Frequency generalization constrained by pitch processing in the European starling?

Abstract

Earlier work with pitch processing has shown that the European starling (Sturnus vulgaris)—unlike humans—fails to transfer learned pitch discriminations out of the original frequency range (S. Hulse, J. Cynx, and J. Humpal, “Effects of shift in pitch context on serial pitch perception in birds,” in preparation). The present work was undertaken to determine if the failure to generalize is due to the simultaneous active processing of pitch or the inability to make generalizations from simple frequencies. Four wildcaught adult starlings were trained to peck at a lit key only on trials during which a 2000‐Hz tone was absent. Once discrimination was achieved, probes were introduced every other session at p = 0.50 to determine generalization from 1000 to 4000 Hz. Findings are in agreement with earlier work, using a Pavlovian procedure, which indicated a range constraint for frequencies [J. E. Trainer, “The auditory acuity of certain birds,” unpublished doctoral dissertation, Cornell Univ. (1946)], but also show that the constraint is interactive with the processing of relative and absolute pitch information.