拥挤效应的特征加工机制

拥挤效应指对外周视野内目标刺激的识别受到该刺激周围无关刺激干扰的现象。大部分研究者认为拥挤效应发生在特征加工水平, 是由刺激特征间的过度整合引起的, 并基于此提出多种理论假设, 包括特征整合、重心解释、强制平均以及相应的量化模型, 但这些模型还缺乏直接的支持性证据。未来的研究应该结合ERP技术, 采用多种刺激(如运动刺激等等), 考察时间和空间维度上的拥挤效应的产生机制。     

面孔识别中脑电成分N170的研究概述

N170是在面孔刺激呈现后的130-200ms记录到的并在160~170ms时达到峰值的一种脑电负成分。目前, 在N170的研究中存在争议性的问题有：N170反映面孔结构编码还是面孔特征编码; N170是否是面孔特异性成分; 以及N170是否受注意的影响等。这些争议也为N170后续研究指明了方向, 即探讨结构编码和特征编码在诱发N170成分上起着怎样的作用; 比较不同熟悉度的刺激材料所诱发的N170反应差异; 探讨N170成分与识别电位间的关系;采用多研究方法的结合从不同层面深入揭示N170的认知机制。     

浅谈影像诊断思维特征

人类的科学思维方式是一个多层次、多形态、多要素的系统。对每一种事物的认识过程都有特定的思维方式。疾病的诊断是一个主观反映客观的认识过程,反映客观的真实程度愈高,诊断的正确性愈高,而客观真实性的再现,在相当程度上取决于人的主观意识,人的主观意识又通过人的思维活动来实现。所以,人的思维在疾病的诊断中占有重要意义。而医学影像诊断思维又有其特点,即以形象思维为先导,以逻辑思维来归结,又有非逻辑思维闪现,如直觉、灵感、经验思维。只有各种思维形式有机的交叉运用,才能得出最接近真实的诊断结论。     

类别使用的特征诊断效应

运用预备实验评定过的鱼轮廓图,考察了类别判断和特征预测这两种类别使用方式下的特征诊断效应。被试是48名大学生,学习材料是两类鱼的类别成员,在测验阶段,实验1判断新项目类别标签,实验2预测新项目的缺失特征。结果表明,类别判断条件下,单个特征诊断力加强和诊断性特征数量增加都对类别判断有促进作用;特征预测条件下,只有单个特征诊断力加强可以促进特征预测,诊断性特征数量增加无助于特征预测     

"象言"与"道"韵——儒道两家诗性语言学思想及其现代意义

本文从语言哲学的角度研究儒道两家汉语言学思想的诗性特征及其对汉语言学发展的重要影响。认为不论道家还是儒家都强调汉语言以"象"为传意中介,"呈象"、"构象"是汉语言话语表达的核心机制,这充分显现了汉语的诗性特征。而汉字的象形又大都根植于自然的物象,就是这种人与自然的诗性关联既强化了"象"的隐喻述谓功能,同时也深化了汉语言的意蕴,使汉语言不仅仅是思想传达和交流的工具,同时也是艺术。     

归类不确定时样例代表性对特征归纳预测的影响研究

作者用以大学生被试的一个实验考察归类不确定情景下样例的代表典型性对特征归纳预测的可能影响。实验结果表明,预测特征相对于目标特征的综合条件概率影响特征归纳预测,而样例的代表典型性并不影响特征归纳预测,没有出现样例的代表典型性效应。预测特征综合条件概率策略能预测解释这种结果。     

归类不确定情景下特征推理的综合条件概率模型

用大学生被试,通过三个实验探讨在集中呈现类别成员样本信息的归类不确定情景下的特征推理。实验结果表明,单纯的归类确定性程度和靶类别靶特征的代表性并不直接影响被试的特征推理,而是预测特征相对于目标特征的综合条件概率直接影响被试的特征推理;特征推理不是基于类别中介的间接推理,而是基于特征关联综合条件概率的直接推理。实验结果支持作者提出的预测特征综合条件概率模型。     

视觉工作记忆中的特征捆绑

特征捆绑是认知科学和神经科学研究的前沿问题,近来已经成为研究者们关于意识问题争论的焦点所在。很多心理活动涉及复杂对象各种特征的捆绑,在工作记忆中保持这些捆绑的机制是心理加工得以有效进行的基础。视觉工作记忆中的特征捆绑近来成为研究热点之一,有关研究大多凭借变化检测范式和单刺激探测范式,探讨了视觉工作记忆中捆绑特征的保持是否需要注意参与,以及分离特征存储和捆绑特征存储的关系等问题,但目前这些问题仍都没有明确的答案。     

“All I remember is the black eye”: A distinctive facial feature harms eyewitness identification

Many crimes occur in which a perpetrator has a distinctive facial feature, such as a tattoo or black eye, but few eyewitness identification (ID) studies have involved such a feature. We conducted an experiment to determine how eyewitness ID performance is impacted by a distinctive facial feature, and how police could deal with this issue. Participants (N = 4,218) studied a target face with or without a black eye, and later viewed a simultaneous photo lineup either containing the target or not. For those who saw a target with a black eye, this feature was either replicated among all lineup members or was removed. The black eye harmed empirical discriminability regardless of replication or removal, which did not differ. However, participants responded more conservatively when the black eye was removed, compared to replication. Lastly, immediate confidence was consistently indicative of accuracy.     

Shock as a signal for shock or no-shock: a feature-negative effect in conditioned suppression.

Rats were trained in conditioned suppression discriminations where shock at the beginning of a trial signaled either shock or no-shock at the end of the trial. In the shock-positive condition, shock at the beginning of a presentation of white noise signaled that noise would end with shock; noise that did not begin with shock did not end with shock. In the shock-negative discrimination, shock at the beginning of noise signaled that noise would not end with shock; presentations of noise that did not begin with shock ended with shock. In shock-random training, shock at the beginning of noise did not reliably signal whether the noise presentation would or would not end with shock. Most subjects in shock-negative training quickly developed a differential pattern of suppression on positive (shock reinforced) trials and no suppression on negative (nonreinforced) trials. The shock-positive discrimination was much more difficult to establish and was not acquired by the majority of the rats. This "feature-negative" effect is a clear exception to the general superiority of feature-positive learning commonly observed in discriminations based on a single distinguishing feature. The results are discussed in terms of Pavlovian stimulus-shock contingencies in the shock-positive and shock-negative paradigms, which appear to favor rapid development of the shock-negative discrimination.