The Study on Different Biological Significances with Respect to notes of Advertisement Calls in the Emei Music Frogs
Author of the article:Yue XZ, Jiang F, Xue F, Fang GZ, Tang YZ
Author's Workplace：Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, P. R. China
Key Words：advertisement call; note; mismatch negativity (MMN); auditory lateralization; Babina daunchina; pseudoreplication
Abstract：Complex acoustic communication sounds play a crucial role in coordinating social and reproductive behavior in many terrestrial species. Nevertheless it is unclear how the biological significance of each component of such complex sounds may differ. For most anuran species male calls are composed of a series of notes and intervals. For example male advertisement calls of the Emei music frog (Babina daunchina) always contain at least one and as many as ten or more notes separated by intervals of approximately 150 ms. Consequently the music frog is an interesting model for exploring how the biological significance of each note might vary. This study applied the optimized paradigm of mismatch negativity (MMN) in which one standard stimulus (white noise) and five deviant stimuli (five notes from one advertisement call) were played back to frogs from which multichannel electroencephalogram (EEG) recordings were obtained. The results showed that the MMN amplitudes were greater in the left hemisphere implying a left brain advantage for perceiving these deviations while the MMN amplitude of the first note was significantly larger than the others. Insofar as the MMN amplitude is thought to reflect not only the difference between the standard and deviant stimuli but also the brain resources devoted to cognitive processing, it is reasonable to speculate that the first note is the most important unit for vocal communication in frogs.