New publication in Cortex by Ada Tsouli on the interaction between Numerosity and Time

It has been proposed that number and time processing develop their specialization from a common cortical system. We investigated the potential interaction of numerical and temporal information using cross-adaptation between numerosity and duration. Participants adapted to visual numerosity or visual duration and then performed a numerosity or duration discrimination task. We found that numerosity adaptation altered numerosity perception, and duration adaptation altered duration perception. In the cross-adaptation conditions, duration adaptation affected numerosity perception, whereas numerosity adaptation did not seem to affect duration perception. We suggest that although unbalanced, there is indeed a common processing mechanism dedicated to numerosity and time perception.


Tsouli, A., Dumoulin, S. O., te Pas, S. F., & van der Smagt, M. J. (in press). Adaptation reveals unbalanced interaction between numerosity and time. Cortex,

New publication by Jim Maarseveen and colleagues in Scientific Reports

Scientific Reports

Figure 1

Jim Maarseveen, Hinze Hogendoorn, Frans Verstraten, and Chris Paffen just published their study: Attention Gates the Selective Encoding of Duration in Scientific Reports. The article is published with open access, and available at:

NVP 2017

The NVP-winterconference 2017 (The Dutch Society of Psychonomics) is just around the corner, from 14-12-2017 to 16-12-2017. We are happy to announce that the Perception Group Utrecht will be well represented. Below are the titles and authors of the abstracts on which our group contributed.

The eye’s pupil does not imitate others’ pupil sizes but it does respond to negative emotional expressions by Madou Derksen, Juliette van Alphen, Sander Schaap, Marnix Naber

Eye dominance, a multifaceted phenomenon with variable definitions and expressions by Yun Ding, Marnix Naber, Surya Gayet, Chris Paffen, Stefan van der Stigchel

Limitations of pupillometry as a measure of mental effort during product search on webpages by Felix Hermsen, Marnix Naber

Occipital lobe involvement in evoking pupillary responses: evidence from hemianopia patients by Marnix Naber, Alessio Fracasso, Carlien Roelofzen, Joris Elshout, Giorgio Porro, Douwe Bergsma, Mies van Genderen, Serge Dumoulin

Multisensory Integration and the Pupil Response by Chiara Notaro, Nathan van der Stoep, Maarten van der Smagt, Marnix Naber

Pupillometry as a measure of emotional processing and withdrawal responses to robotic faces by Anne Reuten, Maureen van Dam, Marnix Naber

Remote heart rate detection with a webcam by Koen van der Kooij, Marnix Naber

The fMRI contrast response function to natural images is enhanced according to local subjective importance by Wietske Zuiderbaan & Serge O. Dumoulin

Prioritized access to awareness of the naked human body obscured by systematic variations in image- properties by Stuit, S.M., Barendregt, M., & te Pas, S. F.

Change blindness: Is V1 actually blind? by Akhil Edadan, Wietske Zuiderbaan, Alessio Fracasso, Serge O. Dumoulin

The impact of asymmetrical hearing loss on multisensory integration: Sensory conflict increases saccade latencies to audiovisual stimuli by Van der Stoep, N., Groenewege, B. J. H., & Van der Stigchel, S.

Laminar imaging: from population receptive fields to attention by S.O. Dumoulin

The location of covert spatial attention is continuously reflected by pupil size by Martijn Schut, Jim Maarseveen, Jasper Fabius, Annelies Wittenberg, Nathan van der Stoep, & Stefan van der Stigchel

Evidence for the world as external memory: a trade-off between internal and external visual memory storage by Stefan Van der Stigchel, Rosyl S. Somai, Martijn J. Schut

Probing visual field integrity using an anatomical measure of the stria of Gennari at ultra-high field MRI by Carlien Roelofzen, Alessio Fracasso, Giorgio Porro, Douwe Bergsma, Mies van Genderen, Serge Dumoulin

Linear responses across V1 lamina using sub-millimetre resolution fMRI by J.A. van Dijk, A. Fracasso, S.O. Dumoulin

Radial asymmetries in population receptive field size and cortical magnification factor in early visual cortex by Ben M Harvey, Jan W Brascamp, Sónia Ferreira, Miguel Castelo-Branco, Serge O Dumoulin, Maria Fatima Silva



New publication by Sjoerd Stuit in Journal of Vision

Binocular rivalry refers to alternations of perception when incompatible images are presented to the two eyes. While the percept is most often of a single monocular image, suggesting monocular spatial integration, perception can also resemble a patchwork of parts of both eyes’ images, suggesting spatial integration at a higher level of processing. Here we investigated the spatial profiles of integration during binocular rivalry to differentiate higher- from lower-level influences on spatial integration during rivalry. Our results suggest that image-based integration, typically referred to as higher-level, is subject to similar spatial constraints as monocular, eye-based integration, suggesting both rely on similarly sized receptive fields and thus levels of processing. Read the full, open access, article here.