Hedderik van Rijn

Experimental Psychology / Statistical Methods and Psychometrics
University of Groningen

prof. dr. Hedderik van Rijn
Heymansbuilding, room 2.76
Grote Kruisstraat 2/1
NL-9712 TS Groningen

+31-50-363 6290

Temporal Cognition

All behavior takes place in time. My general research goal is to understand how cognitive processing is influenced by temporal constraints, how temporal patterns extracted from human behavior can be used in applied settings to improve personalization of artificial systems, and how the brain keeps track of time.

Although I use many different methods, from functional magnetic resonance imaging (fMRI), electroencephalography (EEG), pupil dilation, and behavioral studies to behavioral genetics using drosophila, the goal of all these approaches to inform formal models of temporal cognition. Depending on the purpose, these formal models can take the form of higher level mathematical (e.g., drift diffusion or linear-ballistic accumulator models), symbolic process (ACT-R based) models, the combination of both, or neurobiological modeling of low-level biological processes underlying time perception.

In addition to my work on temporal cognition, I have a keen interest in developing new methods for studying human cognition. For example, together with my colleagues I have developed new methods for model-based neuroscience, methods to assess whether behavior is driven by competing strategies in cognitive tasks, algorithms to deconvolve the pupillary response, and I have developed new apparatus and methods to do behavioral, cognitive experiments with drosophila.

Time as Cognitive Control

Although often not ackowledged, in many experimental tasks time plays an important role, if only because participants need to balance speed and accuracy. But temporal aspects also influence the nature of human performance, for example when one type of information is available earlier than another type (e.g., picture-word interference studies), when one needs to switch tasks in the context of sequential multi-tasking (e.g., glances in rear-view mirror), or when the speed of an incoming speech-signal determines how much time is available for language processing. In all these cases, temporal constraints can be seen as an additional source of cognitive control.

If one aims for precise descriptions of behavior, research cannot suffice with qualitative descriptions of these tasks as an exact duration is needed when one wants to predict the interference between to sources of information. Therefore, my work focusses on building detailed computational process models that take into account all relevant aspects of the task at hand - not just the decision stage.

Time-based Personalization

Good theories should allow us to predict what behavior can be observed in situations not yet scrutinized. Most theories in Experimental Psychology are based on distributions of response times, typically summarizing the data over many participants and trials. However, modern computers make it possible to process the response times generated by a participant as they come in, and thus allow us to update our knowledge of the underlying processes used by that individual on-the-fly.

This principle is used in the fact-learning method "SlimStampen" which is based on the memory theories of the ACT-R cognitive architecture. If, during a learning session, a to-be-learned item can be recalled fast and effortlessly, this item is probably stored well enough in memory. Therefore, learning time can better be spent on other items, and one can delay revisiting this item. On the other hand, if the correct answer was only provided after a long delay, this item should be revisted soon, because it apparently is not well stored yet.

The "SlimStampen" has been used at three different Universities in the Netherlands, at special-needs education centers in Portugal, Ireland and The Netherlands, and has been tested at many secondary education schools. As of academic year 2014/2015, the "SlimStampen" system will be offered to all students using the online learning system of Noordhoff Publishers, a major Dutch publishing house of secondary education materials.

Time in our Brain

Given the importance of time for accurate cognitive performance, it is striking to realize that it is still not known where the "clock" can be found in the brain that drives interval timing, the name for time perception at the (hundreds of) milliseconds to minutes range.

The best known information processing models of interval timing assume that an internal pacemaker generates pulses that can be integrated in an accumulator. By reading out how many pulses have accumulated, the system can have a sense of how much time has passed. If the system has to recreate the same interval, it can restart the accumulation process and wait until the same amount of pulses is accumulated.

Although this theory is very attractive because of its simplicity and face-value validity, decades of research have not been able to pinpoint the pacemaker. Even more, although EEG studies claimed to have located the "accumulator", work from my lab has demonstrated that the observed phenomena are at best an epiphenomena of time.

My work has therefore focussed on alternative accounts on interval timing, in which the source of time might be associated to other cognitive functions, such as working memory updates. To test some of these ideas, I collaborate with Drosophila experts at the research school of Behavioral and Cognitive Neurosciences and the University Medical Center Groningen to unravel the genetic bases of interval timing using fruitflies as a model animal.

Nevertheless, even though research has not settled on the neural substrate of interval timing, part of my work also focusses on the functional descriptions of interval timing and on the real-life applications and consequences of deviations between subjective and objective time.


Lab Members

Current PostDocs

  • Florian Sense, Learning and Forgetting of CPR (in Virtual Reality Settings)

Current PhD students

  • Margreet Vogelzang, Pronoun Processing (together with Petra Hendriks)
  • Andrea Soto Padilla, Interval Timing in Drosophila (together with Jean-Christoph Billeter, Ody Sibon)
  • Atser Damsma, Working Memory and Interval Timing (together with Niels Taatgen, Ritske de Jong)
  • Nadine Schlichting, Oscillations in Interval Timing (together with Ritske de Jong)
  • Sarah Maass, Modulations of Time

Current Junior Researchers / Research Assistants / Programmers

  • Michael LeKander, Research Programmer
  • Max Ziegler, Research Assistent

Alumni PhD students


Over the years, my work has been supported by grants from:

NWO Netherlands Organization for Scientific Research

Horizon 2020: EU Framework Programme for Research and Innovation

EU Leonardo da Vinci Life Long Learning Programme

Innovative Action Programme Groningen

Gratama Stichting

Kennisnet, Dutch Ministry of Education

New Agendas for the Study of Time, sponsored by John Templeton Foundation

European Cooperation in Science and Technology, Intergovernmental EU Framework

Granting agencies that have specifically sponsored conferences that I have (co-)organized are:

Deutsche Forschungsgemeinschaft

Office of Naval Research, International Office

European Office of Aerospace Research & Development


Last updated: see "News" bar on the right, Hedderik van Rijn


September 2017
* With the start of Sarah Maass' PhD project and Max Ziegler's research assistent position, we're starting the VICI project!
February 2017
* Received a prestigious VICI grant to work on timing in the real world. Will be looking for postdocs and PhD students soon.
* Inaugural lecture: Video (Dutch), Photos

April 2016 - January 2017
* Too many great things happened to keep track ;-)

March 2016
* Nature published my review on Marc Wittmann's "Felt Time", a highly recommendable book on the role of time in everyday life.
* Internal promotion, now Professor
February 2016
* Congratuations to Florian Sense for winning the BCN poster prize for his poster on SlimStampen.
January 2016
* For a number of recently accepted papers, see link to the my list of publications
September 2015
* Nadine Schlichting has joined my lab as PhD student, and Sarah Maass as research assistent.
July 2015
* The Executive Board of the University of Groningen has awarded us a grant to develop the RUGged Learning app to offer adaptive, optimized learning to all students of the RuG!
* Congratulations to Wanja Mössing for winning the BCN poster prize for the poster discussing his thesis project!
June 2015
* Workshop Timed Behavior and Temporal Cognition planned for June 19.
* Two! papers first authored by Tadeusz Kononowicz accepted in Neuropsychologica! May 2015
* Atser Damsma has started working as a PhD student on the TiIMESTORM project. Apr 2015
* Tadeusz Kononowicz' PhD thesis has been approved by the reading committee! The oral defense is planned for June 18.
* Hired two new PhD students who will start May 15 and September 1st, working on the EU TimeStorm project
Mar 2015
* Paper by Florian Sense et al won the Allan Newell Award for best student paper at ICCM 2015!
* Paper by Jelmer Borst, Niels Taatgen and me won CHI2015 Best Paper Award
Feb 2015

* Congratulations to Florian Sense for winning the BCN poster prize with a poster on his SlimStampen work.
* Adversarial collaboration paper published in JEP:General.
Jan 2014
* Nature discusses our meta-analysis and failure to replicate the unconscious thought effect.
Dec 2014
* Multi-lab, multi-author, multi-method paper accepted on the (non-)existence of the "Unconscious thought advantage".
Oct 2014
* Nominated for Teacher of Year award at the department of Artificial Intelligence.
Sept 2014
* EEG-network oscillation paper in Frontiers in Human Neuroscience
Aug 2014
* EU Horizon 2020 Grant has been awarded! Will be looking for new lab members soon.