Aprosodia

Aprosodia is a neurological condition characterized by the inability of a person to properly convey or interpret emotional prosody. Prosody in language refers to the ranges of rhythm, pitch, stress, intonation, etc. These neurological deficits can be the result of damage of some form to the non-dominant hemisphere areas of language production. The prevalence of aprosodias in individuals is currently unknown, as testing for aprosodia secondary to other brain injury is only a recent occurrence.

One cause of aprosodia is suffering brain trauma to one of several specific areas of the brain, resulting in the inability to properly process or convey emotional cues. This brain damage can occur in the form of ischemic damage from stroke, removal during surgery, brain lesions, or trauma such as a localized bullet wound. It is worth noting however, that this localization occurs over a range of areas that can vary from person to person and more research is required to further define these areas. Diagnostic confirmation of aprosodia using brain scanning techniques is a relatively recent occurrence, at least with respect to quantitative specificity. As brain imaging techniques are refined to allow for greater temporal and spatial resolution, it is hoped that more will be able to be learned about aprosodias at a functional anatomical level.

An inability to process or exhibit emotions in a proper manner has been shown to exist in alcoholics and those who were exposed to alcohol while fetuses (FAexp). Initially, when detoxified alcoholics and FAexp individuals were tested for impairment in cognitive function, it was limited to testing the non-affective aspects of language, as those were the more easily recognized by a physician not trained in analyzing affective prosody. When tested using the aprosodia battery, it was found that detoxified alcoholics and FAexp individuals demonstrated significant impairment in their ability to detect affective prosody when used by others. The major factors which influence affective prosody in those impacted by alcohol use, from greatest to least impact, are: alcohol use by mother, age at onset of chronic abuse of alcohol, age at initial abuse, how chronic the abuse is, and the age when a person first becomes drunk.

Aprosodia has also been shown to appear secondary to several diseases such as multiple sclerosis or post traumatic stress disorder. It is likely that as time passes more diseases will be shown to exhibit aprosodia as a symptom. Aprosodia is a condition that was not often tested for in the presence of neurological deficits; however, as more becomes known about it, the aprosodia battery will likely be administered more frequently. For example, the first study testing for aprosodia in MS did not occur until 2009. This is surprising given that changes in emotional affect would be expected to be noticed in patients exhibiting other changes in speech patterns. This is especially so given that the patients tested in these studies scored poorer than the controls by a statistically significant amount.

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