How do spatial representations enhance cognitive numerical processing?

Several philosophical theories attempt to explain how actions performed in the world enhance cognitive processing: internalism, active externalism, and cognitive integration. The aim of this paper is to examine whether the use of spatial representations in arithmetic can shed light on this debate. Relying on philosophical analysis, on a discussion of empirical work in the cognitive neuroscience of number, and on a historical case study, I will show that spatial representations of number indicate an integration between internal and external cognitive processes.