Communication is the act of conversing with others, involving both receiving and expressing information in the form of words, gesture, facial expression, body language and intonation. Speech or language disorders occur in as many as 40% of patients who suffer from stroke. Unlike that of the left hemisphere of the brain, trauma to the right hemisphere results in problems which are not linguistically based. These extralinguistic aspects of communication, such as tone of voice, body language, facial expression and gesture, help to extend communicated meaning beyond the literal sense.

DISORDERS RELATING TO RECEIVING EXTRALINGUISTIC INFORMATION

Inference Deficit - Difficulty interpreting and inferring meaning. Inference depends on the attention, selection, integration and association of previously experienced cues. A RHD patient's inability to easily make interpretations or inferences, causes them to become overly dependent on the linguistic system. This leads to a greater likelihood for patients to interpret literally, and sometimes lose the intended meaning of a conversation or joke, particularly where it involves sarcasm. RHD Patients may also have difficulty comprehending prosodic features of conversation, such as alterations in pitch, volume, and pausing time. The added disadvantage of being unable to interpret the facial expression and body language of the conversational partner, makes it even more difficult for the patient to comprehend the emotional content and impact of the conversation.

DISORDERS RELATING TO EXPRESSING EXTRALINGUISTIC INFORMATION

RHD patients often have a very flat, monotone voice which has little expression and variation. This leads to difficulties for the patient in following generally accepted rules of conversation, in expressing emotional content, and may cause the patient to appear insenstive or impolite. It also commonly results in audience habituation, whereby conversational partners tire of and eventually become habituated to the constant monotony of the patient's voice. Another characteristic expression of patients is rambling tangential speech which is commonly egocentric. Other communicative deficits, such as dysarthria and dysphonia involve poor articulation, speech production and oral weakness as a direct result of physical impairment from the stroke. With these communicative disorders, rapid spontaneous improvement is common, however persisting disorders may cause considerable social problems. In treating right hemisphere communicative disorders, the main aims are to increase the awareness of deficits, reinstate the disrupted communicative behaviours, and provide compensatory techniques when restoration is not possible. Because right hemisphere language disorders are complex and their treatment is a relatively new field, the effectiveness of treatment has not been fully evaluated.