The effect of spatial frequency information and visual similarity in threat detection

In the current research, we sought to examine the role of spatial frequency on the detection of threat using a speeded visual search paradigm. Participants searched for threat-relevant (snakes or spiders) or non-threat-relevant (frogs or cockroaches) targets in an array of neutral (flowers or mushrooms) distracters, and we measured search performance with images filtered to contain different levels (high and low) of spatial frequency information. The results replicate previous work demonstrating more rapid detection of threatening versus non-threatening stimuli [e.g. LoBue, V. & DeLoache, J. S. (2008). Detecting the snake in the grass: Attention to fear-relevant stimuli by adults and young children. Psychological Science, 19, 284–289. doi:10.1111/j.1467-9280.2008.02081.x]. Most importantly, the results suggest that low spatial frequency or relatively coarse levels of visual information is sufficient for the rapid and accurate detection of threatening stimuli. Furthermore, the results also suggest that visual similarity between the stimuli used in the search tasks plays a significant role in speeded detection. The results are discussed in terms of the theoretical implications for the rapid detection of threat and methodological implications for properly accounting for similarity between the stimuli in visual search studies.     

Reduced effects of pictorial distinctiveness on false memory following dynamic visual noise

High levels of false recognition for non-presented items typically occur following exposure to lists of associated words. These false recognition effects can be reduced by making the studied items more distinctive by the presentation of pictures during encoding. One explanation of this is that during recognition, participants expect or attempt to retrieve distinctive pictorial information in order to evaluate the study status of the test item. If this involves the retrieval and use of visual imagery, then interfering with imagery processing should reduce the effectiveness of pictorial information in false memory reduction. In the current experiment, visual-imagery processing was disrupted at retrieval by the use of dynamic visual noise (DVN). It was found that effects of DVN dissociated true from false memory. Memory for studied words was not influenced by the presence of an interfering noise field. However, false memory was increased and the effects of picture-induced distinctiveness was eliminated. DVN also increased false recollection and remember responses to unstudied items.     

不相关言语对视觉觉察的影响

前人多在记忆层面探讨不相关言语效应(the Irrelevant Speech Effect, ISE), 而本文选择在意识觉察(conscious awareness)阶段观察这一现象。所有实验均采用视觉掩蔽及听觉输入不相关声音的视听交互方式。实验1在安静、纯音及不相关言语3种听觉背景下让被试对简单图片做视觉觉察判断, 结果发现不相关言语干扰了视觉觉察, 而纯音则未产生干扰。实验2在相同的3种听觉背景下要求被试对复杂图片做视觉觉察判断, 结果同实验1。实验3采用事件相关电位技术, 在同样的3种听觉背景下观察被试对简单图片做视觉觉察判断时的脑电变化, 结果发现不相关言语干扰了视觉觉察负波的形成, 验证了行为学研究的结果。本文结果表明不相干言语在视觉意识觉察阶段就对被试的行为产生了干扰。     

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。     

Visualizing homelessness: a study in photography and estrangement

This article reports a qualitative study of how homeless people visualize their life in hostels and on the streets of London. Using a photo‐production technique, the research enabled participants to show their situation as well as to tell about their experiences. Participants were given cameras and asked to take photographs typical of their day as homeless people, this material being the subject of a subsequent interview. This provided both visual and text data that were analysed together so as to establish different engagements of the participants with the city and with domiciled people. Presenting the material from six of the participants, these different engagements are described with reference to issues of estrangement, exclusion and visualization employed as explanatory concepts. The article identifies and compares the different ways in which homeless people attempt not only to survive but also to [make their home] in the city. Copyright © 2005 John Wiley & Sons, Ltd.     

The Occipital Cortex in the Blind

ABSTRACT— Studying the brains of blind individuals provides a unique opportunity to investigate how the brain changes and adapts in response to afferent (input) and efferent (output) demands. We discuss evidence suggesting that regions of the brain normally associated with the processing of visual information undergo remarkable dynamic change in response to blindness. These neuroplastic changes implicate not only processing carried out by the remaining senses but also higher cognitive functions such as language and memory. A strong emphasis is placed on evidence obtained from advanced neuroimaging techniques that allow researchers to identify areas of human brain activity, as well as from lesion approaches (both reversible and irreversible) to address the functional relevance and role of these activated areas. A possible mechanism and conceptual framework for these physiological and behavioral changes is proposed.     

人脑眶额皮质表征奖赏信息的进展

文章围绕人脑眶额皮质在表征奖赏信息上的核心作用展开,分别从人脑眶额皮质表征奖赏信息的共同神经表征和特异性神经表征特点,奖赏加工和该脑区局部形态特征之间的关系以及眶额皮质表征奖赏信息的时间动态性等角度对最近的重要研究进展进行了一定的梳理和概括。最后,文章讨论了未来研究需要解决的由奖赏类型多样性和脑区间奖赏信息整合复杂性带来的系列问题。     

对感觉记忆在相同范畴视觉搜索中作用的研究

该文以三种字母卡片为刺激物,通过两种靶字母搜索实验,探讨了感觉记忆在相同范畴视觉搜索中的作用。实验结果显示,感觉记忆和短时记忆信息都可能利用时的搜索成绩,明显高于限用短时记忆信息时的搜索成绩。这表明,感觉记忆信息可以直接用于相同范畴的视觉搜索。     

时-空整合影响图形识别的眼动研究

采用眼动追踪的方法对在不同方向(上、下、左与右)及距离(2.0°‘和4.0°视角)上先后出现的特征组合不同的图形识别过程进行了研究。结果表明。首先,对由不同颜色和形状构成的图形的识别受到图形特征组合的影响,视觉系统对颜色和形状的加工存在明显差异,与颜色加工相比,视觉系统需要更多的时间才能完成形状识别。此外,虽然图形识别的速度和准确性受运动方向与距离的影响较小,但在不同运动方向和距离上,视觉系统是通过改变眼动的时间和空间特性来完成识别任务的,视觉系统在识别过程中的这种时间与空间的整合特点还有待于进一步研究。     

自闭症幼儿的视觉性自我认知实验研究

通过对平均心理年龄为23个月的6名自闭症幼儿的实验研究．甄别他们是否能从视觉上进行自我与他人的分化认知并进一步探索自闭症幼儿对镜像自我认知与录像自我认知上的差异;以秒为单位．对实验结果和过程进行了编码分析。结果表明：这6名幼儿在看自己的录像时,比看同伴的表现出更多的关注和喜悦;对录像的自我进行认知寸表现出更大的关注和积极情绪。由此推断他们已具有初步的自我认知。