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I'm currently finishing my PhD program in neuropsychology at McGill and the Montreal Neurological Institute under the supervision of Dr. Robert Zatorre. My main research interest is investigating what goes on in our brains that makes us able to decode, appreciate, and enjoy the sounds that make up a musical experience. My thesis focuses on the neural correlates of pitch perception, and how that perception can change within a tonal context. I've listed my research presentations and brief descriptions of my research projects below, along with links to McGill, the Montreal Neurological Institute, and the McConnell Brain Imaging Centre, and other academic links. |
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| 1996 - | Warrier, C., & Zatorre, R. (1996). The Effect of Melodic Context on Interactions
Between Pitch and Timbre. Paper presented
at the 4th International Conference on Music Perception and Cognition,
Montreal, Quebec. |
| 1998 - | Warrier, C.M., Zatorre, R.J., Peretz, I., Besson, M., &
Evans, A.C. (1998, June). PET Study Investigating the Separation of Lyrics and Music in
Song. Poster presented at the 4th
International Conference on Functional Mapping of the Human Brain, Montreal, Quebec. |
| 1998 - | Zatorre, R.J., Bermudez, P., Warrier, C.M., & Evans, A.C.
(1998, June). Cerebral Mechanisms Associated with Encoding and Recognition of Melodies. Poster presented at the 4th
International Conference on Functional Mapping of the Human Brain, Montreal, Quebec. |
| 1999 - | Warrier, C.M., & Zatorre, R.J. (1999, August). The Role of Right Temporal Cortex in Effects of Melodic Context. Paper presented at the Society for Music Perception and Cognition, held at Northwestern University, Evanston, Illinois |
| 1999 - | Warrier, C.M., Belin, P., Merlet, I., and Zatorre, R.J. (1999, October). fMRI study title. Poster presented at the Society for Neuroscience conference, Miami, Florida. |
Tested
undergraduates’ ability to make pitch discriminations while ignoring interfering
timbral changes. The same test tones were
presented in different contexts: melodic, non-melodic tone series, and two-tones only. We found that although timbre interfered with
pitch judgments in all conditions, people were more able to ignore this interference in
the tone-series condition than in the two-tone condition, and even more so in the melodic
condition.
Tested
patients who have had surgical excisions within their temporal lobes for treatment of
intractable seizures due to epilepsy on the same tests as described in the psychophysical
behavioral study. When the
patients’ excisions included right secondary auditory cortex, they not only had more
difficulty in general with the task, but they were not able to use the facilitating cues
of the melodic context to the same extent as the control group.
When and
where is the facilitatory effect of melodic context on pitch discrimination occurring in
the normal brain? The timing accuracy of EEG
is perfect for addressing the “when” part of this question. Participants discriminated the pitches of the last
two notes of a melody, random tone series, or two-tone pair while hooked up to the EEG. We will be comparing the resulting evoked
potential (EP) waveforms of each condition and analyzing when and how they begin to
differ. This will be complemented by a dipole
analysis of the same data. We will be running
the same subjects on the same tasks with an event-related fMRI protocol shortly. This will enable us to compare areas of increased
BOLD signal between conditions, as well as provide an objective way of constraining the
inverse problem of dipole modeling of the EP’s.
We will co-register the individual anatomical scans to both the fMRI and
dipole analysis data for ease of interpretation.
This study
investigated the separation of lyrics and melody in song.
Francophone musicians listened to short excerpts of French opera sung a
capella and decided if the last note was sung correctly, out of tune, and/or with the
wrong word. During each scan they were
instructed to pay attention to either the melody or the lyrics. Due to the complex auditory stimuli, all scans
showed a large increase in cerebral blood flow (CBF) to the superior temporal gyrus
bilaterally. When attending to the lyrics,
left inferior frontal areas were included in the pattern of activation. When attending to the melody, a different although
less consistent pattern was observed, indicating that lyrics and melody are processed
separately in the brain.
Cajal Medical and Scientific Illustration
Psychonomic Society Publications
APA style guide from the University of Illinois
