p545fig15.10 When the activity spectrum xi generates a spectrum of sigmoidal signals (f(xi), the corresponding transmitters habituate at different rates.  The output signals f(xi)*yi therefore generate a series of unimodal activity profiles that peak at different times, as in Figure 15.3a.<BR>||  A timed spectrum of sampling intervals.  [f(xi) activation, yi habituation, f(xi)*yi gated sampling] spectra.  gated = sampling intervals.