Dysprosody - Dysprosody in The Brain

Dysprosody in The Brain

Since the discovery of dysprosody, scientists have been attempting to declare a particular area of the brain responsible for prosodic control. It was long believed that the right hemisphere of the brain was responsible for prosodic organization, ultimately leading to a grossly oversimplified hemispheric model. This model argued that the organization of language, centered in the left hemisphere, parallels the organization of prosody in the right hemisphere. Since its release, however, very few studies have given the model any substantial support.

Scientists have attributed major control of the temporal aspects of prosody, including rhythm and timing, to the left hemisphere of the brain. On the other hand, pitch perception, such as singing and linguistics related to emotion, are believed to be organized in the right hemisphere. This belief led to the development of the “Functional Lateralization” hypothesis, stating that dysprosody can be caused by lesions in either the right or left hemispheres. It further states that the left is responsible for acoustic and temporal aspects of prosody, while the right is responsible for pitch and emotion. This hypothesis, however, has also been a cause for concern as studies have shown that people with left hemispheric damage exhibit prosodic deficiencies associated with the right hemisphere as defined by the Functional Lateralization hypothesis and vice versa. In addition, it has also been found that damage to the medulla, cerebellum, and basal ganglia may cause dysprosody. These conclusions have led scientists to believe that prosodic organization in the brain is extremely complex and cannot be attributed to hemispheric divisions alone. Although not well understood as of yet, studies to identify prosodic organization in the brain continue, primarily through the examination of damaged brain areas in patients suffering from dysprosody and their resulting vocal deficiencies. In addition, dysprosody has been associated with several other diseases, including Parkinson's Disease, Huntington's Disease, gelastic epilepsy (gelastic seizure), and behavioral disorders such as apathy, akinesia and aboulia. Understanding these disorders and the areas of the brain affected in each case is key in conducting further studies of dysprosody. Scientists are continuing to study these patients in the hope of creating more concrete connections between areas of brain damage and prosodic abnormalities, which will hopefully someday lead to a full understanding of prosodic organization in the brain.