Pitch perception is not unitary: Evidence for the perception of pitch chroma in black-capped chickadees.

• Author / Creator

  Hoang, John

• Pitch perception is mediated by two attributes: pitch height and pitch chroma. These two attributes can be pitted against one another during an octave equivalence task in order to clarify the dominant perceptual mechanism. Pitch chroma mediates the perceptual phenomenon of octave equivalence, which occurs when two acoustic events are perceived as similar because they share the same chroma. Pitch height perception is the perception that a larger difference in frequency leads to a larger difference in perceived pitch. Previous research tested chickadees on a standardized octave equivalence task and suggested that pitch height use by chickadees may have overshadowed their ability to use pitch chroma. To disambiguate this possibility, we presented humans and chickadees with two novel discrimination tasks. Humans and chickadees were trained to discriminate three pairs of notes. After training, both humans and chickadees were presented with novel note pairs with either the same or different pitch chroma. Humans were able to transfer discrimination performance to stimuli with the same pitch chroma whereas chickadees are unable to generalize or transfer the discrimination. Results also indicate that the partial-reversal of response contingencies for pitch chroma related notes interferes with the learned discrimination. My results suggest that both humans and chickadees perceive pitch chroma; however, chickadees show preferential use of pitch height over pitch chroma.

• Subjects / Keywords

  • Perceptual
  • Octave equivalence
  • Comparative cognition
  • Pitch chroma
  • Behavioural
  • Black-capped chickadees

• Graduation date

  Fall 2015

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3T727W6X

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.