精神病超高危人群自由视图眼动特征分析

Characteristics of free visual exploration patterns in subjects at ultra-high risk for psychosis

目的分析未服药精神病超高危人群自由视图过程中的眼动特征。方法对符合前驱期综合征诊断标准的50例精神病超高危被试者（前驱组）和性别、年龄及教育年限与之匹配的40名健康志愿者（对照组）进行自由视图的眼球运动测试，应用EyeLink桌面式眼动仪收集眼动信息，分析比较2组自由视图时注视次数、注视时间、平均注视时长、扫视次数、平均扫视幅度和扫视总路径；并进一步分析2组上述指标随时间进程的变化。结果与对照组相比，前驱组注视次数减少[（24±1）次与（26±1）次，t=2.314，P=0.023]、扫视次数减少[（23±4）次与（25±3）次，t=2.322，P=0.023]、扫视总路径缩短[（113±29）°与（130±28）°，t=2.772，P=0.007]和平均注视时长延长[（362±85） ms与（321±52）ms，t=-2.866，P=0.005]。前驱组与对照组的注视时间和平均扫视幅度差异无统计学意义。2组间分时段进行比较，平均扫视幅度具有组别×时间的显著性交互作用[F组别×时间（3, 86）=3.115，P=0.030]。结论精神病超高危人群较健康对照者表现出受限的眼动模式，其病理生理学意义值得进一步探究。

Objective To investigate the eye-movement feature of free visual exploration in medication-naive subjects at ultra-high risk for psychosis.Methods Eye movements of 50 subjects at ultra-high risk for psychosis and 40 healthy controls evaluated by the Structured Interview for Prodromal Syndromes were recorded using EyeLink desktop eye tracking system. Healthy controls were matched with subjects at ultra-high risk for psychosis in gender, age and education level. The differences in fixation count, total time, fixation duration, saccadic count, saccadic amplitude and scanpath length as well as changes of these indices over the exploration course were analyzed.Results Subjects at ultra-high risk for psychosis statistically showed fewer fixation count （24±1 vs. 26±1, t=-2.314, P=0.023）, fewer saccadic count （23±4 vs. 25±3, t=2.322, P=0.023）, shorter scanpath length （（113±29）° vs. （130±28）°, t=2.772, P=0.007） and longer fixation duration （（362±85） ms vs. （321±52） ms, t=-2.866, P=0.005） compared to healthy controls. There were no statistical differences in total time and saccadic amplitude. A significant interaction of group×time（Fgroup×time （3, 86）= 3.115, P=0.030） in saccadic amplitude was found when testing changes in fixation duration and saccadic amplitude over the exploration time course.Conclusions Subjects at ultra-high risk for psychosis showed a limited scanpath pattern of visual exploration comparing with healthy controls. The pathophysiological significance of eye-movement abnormality in subjects at ultra-high risk deserves further research.