A new study has discovered that the brains of people suffering from tone deafness are in fact lacking in white matter. The study, published in the current issue of Brain, was conducted by a team of researchers from the Université de Montréal, the Montreal Neurological Institute and the Newcastle University Medical School.
Tone deafness (or congenital amusia) is a lifelong disability that prevents otherwise normal-functioning individuals from developing basic musical skills. The study examined the structural neural correlates of tone deafness. Magnetic resonance imaging data from a group of tone deaf people were compared with the images of people with normal musical ability to find out what area of the brain was responsible for this condition and what possible anatomical anomaly could correlate with this "music disorder."
"The results were consistent across samples in highlighting a reduction in white matter concentration in the right inferior frontal gyrus of amusic individuals," explained Dr. Isabelle Peretz of the Université de Montréal. "The data points to the integrity of white matter tracts in right frontal brain areas as being key in acquiring normal musical competence."
"We used a technology called voxel-based morphometry (VBM), which is a computerized and automated procedure that allows one to search throughout the whole brain for structural differences in terms of brain tissue concentration," explained Dr. Krista L. Hyde of the Montreal Neurological Institute at McGill University and the Department of Psychology at the Université de Montréal. "The individuals who participated in the study were considered tone deaf on the basis of two main criteria: difficulty recognizing familiar tunes without the assistance of lyrics, and the inability to detect when they are singing out of tune."
The present study constitutes the first investigation into the structural neural correlates of tone deafness. The results have implications for the understanding of normal acquisition of musical abilities and for the diagnosis and remediation of this music-specific disorder.
The study was supported by funds from the Fonds de recherche en santé du Québec and the Centre for Interdisciplinary Research in Music Media and Technology to Krista L. Hyde, by funds from Canadian Institutes of Health Research to Isabelle Peretz, and by funds from the Wellcome Trust (UK) to Timothy D. Griffiths.
This research also stems from the International Laboratory for Brain, Music and Sound Research, or BRAMS, which is a collaboration between the Université de Montréal, the Montreal Neurological Institute and McGill University. It is an inter-university research and training facility that has made Montreal the global centre for the study of the musical brain. Co-directed by Dr. Isabelle Peretz and Dr. Robert Zatorre from the MNI, the laboratory brings together researchers who share an interest in understanding the cerebral substrates of auditory cognition and, in particular, the processing of music by humans.
A complete list of the study's authors and their affiliations:
Krista L. Hyde (1, 2), Robert J. Zatorre (2), Timothy D. Griffiths (4), Jason P. Lerch (3) and Isabelle Peretz (1)
(1) Department of Psychology, Université de Montréal, Montreal, Quebec
(2) Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec
(3) Toronto Hospital for Sick Children, Toronto, Ontario
(4) Newcastle University Medical School, Newcastle Upon Tyne, UK
About the Université de Montréal
Founded in 1878, the Université de Montréal today has 13 faculties and together with its two affiliated schools, HEC Montréal and École Polytechnique, constitutes the largest centre of higher education and research in Québec, the second largest in Canada, and one of the major centres in North America. It brings together 2,400 professors and researchers, accommodates more than 55,000 students, offers some 650 programs at all academic levels, and awards about 3,000 masters and doctorate diplomas each year.
About the Montreal Neurological Institute
The Montreal Neurological Institute is a McGill University research and teaching institute, dedicated to the study of the nervous system and neurological diseases. Founded in 1934 by the renowned Dr. Wilder Penfield, the MNI is one of the world's largest institutes of its kind. MNI researchers are world leaders in cellular and molecular neuroscience, brain imaging, cognitive neuroscience and the study and treatment of epilepsy, multiple sclerosis and neuromuscular disorders. The MNI, with its clinical partner, the Montreal Neurological Hospital (MNH), part of the McGill University Health Centre, continues to integrate research, patient care and training, and is recognized as one of the premier neuroscience centres in the world.