图形异同判别ERP技术检测伪装认知损害的研究

目的探讨图形异同判别ERP范式对鉴别伪装认知损害的法医学价值。方法 40例健康志愿者在合作和伪装认知损害两种情境下,进行二项必选数字记忆测验(BFDMT)及图形异同判别ERP范式检测,对照组为20例合作的三级脑外伤者。结果三组被试完成相同、无关、相似图形刺激后引出的ERP波均包括N1、P2、N2、P3和N3五个成分,三组样本组间的N2、P3和N3的潜伏期和波幅均存在差异。其中,伪装组相同图形的N3潜伏期与正常组无显著性差异,明显短于外伤组(P<0.01);伪装组无关图形的N3潜伏期较正常组延长,但短于外伤组,波幅较正常组降低(P<0.05);伪装组相似图形的N3潜伏期较正常组和外伤组缩短(P<0.01),波幅较正常组降低(P<0.01)。以N3潜伏期为指标进行判别分析,探查伪装认知损害的敏感性为81.8%、特异性为76.9%、命中率为79.2%。结论图形异同判别范式可引出稳定的特征性ERP成分,其中N3的波幅和潜伏期有显著的组间差异,对判断伪装认知损害有一定的参考价值。

The study on detecting malingering cognitive impairment by event-related potentials of figures difference judgment paradigm

Objective To investigate the application value of event-related potentials(ERP) with figures difference judgment paradigm to detect malingering cognitive impairment.Methods Forty healthy volunteers completed the BFDMT and a paradigm of judge figures difference while perform honestly(HON) then instructed to malinger(MAL),and 20 traumatic brain injury(TBI) to be control.Results The components of ERP elicited by figures difference judgment paradigm in responders in three groups all included N1,P2,N2,P3 and N3.There was a significant difference for N2,P3 and N3 latency and amplitude between three groups.The N3 latency for identical figures of MAL were shorter than TBI(P<0.01) but no significant difference compared to HON.The N3 latency for irrelevant figures of MAL were longer than HON but shorter than TBI,and the N3 amplitude were lower than HON(P<0.05).The N3 latency for similar figures of MAL were shorter than HON and TBI(P<0.01),and the N3 amplitude were lower than HON(P<0.01).Specificity of 81.8% and specificity 76.9% and hit rate 79.2% were obtained when using N3 latency.Conclusion The figures difference judgment paradigm can induce stabile ERP components and there was a significant difference for the amplitude and latency of N3 component,which was demonstrated as a reliable indicator for malingering detection.