Ronald Van den Berg Foto: Psykologiska institutionen/HD
Ronald Van den Berg

Q: You have got a time grant from SUBIC for your project “Investigating the neural basis of flexibility in the allocation of visual working memory resources”. Can you describe what the project is about?

It has been known for a long time that humans have very limited working memory resources. For example, if I would present you with a series of 10 digits and then ask you a few seconds later to recall the series, you would almost certainly make a few mistakes.

An interesting finding from recent behavioral work is that the brain seems to make the best out of this limitation by entertaining a high amount of flexibility in how it distributes this resource across objects. In particular, there are indications that the amount of resource spent on remembering an object is positively related to the object’s importance.

In terms of the earlier example, if I would pay you 2 crowns for each correctly remembered digit in the first half of the series, but only 1 crown for each digit in the second half, the present evidence predicts that you would remember the first half of the series with higher precision than the second half. Moreover, the larger I would make the payment difference, the larger the expected difference in memory precision.

The purpose of the present project – which I will perform in collaboration with Mikael Lundqvist, Cris Villalba García, and Maria Mystakidou – is to start building an understanding of how this kind of flexibility in resource allocation is realized at the neural level. Besides providing new insights into neural mechanisms, such knowledge can help us constrain current and future models of working memory.

Q: SUBIC is a brain imaging centre at Stockholm University with many tools or platforms for investigating what happens in our brains in various conditions. What will be your main tool to use in your study and why is that the best choice?

Our main tool will be electroencephalography (EEG). While this is already a standard tool in the field of working memory research, it has mainly been used to investigate questions about the number of items in memory. By using a novel analysis method – that was co-developed by my collaborator Mikael – we will here instead focus on questions related to neural correlates of memory precision.

Thanks to the high temporal resolution of EEG, we may even be able to track neural representations of memories as they unfold over time. While not being the main focus, we are planning to simultaneously record eye movements during the EEG experiments, because pupil size and tiny little eye movements called "micro-saccades" may tell us something about a subject’s attentional states, which can be useful when trying to link the neural data to behavior.

Q: You are from Belgium, right, and fairly new at Stockholm University (2019?). It’s been a strange spring for everyone, but how do you like working at SU?

Almost correct! I’m from the Netherlands and indeed started working at Stockholm University in late 2019, after having spent 4 years at another university just 70 kilometers north of here. It’s been a crazy spring as you said, with much less time spent at office than I had wished. So far I have really been enjoying the work environment here at SU, though, both professionally and socially. Since I have a background in psychophysics, I feel particularly at home in the Gösta Ekmans Laboratory. I haven’t ventured out so much into other parts of the department yet, but I hope to do so next semester – hopefully without the need of a facemask.

Read more about the SUBIC time grants