Publications
Sort by:
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Kessler, Enge & Skeide (2025).
How EEG preprocessing shapes decoding performance.
Communications Biology.
Arxiv Link
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Kessler & Skeide (2025).
Electrophysiological decoding captures
the temporal trajectory of face categorization in infants. |
Developmental Cognitive Neuroscience.
BioRxiv Link
- Kessler & Skeide (2024). [Dataset] EEG Dataset of 38 Infants (Aged 5-13 Months) Viewing Human and Monkey Faces (Two Identities Each). | Zenodo.
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Yücel, Luke, Mesquita, von Lühmann, ..., Kessler, ... (2025).
NIRS reproducibility varies
with data quality, analysis pipelines, and researcher experience. |
Communications Biology.
MetaArXiv Link
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Kessler, Raja, Tapia & Busch (2024).
Towards
Minimizing Efforts for Morphing Attacks - Deep Embeddings for Morphing Pair Selection and Improved
Morphing Attack Detection. |
PLOS ONE.
Arxiv Link
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Kessler, Philipp, Wilfer & Kostev (2023).
Predictive attributes for developing
long COVID – a study using machine learning and real-world data from primary care physicians in Germany.
Journal of Clinical Medicine.
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Kessler & Heinrich (2022).
Temporal frequency
dependence of the polarity inversion between the upper and lower visual field in the pattern-onset
steady-state visual evoked potential. |
Documenta Ophthalmologica.
-
Kessler, Rusch, Wende, Schuster & Jansen (2021).
Revisiting the
effective connectivity within the distributed cortical network for face perception. | Neuroimage:
Reports.
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Thome, Hohmann, Rusch, Smith, Kessler & Jansen (2021).
"I Spy with my Little
Eye, Something that is a Face…”: A Brain Network for Illusory Face Detection. |
Cerebral Cortex.
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Kessler, Henniger & Busch (2021).
Fingerprints, forever young? |
Proceedings of the 25th International Conference on Pattern Recognition (ICPR).
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Sahraei, Hildesheim, Thome, Kessler, Rusch, Sommer, Kamp-Becker, Stark & Jansen (2021).
Developmental changes
within the extended face processing network: A cross‐sectional functional magnetic resonance imaging
study. |
Developmental Neurobiology.
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Kessler, Schmitt, Sauder, … & Jansen (2020).
Long-Term
Neuroanatomical Consequences of Childhood Maltreatment: Reduced Amygdala Inhibition by Medial Prefrontal
Cortex. |
Frontiers in Systems Neurosciences.
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Hildesheim, Debus, Kessler, ... & Jansen (2020).
The Trajectory
of Hemispheric Lateralization in the Core System of Face Processing: A Cross-Sectional Functional Magnetic
Resonance Imaging Pilot Study. |
Frontiers in Psychology.
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Kessler, Bach & Heinrich (2017).
Two-Tactor Vibrotactile
Navigation Information for the Blind - Directional Resolution and Intuitive Interpretation. |
IEEE Transactions on Neural Systems and Rehabilitation Engineering.
Talks
- May 2024
- Psychologie und Gehirn (PUG), Hamburg: Is EEG better left alone for decoding? [slides] [poster]
- June 2023
- Psychologie und Gehirn (PUG), Tübingen: Visual and auditory population coding for quantity in human cortices. [slides]
- March 2021
- German Teletrust Biometric Working Group, European Association for Biometrics: Fingerprints, forever young?
- January 2021
- International Conference for Pattern Recognition (ICPR), Milan, Italy: Fingerprints, forever young? [slides] [poster] [TODO Video recording]
- March 2020
- 2nd Symposium of the AGNP and DGNP: A bilateral model of congenital prosopagnosia – connectivity between FFA and ATL.
- October 2017
- World Congress of Psychiatry, WPA XVII, Berlin: The watchdog won't stop barking. Reduced Amygdala Inhibition in Major Depression. Normalization via Medication, and the Impact of Genetic and Environmental Risk Factors.
Education
PhD Cognitive Neurosciences (Dr. rer. nat.)
Philipps University Marburg · Department for Psychiatry ·
Institute of Medicine
Doctoral thesis: Connectivity models in the face perception domain - interfaces to understand the brain in health and disease?
with Prof. Dr. Andreas Jansen
11/2016–07/2022
M.Sc. Data Science
University of Applied Sciences Darmstadt, Germany & Norwegian Institute for
Science and Technology Gjøvik, Norway
Thesis: Analysis of face embeddings to facilitate image pre-selection for face morphing
with Prof. Dr. Christoph Busch
Term project: Data mining methods for improved understanding of prognostic factors in the US kidney transplantation system. Press: Well ordered chaos
10/2019–01/2022
M.Sc. Cognitive and Integrative Systems Neurosciences
Philipps University Marburg, Germany
Thesis: Network models of emotional face perception
with Prof. Dr. Andreas Jansen
10/2014–09/2016
B.Sc. Biology
Albert Ludwigs University Freiburg, Germany
Thesis: Vibrotactile transmission of directional information
with PD Dr. Sven Heinrich & Prof. Dr. Michael Bach
10/2010–07/2014
Work
Postdoctoral researcher (Data Science & Neuroscience)
Max Planck Institute for Human Cognitive and Brain Sciences · Department for Neuropsychology · Working
group learning in early childhood
since 2022
Data Analyst / Data Scientist
IQVIA GmbH & Co OHG · Real World Evidence
2022
Stipendiary
Norwegian University of Science & Technology
2021–2022
Doctoral researcher
Philipps University Marburg · Medical Faculty · Laboratory for Multimodal Neuroimaging
2016–2021
Guest researcher
Section of functional vision research · University Clinics Freiburg
2016
Student assistant
Philipps University Marburg · Medical Faculty · Laboratory for Multimodal
Neuroimaging
2015–2016
Student assistant
University clinics Freiburg · Central clinical research
2013
Student employee
Eurofins GeneScan GmbH · Freiburg
2011–2013
Stipends
| Year | Type | Amount | Institution |
|---|---|---|---|
| 2021 | Scholarship | 5000 € | National Research Center for Applied Cybersecurity (ATHENE) |
| 2019 | Travel grant | 1030 € | Deutscher Akademischer Austauschdienst (DAAD) |
| 2018 | Travel grant | 1560 € | Marburg International Doctorate (MID) |
| 2018 | Travel grant | 250 € | Marburg University Research Academy (MARA) |
| 2017 | Conference grant | 660 € | World Psychiatric Association (WPA) Young Fellowship Program |
| 2017 | Travel grant | 1860 € | Marburg International Doctorate (MID) |
| 2016 | Workshop grant | 500 € | Gesellschaft für neurobiologische Forschung und Therapie e.V. |
Tools & Materials
Teaching
Course materials
| tba |
Some private hacks
Simplify Debts
If using apps like Splitwise for keeping track of holiday expenses with friends, but don't want to pay
for the
simplify debts
option.
The option calculates the minimum number of transactions to settle all debts between N
friends, reducing the
amount of transactions from up to N × N – N to ≤ N transactions for the whole
group.
The following Shiny app server does the same for you:
➝ Simplify Debts (reduce transactions)
Some work hacks
Zotero incl. free large storage for synchronization between devices
It is very handy to use Zotero between devices (Laptop, iPad, ...), as the synchronization not only of the papers, but also of the comments, hand drawings, etc. works quite reliably!
The free storage from Zotero in the free plan is however limited. With an own cloud service, one can bypass this and get a larger storage (in this example 5 GB) by using e.g. Webo Hosting as free cloud. With the free account and space, go to Zotero Settings → Sync, and choose WebDAV as sync method. The WebDAV URL is the one you can find in Webo Hosting, and the username and password are the ones from your Webo Hosting account.
A super useful add-on I found is a reading list, where you can classify each Zotero item to a read status (i.e., want to read...). No need to keep track of this by hand or separate folders anymore: Zotero Reading List (GitHub)
Language learning
Overview
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