People who will sing but not speak.
There are some cases when a person who is not able to speak will still be able to sing as the result of a specific aphasia.
Aphasia is an impairment or loss of the faculty of understanding or using spoken or written language, even though there is integrity of the neuromuscular structures that produce language. Aphasia is caused by brain damage, and is produced by left brain hemisphere damage in right-handed people.
Almost 90% of the population is right handed and of this percentage, more than 99% have a strong left hemisphere dominance for the linguistic functions. This is the reason why in right handed people, only left hemisphere brain damage will cause aphasia. Left-handed people will have a different hemispheric brain pattern, so their linguistic functions will be represented in both brain hemispheres. As a result, damage in any hemisphere will produce aphasia which will be less severe than those with the same damage in right-handed people.
The anterior area of language is related to linguistic production. It corresponds to the lower frontal lobe (usually on the left) and is known as the “Broca area”. It is like a transmitter region.
Broca aphasia affects this specific area. People with this sort of aphasia can typically process and understand speech perfectly, but they can’t utter a single word. The posterior area of language, traditionally referred as the “Wernicke area”, is the cortical area related with the comprehension of spoken language. Wernicke aphasia is when people don’t understand speech, but they nevertheless “talk a lot”.
Neurologist Norm Mueller made the observation that there were cases recorded in the medical literature about people who could not speak, but they could sing. Mueller was struck by the fact that the human central nervous system did not process musical sounds the same way it did the auditory patterns of speech. He had found and described several patients with strokes involving the left hemisphere who were aphasic. They couldn’t utter a word. But… they could still sing! So the Mueller theory held that musical ability would not be affected by damage localized to the inferior left frontal lobe.
Recent studies had shown that singing involves right hemisphere activity, so people with aphasia due to left hemisphere lesions are able to sing the text of a song while they are unable to speak the same words.
Remember that left hemisphere dominance is the “right-handed” dominance. The left hemisphere is foursquare, upright, sensible, direct, true, and more analytical. Right hemisphere dominance is “left-handed”. The right hemisphere is meandering, flexible, more complex, and more intuitive.
The Scalpel and the Soul. Encounters with Surgery, the Supernatural, and the Healing. Allan J. Hamilton, M.D., FACS.
Elif Özdemir,a,b Andrea Norton,a and Gottfried Schlaug. Shared and distinct neural correlates of singing and speaking. NeuroImage 33 (2006) 628–635
Left and Right Sides of the Brain: Which is your dominant side? [link]
Hemispheric Dominance Test [link]Share