After finishing the recording, we measured the volumes of forebrain song control nuclei: HVC, RA and Area X and a control nucleus, rotundus nucleus (Rt) (a diencephalic nucleus involving in visual relay).

• 然后 ,测定了前脑三个鸣啭学习控制核团和一个与发声无关的视觉参考核团体积 ,分析了鸣唱语句复杂性和这些核团大小间的相关关系。