特质自我控制对食物线索注意偏向的影响及干预：来自眼动的证据

采用眼动技术,以BMI指数处于正常范围的女性为被试,考察特质自我控制对食物线索注意偏向的影响以及注意偏向训练在改变注意偏向强度上的干预效果。结果发现,对于高热量食物线索,低特质自我控制水平女性表现出了更强的注意偏向;注意偏向训练有效降低了低特质自我控制水平女性对高热量食物线索注意偏向的强度。上述结果表明,特质自我控制影响个体对食物线索的注意偏向,注意偏向训练能有效改变个体对食物线索注意偏向的强度。     

Stroke damages attentional maintenance in working memory

Stroke is the main cause of acquired disability in adults, and specific deficits in working memory (WM) are among the most common cognitive consequences. In neuropsychological routine, WM is most of the time investigated in the framework of the multicomponent model (Baddeley & Hitch, 1974, The psychology of learning and motivation, 47). Using a more recent theoretical WM model, the time-based resource-sharing (TBRS) model (Barrouillet et al., 2011, Psychol. Rev., 118, 175), the aim of the present study was to investigate in young post-stroke patients to which extent attentional maintenance is impaired in WM. To address this question, we discarded other factors known to directly influence WM performance, that is processing speed and short-term memory span. We proposed to 53 post-stroke patients and to 63 healthy controls a complex span paradigm in which participants were asked to alternate between the memorization of a series of images and a concurrent parity judgement task of a series of digits. To investigate the attentional maintenance processes, we manipulated the cognitive load (CL) of the concurrent task. CL effect is typically interpreted as the involvement of attentional maintenance processes. The task was adapted to each participant according to their processing speed and memory span. As expected, the results showed higher recall performance in healthy controls compared with post-stroke patients. Consistent with the literature, we also observed higher performance when the CL was low compared with high. However, the improvement in recall at low CL was smaller for post-stroke patients compared with controls, suggesting that post-stroke WM deficit could be in part due to a deficit of the attentional maintenance processes.     

No attentional bias for pictoral stimuli in spider-fearful subjects

A number of experiments have shown that (spider) fearful subjects direct their attention to fear-relevant words, even when these words are irrelevant to the completion of a target task (e.g., color naming). The present study examined whether subjects with an intense fear of spiders also display such attentional bias for a fear-relevant pictoral stimulus. Female spider-fearful (n=13) and control subjects (n=13) saw neutral patterns (i.e., horizontal and vertical bars). One pattern served as target for a reaction time, while the other pattern served as nontarget. Targets and nontargets were accompanied by either fear-relevant or neutral pictoral material (i.e., a picture of a spider or a picture of a flower, respectively). The fear-relevant picture did not selectively delibate reaction time performance of spider-fearful subjects. Thus, no evidence was found for an attentional bias for fear-relevant pictoral material in subjects with an intense fear of spiders. Instead, fearful subjects exhibited a general inhibition of performance which became stronger over trials. This suggests that the fear-relevant picture induced a state of anxious arousal or defensive withdrawal that interfered with reaction time performance on both fear-relevant and neutral trials.     

目标探测对记忆提取的影响

采用经典的"学习–再认"范式,在测验阶段设置了目标探测的干扰任务,通过比较目标探测和分心拒绝是否会对记忆提取产生不同的影响,以进一步探讨提取干扰与再认记忆之间的关系。结果发现,无论对目标进行显性(实验1)还是隐性(实验2)的探测反应,目标探测下旧词的再认反应均要比分心拒绝下更优,表明外显记忆的提取也会受到注意资源的调节。但更为重要的是,在辨别力指数(d′)及判断标准(C)上的差异分析发现,目标探测并没有提高被试的再认水平,而是降低了被试的判断标准,使得被试在目标探测条件下更容易对词做出"旧"反应。这种反应倾向与目标探测的动作反应方式无关,也不受词汇的编码加工水平深浅的调节。由此可见,外显记忆提取并非完全的"自动化加工",仍会受到注意资源的调节。     

左侧眶额皮层在自动情绪调节下注意选择中的作用：来自经颅直流电刺激的证据

前人研究表明自动情绪调节能够自上而下地影响情绪及情绪性注意过程。近来有研究提示自动情绪调节与眶额皮层(orbitofrontal cortex, OFC)有关。也有研究表明左侧OFC的激活影响负性注意偏向。本研究采用经颅直流电刺激技术,考察阈下启动情绪控制目标条件下,抑制左侧眶额皮层兴奋性是否影响负性注意偏向。结果发现,使用阴极刺激抑制左侧OFC活动可以加快被试对与恐惧刺激位置一致的探测点的反应。该结果提示左侧眶额皮层是自动情绪调节下情绪性注意选择相关的重要脑区。     

不同康复时相戒除者对海洛因相关线索的注意偏向

以84名生理脱瘾后处于不同康复时相的海洛因戒除者为被试,采用情绪Stroop范式,以海洛因相关线索为自变量,考察了海洛因戒除者的注意偏向特性及其动态变化。结果发现:(1)海洛因戒除者对相关线索存在着显著的注意偏向;(2)海洛因戒除者对相关线索的注意偏向随康复期的延长无显著改善。该研究支持了Franken关于药物成瘾的注意偏向模型。     

类别注意控制定势在注意捕获中的加工机制

注意捕获是指注意定向的过程中刺激不自觉地捕获注意的现象。在复杂的视觉搜索任务中,类别注意控制定势(cACS)能够帮助我们将注意引导到与目标定义类别匹配的刺激上,并对其进行优先加工。探讨cACS在注意捕获中的加工机制,不仅能够扩展注意捕获领域的理论研究,还能对实际生活提供指导。通过文献梳理,从cACS的作用阶段、cACS的加工强度及cACS作用时的激活脑区三个方面总结了注意捕获中的cACS的加工机制。未来研究可以就抑制分心物的ACS、不同类型的cACS加工差异和人工类别ACS加工过程等进行探讨。     

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。     

冲突水平的变化诱发冲突适应

冲突适应是重要的认知控制现象, 反映了认知控制的动态过程。然而, 目前为止对于冲突水平上的差异能否诱发冲突适应尚不清楚。本研究采用字母Flanker的变式, 通过改变目标-分心物的一致性操纵冲突水平, 探究冲突水平的变化对认知控制调整的影响。结果发现被试的反应时间随冲突水平的提高而增加; 而且先前试次的一致性影响当前试次的干扰效应, 无冲突和低冲突、无冲突和高冲突、低冲突和高冲突条件之间均出现了典型的冲突适应。本研究结果表明, 除了冲突的有无, 冲突水平的变化也能诱发冲突适应, 支持更大的冲突驱动更强的认知控制, 而且冲突诱发的认知控制的功能可能通过注意聚焦实现。这一发现为冲突监测理论的注意调节机制提供了直接的支持证据, 对于促进冲突适应的相关研究具有重要意义。