Flatter 1/f PSD in invertebrates

[MakotoMiyakoshi]

Bullock TH, Basar E. (1988). Comparison of ongoing compound field potentials in the brains of invertebrates and vertebrates.
Brain Res 472:57-75. DOI: 10.1016/0165-0173(88)90005-7, PMID: 3342336

From Summary:

(3) Power spectra in the cerebral ganglia of various higher invertebrates are similar; activity is fast and spiky (with the exception of Octopus). Integrated energy above 50 Hz exceeds that from 2–50 Hz and falls slowly with frequency; in Aplysia the power spectrum falls <10 dB between 10 and 300 Hz. In vertebrates from fish to mammals, activity is similar in being mainly slow (<40 Hz); it commonly falls >20 dB between 10 and 50 Hz.

(5) Coherence decline with distance, measured tangentially at different electrode separations in the millimeter range, is used as an estimator of synchrony. Averaged coherence between loci 1 mm apart is negligible in Aplysia in any band from 3 to 100 Hz; in the ray tectum it is low, 0.25–0.5 between 3 and 16 Hz. In the turtle dorsal pallium it is higher, at 2 mm, 0.6–0.75 in this band. In the rabbit cortex coherence is even higher, typically >0.7 at 1 mm, and >0.3 at 4 mm in this band.