University of Kentucky
Auditory Discrimination Learning by Pigeons
Institution
University of Kentucky
Faculty Advisor/ Mentor
Thomas R. Zentall
Abstract
We asked if pigeons were as good at tone discriminations as song birds (zebra finches). Five pigeons were trained to discriminate among 27 different tones. Nine tones between 607 Hz and 967 Hz were defined as correct, whereas nine lower frequency tones between 359 Hz and 572 Hz and nine higher frequency tones between 1025 Hz and 1633 Hz were defined as incorrect. Adjacent tones were 6% apart. Pigeons initiated a trial with a peck to a ready button. A response to a report button during a 2-sec correct tone produced 2-sec of mixed grain and another began immediately. The tones were presented in random order. A response to the report button during a 2-sec incorrect tone produced no food and resulted in a 30-sec timeout before the next trial began. Pigeons showed good discrimination of the tones, achieving a mean discrimination ratio [responses to positive tones/(responses to positive tones + .5(responses to negative tones))] of .83, similar to that found with human participants but not as good as results found with song birds. Thus, pigeons (like humans) have relative pitch, whereas song birds have absolute pitch. The data suggest that absolute pitch is not a general phenomenon found in all avian (bird) species, but is probably a specifically evolved ability possessed by species for which the detection of absolute frequencies is important for them to discriminate members of their own species from members of other (perhaps closely related) species.
Auditory Discrimination Learning by Pigeons
We asked if pigeons were as good at tone discriminations as song birds (zebra finches). Five pigeons were trained to discriminate among 27 different tones. Nine tones between 607 Hz and 967 Hz were defined as correct, whereas nine lower frequency tones between 359 Hz and 572 Hz and nine higher frequency tones between 1025 Hz and 1633 Hz were defined as incorrect. Adjacent tones were 6% apart. Pigeons initiated a trial with a peck to a ready button. A response to a report button during a 2-sec correct tone produced 2-sec of mixed grain and another began immediately. The tones were presented in random order. A response to the report button during a 2-sec incorrect tone produced no food and resulted in a 30-sec timeout before the next trial began. Pigeons showed good discrimination of the tones, achieving a mean discrimination ratio [responses to positive tones/(responses to positive tones + .5(responses to negative tones))] of .83, similar to that found with human participants but not as good as results found with song birds. Thus, pigeons (like humans) have relative pitch, whereas song birds have absolute pitch. The data suggest that absolute pitch is not a general phenomenon found in all avian (bird) species, but is probably a specifically evolved ability possessed by species for which the detection of absolute frequencies is important for them to discriminate members of their own species from members of other (perhaps closely related) species.