"[...] the timing of computers and networks is rigidly coupled to regular cycles of an underlying clock; the wide variation in impulse timings in neuronal systems, often with a strong apparently random component, contrasts markedly with the temporal regimen in these computational devices." (p. 42)
Donald H. Perkel, "Computational Neuroscience: Scope and Structure," in Computational Neuroscience, pp.38-45. Edited by Eric L. Schwartz. 1993. MIT Press.