[Study of attentional bias in neglect patients by grey discriminant test]

To explore the attentional bias in unilateral spatial neglect (USN) patients.

The grey discriminant test was conducted on 12 right-brain-damaged patients with USN (USN+), 12 right-brain-damaged patients with no evidence of USN (USN-) and 20 health controls (HC). They were matched for age, years of education, mini-mental state examination (MMSE) scores and handedness. And all patients were recruited from First Affiliated Hospital of Anhui Medical University. The attentional deviation scores were compared between three groups.

The differences in scores of neglect tests for the USN+, USN- and HC groups were significant (Albert test: USN+ group -0.56 ± 0.39, USN- group 0.00 ± 0.00, HC group 0.00 ± 0.00, F((2, 41)) = 33.708, P < 0.001; line bisection test: USN+ group 0.28 ± 0.29, USN- group 0.03 ± 0.04, HC group -0.02 ± 0.04, F((2, 41)) = 14.527, P < 0.001; clock drawing by memory: USN+ group 3.58 ± 4.03, USN- group 0.08 ± 0.29, HC group 0.00 ± 0.00, F((2, 41)) = 12.558, P < 0.001; daisy copying: USN+ group 0.83 ± 0.65, USN- group 0.13 ± 0.23, HC group 0.00 ± 0.00, F((2, 41)) = 21.621, P < 0.001). The comparative results of lesion locations showed that USN+ patients were predominantly related to lesions in temporal-parietal junction. The attentional deviation scores for the USN+, USN- and HC groups were 0.92 ± 0.11, 0.41 ± 0.12 and -0.28 ± 0.15 respectively. The difference was significant (F((2, 41)) = 334.324, P < 0.001). There was with a small leftward bias in the HC group and a rightward bias in the USN+ and USN- groups. LSD test revealed that the USN+ group displayed a rightward bias much strongly than the USN- group (P < 0.001). And the results of grey discriminant test were consistent with the neglect symptoms.

The USN patients show a marked attentional bias toward the right side of space. And it may be attributed to the dysfunction of temporal-parietal junction.