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1.
Sixty infants divided evenly between 5 and 7 months of age were tested for their knowledge of object continuity versus discontinuity with a predictive tracking task. The stimulus event consisted of a moving ball that was briefly occluded for 20 trials. Both age groups predictively tracked the ball when it disappeared and reappeared via occlusion, but not when it disappeared and reappeared via implosion. Infants displayed high levels of predictive tracking from the first trial in the occlusion condition, and showed significant improvement across trials in the implosion condition. These results suggest that infants possess embodied knowledge to support differential tracking of continuously and discontinuously moving objects, but this tracking can be modified by visual experience. 相似文献
2.
基于背景减的Mean shift目标跟踪算法 总被引：1，自引：0，他引：1
江绍明 《内江师范学院学报》2010,25(12):45-48
为了解决初始窗口离跟踪目标较远或受干扰时,容易跟踪失败的问题,提出一种基于背景差的Mean shift跟踪模型的算法.采用背景差提取当前帧运动目标,并在当前帧运动目标位置附近进行Mean shift迭代,以巴氏系数判断当前目标和历史目标的匹配程度,根据匹配结果决定当前帧目标为跟踪目标或新增目标.实验分析,该算法可实现快速、有效目标跟踪. 相似文献
3.
P Willatts 《Child development》1979,50(3):911-913
4-month-old infants manipulated and fixated an object less when it was presented in a new rather than a familiar place. Evidence was also found for persistence of manipulation and fixation at the empty place previously occupied by the object. At 5 months, changing the position of an object had no effect on the manipulation and fixation of the same infants, and there were no signs of persistence of manipulation and fixation at the object's original place. A comparison is made between these changes in reaching and changes in tracking behavior. 2 hypotheses are considered to account for these changes, 1 based on the development of an object concept and the other on improvement of motor skill. 相似文献
4.
A method was presented to implement the detecting and tracking of moving targets through omnidirectional vision.The method combined optical flow with particle filter arithmetic.in which optical flow field was used to detect and locate moving targets and particle filter was used to track the detected moving objects.According to the circular image character of omnidirectionaI vision.the calculation equation of optical flow field and the tracking arithmetic of particle filter were improved based on the polar coordinates at the omnidirectional center.The edge of a randomly moving object could be detected by optical flow field and was surrounded by a reference region in the particle filter.A dynamic motion model was established to predict particle state.Histograms were used as the features in the reference region and candidate regions.The mutual information(MI)and Gaussian function were combined to calculate particle weights.Finally,the state of tracked object was computed by the total particle states with weights.Experiment results show that the proposed method could detect and track moving objects with better realtime performance and accuracy. 相似文献
5.
A method was presented to implement the detecting and tracking of moving targets through omnidirectional vision. The method
combined optical flow with particle filter arithmetic, in which optical flow field was used to detect and locate moving targets
and particle filter was used to track the detected moving objects. According to the circular image character of omnidirectional
vision, the calculation equation of optical flow field and the tracking arithmetic of particle filter were improved based
on the polar coordinates at the omnidirectional center. The edge of a randomly moving object could be detected by optical
flow field and was surrounded by a reference region in the particle filter. A dynamic motion model was established to predict
particle state. Histograms were used as the features in the reference region and candidate regions. The mutual information
(MI) and Gaussian function were combined to calculate particle weights. Finally, the state of tracked object was computed
by the total particle states with weights. Experiment results show that the proposed method could detect and track moving
objects with better real-time performance and accuracy.
Supported by Tianjin Higher Education Technology Development Foundation (No.20071308), Tianjin Natural Science Foundation
(06YFJMJC03600) and National Natural Science Foundation of China (No.60773073).
YANG Shuying, born in 1964, female, Dr, Prof. 相似文献
6.
Previous research yielded conflicting results about when children can accurately assess their epistemic states in different hiding tasks. In Experiment 1, ninety‐two 3‐ to 7‐year‐olds were either shown which object was hidden inside a box, were totally ignorant about what it could be, or were presented with two objects one of which was being put inside (partial exposure). Even 3‐year‐olds could assess their epistemic states in the total ignorance and the complete knowledge task. However, only children older than 5 could assess their ignorance in the partial exposure task. In Experiment 2 with one hundred and one 3‐ to 7‐year‐olds, similar results were found for children under 5 years even when more objects were shown in partial exposure tasks. Implications for children’s developing theory of knowledge are discussed. 相似文献
7.
Infants’ pointing gestures are a critical predictor of early vocabulary size. However, it remains unknown precisely how pointing relates to word learning. The current study addressed this question in a sample of 108 infants, testing one mechanism by which infants’ pointing may influence their learning. In Study 1, 18‐month‐olds, but not 12‐month‐olds, more readily mapped labels to objects if they had first pointed toward those objects than if they had referenced those objects via other communicative behaviors, such as reaching or gaze alternations. In Study 2, when an experimenter labeled a not pointed‐to‐object, 18‐month‐olds’ pointing was no longer related to enhanced fast mapping. These findings suggest that infants’ pointing gestures reflect a readiness and, potentially, a desire to learn. 相似文献
8.
The perceived spatiotemporal continuity of objects depends on the way they appear and disappear as they move in the spatial layout. This study investigated whether infants' predictive tracking of a briefly occluded object is sensitive to the manner by which the object disappears and reappears. Five-, 7-, and 9-month-old infants were shown a ball rolling across a visual scene and briefly disappearing via kinetic occlusion, instantaneous disappearance, implosion, or virtual occlusion. Three different measures converged to show that predictive tracking increased with age and that infants were most likely to anticipate the reappearance of the ball following kinetic occlusion. These results suggest that infants' knowledge of the permanence and nonpermanence of objects is embodied in their predictive tracking. 相似文献
9.
10.
Four experiments assessed visual short-term memory capacity in 4- to 13-month-old infants by comparing their looking to changing and nonchanging stimulus streams presented side by side. In each stream, 1 to 6 colored squares repeatedly appeared and disappeared. In changing streams, the color of a different randomly chosen square changed each time the display reappeared; the colors remained the same in nonchanging streams. Infants should look longer at changing streams, but only if they can remember the colors of the squares. The youngest infants preferred changing streams only when the displays contained one object, whereas older infants preferred changing streams when the displays contained up to 4 objects. Thus, visual short-term memory capacity increases significantly across the first year of life. 相似文献
11.
Attention to novel objects during verb learning 总被引：1，自引：0，他引：1
Three experiments provided evidence that 3.5- to 4-year-old English-speaking children (N = 72) attend to the appearances of novel objects, not only when they hear a novel noun, but also when they hear a novel verb. Children learning nouns in the context of novel, moving objects attended exclusively to the appearances of objects, even though nouns were also related to the motions of those objects. Children learning verbs attended equally to the appearances of objects and their motions. The latter result contrasted with the results from adults (N = 20), who focused more strongly on motions than on the appearances of objects when learning verbs. When familiar objects were instead employed, child verb learners attended more to motions than to the appearances of objects. Children may attend to novel objects during verb learning because knowledge of an object may be prerequisite to understanding what a verb means in the context of that object. 相似文献
12.
Seven and nine year olds were asked to draw two three‐dimensional objects (a cube and a wedge). When there was disjunction between their knowledge of the object's structure and its appearance (cube), they depicted the invariant rather than the variant features and produced rectangular solutions. When differences between the structure and the appearance of the object were minimised (wedge) most children drew a converging form. They could also accurately copy a two‐dimensional converging form. However, the children's knowledge of what the line drawing was supposed to represent did have an effect: in particular, they drew fewer converging obliques when the same line drawing was called a ‘building block’ (a rectangular object) than when it was called a ‘shape’ or a ‘house’ (an object known to contain obliques). A similar pattern of results was observed in a second experiment in which a selection task was used. 相似文献
13.
Two experiments provide evidence that preschoolers selectively infer history when explaining outcomes and infer past events that could have plausibly happened. In Experiment 1, thirty‐three 3‐year‐olds and thirty‐six 4‐year‐olds explained why a character owns or likes certain objects. In Experiment 2, thirty‐four 4‐year‐olds and thirty‐six 5‐year‐olds explained why a character either owns or is using the objects. Children aged 4 and 5 years, but not 3 years, inferred history when explaining ownership, but not when explaining liking or use. They also tailored their explanations to reflect likelihood, allowing them to infer plausible past events. These findings are informative about the development of children's ability to infer history in their explanations and also suggest that preschoolers appreciate that ownership depends on past investment. 相似文献
14.
Sarah E. Maylott Jilian R. Sansone Krisztina V. Jakobsen Elizabeth A. Simpson 《Child development》2021,92(4):e621-e634
Females generally attend more to social information than males; however, little is known about the early development of these sex differences. With eye tracking, 2-month olds’ (N = 101; 44 females) social orienting to faces was measured within four-item image arrays. Infants were more likely to detect human faces compared to objects, suggesting a functional face detection system. Unexpectedly, males looked longer at human faces than females, and only males looked faster and longer at human faces compared to objects. Females, in contrast, looked less at human faces relative to animal faces and objects, appearing socially disinterested. Notably, this is the first report of a male face detection advantage at any age. These findings suggest a unique stage in early infant social development. 相似文献
15.
Jared M. J. Berman Susan A. Graham Dallas Callaway Craig G. Chambers 《Child development》2013,84(5):1791-1805
Two experiments examined 4‐ and 5‐year‐olds' use of vocal affect to learn new words. In Experiment 1 (n = 48), children were presented with two unfamiliar objects, first in their original state and then in an altered state (broken or enhanced). An instruction produced with negative, neutral, or positive affect, directed children to find the referent of a novel word. During the novel noun, eye gaze measures indicated that both 4‐ and 5‐year‐olds were more likely to consider an object congruent with vocal affect cues. In Experiment 2, 5‐year‐olds (n = 15) were asked to extend and generalize their initial mapping to new exemplars. Here, 5‐year‐olds generalized these newly mapped labels but only when presented with negative vocal affect. 相似文献
16.
Infants of 12 months were familiarized in the dark with an object of either a hard or an elastic (spongy) substance. Following 60 sec of manipulation, a visual preference test was given with simultaneous presentation of 2 films of identical objects, 1 moving in a pattern characteristic of a rigid object and 1 moving in a pattern characteristic of an elastic object. Infants handled the 2 substances differently in an appropriate manner and looked preferentially with more and longer first looks to the type of substance familiarized. A replication of this experiment with familiarization in the light yielded comparable results. A third experiment with 1-month-old infants allowed them to mouth objects of either a hard or a soft substance for haptic familiarization and then tested looking preferences with real objects moving rigidly or deforming. These infants looked longer at the object moving in a manner characteristic of the novel substance. The results, together, suggest that quite young infants detect intermodal invariants specifying some substances and perceive the affordance of the substance. 相似文献
17.
The effects of object orientation and object type on children's interpretation of the word big 总被引：1，自引：0，他引：1
Previous research indicates that preschool children have persistent difficulty interpreting big: 4-5-year-olds typically interpret big to mean tall, and 3-year-olds fail to use any consistent interpretation. We propose that children's interpretation may vary depending on 2 contextual factors: type of object and orientation of object. 40 children (ages 3 and 5) each saw 35 pairs of items and, for each pair, were asked to point to "the big one." Type of object was varied by showing each child 3 kinds of objects: "people," "brownies," and rectangles. Orientation of object was varied by presenting objects either standing perpendicular to the tabletop (vertical condition) or lying flat on the tabletop (horizontal condition). Older children relied on height more consistently than younger children, all subjects relied on area more often in the horizontal condition than in the vertical condition, and 3-year-olds relied on height more when judging the bigness of people than of rectangles matched for size. Taken together, these results demonstrate that contextual factors clearly influence children's responses. These results demonstrate the interplay of cognitive and semantic factors in the process of semantic development. 相似文献
18.
本文采用了一种运动目标存在情况下的背景重建算法,能较好地抑制外界环境变化带来的影响。该运动目标检测算法通过一定数量帧的学习、统计,找到各坐标点像素灰度等级的分割阈值。在对当前帧图像进行背景差分后,分割出运动目标区域。若存在运动目标,则根据串行边界跟踪算法获得运动目标轮廓。获得边界后,模型将绘制方框显示运动物体,并发出警报。该运动目标检测模型用VisualC＋＋给予实现。 相似文献
19.
This article presents an eye‐tracking study using a novel combination of visual saliency maps and “area‐of‐interest” analyses to explore online feature extraction during category learning in infants. Category learning in 12‐month‐olds (N = 22) involved a transition from looking at high‐saliency image regions to looking at more informative, highly variable object parts. In contrast, 4‐month‐olds (N = 27) exhibited a different pattern displaying a similar decreasing impact of saliency accompanied by a steady focus on the object’s center, indicating that targeted feature extraction during category learning develops across the 1st year of life. These results illustrate how the effects of lower and higher level processes may be disentangled using a combined saliency map and area‐of‐interest analysis. 相似文献
20.
多目标跟踪的概率假设密度滤波 总被引：1，自引：0，他引：1
在多目标跟踪技术中,当目标数未知或随时间变化时,可将目标集看作随机集.阐述了随机集的有限集统计（FISST）理论,研究了用PHD滤波实现跟踪随机集的方法.实验表明,在杂波环境下,概率假设密度滤波可以稳健地跟踪目标状态和目标数. 相似文献