Is dichotic word listening a valid predictor of cerebral language dominance?

Although the pattern of ear asymmetry derived from dichotically presented verbal stimuli is used to predict cerebral language dominance, the reliability of this procedure for individual patients has not been adequately established. To determine the accuracy with which verbal dichotic stimuli can predict cerebral language dominance, dichotic word listening performances of 106 patients whose language dominance had been determined by Wada (intracarotid amobarbital) testing were examined. On a group level, ear advantages were in the expected direction, however, no statistically significant differences between left, bilateral, and right language dominance patients were obtained. Predicting side of language dominance was even more ineffective in the individual patient regardless of ear asymmetry criterion. Results suggest that the dichotic word listening task employed in this study is not a valid predictor of cerebral language dominance in adults. Thus, caution should be exercised when inferring language lateralization based solely upon dichotic word listening performance.