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。     

颜色知觉突显对预览效益的影响

本研究通过预览搜索范式考察靶子在颜色高突显情况下的预览效益,探讨其优先选择机制。结果发现在靶子颜色高突显的情况下,预览效益没有出现,说明预览效益的出现有其一定的条件和限制,并为基于刺激特征的抑制的解释提供了支持证据。本文还探讨了预览效益消退的可能原因。     

不同位置的情绪面孔加工对返回抑制的影响

分别将情绪面孔图片作为线索（实验一）或靶子（实验二）呈现,利用线索-靶子范式考察了定位任务中情绪面孔加工对返回抑制的影响。结果发现：以不同情绪面孔作为线索时,返回抑制稳定出现,表现出与情绪加工的分离;而当情绪面孔作为靶子时,与中性面孔相比,情绪面孔引发的返回抑制量显著较小。该研究表明,在定位任务中,返回抑制不受线索生物性的影响,但是会受到靶子性质的影响,反映出机体在不同条件下对空间注意和情绪加工的灵活性。     

创造性思维与认知抑制的关系

抑制是创造性思维过程中的一种重要的认知加工机制。创造性思维与认知抑制的关系主要有三种观点：创造性思维的认知去抑制假说、认知抑制假说和适应性认知抑制假说。本文系统评述了创造性思维与认知抑制关系的相关理论、研究新进展和神经机制。未来研究应加强创造性思维与认知抑制关系的理论整合与构建,分析创造性思维的不同阶段的认知抑制机制,采用无意抑制与有意抑制研究范式,对创造性思维与认知抑制的关系、影响因素及神经机制进行深入研究。     

动态非注意盲中的分心物加工机制：是否存在抑制

系统考察在控制目标与非目标颜色特征属性的条件下, 动态非注意盲中视觉系统是否存在对分心物的抑制机制。实验一为基线实验, 将目标与非目标设置为相同的白色圆形, 考察被试对不同颜色特征(白色或者黑色)新异刺激的觉察情况; 实验二和实验三通过改变目标与非目标的颜色特征, 进一步探讨视觉系统对分心物(包括非目标和新异刺激)的抑制机制。结果发现, 视觉系统对干扰目标追踪(并计数)任务的分心物均产生抑制作用, 并且不同颜色特征的分心物受到的抑制作用不同, 与目标颜色特征相同的分心物受到的抑制作用较大, 相应新异刺激的觉察率低; 与目标颜色特征区分明显的分心物受到的抑制作用较小, 相应新异刺激的觉察率较高。     

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.     

ADHD and Behavioral Inhibition: A Re-examination of the Stop-signal Task

The current study investigates two recently identified threats to the construct validity of behavioral inhibition as a core deficit of attention-deficit/hyperactivity disorder (ADHD) based on the stop-signal task: calculation of mean reaction time from go-trials presented adjacent to intermittent stop-trials, and non-reporting of the stop-signal delay metric. Children with ADHD (n = 12) and typically developing (TD) children (n = 11) were administered the standard stop-signal task and three variant stop-signal conditions. These included a no-tone condition administered without the presentation of an auditory tone; an ignore-tone condition that presented a neutral (i.e., not associated with stopping) auditory tone; and a second ignore-tone condition that presented a neutral auditory tone after the tone had been previously paired with stopping. Children with ADHD exhibited significantly slower and more variable reaction times to go-stimuli, and slower stop-signal reaction times relative to TD controls. Stop-signal delay was not significantly different between groups, and both groups’ go-trial reaction times slowed following meaningful tones. Collectively, these findings corroborate recent meta-analyses and indicate that previous findings of stop-signal performance deficits in ADHD reflect slower and more variable responding to visually presented stimuli and concurrent processing of a second stimulus, rather than deficits of motor behavioral inhibition.