Absolute pitch in boreal chickadees and humans: Exceptions that test a phylogenetic rule

This research examined generality of the phylogenetic rule that birds discriminate frequency ranges more accurately than mammals. Human absolute pitch chroma possessors accurately tracked transitions between frequency ranges. Independent tests showed that they used note naming (pitch chroma) to remap the tones into ranges; neither possessors nor nonpossessors were accurate at octave (pitch height) naming. Boreal chickadees discriminated frequency ranges less accurately than other birds; they tracked reward across several lower frequency ranges but failed at frequencies over 4000 Hz. The results revealed the error of describing species differences solely in terms of their discrimination of frequency ranges. Exceptions to the rule disappear when the rule is restated in terms of underlying mechanism: birds are superior to mammals in the ability to use absolute pitch height perception to discriminate pitches and ranges of pitches.     

Expectancies generated by recent exposure to melodic sequences

In four experiments, we examined the effects of exposure to unfamiliar tone sequences on melodic expectancy and memory. In Experiment 1, 30 unfamiliar tone sequences (target sequences) were presented to listeners three times each in random order (exposure phase), and listeners recorded the number of notes in each sequence. Listeners were then presented target and novel sequences and rated how well the final note continued the pattern of notes that preceded it. Novel sequences were identical to target sequences, except for the final note. Ratings were significantly higher for target sequences than for novel sequences, illustrating the influence of exposure on melodic expectancy. Experiment 2 confirmed that without exposure to target sequences, ratings were equivalent for target and novel sequences. In Experiment 3, new listeners were assessed for explicit memory for target sequences following the exposure phase. Recognition of target sequences was above chance, but unrelated to expectancy judgments in Experiment 1. Experiment 4 replicated the exposure effect, using a modified experiment design, and confirmed that the effect is not dependent on explicit memory for sequences. We discuss the idea that melodic expectancies are influenced by implicit memory for recently heard melodic patterns.