Aprosodia - Brain Regions

Brain Regions

Research into the perisylvan region of the right hemisphere has shown that there are similarly mapped analogues to the speech center in the left hemisphere. This is especially evident in those areas resembling Broca's area and Wernicke's area. The similarity of these regions has led scientists to view aprosodias in a similar manner to how some aphasias are viewed. Because the presence of an aphasia is often more pronounced in an individual than an aprosodia might be, apahsias have traditionally been more heavily studied. Because aphasias are rooted in deficiencies in language modalities rather than affective aspects of language, it has been easier to characterize the underlying impairment caused by brain damage (e.g. inability to choose the right word or inability to speak due to motor control). Combining aphasic research with right-left analogue mapping has allowed for researchers to produce hypotheses on the underlying process behind various aprosodias.
Additionally, in studying the brain regions associated with aprosodia, brain imaging tests were performed to determine if aprosodia is both a lateralized and dominant function of the right hemisphere areas of language production. Aprosodia can be considered a dominant function of the right hemisphere because strong correlation was found between deficits in affective prosody and distribution of lesions in the cortices of those with right brain damage. No correlation was found between the distribution of cortical lesions in patients with left brain damage and the types of aphasic deficits pronounced in those patients. Aprosodia can be considered a lateralized function of the right hemisphere because of the differences in the ability of a patient to respond to affective prosodic information in those with left brain damage when compared to those with right brain damage. Patients with affective-prosodic deficits in the left hemisphere (dysprosodic patients) showed improvement in understanding and repeating prosodic information when other conveyed linguistic information was simplified, i.e. requiring the patient to mainly determine prosodic information contained in an interaction. This improvement in processing affective prosodic information under reduced linguistic processing demands did not occur for patients with right brain damage.