In connection with Daniel Gramm Kristensen’s PhD defence, Thursday 29 August 2019, we have arrange for his external assessors to present their own work in a mini-symposium. Dr Peter Kok from University College London and Dr Serge Dumoulin, Spinoza Centre for Neuroimaging, Amsterdam.

16.08.2019 | Henriette Blæsild Vuust

Dr Peter Kok
University College London, London, UK.

Title: The role of prior expectations in sensory processing

Abstract:
Our senses are constantly bombarded with noisy and ambiguous sensory information. It has been suggested that we use prior knowledge to constrain sensory processing, resulting in a best possible guess of what's out there in the world. However, the neural mechanisms by which the brain achieves this are largely unknown. Exciting novel methods such as population receptive field mapping (pRF) and layer-specific fMRI allow us to investigate these questions in human with unprecedented detail. In this talk, I will discuss how predictions based on both long term knowledge and short-term statistical regularities modulate processing in the visual cortex. Finally, I will discuss the potential role of the hippocampus in generating associative predictions. Together, this body of work suggests that prior expectations are a fundamental part of sensory processing from the earliest stages onward.

Dr Serge Dumoulin
Spinoza Centre for Neuroimaging, Royal Netherlands Academy of Sciences, Amsterdam, Netherlands.

Title: Attention distorts perception

Abstract:
Visual attention selects relevant and ignores irrelevant information, properties that make it vital for human perception and behaviour. Attention to a visual field position (spatial attention) improves perception at that location. Most theories of spatial attention deal with local improvements. Less-appreciated aspects of these theories predict visual field distortions as fundamental mechanisms of attention. I report on experiments to measure these distortions using a computational model, human neuroimaging and psychophysics to capture perceptual consequences. We show that attention attracts receptive fields towards its focus throughout the visual cortex, thereby transforming the entire neural representation of visual information. We propose that global visual field distortions underlie local spatial attention and link neuronal and perceptual consequences within the same computational framework.

We hope to see many of you there for the mini symposium AND for Daniel’s defense in the Merete Barker Auditorium at 2.00 pm the same day.

ALL ARE WELCOME.