Interacting in a quantitative world: number, space, and time with ultra-high resolution 7T fMRI

Speaker: Dr Jacob Paul

24th June 2021

Abstract: We use quantities in everyday life to guide our decisions: we judge the size and number of vegetables at the market; we dance following the tempo of music; we compare how many steps we need to reach our daily goal. How are we able to flexibly interact with such different quantities in our environment? Ultra-high resolution (7 Tesla) fMRI combined with population receptive field modelling has revealed a widespread network of brain areas that selectively process quantities, such as numerosity (object number) and object size, which are organised as topographic maps. These maps are distinct but overlap with visual field maps representing orientation and eccentricity. In this talk, I will discuss four of my recent projects that extend this line of work and illustrate (1) a network of topographic maps in association cortex that hierarchically transforms visual timing-selective responses, (2) local image contrast representations in early visual cortex are transformed into location-independent numerosity tuning in extrastriate cortex, (3) a similar derivation follows for visual timing-tuned neural responses from early visual stimulus representations, and (4) the extent of overlap and topographic direction between maps for numerosity and visual event timing supports the view of a supramodal functional network for cognitive quantities that facilitates cross-modal interactions. I will conclude by considering the implications of a supramodal functional network for learning to map quantities to symbols.

Bio: Dr Jacob Paul is a cognitive neuroscientist at the Melbourne School of Psychological Sciences. His interests include visual perception, numerical cognition, and the neurocognitive development of maths reasoning. His research spans multiple levels of explanation from modelling longitudinal patterns of maths learning, to characterising individual differences in numerical decision making, and mapping the organisation of neural circuits underlying transformations of visual quantities. He has recently returned to Melbourne after postdoctoral work in the Utrecht (Netherlands) combining ultra-high resolution 7T fMRI and computational modelling to characterise how the brain encodes basic quantities like number and time. He is passionate about translating his research findings to help enhance functional numeracy levels in the population, improve learning and instruction of mathematics, as well as constructing brain-based interventions and remediation programs for individuals with maths learning difficulties.

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