Figure 1.

Oscillatory interference patterns. Effect of addition (a, b) and multiplication (c, d) of a sinusoidal (a, c) or punctate (b, d) “active” 9Hz oscillation (red, frequency f_a=9Hz) with a sinusoidal “baseline” 8 Hz oscillation (blue, frequency f_b=9Hz). Note that all of the combined oscillations (black) have raised areas of similar extents, but the peaks of the combined oscillation occur over different ranges of phase relative to the baseline oscillation (black diamonds) for the two the types of active oscillation (a,b vs c,d). Both interfering oscillations have range [0, 1] before being combined. Sinusoidal oscillations are: V(t)=(1+cos{2πft})/2, with f = 8 or 9. Punctate oscillations are: V(t)⁵⁰. Figure 1a is adapted from Burgess et al. (2007).