| Abstract: | Previous data have shown that stereotaxic center median lesions alone or lesions in the amygdala, unilateral left and right and bilateral, do not impair verbal paired-word associates learning. However, “interactional” combined lesions in the amygdala and center median nucleus on the left side result in a significant decrease in test scores. Analysis of the types of errors made postoperatively by the six patients with this lesion combination indicates the persistence over trials of misnaming errors vs errors of omission. These findings are compatible with hypotheses of an alerting function performed by medial thalamic structures which, for effective learning, cosponsor attention to stimulus cues. Defective alerting is held to result in faulty labeling and subsequent mismatching (see Ojemann, 1975, Brain and Language, 2, 101–120, and Fedio &; Van Buren, 1975, Brain and Language, 2, 78–100). |
