EFFECT OF STIMULUS CHIRPS ON A CRICKETS CHIRPING (ACHETA DOMESTICUS)

The following phenomena were found when chirps were played to a territorial male cricket: 1. A stimulus chirp not coinciding with a chirp of the cricket inhibits chirping from the 40th to the 180th msec following the onset of the stimulus. 2. It additively increases the chirp rate of the cricket by approximately 0.3 chirps/sec. 3. About 99% of this additive increment decays with a half life period of approximately 2 sec (phasic effect), the rest decays with a half life period of approximately 140 sec (tonic effect). 4. The effects of successive stimulus chirps are superimposed, however neither the phasic nor the tonic total increment ever passes a particular upper limit. If the total tonic increment becomes large enough, a previously silent cricket will start to chirp. 5. If chirps are played at a sufficiently high rate, the cricket tries to chirp in alternation. Phenomena 1 to 4 were represented in a mathematical model which was then tested on an analog computer: The model responded quantitatively in the same way as a cricket to all patterns of stimulation. Alternating chirping as in phenomenon 5 resulted directly from the model and thus does not require any special explanation. © 1969 Springer-Verlag.