| Deception is a common social phenomenon, involving advanced cognitive processing functions such as attention, memory, execution control, and so on. Heroin addicts have always been considered a habit of lying even special pathological liar group, scientific researches have also confirmed that the heroin addicts have antisocial personality disorder behavior characteristics, including the habit of lying. Due to long-term heroin dependence, the brain functions of heroin addicts are mostly damaged, leading to their abnormal advanced cognitive functions including executive function. At the same time, heroin addicts show the dysfunctional neurotransmitter system in the brain, leading to their highly impulsive characteristics such as attention deficit, high delayed reward discount rate, and so on. In order to reduce the harm to society, improve physical and mental health for heroin addicts, at present our country take measures that are given priority to with drug treatment of comprehensive physical-psychological-social intervention on heroin addicts. However, at present there have been some debates whether the advanced cognitive processing functions can be improved after those heroin addicts participate in the community maintain treatment treatment. In view of this, there are important practical and theoretical significance to study executive function and the influence of impulsive in deception behaviors among the heroin-dependent treatment patients (HTP). Concealed information test(CIT) is a classic deception-detection paradigm, and it can distinguish the crucial crime-ralated information from the irrelevant ones, thereby to judge whether one is "guilty". Under the guidance of a more macroscopical thinking frame, this study inspected executive dysfunction during their deception process using event related potential technology. The whole research consists of four series studies, a total of seven experiments.Study1investigated the differences of dynamic changes of brain time process between the HTPs and the healthy normal people in control group, which consists of two experiments in concealed information test and taking countermeasures to the concealed information test. Experiment1compared behavioral and ERP differences under the condition of concealed information between the HTPs and the healthy normal people in control group. The behavioral results showed that HTP significantly had slower reaction time and lower accurate rate comparing with the control group; ERP data showed that the ERP average amplitudes evoked by the three types of stimuli were significantly lower in HTP group than in the control group; the probe P3a(300-450ms) and P3b(450-650ms) average amplitudes were bigger than these of irrelevant stimuli in the controls, while the probe P3a was smaller than irrelevant and there was no difference for P3b in the HTP group. In addition, the detection rate in HTP group(38.9%) was also significantly lower than in the control group(76.7%). The results in Experiment1A suggested that the long-term chronic heroin exposure can lead HTPs to the deficiency of attention orientation and the disorder of decision-making function, so that they were hard to be detected correctly in the concealed information test. According to the previous research results that performing countermeasures in response to irrelevant stimuli could decrease the detection rate in the concealed information test, on the basis of Experiment1A, Experiment1B compared behavioral and ERP differences between the HTPs and the healthy normal people in control group under the condition of countermeasures in concealed information test. The results found that there were the trends of shorter reaction time and lower accuracy for probe than irrelevant stimuli in the pariticipants of both groups; in the HTP group, the P300average amplitudes evoked by the three types of stimuli reduced significantly, and the probe P3a and P3b average amplitudes were both smaller than these of the irrelevant contrary to the control group. In addition, the detection rate in HTP group(20%) was also lower than in the control group(33.3%). This suggested that the process capability of ateentional orientation is weaken, the difference of the deception-related stimuli is reduced, and HTPs can eacape the concealed information test more easily compared with the controls after performing the countermeasures to the irrelevant stimuli.Study2investigated the dynamic time-course change differences of brain cortex from different levels of impulsivity during HTPs were in process of deception. It consisted of two serial experiments. Experiment2A compared the differences of the behavioral and ERP data between two groups of HTPs whose impulsivity were at different levels under the condition of information concealed in concealed information test. The results showed that high impulsive HTPs had more lower accuracy compared with the low impulsivity group, and the Pa3differences between the probe and irrelevant stimuli reduced significantly as well as P3b; the detection rate of high impulsive HTP group(30.8%) was lower than which of the low group(50%). It suggested that there were more serious attention orientation deficit and abnormal decision-making in the high impulsive HTPs than in low impulsive HTPs. Experiment2B compared the differences of the behavioral and ERP data between two groups of HTPs whose impulsivity were at different levels under the condition of countermeasures in concealed information test. The results showed that the slower reaction time and lower accuracy for probe than irrelevant stimuli in the high impulsive HTP group compared the low impulsive group, and the difference of P3a amplitude disappeared between probe and irrelevant stimuli as well as P3b; the detection rate of high impulsive HTP group(0%) was lower than which of the low group(38.5%). It suggested that there are more seriously impaired attention orientation and decision-making function for the high impulsive HTPs than the low impulsive ones. It implies that impulsivity has influence on the cognitive functions in the concealed information test as well as in countermeasure test, and the more higher impulsivity is, the more seriously impaired the cognitive functions are, the more easily the deception can eacape from the concealed information and its countermeasure test.Study3included two serial experiments to explain habitual deception and low deception diagnostic rate among HTPs by means of inspecting their abnormal brain time-course processing and the influence of impulsivity on their excutive function. Experiment3A compared the excutive function of the HTP group with the control group, and found that the N450and SP effects were all disappeared for the participants in the HTP group in the classic color-word Stroop task. This suggested that HTPs exsit anomaly during early stimulus monitoring and late conflict sovling, and explained why the HTPs are hard to be detect successfully in the concealed information test. Based on Experiment3A, Experiment3B compared the differences of behavioral and ERP data between two group from different levels of impulsivity, and found that N450and SP effects were all attenuation in the low level group, while all disappeared in the high level group. The results showed that the more higher the impulsivity level was, the more seriously the excutive function was damaged, and explained further why the attention orientation deficiency and decision-making function were more abnormal and detection rate were more lower in the concealed information test and the countermeasure test in the higher impulsivity lvevl HTPs compared with the lower impulsivity level ones in Study2.The central neuretransmitter activity is one of the neurobiological bases for human behaviors, and the dynfunctional neurotransmitters can result in the abnormal impulvisity for the individuals. Study4discussed the differences of neurotransmitters between the HTPs and the normal healthy people, explained further why the impulsivity level of HTPs was higher than the nomals, and provided the neurobiological evidence for Study1and2. The experiment employed encephalofluctuograph (EFG) to detect the measure power, the relative power, the whole brain total power and the index of brain function from six kinds of neurotransmitters, such as y-aminobutyric acid (GABA), glutamic acid (Glu), serotonin (5-HT), acetyl choline (ACh), norepinephrine (NE), dopamine (DA) and so on. The results showed that compared the control group, the measure power and relative power of GABA and Glu, and the whole brain total power reduced remarkably in HTP group, but5-HT, Ach, NE, DA, the excitatory-inhibitory index and the relative entropy all rised significantly. The results illustrated that the balance between the excitatory and inhibitory neurotransmitter systems was destroyed, and it caused impulsivity to rise markedly in HTPs.In sum, the present research can get following conclusions.(1) In the classical deception detection and countermeasure detection, HTPs exsit abnormal attention orientation and decision-making function, which results in their escape eaily from these tests.(2) To varying degrees, the different levels of impulsive HTPs have abnormal attention orientation and decision-making function, and these cognitive functions are damaged more seriously with the impulsivity level rising in the classical deception detection and countermeasure detection, and deception can escape successfully from these tests.(3) In the classical color-word Stroop task, the HTPs showed abnormal stimulus conflict monitoring and conflict solving, and these excutive functions are impaired more seriously. Therefore, the rising impulsivity is one of reasons why the excutive functions of HTPs are impaired.(4) The neurobiological evidences suggest that the central neurotransmitter system is dysfunction, and the balance between the excitatory and inhibitory neurotransmitter systems is destroyed, resulting in the impulsive level rising markedly in HTPs.The present reseatch reveals the features of dynamic change of the brain time-course in the concealed information test and the countermeasure test among the HTPs, and discusses the influence of impulsivity on the excutive function while the HTPs are deceiving. Furthermore, the evidences from nuerontransmitter system comfirm the neurobiological reason of enhanced impulsivity for the HTPs. These results inspire to discuss the advanced cognitive functions further among the HTPs. |
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