Chord Discrimination by Pigeons

PIGEONS WERE TRAINED IN A GO/NO-GO TASK TO discriminate a major triad from four other chord triads. These latter chords were constructed by altering the third or fifth of the triad by one semitone, creating minor, suspended fourth, augmented, or flat five chords. Experiment 1 used a C root to test these chords. Experiment 2 examined the discrimination of these chords using the D root. Pigeons could discriminate these harmonically complex triads, with manipulations of the fifth supporting better discrimination than manipulations of the third. The augmented chord was perceived as the most dissimilar from the major chord and the suspended fourth chord as the most similar. A combination of attention to sensory consonance and absolute properties of the chords is suggested to account for the results. Comparable human results suggested some overlap in their perception of harmonic elements, but a considerable difference in their flexibility to use this information across different contexts.