Processing of time - Processing time: Temporal invariants and oscillatory mechanisms in perception and memory

In 1864, the German biologist von Baer advanced the idea of a psychological moment defined as the smallest unit of mental time. In our century, building upon this notion, Brecher (1932) suggested for it a duration of 55.5 msec from threshold measurements in tactile vibration which practically showed no dependence on receptor density and no individual variation. Von Bekesy (1936), referring to Brecher, demonstrated for low frequency sound a cascade of discontinuities to exist regularly spaced around this value. Later similar quantal structures were found within other paradigms. In a series of papers (cf. Geissler, 1987, 1992) we have shown that approaches (e.g. of Strouti, 1956) assuming merely one reference period corresponding to one central pacemaker to which other periods are harmonically related must be invalid. Instead, to account for general patterns of results a temporal range architecture is to be assumed. Temporal ranges according to the proposed taxonomic quantum approach, TQM, are simultaneously subject to three fundamental constraints: (1) Any periods within a given range R-q are integer multiples N of a shortest period T-q characteristic of it; (2) there is an integer multiple M = 30 of T-q representing the upper bound of periods included in a range, and (3) any shortest period within a given range is an integer multiple of an absolutely shortest period TQ(0) relevant in cognition of about 4.5 msec duration, the "time quantum". For the smallest of the assumed ranges R-1 and R-2 extending up to about 30 x 4.5 = 135 msec and 30 x 9 = 270 msec, respectively, these claims were corroborated in experiments. Supporting evidence from other researchers and paradigms is presented. We assert that the basic constants of TQM are related to psychophysical invariance properties as discovered by Teghtsoonian (1971). Tn a brief outline of a physiological interpretation of the TQM approach we suggest a fairly direct correspondence between ranges of behaviorally determined periods and bands in which the: relevant portions of EEG activity are organized in a way compatible with classical band definitions.