注意捕获效应受知觉负载及目标与干扰项距离的共同影响

研究考察了无关干扰项引发的注意捕获效应如何受到任务知觉负载以及目标与干扰项距离的共同影响。被试在视觉搜索集中搜索目标并做辨别反应。通过控制搜索集的大小来控制任务知觉负载, 同时在搜索集中存在一个用颜色标定的无关干扰项(奇异项), 该奇异项与当前的搜索目标存在一致、中性或不一致的关系, 该奇异项的位置与当前目标相邻或相距较远。结果发现, 被试在低负载条件下出现显著的干扰效应(不一致条件的反应时减中性条件的反应时), 而在高负载条件下干扰效应减小。此外, 在高负载条件下, 当目标与干扰项相距较近时没有出现干扰效应, 而当目标与干扰项相距较远时存在显著的干扰效应。干扰效应受到任务知觉负载和目标与无关干扰项距离的共同影响。这些结果说明, 与任务无关的刺激是否捕获注意取决于当前任务总体上是否存在可用的剩余注意资源, 也受到其周围临近区域的局部注意资源是否充足的影响。     

奖赏预期调节局部注意干扰效应

局部注意干扰效应(Localized attentional interference, LAI)是指在视觉搜索任务中同时搜索在空间上分离的两个目标时, 或者目标周围存在一个无关奇异项时, 这两个关键刺激相距较近时产生的干扰现象。本实验采用视觉搜索范式, 探讨了奖赏预期对局部注意干扰效应的影响。实验1采用双目标搜索任务, 要求被试判断搜索画面中两个奇异项刺激的形状是否相同。结果显示奖赏条件和无奖赏条件都表现出显著的距离主效应, 随着目标间距离增大, 被试的正确率提高, 反应时下降。同时, 在远距离时, 奖赏条件下的正确率高于无奖赏条件, 而在近距离时, 奖赏条件下的正确率反而低于无奖赏条件, 即, 奖赏条件下局部注意干扰效应反而增大。高动机状态增强了两个目标的表征, 反而不利于解决局部注意干扰效应。实验2采用单目标搜索任务, 要求被试判断特定目标的方位并忽略另一无关奇异项刺激。与实验1不同的是, 实验2仅在无奖赏条件下观察到显著的距离主效应, 即被试行为表现在远距离时更好; 而在奖赏条件下, 被试在近距离和远距离的表现一样好, 即没有局部注意干扰效应。这说明在奖赏预期条件, 个体可以有效抑制分心物刺激的干扰, 将注意集中于目标刺激的加工, 从而对局部注意干扰效应产生调节。整个研究表明, 奖赏整体上能够提高对任务相关刺激的表征, 并抑制任务无关刺激, 虽然这并不总是能够提高任务表现。     

焦虑个体“冷”、“热”执行功能Stroop效应量比较

该文采用Stroop实验范式对筛选出的49名高焦虑个体和48名低焦虑个体的“冷”、“热”执行功能进行测量,以探讨不同焦虑程度个体“冷”、“热”执行功能间的差异。结果表明,在“冷”执行功能方面,高焦虑个体与低焦虑个体Stroop效应量之间没有显著差异;在“热”执行功能方面,两组被试情绪Stroop的效应量无差异;两类词;12的Stroop效应量差异显著;词汇类型×被试类型的交互作用非常显著;进一步的简单效应分析表明,两组被试的情绪Stroop效应量在消极词汇水平差异显著,两类词汇Stroop效应量在低焦虑组差异显著。说明高、低焦虑个体在“冷”执行功能上没有显著差异,高焦虑个体的“冷”执行功能正常,而“热”执行功能下降,表现为高焦虑个体对两极情绪的趋避关系失调,即对消极情绪具有偏向性,对积极情绪具有回避性。     

干扰条件与情绪启动关系的实验研究

在线索提示范式下,设置无干扰条件和干扰条件的阈上和阈下情绪启动,以此考察干扰条件与情绪启动的关系.研究发现:在无干扰条件与干扰条件下均存在显著的阈上情绪启动和阈下情绪启动,并且干扰条件下阈上情绪启动程度明显降低而阈下情绪启动程度不受影响.文章从情绪启动与注意关系的角度讨论了干扰条件与情绪启动的这种表现对于理解情绪启动加工属性及意识与无意识分离现象的意义.     

A comparison of backward and forward spatial spans

The standard Corsi blocks task is frequently used to measure the capacity of visuospatial working memory, but the implications of the use of both forward and backward recall are still unclear. In the present study, we showed that the backward Corsi task is particularly powerful in discriminating between low- and high-spatial-ability individuals and involves different processes from those involved in the forward task. From a sample of 425 participants we selected one group of 20 high-spatial-ability participants and one of 20 low-spatial-ability participants. The results demonstrated that a backward spatial span offers specific information not available from a forward spatial span, and that there was no facilitation due to a descending format. In particular, in the low-spatial-ability group, performance was generally poorer, but backward Corsi recall was lower than forward recall, and participants did not show any advantage following the descending presentation format—which in some contexts is considered to reduce proactive interference. We conclude that the backward Corsi task has specific value and that the assumption of fully parallel verbal and visuospatial working-memory systems can lead to a variety of misunderstandings.     

IABP在心脏直视手术围术期低心排的应用

为了探讨主动脉内球囊反搏（IABP）治疗心脏手术围术期低心输出量综合征（LCOS）的临床疗效,对16例心脏手术围术期LCOS患者,经过股动脉放置IABP导管于降主动脉内进行左心辅助治疗,IABP治疗前、后监测患者连续有创动脉收缩压（SABP）、有创平均动脉压（MABP）、中心静脉压（CVP）、动脉血氧分压（PaO2）、心率（HR）、尿量和血管活性药物的使用。结果显示,IABP辅助治疗时间25h～116h,平均（78．5±40．5）h。行IABP治疗后,SABP、MABP、PaO2较术前明显提高（P〈0．05）,HR、CVP明显下降（P〈0．05）,尿量增加,血管活性药物使用量明显减少（P〈0．05）,12例患者心功能好转而脱离IABP,11例（69．3％）存活,4例死于心源性休克,1例死于多器官功能不全综合征（MODS）。提示正确及时地使用IABP能明显改善心脏手术围术期LCOS患者的血流动力学指标,减少血管活性药物的使用,建议对有适应证者应尽早应用,适时撤离。     

医护人员人文素质缺乏的管理责任及干预策略

医护人员人文素质缺乏与医学教育缺陷、人文管理意识不强、后续人文素质培养不利及执业环境恶化等综合因素密切相关。卫生行政主管部门和医院管理者首先应当确立人文管理理念,营造医院的人文氛围,承担起促进医学教育体制改革、加强岗位培训和着力培养社会需要的“人文科学型”医护人员的责任。     

Interference control in preschoolers: factors influencing performance on the day–night task

Two experiments investigated preschoolers' interference control in variants of the day–night task. The day–night task involves instructing children across 16 trials to say the word ‘day’ when viewing a card depicting a nighttime sky and to say ‘night’ when shown a picture of the daytime sky. The purpose of the experiments was to investigate whether the depiction on each card distracts children because it is semantically associated with the instructed response or because the depicted item cues the alternative (incorrect) response within the response set. The results in the first study (N=23, M=52.65 months) and second study (N=54, M=50.81 months) indicate that a close semantic relation between the picture and the target response does not pose substantial interference for preschoolers. In contrast, the pictured item poses a significant challenge for preschoolers when it depicts the interfering alternative in the response set. Theoretical implications of these results for the development of interference control are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

The role of attentional biases in PTSD: is it interference or facilitation?

Although attentional biases have been demonstrated in individuals with posttraumatic stress disorder (PTSD), the cognitive methodologies used have not allowed for disambiguation of two types of attentional biases. It remains unclear if PTSD involves difficulty disengaging attention from threatening stimuli (interference) or facilitated detection. To differentiate between attentional interference and facilitation, 57 male Vietnam-era veterans (30 High PTSD and 27 Low PTSD) completed a visual search task with a lexical decision component. High PTSD veterans who engaged in the interference task first showed increased interference to threat-relevant words relative to Low PTSD veterans. However, no evidence was found for facilitated detection of threatening stimuli in PTSD.     

The psychological processes underlying symptoms of thought interference in psychosis

Morrison and colleagues have proposed that auditory hallucinations are the result of cognitive intrusions being misattributed to an external source due to such thoughts being inconsistent with the person's beliefs about his or her own mental processes (metacognitive beliefs). The aim of this study was to investigate the applicability of this model to psychotic symptoms of thought interference. Fifty psychotic patients with and without thought interference were compared on (i) frequency of cognitive intrusions, (ii) metacognitive beliefs, (iii) source monitoring and (iv) appraisals of an unrelated anomalous event (a card trick). As predicted, individuals with thought interference had an increased frequency of cognitive intrusions and of maladaptive metacognitive appraisals, lower perceived cognitive control, and were more likely to endorse appraisals regarding 'permeability' of the mind, on the card trick task, in comparison to individuals without thought interference. No significant differences were found on any measure when the patient group was divided into hallucinators and non-hallucinators, once other variables were controlled for. These findings suggest that Morrison's model may be more parsimonious for symptoms of thought interference than for auditory hallucinations.