The effect of unilateral brain damage on the appearance of question-induced CLEM reactions.

Three groups of subjects--34 non brain damaged, 15 left hemisphere damaged patients, and 15 right hemisphere damaged patients--were administered 40 questions facing the questioner while eye-movement following each question was recorded. 20 of the questions required subjects to indicate how many letters were in a given word. 20 questions tested their visuospatial capacity. The control group revealed a marked tendency to look to the left visual field regardless of the content of the question. The tendency to left-look or right-look, however, was not found to be related to education, age, length of hospitalization, the score on the "letters in a word" test, or the score on the visuospatial test. The left hemisphere damaged group performed remarkably like the control in that they too looked more to the left visual field than to the right. The right hemisphere damaged group, however, did not show a significant difference between left looking and right looking in response to both questionnaires. The findings were discussed in relation to the previous work of Kinsbourne (1972), and Gur, Gur and Harris (1975).