A two-sided mirror
When he was working at Rockefeller University in New York, Marler had two extremely brilliant students: Fernando Nottebohm and Mark Konishi. For a long time, scientists had been trying to understand the neuroanatomical bases on which the control of complex behaviours was based. The song system offered a particular advantage, insofar as bird vocalisations are emitted by a specific unique organ: the syrinx. Nottebohm’s idea was that it must be possible to map the areas of the brain connected to the muscles activating the syrinx, by studying degeneration resulting from the severing of the axonal endings.
In other words, there are two ways the information from the HVC can end up in the RA, directly or indirectly. The work of Nottebohm led to a complete description of the neuroanatomical substrates of the control of song. Hence, it attracted the attention of numerous neurobiologists because it offered them a perfectly defined frame of reference to carry out their studies on the neuroendocrine and neurochemical mechanisms governing complex behaviour.