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1.
To investigate whether the functioning of cognitive control is contingent upon the attentional set in attentional blink (AB), which is a deficit in reporting the second (T2) of two targets when it occurs 200—500 ms after the first (T1) in a rapid serial visual presentation (RSVP) stream, this study examined the pattern of cuing effects in which two kinds of colored cues match (i.e., in the same attentional set) or mismatch (i.e., in a different attentional set) the color of the upcoming T2. Participants of the study were asked to monitor T1 and T2 in triple RSVP streams while the cue-T2 onset synchrony (CTOA) varied from 90 ms to 270 ms and the cue and T2 might or might not occur in the same RSVP stream as T1. Relative to the uncued condition, both the same-color and the different-color cues produced cuing effects, but the effect was larger and lasted for a longer time for the former than for the latter, whether the cue (and T2) and T1 occurred in the same stream or not. Cues with short CTOA in general enhanced T2 performance more greatly during the AB period than outside of the AB period, suggesting that cues with short CTOA could open the attentional window in advance of T2 and thus facilitate the T2 processing. These findings are consistent with the theory that the salient stimulus captures attention and opens the attentional window irrespective of the attentional set defined for the target; but the attention capture effect of the cue can be quickly overridden by the top-down control when the cue does not match the attention set. Thus both the top-down attentional control setting and the bottom-up attentional capture process function during attentional blink.  相似文献   

2.
用亲密关系经历量表(ECR)对70名在校大学生进行测试,据此选出焦虑型、回避型、安全型3组被试对象,之后采用Stroop色词命名任务进行实验。结果表明:非安全依恋风格被试对依恋相关信息存在注意偏向,两种非安全依恋风格(焦虑型、回避型)被试之间差异不显著。  相似文献   

3.
针对U-Net网络感受野受限以及信息丢失导致的分割精度低的问题,提出了一种基于感受野扩增和注意力机制的U-Net脑肿瘤MR图像分割算法.首先,在U-Net网络中引入感受野模块(receptive field block,RFB)来增大网络的感受野,解决了网络由于感受野受限带来的分割精度低的问题.此外在网络中引入有效的通道注意模块(efficient channel attention,ECA)来增加网络对有用特征的响应,抑制网络中的冗余特征.使用BraTS(the brain tumor image segmentation challenge)提供的脑肿瘤MR图像数据对本文算法进行测试,用Dice相似性系数等指标进行评价,结果显示在完整肿瘤、核心肿瘤以及增强肿瘤的Dice值分别可达到0.86、0.86、0.79.与U-Net模型以及其他的网络相比得到了提高.实验结果表明,本文提出的算法能够有效提升脑肿瘤分割的精度,具有良好的分割性能.  相似文献   

4.
工作记忆表征能否自上而下地引导视觉注意选择,目前研究结果尚存在争议,而导致争议结果的原因亦不清晰.为了探究导致以往研究中有无发现引导效应的关键因素,该研究设计3个实验,要求被试在工作记忆储存任务的过程中完成一个视觉搜索任务,实验1与3的结果发现,当工作记忆表征包含可引导注意的属性时,不管视觉搜索靶子是否变化,该记忆表征都会引导注意偏向到视觉情境中与之匹配的干扰刺激,而实验2中的工作记忆表征不包含可有效引导注意的属性时,即使采用变化靶子的视觉搜索类型,也没有发现引导效应.此结果表明基于工作记忆表征的注意引导效应是否出现在一定程度上取决于该表征是否包含可有效引导注意的属性,而非视觉搜索类型.  相似文献   

5.
通过去掉RSVP刺激流中第2靶(T2)之后除紧跟T2的那个干扰物之外的其他干扰物,发现了对T2的报告正确率在长间隔条件下出现了不同寻常的降低.要求两名被试积极注意整条刺激流的实验发现,AB曲线回复到常规的U形曲线.这些结果提示:RSVP刺激流中后继干扰物的去除通过使观察者的注意状态出现偏差而影响长间隔时的AB效应.  相似文献   

6.
考察注意偏向与社交焦虑之间的关系, 并探究解释偏向在其中的作用。研究一应用点探测范式对高社交焦虑个体进行连续两天的正性注意矫正训练, 发现训练后社交焦虑个体自我报告的焦虑水平无明显变化; 在刺激–探针间隔500 ms时, 注意偏向由回避正性信息转为偏向正性信息。研究二引入解释偏向, 在研究一的基础上尝试探索三者的关系, 采用大学生样本, 通过回归分析发现解释偏向在注意偏向与社交焦虑之间起调节作用。高解释偏向个体的注意偏向可以预测其社交焦虑, 而低解释偏向个体的注意偏向不能预测社交焦虑。研究结果为注意偏向对社交焦虑的影响提供了新的解释视角。  相似文献   

7.
目的:探讨敌对人群对攻击场面的注意偏向.方法:挑选高敌对、低敌对大学生各16名,让他们观看48张人为布置的箱庭虚拟场面图片,其中包含攻击场面、和平场面的图片各24张,采用眼动追踪技术,采集被试观看图片的眼动数据.结果:两组大学生对攻击场面的注视时间、注视点数均显著多于和平场面,表现出对攻击场面的注意偏向;高敌对组在攻击场面上的首次注视时间显著高于低敌对组,表现出对攻击场面的注意偏向.结论:首次注视时间是鉴别敌对状态的有效指标.  相似文献   

8.
Müller MM  Malinowski P  Gruber T  Hillyard SA 《Nature》2003,424(6946):309-312
By voluntarily directing attention to a specific region of a visual scene, we can improve our perception of stimuli at that location. This ability to focus attention upon specific zones of the visual field has been described metaphorically as a moveable spotlight or zoom lens that facilitates the processing of stimuli within its 'beam'. A long-standing controversy has centred on the question of whether the spotlight of spatial attention has a unitary beam or whether it can be divided flexibly to disparate locations. Evidence supporting the unitary spotlight view has come from numerous behavioural and electrophysiological studies. Recent experiments, however, indicate that the spotlight of spatial attention may be divided between non-contiguous zones of the visual field for very brief stimulus exposures (&<100 ms). Here we use an electrophysiological measure of attentional allocation (the steady-state visual evoked potential) to show that the spotlight may be divided between spatially separated locations (excluding interposed locations) over more extended time periods. This spotlight division appears to be accomplished at an early stage of visual-cortical processing.  相似文献   

9.
采用静态研究范式研究无意视盲的负载问题。结果发现:(1)在低负载和高负载的条件下都有无意视盲现象出现,而且二者的比例无显著性差异;(2)出现无意视盲的被试,其主任务完成情况不受非预期刺激的影响,而注意到非预期刺激的被试则因非预期刺激的出现,反应时延长,正确率下降。  相似文献   

10.
以大学生为被试,采用分配注意范式探讨了短时记忆编码和提取所需的注意资源。研究发现:与集中注意相比,编码阶段进行第二作业导致记忆成绩显著降低,而提取阶段进行第二作业则对记忆成绩没有影响。自由回忆和顺序回忆的结果一致。本研究表明,短时记忆编码是需要较多注意资源的控制加工,而短时记忆提取则是相对无需注意资源的自动加工。这与当前关于长时记忆的研究结果类似,而与早期以第二作业成绩为测量指标的短时记忆研究结果有所不同。  相似文献   

11.
应用事件相关电位(ERP)研究返回抑制(IOR).返回抑制是指当提示和靶出现之间时间间隔延长到一定量,提示不仅不会使对靶的反应易化,反而受到抑制的现象.本实验希望探究IOR的神经机制.实验结果显示IOR效应有明显的P1和N1波出现,且易化使P1波幅增大,N1波幅减小,抑制使P1波幅减小,使N1波幅增大.这提示P1和N1波幅代表不同的神经机制.基于ERP结果及先前对IOR的注意理论解释,提出注意动量流惯性的假说,它能较好地说明IOR的ERP效应.  相似文献   

12.
大学生注意力调控能力的性别比较研究   总被引:1,自引:0,他引:1  
应用Stroop干扰任务,对37名一年级男女大学生的注意力调控能力进行了检测和性别比较.Stroop干扰任务的核心是:受试必须抑制“背景”干扰,正确地提取和处理“前景”信号.与常用的Stroop干扰任务不同的是,运用开发的计算机软件,让受试者通过触摸荧屏来完成任务.通过这套软件,精确地记录了男女大学生的操作正确率和反应时间.结果表明,一年级男女大学生在两个不同难度级别(刺激呈现时间分别为1000ms和750ms)的测试中,反应正确率和反应时间两个行为指标上的得分非常接近.这一结果提示,男女大学生在注意力调控能力方面不存在显著性差异.  相似文献   

13.
S J Luck  S A Hillyard  G R Mangun  M S Gazzaniga 《Nature》1989,342(6249):543-545
The primate visual system is adept at identifying objects embedded within complex displays that contain a variety of potentially distracting elements. Theories of visual perception postulate that this ability depends on spatial selective attention, a mechanism analogous to a spotlight or zoom lens, which concentrates high-level processing resources on restricted portions of the visual field. Previous studies in which attention was pre-cued to specific locations in the visual field have shown that the spotlight has a single, unified focus, even in the disconnected hemispheres of patients who have undergone surgical transection of the corpus callosum. Here we demonstrate that an independent focus of attention is deployed by each of the surgically separated hemispheres in a visual search task, such that bilateral stimulus arrays can be scanned at a faster rate by 'split-brain' subjects than by normal control subjects. The attentional system used for visual search therefore seems to be functionally and anatomically distinct from the system that mediates voluntary orienting of attention.  相似文献   

14.
针对传统钢材表面缺陷检测方法存在检测效率低、检测精度差等问题,提出一种基于改进YOLOv5的钢材表面缺陷检测算法。首先使用GhostBottleneck结构替换原YOLOv5网络中的C3模块和部分卷积结构,实现网络模型轻量化;其次在Backbone部分引入SE注意力机制,对重要的特征通道进行强化;最后针对数据集特点在网络中增加一个检测层,强化特征提取能力,并在Neck部分增加特征融合结构,使用DW卷积替换部分标准卷积以减少运算量。实验表明,改进的YOLOv5sGSD算法,模型体积减少了10.4%,在测试集上的mAP值为76.8%,相比原YOLOv5s网络提高了3.3%,检测精度和速度也明显高于一些主流算法。相比传统的钢材表面缺陷检测方法,提出的算法能够更加准确、快速地检测出钢材表面缺陷的种类和位置,并且具有较小的模型体积,方便于在移动端的部署。  相似文献   

15.
针对目前胶囊内窥镜病灶检测模型存在检测疾病单一且效率低等问题,提出了一种基于YOLOv5的胶囊内窥镜病灶区域检测方法。该方法在原始YOLOv5基础上进行了如下改进:首先,在主干网络Backbone部分,添加一个CBAM(convolutional block attention module)模块,增强模型对重要特征的突出能力;其次,在头部网络Head部分,添加一个检测头,增强模型对小目标的检测能力;最后,将原始YOLOv5的泛化交并比(generalized intersection over union, GIoU)损失函数替换成完整交并比(complete intersection over union, CIoU)损失函数,使模型训练时更快地收敛。本文提出的方法在长江大学第一临床医学院提供的胶囊内窥镜影像数据上进行了实验,精确率达到了93.6%,召回率达到了94.3%,mAP@0.5达到了97.2%,而且检测速度达到了每帧0.027 2 s。实验结果表明提出的方法是有效的、灵活的、鲁棒的,能够满足临床医学诊断的实际需求。  相似文献   

16.
Attention exerts a strong influence over neuronal processing in cortical areas. It selectively increases firing rates and affects tuning properties, including changing receptive field locations and sizes. Although these effects are well studied, their cellular mechanisms are poorly understood. To study the cellular mechanisms, we combined iontophoretic pharmacological analysis of cholinergic receptors with single cell recordings in V1 while rhesus macaque monkeys (Macaca mulatta) performed a task that demanded top-down spatial attention. Attending to the receptive field of the V1 neuron under study caused an increase in firing rates. Here we show that this attentional modulation was enhanced by low doses of acetylcholine. Furthermore, applying the muscarinic antagonist scopolamine reduced attentional modulation, whereas the nicotinic antagonist mecamylamine had no systematic effect. These results demonstrate that muscarinic cholinergic mechanisms play a central part in mediating the effects of attention in V1.  相似文献   

17.
fMRI evidence for objects as the units of attentional selection.   总被引:18,自引:0,他引:18  
K M O'Craven  P E Downing  N Kanwisher 《Nature》1999,401(6753):584-587
Contrasting theories of visual attention emphasize selection by spatial location, visual features (such as motion or colour) or whole objects. Here we used functional magnetic resonance imaging (fMRI) to test key predictions of the object-based theory, which proposes that pre-attentive mechanisms segment the visual array into discrete objects, groups, or surfaces, which serve as targets for visual attention. Subjects viewed stimuli consisting of a face transparently superimposed on a house, with one moving and the other stationary. In different conditions, subjects attended to the face, the house or the motion. The magnetic resonance signal from each subject's fusiform face area, parahippocampal place area and area MT/MST provided a measure of the processing of faces, houses and visual motion, respectively. Although all three attributes occupied the same location, attending to one attribute of an object (such as the motion of a moving face) enhanced the neural representation not only of that attribute but also of the other attribute of the same object (for example, the face), compared with attributes of the other object (for example, the house). These results cannot be explained by models in which attention selects locations or features, and provide physiological evidence that whole objects are selected even when only one visual attribute is relevant.  相似文献   

18.
目前主流图像去雾算法输出的结果图像存在颜色失真、边缘模糊的问题.为改善上述问题,提出一种基于深度学习的图像去雾算法,所提算法由两个模块构成:注意力特征融合模块和雾霾模型参数估计模块.注意力特征融合模块用于充分提取雾霾图像的颜色、边缘特征;基于稠密连接空洞卷积自编码器的雾霾模型参数估计模块用于估计雾霾模型的参数,改善网络退化的问题.在浓雾图像、薄雾图像数据集上的实验表明,本文提出的算法有效地实现了图像去雾,与主流的图像去雾算法相比具有更高的结构相似性(SSIM),更低的均方误差(mean-square error,MSE)和边缘误差e○edge.  相似文献   

19.
对24名左利手和24名右利手被试在三种注意条件(刺激驱动、注意左耳和注意右耳)下进行双耳分听汉字测验,检查中国人利手与汉字听觉词汇加工大脑两半球功能优势的关系,同时考察被试的注意偏向对优势效应的影响.结果表明:(1)汉语母语左利手被试加工汉字听觉词汇的大脑功能偏侧化组织明显不同于右利手;(2)右利手被试在刺激驱动条件下的右耳(左半球)优势易受注意偏向的调节出现明显波动;(3)注意偏向对左利手被试的影响主要表现为优势的左耳(右半球)成绩的下降与非优势的右耳(左半球)成绩的提高,这暗示汉语母语左利手者可能存在汉字听觉词汇加工的潜在两半球表征.  相似文献   

20.
ASYMMETRIES OF HUMAN VISUAL INFORMATION PROCESS- ING ACROSS VISUAL FIELDS HAVE BEEN AN INTERESTING ISSUE IN COGNITIVE PSYCHOLOGY AND NEUROSCIENCE. IN ADDITION TO INVESTIGATIONS OF THE ASYMMETRIES BETWEEN THE LEFT AND RIGHT VISUAL FIELDS THAT ARE BELIEVED …  相似文献   

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