The ease of lying

Brain imaging studies suggest that truth telling constitutes the default of the human brain and that lying involves intentional suppression of the predominant truth response. By manipulating the truth proportion in the Sheffield lie test, we investigated whether the dominance of the truth response is malleable. Results showed that frequent truth telling made lying more difficult, and that frequent lying made lying easier. These results implicate that (1) the accuracy of lie detection tests may be improved by increasing the dominance of the truth response and that (2) habitual lying makes the lie response more dominant.     

贝叶斯推理中的“自击中率参照抑制”

本文旨在研究贝叶斯推理中基础比率、击中率起作用的机制。通过设置肝炎情境、中彩情境的贝叶斯推理问题,同时操作基础比率和击中率的水平,考察449名大学生被试的概率估计情况。结果表明,总体上,贝叶斯推理中的基础比率和击中率均起作用,表现为后验概率估计值随基础比率水平的提高而增加,随击中率水平的提高而增加。然而,在低基础比率的中彩情境中,后验概率估计值先随击中率的增加而增加;之后却随击中率水平的继续提高而显著降低,出现自击中率参照抑制。这似乎说明,击中率在贝叶斯推理中并非一致地起作用,而可能与推理者的知识经验对击中率加工的调节有关。     

中央线索化对听觉障碍人群辨别任务返回抑制的影响

选取一组先天聋被试和与之匹配的听力正常被试,采用线索提示范式考察中央线索化对听觉障碍被试在辨别任务中基于位置返回抑制的影响。实验结果发现,在有中央线索化的任务实验中,听力正常和听觉障碍被试都出现了返回抑制,但是听觉障碍被试消失得比听力正常被试早。无中央线索化的辨别任务实验中,听力正常被试组仅在SOA=650ms时,听觉障碍被试没有发现返回抑制现象。结果表明听觉障碍被试辨别任务的返回抑制更易受中央线索化条件的影响,听障被试的空间注意调节机制更具策略性和有效性。     

焦虑情绪状态下老年个体返回抑制成分的特征*

考察焦虑情绪状态对老年个体基于位置和基于颜色返回抑制的影响。被试为22名焦虑老年者和21名正常老年者,实验为E-prime软件编程、返回抑制为范式的行为实验。实验任务要求被试辨别靶刺激的颜色,记录被试反应时和错误率。结果：（1）焦虑组老年者和正常组老年者均出现了基于位置的返回抑制,且两组效应量差异不显著。（2）正常老年组出现了基于颜色的返回抑制,焦虑老年组并未出现该效应,且两组的效应量差异显著。因此,焦虑作为一种负性的情绪状态,影响了老年组被试基于颜色特征返回抑制的出现,导致被试对于相同颜色的抑制失败,而基于位置特征返回抑制的出现却没有影响。     

不同性质的评价对特质焦虑者抑制功能影响的ERP研究

特质焦虑者作为焦虑障碍易感性个体,会表现出对威胁性刺激的注意偏向,从而损害中央执行系统的抑制功能。但是不同情绪性评价刺激会如何调控特质焦虑者的抑制功能还不太清楚。为此,本研究以脑电P3b为抑制功能指标,要求高低特质焦虑组在三种不同评价下完成反向眼跳范式,考察不同性质的评价如何影响特质焦虑的抑制功能。行为结果发现,高焦虑组比低焦虑组错误率更高;积极评价条件下,高焦虑组的反应时慢于低焦虑组。ERP结果进一步发现,无评价条件下,高焦虑组的P3b波幅大于低焦虑组;低焦虑者在积极评价条件下的P3b波幅大于消极评价条件,但是高焦虑者没有显著差异。结果表明,积极评价会损害高特质焦虑者的抑制功能,而消极评价则促进了高特质焦虑个体的抑制功能。     

Estrogen abolishes latent inhibition in ovariectomized female rats

Estrogen is frequently prescribed as a method of birth control and as hormone replacement therapy for post-menopausal women with varied effects on cognition. Here the effects of estrogen on attention were examined using the latent inhibition (LI) behavioral paradigm. Ovariectomized (OVX) female rats were given either estrogen benzoate (EB, 10 or 100 microg/ml/kg; SC) or sesame oil vehicle. Males and OVX females receiving vehicle displayed normal LI. In contrast, LI was abolished in OVX females receiving EB. The lack of LI in OVX females receiving EB was a result of low suppression ratios, reflecting strong conditioning between the tone and the shock in these subjects even if they were pre-exposed to the tone. Thus, estrogen impaired the ability of OVX females to ignore irrelevant stimuli. Since different cognitive tasks vary in their required ability to ignore irrelevant stimuli, these results may account for some of the variations in the current literature on estrogen and cognition.     

Intra-individual reaction time variability in schizophrenia, depression and borderline personality disorder

Intra-individual reaction time variability (IIV) in neuropsychological task performance reflects short term fluctuations in performance. Increased IIV has been reported in patients with schizophrenia and could be related to a deficient neural timing mechanism, but the role of IIV in adult patients with other psychiatric disorders has not been established. Therefore, we compared IIV measures obtained in a Go/Nogo task from patients with schizophrenia, major depression and borderline personality disorder. IIV was increased for patients with schizophrenia. When correcting for differences in mean reaction time, depressive and borderline patients also showed increased IIV. Importantly, all groups showed a strong association between IIV and accuracy of task performance. This suggests that increased IIV might be a sensitive marker for the efficiency of top-down attentional control in all diagnostic groups. Aside from these similarities, the complete results including measures of IIV, mean reaction time and accuracy show differential patterns for patients with schizophrenia compared to those with borderline personality disorder or depression. These results are discussed with respect to common versus disorder-specific neural mechanisms underlying increased IIV.     

Children's false memory and true disclosure in the face of repeated questions

The current study was designed to investigate children's memory and suggestibility for events differing in valence (positive or negative) and veracity (true or false). A total of 82 3- and 5-year-olds were asked repeated questions about true and false events, either in a grouped order (i.e., all questions about a certain event asked consecutively) or in a nongrouped order (i.e., questions about a certain event were interspersed with questions about other events). Interviewer gender was also varied. Individual differences, including attachment style, inhibition, and behavioral adjustment, were examined as potential predictors of memory and suggestibility. Results revealed significant age, valence, and veracity effects on children's memory reports. Path analysis demonstrated that individual differences in behavioral problems and inhibitory ability predicted children's provision of inaccurate information. Implications for psychological theory and legal application are discussed.     

Further evidence for the summation of latent inhibition and overshadowing in rats’ conditioned taste aversion

Repeated exposures to a target taste (X) attenuated subsequent development of rats’ conditioned aversion to X (latent inhibition effect). Presentation of another taste (A) after X in conditioning (serial X-A compound conditioning) also attenuated conditioned X aversion compared with conditioning without A (overshadowing). Furthermore, the latent inhibition and overshadowing effects summed to show the least conditioned aversion in the rats given both the target preexposures and the serial X-A compound conditioning treatment. These results question the validity of the comparator hypothesis as an explanation for Pavlovian conditioning of rats’ conditioned taste aversion.     

对听感觉运动门控自上而下调节的动物模型和神经机制

对惊反射的前脉冲抑制是减少干扰影响、保护脑内信息加工的重要机制。它既是研究感觉运动门控的模型, 也是探究精神分裂症机制的模型。前脉冲抑制可被选择性注意和情绪等高级认知活动所调节。本论文工作围绕着恐惧条件化和知觉空间分离去掩蔽(空间选择性注意)对听觉前脉冲抑制多层次化的自上而下调节, 在大鼠行为模型、神经通路、神经电生理机制等几个层次上开展了系统性研究, 并引入了精神分裂症的神经发育模型, 证实早期社会隔离饲养对前脉冲抑制注意调节的破坏影响。本论文研究成果不仅对认识正常情况下脑在复杂刺激场景中的信息加工机制有重要意义, 以感觉运动门控认知调节功能缺失为基础的动物模型也将推动精神分裂症心理学和神经生物学机制的研究。