ABSTRACT
In this chapter a very old problem is reexamined: Is human cortical information processing continuous or temporally discretely structured? Many early contributions to this problem argued in favor of the second possibility: Fechner (1860) related consciousness to a superimposition of fast and slow rhythms. In 1864, von Baer (von Baer, 1864) suggested that temporal resolution of our perception is limited by a smallest unit called moment. This led to the view that we perceive the outside world as a stream of short static impressions (Uexkuell, 1928). The discovery of the electroencephalogram (EEG) (Berger, 1938) and its band structure and later the interpretation of cortical processes by computer analogies motivated attempts to prove that a temporal structure exists in form of a cortical central clock, which, however, did not succeed (Allport, 1968; Harter & White, 1968; Stroud, 1955; Vroon, 1974). Many of the current approaches to psychophysical modeling rest on the assumption that the information flow in the perceptual sys-tem is continuous or that its discreteness can be neglected (Luce & Green, 1972; McGill, 1963; Townsend & Ashby, 1983; Wickens, 1982). If perceptual decisions on a macroscopic scale are modeled by stochastic processes, as in random-walk models, on the microscopic scale this usually corresponds to
an assumed random mode of operation of single information processing units that accumulate their contributions independently of each other.
