Lower correlation between saccade velocity asymmetry and amplitude during visually guided saccade in schizophrenia patients
Xin‐hui Xie, Xiaohui Liu, Chen Wang, Chunyan Zhu, Hong Cui · Chin J Psychiatry · 2014
Objective To explore the abnormal eye tracking capabilities of schizophrenia by using visually guided saccade paradigm. Methods Visually guided saccade was checked on 27 schizophrenia patients who met the criteria of ICD-10 and 27 matched normal controls.Firstly, the acceleration asymmetry index of each saccade was calculated. Secondly, the relation of amplitude and acceleration asymmetry index (Raa) of each participant was also calculated. Thirdly, the Raa values of schizophrenia and normal control group were compared. Forthly, receiver operating characteristic curve of Raa was sketched and area under curve was calculated to evaluate the general diagnostic power of this index. Results Compared with normal controls, Raa values of schizophrenia group were significantly lower (0.57±0.13 vs. 0.27±0.13, Mann-Whitney U test，Z=-5.562，P<0.01), in receiver operating characteristic analysis, area under curve of Raa was 0.941, asymptotic 95% confidence interval was from 0.875 to 1.000. Conclusion Compared with normal control group, the correlation between saccade velocity asymmetry and amplitude during visually guided saccade may be lower in schizophrenia patients. Key words: Schizophrenia; Eye tracking; ROC curve; Velocity