Males are the ones calling, and to do so, they must have a neural structure for creating the necessary motor pattern. The main idea behind the Common Element Hypothesis is that females have the same or similar structure that males use to produce calling song. So, in recognition, females use this pattern generator to create a temporal sequence that they can compare to the incoming signal. If the patterns match, you've got a conspecific. In the words of Pires and Hoy: "The Common Neural Elements hypothesis posits that homologous neurons in a neural system shared by sender and receiver are involved in both signal pattern generation and recogniton." (Pires and Hoy,'92)
This graph shows the spike activity (membrane potential) for a noisy conspecific signal (34 ms SRI). Noise was added using an average spike rate of 40/sec.
The duty cycle was chosen to be 50% SRI and the chirp duration was varied along the x-axis. The response magnitude, which is the percentage of correctly recongnised syllables is shown against SRI in the image above. This simulation is very noise insensitive as can be seen at the red line. Nevertheless, at longer SRI's the response is even getting higher than 100% indicating that the rec-cell is discharging more than one time upon longer chrips and SRI's.
Back to Introduction
Other computer simulations:
Delay line simulation
Rebound effect simulation
Anded filter hypothesis