Numbers and Force: The sensorimotor grounding and embodiment of magnitudes

Magnitudes are often highly correlated in natural environments. Compared to a small stone, a larger stone of the same type is often wider, occupies more space, and weighs more. When we decide to drop the larger stone it will fall faster, produce more noise during the fall, and also crash harder on the ground than the smaller stone. When we interact with such an object, we also accumulate knowledge about this object. In the first part of this thesis, I theorize how exactly we might accumulate such knowledge and whether our body itself could have contributed to the learning processes. I also attempt to bridge how the physical interactions with continuous magnitudes as size and space might shape the learning of number size and spatial order.
In the second part of this thesis, I present four studies across which we empirically tested how numbers affected motor behavior in and outside spatial conditions. During the first two studies, we decided to measure motor behavior as passive force recordings. In the first experiment we neither found an effect of numbers on motor behavior nor how motor behavior in spatial conditions affected the production of numbers. In the second study, we found how numbers are directly coupled with motor behavior and how smaller numbers induced smaller motor magnitudes compared to larger numbers.
In the next two studies, we decided to extend the findings of the first two studies by measuring motor behavior as active responses. In study 3A we found no effect of numbers on motor magnitudes. In study 3B we found an interaction of numbers and spatial responses in which responses for smaller numbers produced smaller motor magnitudes in the left space and larger motor magnitudes in the right space compared to larger numbers. In the discussion, I connect these results to theory and argue for different mechanisms in how we represent different magnitudes.

Altogether, this dissertation adds to theoretical development by connecting and pointing out differences between different theoretical approaches. It also adds to methodological development as I describe a novel method on how to capture the processing of magnitudes. I further attempt to quantify and specify the found effects and connect them to the general field. Finally, I specify the limitations of the research project and describe practical relevance for the scientific field.