Tuesday, November 18, 2008

Musical Disorders

1. Reference
Musical Disorders
From Behavior to Genes
By Isabelle Peretz
University of Montreal
Current Directions in Psychological Science
For Dr. Lee Bartel – Music and the Brain 2122H
A Summary, Review and Response
Lani Sommers

2. Summary
Humans are born with the potential to speak and make music. A minority of individuals never acquire the ability to acquire music abilities. This is referred to as note deafness, tone deafness, tune deafness, dysmelodia and congenital amusia. These terms refer to a condition where by a person has “a lifelong deficit in melody perception and production that cannot be explained by hearing loss, brain damage, intellectual deficiencies, or lack of music exposure.”

Approximately half of individuals suffering from amusia also have a rhythm deficit but most cases deal with a deficit in the processing of pitch in a musical context. Speech does not seem to be affected by people with amusia – they are able to understand and communicate using speech with no problems.
Evaluating whether a person has amusia is done using six tests (180 stimuli) that assess the different components in melody processing (pitch contour, musical scales, pitch intervals, rhythm, meter, and memory). People with amusia score two standard deviations below the mean of normal controls.

Pertez believes that the problem with individuals with amusia lays in a lack of pitch-processing normally and automatically acquired by ordinary people. This is called, “tonal encoding of pitch” and people with amusia are missing this system/lacking this knowledge.

Amusic brains do not have any detectable neurological abnormality except that they have less white matter in the right inferior frontal cortex than normal brains and a thicker cortex in the same right inferior frontal area and right auditory area. These regions of the brain have been shown to be important in musical-pitch processing.

Research has also been conducted on the genetics of congenital amusia and whether it is passed on to family members. Findings show that 39% of amusic families have relatives with the same cognitive disorder and only 3% in the control families.

Other areas to study on this topic are the occurrences of congenital amusia in tone languages like Cantonese and Mandarin. Pertez predicts that Western individuals with amusia may have difficulty learning a tone language and congenital amusia may be rare in people who speak in tone languages because of early exposure to the tone language.

3. Response
I chose to read an article written by Isabelle Pertez after completing her on-line music listening test. The musical disorder of Amusia is a fascinating and I decided to do some further research on the condition. It seems that it is indeed a genetic condition that can be passed down through families and it may also be something that only individuals suffer from in countries where the language is non-tonal.

I had a lot of trouble singing pitches to my aural perception professor during my undergraduate degree. My professor would get very frustrated with me and told me that I had a “tin ear” and that there was little hope for me musically. I knew that I didn’t have a tin ear and that I could hear the different pitches quite clearly, I just had trouble producing them with my own voice. I persevered and worked very hard. I had aural perception lessons and singing lessons to help me get through the course. Even though I failed the course the first time (with a C+ - one mark away from the required B -!), I kept trying. I knew that with practice I could improve my pitch recognition and production. Now I feel very confident with my skills aurally. I can sing back a variety of pitches (within reason) quite effectively and almost always in tune. I certainly was not tone deaf or suffering from “tin ear” I simply needed to practice and refine my skills.

I wonder if people who suffer from true tone deafness/amusia could also improve their musical skills with practice. Pertez’s findings seem to be consistent with individuals who removed themselves from music and musical situations. If they become reintegrated into music listening, could they start to improve? With some sort of sound-therapy could these individuals improve their musical perception? Could music be broken down into smaller sections/layers and then reintroduced in larger sections/layers gradually in order to help the individual become accustomed to the sound? I overcame my problematic “tin ear” but that was more than likely simply a lack of exposure to a certain type of musical practice. Could amusics overcome their neurological shortcomings through practice and exposure or are they doomed to a music-less life because of genetics?

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