Long-term effects of focal, cortical injuries upon articulation and discrimination performance.

Residual, long-term effects of cortical injuries upon speech production are rarely examined. In this study, we examined the articulation and discrimination abilities in twelve subjects who received focal, cortical injuries in Vietnam during 1968-1971. The subjects were divided into two groups based upon the hemisphere (right or left) of lesion. Data revealed the left-hemisphere injured group produced a greater number of articulation and discrimination errors than the right-hemisphere injured group. Articulation errors occurred more often than discrimination errors in both groups. However, a feature analysis revealed the left-hemisphere injured group made predominantly combination errors and the right-hemisphere injured group made predominantly place errors. Taken overall, the data suggest the left-hemisphere injured group may experience residual difficulties with the encoding of phonological units while the right-hemisphere injured group appears to have residual problems that may be related to the spatial correlates of speech.