Subtracting Pigeons: Logarithmic or Linear?

Dehaene S. (1997). The number sense. New York: Oxford University Press.

Dehaene S. Changeux J.P. (1993). Development of elementary numerical abilities: A neuronal model. Journal of Cognitive Neuroscience, 5, 390–407.

Hauser M.D. Carey S. Hauser L.B. (2000). Spontaneous number representation in semi-free-ranging rhesus monkeys. Proceedings of the Royal Society of London B, 267, 829–833.

Hauser M.D. MacNeilage P. Ware M. (1996). Numerical representations in primates. Proceedings of the National Academy of Sciences, USA, 93, 1514–1517.

Meck W.H. Church R.M. (1983). A mode control model of counting and timing processes. Journal of Experimental Psychology: Animal Behavior Processes, 9, 320–334.