与当前任务无关的规则对自动反应激活过程的影响

摘要：本研究致力于探讨自上而下的任务因素对自动反应激活过程的影响。研究包含两个实验,采用掩蔽启动范式,选取字母和数字作为刺激,任务因素为与当前任务无关的处于预备状态的任务规则。实验一初步验证了与当前无关的处于预备状态的任务规则可以影响自动反应激活过程;实验二进一步证明了这种影响具有广泛性,即与当前无关的任务规则所设定的所有刺激系列都可以影响当前任务中的反应启动过程。研究总结论为：与当前任务目的无关、且存在自动刺激-反应联结的其他任务规则也能通过对被掩蔽的启动刺激反应的调节来影响对靶刺激的反应,从而影响启动效应的发生。     

任务定势对自动语义激活过程调节作用的ERP研究

摘要：本研究致力于探讨自上而下的因素对自动加工的影响。选取的自上而下因素为任务定势,自动加工过程为自动语义激活过程。研究采用ERPs技术,中文词汇为刺激,利用掩蔽启动范式,采用反应时和N400为指标。实验任务有三个：对问号后出现的词进行生物/非生物的词汇分类判断;对圆圈后出现的词进行是否含上下结构的字的词汇结构判断;对带“*”的词进行真词/假词判断。研究发现先前完成的任务形成的任务定势会对随后的自动语义激活过程产生调节作用：在词汇分类判断任务后,掩蔽启动刺激对靶刺激产生启动效应。在词汇结构判断任务后,掩蔽启动刺激对靶刺激没产生显著的启动效应。     

自上而下的因素对掩蔽启动中自动加工过程的影响

本文综述并探讨了自上而下因素的调节对启动过程的影响作用。自上而下因素的调节作用是指根据外界不断更新的对行为的要求, 大脑皮层的活动被设定于某种特殊的工作模式中。启动过程是指先前出现的启动刺激对随后目标刺激加工的易化和抑制, 是自动加工过程的体现。近年来, 部分研究认为启动范式引发的自动加工过程(包括知觉加工、语义加工和反应过程)可受到与注意、任务相关的自上而下因素的调节, 例如, 任务指导语的作用、对注意范围的设定等等。本文对此领域的研究及年龄因素进行了总结、分析和展望。启动效应可受到自上而下的注意、目的、任务要求等因素的调节, 且存在年龄因素的影响。     

情境特异比例一致变化对冲突效应的影响

采用Hedge和Marsh任务与比例一致性操纵相结合,分别以刺激的空间位置和形状作为比例一致操纵的情境线索,考察刺激-反应联结学习与注意调节在比例一致效应中的作用。结果发现,在情境比例一致操纵下,冲突效应的效应量受到比例一致操纵的影响产生反转。表明刺激-反应联结学习在情境特异比例一致效应中起到主要作用。     

任务刺激的类型对任务切换的影响

为揭示联结竞争对任务切换的影响机制,我们采用了任务线索范式比较双向刺激与单向刺激对任务切换的影响。通过对数字任务和字母任务反应时的分析发现:在当前任务的刺激类型不同时,单向刺激的反应时明显小于双向刺激的反应时;在当前任务的刺激类型相同时,反应时差异不显著。这表明,联结竞争是通过当前任务的刺激影响任务切换的。     

前额叶神经振荡活动反映了稳固的刺激冲突和反应冲突

为考察典型Flanker任务中练习对刺激冲突和反应冲突的影响,本研究采用练习范式记录被试完成2:1字母Flanker任务时的行为和脑电数据。行为结果发现,练习对这两类冲突无显著影响。神经震荡能量结果发现,前额叶theta能量随练习而显著减弱,这暗示刺激-反应之间的联结因练习而提升;前额叶alpha能量差异不随练习而变化,这可能反映了Flanker任务中稳定的刺激冲突和反应冲突加工机制。因此,本研究揭示了典型Flanker任务中刺激冲突和反应冲突的稳定特征。     

工作记忆内容对不同学业水平学生自上而下注意控制的影响

该研究采用视觉搜索任务范式,以小学五年级学优生与学困生为被试,探讨了工作记忆内容对不同学业水平学生自上而下注意控制的影响。结果发现:(1)学优生与学困生的自上而下注意控制能力存在显著差异,学优生的反应时显著短于学困生;(2)工作记忆内容影响自上而下注意控制,靶相关信息能促进对靶刺激的搜索,而靶无关信息却会干扰对靶刺激的搜索。     

情境特异比例一致性变化对冲突效应的影响

采用Hedge和Marsh任务与比例一致性操纵相结合,分别以刺激的空间位置和形状作为比例一致操纵的情境线索,考察刺激-反应联结学习与注意调节在比例一致效应中的作用。结果发现,在情境比例一致操纵下,冲突效应的效应量受到比例一致操纵的影响产生反转,表明刺激-反应联结学习在情境特异比例一致效应中起到主要作用。     

刺激–反应联结学习在项目特异性比例一致效应中的作用

比例一致效应通常被用来研究认知控制的动态变化,其中项目特异性比例一致效应是其重要分支。当前研究分别以任务的无关属性(空间位置)与相关属性(颜色)进行比例偏置操纵,考察联结学习与注意调节在比例一致效应中的作用。结果发现,在刺激–反应编码具有显著性优势的条件下,当位置作为信号时,被试可以利用刺激–反应联结学习反转比例一致效应;当颜色作为信号时,联结学习不起作用,比例一致效应消失。这些结果表明刺激–反应联结学习在比例一致效应中起到主要作用,符合显著性编码假说的预期。     

刺激同一性对错误后反应的影响

当错误发生后,人们往往会放慢错误后反应的速度,以避免错误的再次发生,许多研究者认为,这是自上而下的认知控制对错误后反应的影响.为了探讨刺激属性是否也在错误后的反应中起作用,本研究从刺激同一性角度出发,探讨错误反应刺激与错误后刺激的同一性以及反应-刺激间隔时间(RSI)对错误后反应的影响.结果发现,当错误后的刺激与错误反应的刺激一致时,可减小错误后反应时延长的程度,同时,RSI越大,PES越小.本研究得出结论,刺激同一性和RSI作为自下而上的刺激驱动在PES的产生过程中发挥了作用.     

Age-related increase in top-down activation of visual features

Previous research suggests that, during visual search and discrimination tasks, older adults place greater emphasis than younger adults on top-down attention. This experiment investigated the relative contribution of target activation and distractor inhibition to this age difference. Younger and older adults performed a singleton discrimination task in which either an E or an R target (colour singleton) was present among distractor letters. Relative to a baseline condition in which the colours of the targets and distractors remained constant, an age-related slowing of performance was evident when either the colour of the target or that of the distractors varied across trials. The age-related slowing was more pronounced in response to target colour variation, suggesting that older adults place relatively greater emphasis on the top-down activation of target features.     

Age-related increase in top-down activation of visual features

Previous research suggests that, during visual search and discrimination tasks, older adults place greater emphasis than younger adults on top-down attention. This experiment investigated the relative contribution of target activation and distractor inhibition to this age difference. Younger and older adults performed a singleton discrimination task in which either an E or an R target (colour singleton) was present among distractor letters. Relative to a baseline condition in which the colours of the targets and distractors remained constant, an age-related slowing of performance was evident when either the colour of the target or that of the distractors varied across trials. The age-related slowing was more pronounced in response to target colour variation, suggesting that older adults place relatively greater emphasis on the top-down activation of target features.     

颜色字词的识别真的无需注意力资源的参与?——来自Stroop范式的证据

3个实验采用颜色词、颜色词同音词以及颜色语义联想词作为启动词,使启动词的语义和颜色实现时空分离、启动词处于非空间注意焦点位置、降低启动词可视度的情境下,考察具有自动化加工特征的启动词是否受到注意力资源的制约以及启动词在获得不同数量的注意力资源时其自动化程度是否存在显著的差异。结果发现:(1)注意力资源实质性地决定着自动化加工能否顺利进行,具有自动激活特征的刺激在无法获得注意力资源时,自动化加工过程终止。(2)可用的注意力资源数量调控着自动化加工的效率和语义提取的效果,可用的注意力资源数量越多,对启动刺激的语义加工越完善,对目标刺激的促进效果也越有效。本研究结果支持注意力敏感模型关于自动化加工受认知系统的支持和配置才能完成的假设。     

Event-related FMRI study of context processing in dorsolateral prefrontal cortex of patients with schizophrenia

Context processing is conceptualized as an executive function involved in voluntary, complex actions such as overcoming automatic responses. The present study tested the hypothesis that context-processing deficits in patients with schizophrenia are associated with a dysfunction of left dorsolateral prefrontal cortex (DLPFC). Using event-related functional magnetic resonance imaging (fMRI), 17 controls and 17 medicated patients performed a version of the AX task in which a learned, automatic response had to be inhibited. In controls, left DLPFC activity increased when preparing to overcome an automatic response, whereas patients with schizophrenia showed no differential activation. In controls, context processing appeared to be associated with the differential representation of cues associated with the need to provide top-down support for overcoming automatic responses. This mechanism appeared to be impaired in patients with schizophrenia.     

自动情绪调节对负性情绪面孔注意偏向的影响

本研究通过成语匹配任务启动情绪调节目标,在情绪flanker任务中考察了自动情绪调节启动对注意偏向的影响。结果表明,中性启动条件下,被试表现出对负性情绪面孔的注意偏向,而情绪调节启动条件下,被试对正性、负性情绪面孔的注意分配不存在显著差异。这一结果说明自动情绪调节可以有效地减弱被试的负性情绪面孔注意偏向。     

Elimination of the enhanced Simon effect for older adults in a three-choice situation: Ageing and the Simon effect in a go/no-go Simon task

In a Simon task, participants show better performance when the irrelevant stimulus location corresponds with the response location than when it does not, and this effect is typically greater for older adults than for younger adults. To study the effect of cognitive ageing in the Simon task, we compared young and old adults using two versions of the Simon task: (a) a standard visual Simon task, for which participants respond with left and right key-presses to the red and green colours of stimuli presented in left and right locations; (b) a go/no-go version of the Simon task, which was basically the same, except that the shape of the stimulus in one third of the trials indicates that no response is to be made. In both tasks, both age groups showed the Simon effect. The magnitude of the effect for the standard Simon task was greater for the older adults than for the younger adults. Nevertheless, the two groups showed an equivalent Simon effect in the go/no-go version of the Simon task. Reaction time distribution analyses revealed basically similar functions for both age groups: a decreasing pattern of the Simon effect in the standard task and an increasing pattern of the effect in the go/no-go version of the task. The results suggest that older adults find it more difficult to suppress an automatic activation of the corresponding response, though this automatic activation was reduced in situations where the response was frequently inhibited.     

认知老化中有意控制对自动抑制的调节作用

结合比例控制范式与基于空间位置的返回抑制范式, 探讨了认知老化过程中自上而下的有意认知控制对自动抑制的调节作用。结果表明, 当线索有效率由50%提升至80%时, 两组被试的返回抑制量均下降, 老年组表现为返回抑制消失, 但年轻组出现返回抑制的反转, 表明有意认知控制对自动抑制的调节作用受认知老化的影响而发生衰减。同时文章还就认知老化机制的新兴理论—— 执行衰退假说进行了讨论。