近红外光学成像技术检测视觉搜索任务期间大脑前额叶氧合血红蛋白水平变化

目的 研究视觉搜索对大脑前额叶氧合血红蛋白水平变化的影响.方法 25名右利手健康大学生被试者在一列非靶字母中搜索靶字母,依据非靶字母数目(2个或6个),将任务分为2个水平(任务1或2).实验期间同时记录被试者行为反应和前额叶脑区氧合血红蛋白水平变化.结果 1)与任务1相比,任务2期间被试者反应时延长、正确率下降,前额叶脑区氧合血红蛋白水平明显上升;2)任务2期间被试者前额叶脑区激活水平与反应时呈负相关.结论 前额叶区域氧合血红蛋白反应与视觉搜索行为结果相一致,较高的氧合血红蛋白水平有可能缩短行为反应时间.

Oxygenated Hemoglobin Responses in Prefrontal Area during Visual Search Tasks Measured with Near-infrared Spectroscopy

Objective To observe concentration changes of oxygenated hemoglobin (HbO2) in prefrontal area during visual search tasks. Methods Twenty-five healthy college students were asked to do two levels of visual search tasks during which changes of concentration of HbO2 were measured. Results 1) HbO2 increased during the task of detecting a target letter from eight non-target letters as compared with that during the task of detecting a target letter from 2 non-target letters. 2) The enhancement of HbO2 measured by NIRS on prefrontal cortex was negatively correlated with performance of the tasks. Conclusion The HbO2 response of prefrontal area is consistent with the behavioral result of visual search tasks, suggesting that higher hemodynamic response may reduce the response time of visual search task.