Fig. 5. Power-spectra for antennal and leg movements in a searching cockroach. (A) Spectra for horizontal (H) and vertical (V) deflections in pausing. Their major peaks were distributed mainly at <3 Hz (H) and <4 Hz (V), respectively. (B) Power-spectra for antennal (H and V) and foreleg (L) movements in walking. Lower frequency components at <2 Hz were largely suppressed for horizontal deflections (H). Higher frequency components around 4 Hz became remarkable for vertical deflections (V) instead. Note that no conspicuous peak is observable in the H and V spectra at the frequency corresponding to major peaks in the L spectrum (2–3.5 Hz). Inset in each spectrum is part of the time course before FFT. These spectra were obtained from data for a 31 s period each.