特质焦虑个体的注意偏向和注意控制特点及其认知神经机制研究

发布时间：2018-09-12 11:09

【摘要】：目的:特质焦虑易引发个体对威胁刺激的注意偏向,且这种负性注意偏向在焦虑和焦虑障碍的发生发展过程中起核心作用。然而由于以往研究者使用的实验范式不一、采用的被试群体不一而导致了实验结果存在很大的分歧。至今为止尚未明确特质焦虑的注意偏向成分及其在时间进程上的变化特点。此外,特质焦虑和注意偏向之间的关系可能由注意控制所调控。因此特质焦虑个体的注意偏向和注意控制就成为了本研究的重点所在。本课题行为学结合脑电研究,招聘来自正常人群低特质焦虑(low trait anxiety,LTA)、正常人群高特质焦虑(high trait anxiety,HTA)和临床焦虑障碍(generalized anxiety disorder,GAD)三组被试开展实验,以期阐明焦虑神经认知模型和注意控制理论的不同适用范围,明确不同水平特质焦虑个体的注意偏向和注意控制的特点及其潜在神经机制。方法:(1)采取情绪空间-线索注意范式,线索与刺激之间的刺激间距设置为50ms和800ms,来深入考察不同水平特质焦虑群体注意偏向的特点及其在时间维度上的变化,并分析静息态脑电前额区alpha波的非对称性揭示潜在神经机制。(2)研究2和研究3分别在情绪和非情绪Flanker实验任务下考察正常人群高、低特质焦虑和临床焦虑障碍三组被试的分心抑制和冲突适应特点,并对Bishop的焦虑神经认知模型和Eysenck等人的注意控制理论进行验证。(3)研究4采用单任务情绪Flanker实验和双任务情绪Flanker实验任务,考察不同水平特质焦虑个体的注意转换功能及潜在认知神经机制。结果:(1)情绪空间-线索实验发现GAD组的反应时(473.74±15.50)显著长于LTA组(383.75±14.64,p0.001)和HTA组(381.24±12.92,p0.001)的反应时,而LTA组和HTA组之间无显著差异(p=0.898)。线索与目标之间的刺激间距为50ms时,三组被试没有呈现出注意偏向方面的组间差异。刺激间距为800ms时,高特质焦虑组表现为对负性刺激的注意解除困难,临床GAD患者对负性刺激表现出注意回避。静息态脑电结果发现,在控制抑郁的情况下,焦虑能够显著预测前额区alpha波的非对称性;组间差异比较发现GAD患者显著比LTA、HTA两组被试alpha波偏侧化程度低,即大脑左侧脑区的激活水平偏低。(2)情绪Flanker脑电实验研究发现GAD组的反应时(930.38±22.87)长于LTA组(632.98±19.81,p0.001)和HTA组(655.11±17.71,p0.001)。GAD组的错误率(2.51±0.40)大于LTA组(1.40±0.31,p=0.038)和HTA组(1.37±0.31,p=0.027)。在不一致试次上,与LTA组和HTA组相比,GAD被试表现出N2潜伏期延长、振幅降低。与LTA组被试相比,HTA组和GAD组的P3振幅明显低下。在冲突适应指标上,HTA和GAD组在行为学和N2成分上均表现出冲突适应不良的特点。(3)非情绪Flanker脑电实验发现GAD组的反应时(619.69±129.85)均显著长于LTA组(480.52±48.18,p0.001)和HTA组(479.37±57.71,p0.001),LTA组和HTA组则无显著差异(p=0.945)。反应时的干扰效应分析发现GAD组的干扰效应显著大于LTA组(p=0.001)和HTA组(p0.001);而LTA组和HTA组之间则无显著差异。错误率指标上,GAD组冲突适应水平显著低于LTA组(p=0.016)。GAD组的N2成分潜伏期(265.89±5.45)长于LTA组(243.70±5.45,p=0.005)和HTA组潜伏期(252.54±4.78,p=0.070)。GAD组P3的振幅(4.94±0.86)显著小于LTA组(9.10±0.86,p=0.001)和HTA组(7.87±0.75,p=0.013),LTA组和HTA组间无显著差异(p=0.287)。(4)双任务情绪Flanker任务下,GAD组的反应时(1052.39±209.40)显著长于LTA组(719.88±127.87,p0.001)和HTA组(736.76±106.72,p0.001);GAD组被试的错误率(5.38±0.63)显著长于LTA组(3.05±0.52,p0.001)和HTA组(2.95±0.46,p0.001)。在错误率指标上,GAD患者的转换代价(6.10±5.74)显著大于LTA(3.33±2.47,p=0.012)和HTA组(3.11±2.27,p=0.005)。脑电指标上这三组并未表现出显著差异。(5)研究发现在情绪空间-线索实验任务中,临床GAD患者的反应时变异性(3.52±0.64)显著大于LTA组(3.07±0.62,p=0.012)和HTA组(2.96±0.63,p=0.001),LTA组和HTA组则无显著差异(p=0.487)。在情绪Flanker实验、非情绪Flanker实验和双任务的情绪Flanker实验中,均得到了类似结果。结论:(1)在注意晚期加工阶段高特质焦虑被试对负性刺激存在注意固着;焦虑障碍患者存在注意回避。GAD患者alpha波偏侧化程度低,即大脑左侧脑区的激活水平偏低与其负性注意回避关系密切。(2)临床GAD患者在情绪和非情绪刺激背景下均表现出冲突适应不良、注意抑制和转换能力低下,存在自上而下的注意控制不足。正常人群高特质焦虑个体仅在情绪刺激下表现出冲突适应不良,抑制和转换能力在情绪和非情绪刺激背景下均表现正常。高特质焦虑、低注意控制可能是诱发临床焦虑障碍的内在根本原因。神经认知模型能较好的解释临床焦虑障碍患者的注意特点,而注意控制理论则更适用于正常人群高特质焦虑个体。(3)反应时变异性是衡量注意控制的一个重要指标,可较好地区分临床焦虑障碍患者与正常人群,具有跨实验范式和实验材料的稳定性。
[Abstract]:AIM: Trait anxiety tends to induce individual attention bias toward threatening stimuli, and this negative attention bias plays a central role in the occurrence and development of anxiety and anxiety disorders. In addition, the relationship between trait anxiety and attention bias may be regulated by attention control. Therefore, attention bias and attention control of trait anxiety individuals become the focus of this study. Three groups of subjects, low trait anxiety (LTA), high trait anxiety (HTA) and generalized anxiety disorder (GAD), were tested in order to clarify the different application scope of anxiety neurocognitive model and attentional control theory, and to clarify the individual trait anxiety at different levels. Methods: (1) Using the emotional space-cue attention paradigm, the stimulus spacing between cues and stimuli was set at 50 ms and 800 ms to investigate the characteristics of attention bias and its temporal variation in different levels of trait anxiety, and to analyze resting state EEG. The asymmetry of alpha waves in the prefrontal region reveals the underlying neural mechanisms. (2) Study 2 and Study 3 examined the characteristics of distraction inhibition and conflict adaptation in normal subjects with high, low trait anxiety and clinical anxiety disorder under emotional and non-emotional Flanker tasks, and paid attention to Bishop's anxiety neurocognitive model and Eysenck's attention. Control theory was validated. (3) In study 4, single-task emotional Flanker test and two-task emotional Flanker test were used to investigate the attention-switching function and potential cognitive neural mechanism of trait anxiety individuals at different levels. There was no significant difference between LTA group and HTA group (p = 0.898) in response time between p0.001 and HTA group (381.24 (+ 12.92), but there was no significant difference between LTA group and HTA group (p = 0.898). The results of resting state EEG showed that anxiety could significantly predict the asymmetry of alpha waves in the prefrontal region under depression control; the differences between groups showed that GAD patients were significantly higher than LTA, while HTA patients had a lower degree of alpha wave lateralization, i.e. a lower activation level in the left cerebral region. Flanker EEG study found that the response time of GAD group was longer than LTA group (632.98+19.81, p0.001) and HTA group (655.11+17.71, p0.001). The error rate of GAD group (2.51+0.40) was higher than LTA group (1.40+0.31, p=0.038) and HTA group (1.37+0.31, p=0.027). In inconsistent trials, compared with LTA group and HTA group, the N2 latency of GAD group was higher. Compared with LTA group, P3 amplitude of HTA group and GAD group was significantly lower. Both HTA group and GAD group showed poor conflict adaptation in behavior and N2 components. (3) Non-emotional Flanker EEG test showed that the response time of GAD group (619.69 1) There was no significant difference between HTA group and LTA group (p = 0.945), but there was no significant difference between LTA group and HTA group (p = 0.001) and between LTA group and HTA group (p = 0.001). The latency of N2 component (265.89 +5.45) was longer in LTA group (243.70 +5.45, P = 0.005, P = 0.005) and HTA group (252.54 +4.78, P = 0.070) than in LTA group (243.70 +5.45, P = 0.45, P = 0.005) and HTA group (252.54 +4.54 +4.78, P = 0.78, P = 0.070). The amplitudeof P3 (4.94 [(4.94 +0.86) in GAD group was significantly lower than that in LTA group (9.10 [(9.10 +0.86, P = 0.86, P = 0.86, P = 0.001 Responses of the GAD group to the task The error rate of GAD group was significantly higher than that of LTA group (3.05 + 0.52, P 0.001) and HTA group (3.05 + 0.52, P 0.001) and LTA group (719.88 + 127.87, P 0.001) and HTA group (719.88 + 127.87, P 0.001) and HTA group (736.76 [106.76 [106.72, P 0.72, P 0.001, P 0.001); the error rate of GAD group (5.38 [(5.38 [(0.63) was significantly higher than LTA group (3.38.38 [(3.38 [(3.38 [0.38] [0.63) significantly higher than LTA group (3.05 [(3.HTA group ( There was no significant difference in EEG parameters among the three groups. (5) In the emotional space-cue task, the response time variability of GAD patients was significantly higher than that of LTA patients (3.07 0.62, P = 0.012) and HTA patients (2.96 0.63, P = 0.001), but there was no significant difference between LTA and HTA patients (p = 0.487). Similar results were obtained in the R test, the non-emotional Flanker test and the dual-task emotional Flanker test. Conclusion: (1) In the late attention processing stage, the subjects with high trait anxiety had attention fixation on negative stimuli, and the patients with anxiety disorder had attention avoidance. Low is closely related to negative attention avoidance. (2) In clinical GAD patients, both emotional and non-emotional stimuli show poor conflict adaptation, low attention inhibition and switching ability, and insufficient top-down attention control. High trait anxiety and low attention control may be the underlying causes of clinical anxiety disorder. Neurocognitive model can better explain the attention characteristics of patients with clinical anxiety disorder, while attention control theory is more suitable for normal people with high trait anxiety. Variability is an important indicator of attention control, which can better distinguish the patients with clinical anxiety disorder from the normal population, and has the stability of cross-experimental paradigm and experimental materials.
【学位授予单位】：第三军医大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：B842

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