Abstract
Neuronal activity in the hyperstriatum ventrale, pars caudale (HVc) is associated with and necessary for the production of song by songbirds. HVc neurons also respond to acoustic stimuli. The present investigation assessed the auditory response properties of neurons in HVc by testing with the individual bird's own (autogenous) song and the songs of conspecific birds. Throughout HVc, multiunit clusters preferentially responded to autogenous song. Selectivity for autogenous song was apparent even when compared to similar intradialect songs, and neuronal clusters preferred autogenous song over the (tutor) song model that birds heard during the impressionable phase early in life. The responses to autogenous song were stable in the adult. HVc neurons were sensitive to the acoustic parameters of autogenous song and consistently exhibited a diminished response to modified song. In contrast, field L neurons, which are presumed to be a source of auditory input to HVc, did not exhibit selectivity for autogenous song and showed no special sensitivity to the acoustic parameters of autogenous song. These observations implicate song (motor) learning in shaping the response properties of HVc, but not field L, auditory neurons. It is proposed that HVc auditory neurons may contribute to a bird's ability to discriminate among conspecific songs by acting as an “autogenous reference” during perception of those songs.
