An examination of the crowding hypothesis in epileptic patients who have undergone the carotid amytal test.

Epileptic patients who had undergone the carotid amytal test were assessed on a variety of measures of verbal and non-verbal ability. All patients had left hemisphere dysfunction of early onset. Patients with atypical speech patterns performed as well as patients with left hemisphere speech on most, though not all, measures of language function. Transfer of language to the right hemisphere, however, occurred at a heavy cost. Patients with atypical speech patterns performed more poorly than their left hemisphere speech counterparts on a wide variety of non-verbal tests. These results are discussed in terms of the "crowding" hypothesis.