计算加工ERP在法医学鉴定中的初步研究

发布时间：2018-04-20 12:57

本文选题：事件相关电位 + 计算加工　；参考：《华中科技大学》2009年硕士论文

【摘要】：【研究背景】计算是人们日常生活中最重要的思维活动之一,涉及了多种认知加工环节,如感知觉、判断、比较和推理等,能比较深入地反映个体的脑认知水平。计算能力与个体的智商水平亦密切相关,也是智力测验的重要测查内容,如中国修订韦氏成人智力量表(WAIS-RC)中即包括算术、数字广度和数字符号三个分测验。计算能力下降是颅脑外伤的伤者在临床就诊及法医学鉴定时的常见表现和主诉之一,可对伤者的日常生活、职业劳动及社会交往造成严重影响,客观评定计算能力的受损程度对于评价脑外伤后智能障碍的严重程度具有重要意义。目前,计算能力的检测一般通过提问、心算和笔算等方式来完成,这些检查方法均依赖于被试的主动性与合作程度。法医学鉴定时,伤者受躯体情况、赔偿心理和精神状态等因素的影响,往往配合性较差,测验结果常与其伤后的实际能力水平不相符,限制了WAIS-RC等神经心理学测验技术在法医学领域的应用价值。因此,建立符合法医学鉴定工作需要的计算能力客观检测方法具有重要的实用性和现实意义。事件相关电位(event-related potential, ERP)是用于检测认知加工过程中脑活动的一种无创性检测方法,记录到的瞬间电势变化与刺激(如一个词、一种声音或者一个图像等)的发生有锁时关系,具有很高的时间分辨率。近年来,一些研究者尝试采用ERP技术来探索数量加工的电生理机制、运算能力的发展机制,并发现了一些与数字加工有关的特异性ERP成分,但在法医学领域应用ERP技术来评估计算加工能力在国内外均未见文献报道。本研究尝试建立符合临床法医学鉴定及ERP检测要求的计算加工刺激范式,探索计算加工相关的特异性ERP成分,以期为颅脑外伤后计算能力障碍的检测提供客观的电生理参考指标。【目的】采用后续判断比较任务范式(算式图片与答案图片间隔呈现),编制包含加、减、乘、除运算的算术刺激序列进行检测,比较健康志愿者与颅脑外伤志愿者所诱发的ERP成分的特征和差异,并探讨ERP各成分与WAIS-RC检测结果的相关性。【方法】利用37导Neuroscan ERP仪器对46例正常志愿者(对照组)以及11例重型颅脑外伤志愿者(外伤组)分别进行听觉Oddball范式、计算加工后续判断比较任务范式的ERP检测及WAIS-RC测验,分别比较与计算加工相关的ERP各成分的波幅和潜伏期、头皮分布特征及其与经典听觉P300成分和WAIS-RC测验结果的相关性。【结果】 1.外伤组WAIS-RC各分测验的粗分、量表分、言语智商、操作智商及总智商的均值均明显低于对照组,有极显著差异(P㩳0.01); 2.外伤组听觉P300分化欠佳,潜伏期较对照组延长,且波幅较低,N2潜伏期与对照组比较有显著性差异(P㩳0.05),P3波幅和潜伏期也有极显著差异(P㩳0.01); 3.计算加工范式的刺激呈现后顶枕部各记录点(CZ、P3、P4等)可获得分化明显ERP波形,其中最稳定的记录点在CZ点; 4.不同性别被试的计算加工ERP波形各成分波幅、潜伏期均无显著性差异; 5.对照组检测发现算式、正确结果,错误结果三种刺激均可引出相似波形,该波形由n1、p2、n2和p3四个子成分构成。正确结果引出波形中p2、n2子成分较错误结果波形分化差,算式引出波形中n2、p3子成分较错误结果分化差。错误结果波形p2、n2、p3的潜伏期较正确结果延长,差异有极显著性(P0.01)。错误结果的n2、p3的潜伏期较算式延长,差异有显著性(P0.05);算式的n2、p3的潜伏期较正确结果延长,差异有显著性(P0.05); 6.外伤组各刺激引出的波形与对照组相似,波形分化较对照组差。各成分波幅均比对照组明显降低,尤其正确结果和错误结果的p3波幅明显降低,差异有极显著性(P0.01),各成分潜伏期与对照组相比均有延长,其中正确结果的n2、p3潜伏期的差异在两组有极显著性(P0.01),错误结果的和算式的p2潜伏期在两组也有极显著差异,算式的p3潜伏期在两组有极显著差异; 7.计算错误结果引出的p3潜伏期与总智商呈明显负相关(r=-0.44,P㩳0.01),高于听觉靶刺激诱发的p3潜伏期与总智商的相关程度; 8.采用听觉P300潜伏期推断智商模型只能解释智商变异的5%,单独纳入计算错误结果P3潜伏期指标推断智商模型能解释智商变异的17.2%;联合视觉P300和计算错误结果p3指标则可以解释智商变异的18.8%。【结论】计算加工刺激序列可诱发稳定的ERP成分,算式、正确结果,错误结果三种刺激所引出p3的波幅和潜伏期与计算加工能力密切相关,即计算能力越差,p3的潜伏期越长,波幅越小;该成分以顶枕部的记录点(Cz点)记录可靠。其中计算错误结果引出的p3潜伏期与WAIS-RC总智商呈明显负相关,高于听觉靶刺激诱发的p3潜伏期与总智商的相关程度,采用计算加工ERP刺激范式来检测颅脑损伤后的认知功能障碍比听觉Oddball范式引出P300更为准确,具有一定法医学应用价值。
[Abstract]:[research background]
Calculation is one of the most important thinking activities in people's daily life. It involves a variety of cognitive processing links, such as perception, judgment, comparison and reasoning, which can reflect the level of individual brain cognition. The calculation ability is closely related to the intelligence quotient level of the individual, and it is also an important survey content of the intelligence test, such as the Chinese Revision of Wechsler's formation. The human intelligence scale (WAIS-RC) consists of three subtests including arithmetic, digital breadth and digital symbol. The decline of computational ability is one of the common manifestations and complaints in the clinical and forensic identification of the traumatic brain injury. It can have a serious impact on the daily life, occupational labor and social interaction of the injured, and objectively assess the calculation ability. The degree of loss is of great significance for evaluating the severity of mental disorders after brain injury. At present, the detection of the ability of the brain is usually done by asking questions, mental calculation and writing, all of which depend on the initiative and degree of cooperation of the subjects. In forensic identification, the injured are subject to physical condition, compensation for psychological and mental state, etc. The effect of the hormone is often poor, and the result of the test is often not consistent with the actual level after the injury. It restricts the application value of WAIS-RC and other neuropsychological test techniques in the field of forensic medicine. Therefore, it is of great practical and practical significance to establish the objective testing method of computational ability in accordance with the forensic identification work.
Event-related potential (ERP) is a noninvasive detection method used to detect brain activity during cognitive processing. The transient potential changes recorded by the event have a lock time relationship with the occurrence of stimuli (such as a word, a sound or an image, etc.), with a high time resolution. In recent years, some researchers have tried. ERP technology is used to explore the electrophysiological mechanism of quantitative processing, the development mechanism of operational ability, and some specific ERP components related to digital processing, but the application of ERP technology in the field of forensic medicine to evaluate the computational processing ability is not reported at home and abroad. In order to provide an objective electrophysiological reference index for the detection of the impairment of computational ability after craniocerebral trauma, the required computational processing stimulus paradigm was measured to explore the specific ERP components related to calculation and processing.
[Objective] to use the follow-up judgment to compare the task paradigm (the interval between the calculated picture and the answer picture), to compile the arithmetic stimulus sequence including addition, subtraction, multiplication and operation, to compare the characteristics and differences of ERP components induced by healthy volunteers and craniocerebral trauma volunteers, and to explore the correlation between the components of ERP and the results of WAIS-RC detection.
[Methods] the auditory Oddball paradigm was performed on 46 normal volunteers (control group) and 11 cases of severe craniocerebral trauma volunteers (trauma group) with 37 Neuroscan ERP instruments. The ERP detection and WAIS-RC test of the task paradigm were calculated, and the amplitude and latency of each component of ERP related to processing were compared. Distribution of scalp and its correlation with classical auditory P300 components and WAIS-RC test results.
[results]
1. the scores of gross scores, scores of verbal IQ, IQ and total IQ of WAIS-RC in each group were significantly lower than those in the control group (P? 0.01).
2. of the trauma group, the auditory P300 was poorly differentiated, the latency was longer than the control group, and the amplitude was lower. The latency of N2 was significantly different from the control group (P? 0.05), and the amplitude and latency of P3 were also significantly different (P? 0.01).
3. after calculating the stimulus presentation of the processing paradigm, the dominant occipital recording points (CZ, P3, P4, etc.) can get the obvious ERP waveform, and the most stable recording point is at CZ point.
4. there was no significant difference in the amplitude of each component in the ERP waveform calculated by different gender subjects.
5. control group detection formula, correct results, error results can lead to three kinds of stimulation can lead to the similar waveform, the waveform consists of N1, P2, N2 and P3 four components. The correct results lead to the waveform P2, N2 sub component than the wrong result waveform differentiation, the formula leads to the waveform N2, the P3 sub component is worse than the error results. Error results waveform P2, N2, P3. The incubation period was longer than that of the correct result (P0.01). The latency of N2 in the wrong result was longer than that of the calculation formula (P0.05), and the latency of N2 and P3 was longer than that of the correct result (P0.05).
6. the waveform of each stimulus in the trauma group was similar to the control group, and the waveform differentiation was worse than the control group. The amplitude of each component was significantly lower than the control group. The P3 amplitude of the correct results and the wrong results was significantly reduced, and the difference was very significant (P0.01). The latent period of each component was prolonged compared with the control group, of which the correct results were in the N2, P3 incubation period. The difference between the two groups was very significant (P0.01), and the P2 latency of the error results and the calculating formula also showed significant difference in the two groups, and the P3 latency of the calculation formula was very significant in the two groups.
7. the P3 latency was negatively correlated with the total IQ (r=-0.44, P? 0.01), which was higher than that induced by auditory target stimulation and the degree of correlation between the latency of P3 and the total IQ.
8. using the auditory P300 latency infer that the IQ model can only explain 5% of the IQ variation, and separate the calculated error results from the P3 latency index to infer that the IQ model can explain the IQ variation by 17.2%; the combined visual P300 and the calculated error results can explain the 18.8%. of the IQ variation.
[Conclusion] the calculated processing stimulation sequence can induce stable ERP components, calculation formula, correct results, and error results of three stimuli. The amplitude and latency of P3 are closely related to the calculation and processing ability. That is, the worse the computational ability, the longer the P3 latency is, the smaller the amplitude; the composition is reliable with the record point of the top pillow (Cz point). Among them, the calculation error is wrong. The P3 latency caused by false results is negatively correlated with the total IQ of WAIS-RC. It is higher than the correlation between the latency of P3 induced by auditory target stimulation and the total IQ. It is more accurate to use the calculated ERP stimulation paradigm to detect the cognitive impairment after brain injury than that of the auditory Oddball paradigm, which is of certain forensic application value.

【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：D919

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