[Visual scanning in patients with unilateral visual neglect due to right-sided cerebro-vascular lesion]

The characteristics of visual scanning in patients with unilateral visual neglect (UVN) were studied. Forty-one patients who showed UVN in the figure finding test and 21 patients who showed to UVN in the test were selected from 176 patients with the right-sided cerebro-vascular lesion. They ranged in age from 46 to 78 years. The severity of UVN in each subject was determined by the number of the figures neglected unilaterally in the figure finding test in which a subject was asked to circle the designated figures scattered among the other figures on the test paper. The following two tests were administered to each subject. Test 1 examined binocular peripheral vision by tachistoscopic method in which a white circle of 1 degree was presented for 1/8 sec at 15 degrees from the central fixation point either unilaterally or bilaterally. Test 2 investigated the movement of gazing point while a subject was searching a target on a screen with his or her head stabilized. It was recorded on 16 mm movie film with Eye-Mark Recorder Model IV (Nac Co.) and converted into a series of position coordinates from which a visual scan path was reproduced and values of variables representing characteristics of visual scanning were computed. Six of 19 subjects who demonstrated "mild" UVN were found their peripheral vision intact. The characteristics of their visual scan path did not differ from the ones of the other 9 subjects who demonstrated "no" UVN as well as intact peripheral vision.(ABSTRACT TRUNCATED AT 250 WORDS)