Speech production impairments following left and right hemisphere stroke.

A speech production impairment can occur following damage to either the left or right hemisphere. The nature of the impairment, however, differs depending on which hemisphere is damaged and within the left hemisphere, whether the damage is to the anterior or posterior language areas. This paper reviews the recent literature on the types of speech production impairments that follow damage to the left and right cerebral hemispheres. Damage to the left hemisphere anterior language area causes primarily a phonetic impairment, i.e. a deficit in executing the articulatory maneuvers of sound production with a preserved ability to select the correct sound. Damage to the left hemisphere posterior language area causes primarily a phonological impairment, i.e. a deficit in the correct selection of a sound with an intact ability to implement the articulatory maneuvers for that incorrect sound. Damage to the right hemisphere can cause a speech production problem to the prosodic aspects of language. These differences have direct implications for the theraputic remediation of these speech production impairments.