Fig. 5.

γ-wave stochasticity. (A) A histogram of γ-interpeak intervals exhibits an exponential-like distribution with mean characteristic γ-period, ${\overline{T}}_{\gamma }=18.6\pm 1.9$ ms, about six times smaller than ${\overline{T}}_{\theta }$. (B) The average scores ⟨β_γ⟩ and ⟨λ_γ⟩ are higher than for the θ-wave, indicating that γ-patterns are more diverse than θ-patterns. (C) The dynamics of the λ_γ-score (Top panel) correlate with changes in the speed when the animal moves actively. Note that λ_γ often exceeds the upper bound of the “pink stripe,” i.e., γ-waves often produce statistically uncommon patterns, especially during rapid moves. The β_γ-score (Bottom panel) correlates with the animal’s acceleration, which is lost when lap times increase (gray stripes). (D) Locally averaged λ-score, ${\widehat{\lambda }}_{\gamma }$, grows with speed, while ${\widehat{\beta }}_{\gamma }$ switches from higher to lower value with increasing acceleration (pink arrow).