Phase synchrony, or mean phase coherence [40], of x(t) and y(t) is defined as (2)Rxy=∣1N∑j=1Nei[ϕx(tj)−ϕy(tj)]∣ where ϕx(t) and ϕy(t) denote the phase variables of x(t) and y(t), N is the window sample size, and (3)ϕ(t)=arctans~(t)s(t) for an arbitrary signal s(t) using the Hilbert transform (4)s~(t)=1πp.v.∫−∞+∞s(t′)t−t′dt′ (p.v. denoting the Cauchy principle value).
