共查询到20条相似文献，搜索用时 62 毫秒
1.
Olfactory learning-set formation in rats 总被引：4，自引：0，他引：4
Rats trained on 16 two-odor discrimination problems showed rapid acquisition of a learning set and one-trial learning by the end of the problem series. Learning to sample odor cues before responding and adoption of a "win-stay, lose-shift" strategy probably accounts for the virtually errorless learning. Learning-set performance of rats trained with odor stimulus comparable to that reported for primates trained on visual cues. 相似文献
2.
Learning to associate sensory cues with threats is critical for minimizing aversive experience. The ecological benefit of associative learning relies on accurate perception of predictive cues, but how aversive learning enhances perceptual acuity of sensory signals, particularly in humans, is unclear. We combined multivariate functional magnetic resonance imaging with olfactory psychophysics to show that initially indistinguishable odor enantiomers (mirror-image molecules) become discriminable after aversive conditioning, paralleling the spatial divergence of ensemble activity patterns in primary olfactory (piriform) cortex. Our findings indicate that aversive learning induces piriform plasticity with corresponding gains in odor enantiomer discrimination, underscoring the capacity of fear conditioning to update perceptual representation of predictive cues, over and above its well-recognized role in the acquisition of conditioned responses. That completely indiscriminable sensations can be transformed into discriminable percepts further accentuates the potency of associative learning to enhance sensory cue perception and support adaptive behavior. 相似文献
3.
Learning a language requires both statistical computations to identify words in speech and algebraic-like computations to discover higher level (grammatical) structure. Here we show that these computations can be influenced by subtle cues in the speech signal. After a short familiarization to a continuous speech stream, adult listeners are able to segment it using powerful statistics, but they fail to extract the structural regularities included in the stream even when the familiarization is greatly extended. With the introduction of subliminal segmentation cues, however, these regularities can be rapidly captured. 相似文献
4.
F H Gage A Bj?rklund U Stenevi S B Dunnett P A Kelly 《Science (New York, N.Y.)》1984,225(4661):533-536
Grafts of fetal septal tissue rich in cholinergic neurons were implanted as a dissociated cell suspension into the depth of the hippocampal formation in aged rats with severe impairments in spatial learning abilities. After 2 1/2 to 3 months, the rats with grafts, but not the controls, had improved their performance in a spatial learning test. Their improvement was due, at least in part, to an increased ability to use spatial cues in the task. In all animals the grafts had produced an extensive acetylcholinesterase-positive terminal network in the surrounding host hippocampal formation. Thus, the action of cholinergic neurons in the graft onto elements in the host hippocampal circuitry may be a necessary, but perhaps not sufficient, prerequisite for the observed functional recovery. 相似文献
5.
Two cues, either size or flavor of food pellet, were conditionally paired with either malaise induced by x-ray or pain induced by shock in four groups of rats. The combination of flavor and illness produced as conditioned decrement in consumption, but that of size and illness did not. Conversely, the combination of size and pain produced an inhibition of eating, but flavor and pain did not. Apparently, effective associative learning depends on central neural convergence of the paired afferent input. 相似文献
6.
J Winson 《Science (New York, N.Y.)》1978,201(4351):160-163
Rats learned, using distal room cues, to run to a goal on an elevated, circular track starting from any position on the track. The goal was one of eight equidistant, recessed cups set around the track, the goal cup being distinguished from the others solely by its position in the room. After learning, electrolytic lesions were made in the medial septal nucleus eliminating hippocampal theta rhythm in some animals but not in others. Rats without theta rhythm were no longer able to perform the spatial task, whereas rats with undisturbed theta rhythm retrained normal performance. Although rats without theta rhythm could not find their way directly to the goal, they recognized its location when they came upon it by chance. This type of spatial deficit appears similar to that shown by hippocampally lesioned patient H.M. Subsequent tests demonstrated that rats deprived of theta rhythm before training could nevertheless learn the task. 相似文献
7.
The normal ovarian cycle of female rats is typically replaced by persistent estrus when these animals are housed under constant light. Evidence presented here shows that the maintenance of periodicity in the environment can at least delay (if not prevent) the photic induction of persistent vaginal estrus. Female rats in constant light were exposed to vaginal smearing at random times or at the same time every day. In another experiment, female rats were exposed to either constant bright light, constant dim light, or a 24-hour photic cycle of bright and dim light. The onset of persistent vaginal estrus was delayed in rats exposed to 24-hour time cues even though the light intensities were the same as or greater than those for the aperiodic control groups. The results suggest that the absence of 24-hour time cues in constant light contributes to the induction of persistent estrus. 相似文献
8.
为了提高多Agent系统中的典型的强化学习——Q学习的学习效率和收敛速度,充分利用环境信息和相关的专家经验,提出了改进的多Agent系统强化学习算法（Q学习算法）。该算法通过Agent间对信息的共享,有效地将Q学习算法扩展应用到多Agent系统中。 相似文献
9.
混合式学习整合了传统课堂学习和网络学习的优势,能有效提高教育教学质量。本文针对《Photoshop图形图像处理》课程教学中存在的问题,对课程进行了混合式学习设计。 相似文献
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11.
Stuber GD Klanker M de Ridder B Bowers MS Joosten RN Feenstra MG Bonci A 《Science (New York, N.Y.)》2008,321(5896):1690-1692
Using sensory information for the prediction of future events is essential for survival. Midbrain dopamine neurons are activated by environmental cues that predict rewards, but the cellular mechanisms that underlie this phenomenon remain elusive. We used in vivo voltammetry and in vitro patch-clamp electrophysiology to show that both dopamine release to reward predictive cues and enhanced synaptic strength onto dopamine neurons develop over the course of cue-reward learning. Increased synaptic strength was not observed after stable behavioral responding. Thus, enhanced synaptic strength onto dopamine neurons may act to facilitate the transformation of neutral environmental stimuli to salient reward-predictive cues. 相似文献
12.
The mouse vomeronasal organ (VNO) is thought to mediate social behaviors and neuroendocrine changes elicited by pheromonal cues. The molecular mechanisms underlying the sensory response to pheromones and the behavioral repertoire induced through the VNO are not fully characterized. Using the tools of mouse genetics and multielectrode recording, we demonstrate that the sensory activation of VNO neurons requires TRP2, a putative ion channel of the transient receptor potential family that is expressed exclusively in these neurons. Moreover, we show that male mice deficient in TRP2 expression fail to display male-male aggression, and they initiate sexual and courtship behaviors toward both males and females. Our study suggests that, in the mouse, sensory activation of the VNO is essential for sex discrimination of conspecifics and thus ensures gender-specific behavior. 相似文献
13.
It has been hypothesized that rats and other mammals can use stereo cues to localize odor sources, but there is limited behavioral evidence to support this hypothesis. We found that rats trained on an odor-localization task can localize odors accurately in one or two sniffs. Bilateral sampling was essential for accurate odor localization, with internasal intensity and timing differences as directional cues. If the stimulus arrived at the correct point of the respiration cycle, internasal timing differences as short as 50 milliseconds sufficed. Neuronal recordings show that bulbar neurons responded differentially to stimuli from the left and stimuli from the right. 相似文献
14.
学习型组织与学习型图书馆 总被引：1，自引：0，他引：1
"学习型组织"是企业电子商务转型研究的重要内容,也是近年来对企业管理产生重要影响的现代企业管理理论之一。笔者从学习型组织的内涵、建立学习型图书馆的意义与必要性、建立学习型图书馆的理论思考,分析了把图书馆建成学习型组织的可行性。笔者认为通过自我超越、改进心智模式、建立共同愿景、团体学习和系统思考这五项修炼可以把图书馆转变成新型学习型图书馆,顺应信息环境与信息技术日益发展变化的时代。 相似文献
15.
学习策略大致可分为两大类：管理策略与语言学习策略。外语学习者的学习动机、学习态度、个性、年龄、学习毅力及学习环境等方面的差异会影响学习者学习策略的选择。 相似文献
16.
邵敏 《吉林农业科技学院学报》2011,(1):67-69
在学生自主学习能力还不完善的情况下,建立学生学习档案,是学生开展自主学习、培养自主学习能力的有效途径。本文简要描述了学生学习档案的性质和特点,并着重介绍了学习档案的内容,如何建立与使用学生学习档案。利用学生学习档案记录学习者的学习过程和学习结果,可以帮助学习者有效监控学习进展,培养其对学习的自觉性和自我管理能力,以及对学习的责任感,使学习者逐步具备自主学习的能力,从而为学会学习乃至终身学习奠定基础。 相似文献
17.
The removal of a single dominant individual has been shown to trigger a sex change in some coral-reeffish. In the saddleback wrasse (Thalassoma duperrey), however, female-to-male sex change requires visual stimulation from smaller conspecifics. This change is not dependent on the sex or color of the stimulus fish and can be inhibited by larger conspecifics. On the reef, a female probably changes sex when the relative numbers of larger and smaller conspecifics change within her home range. 相似文献
18.
学习共同体是一种关于学习和学习者的社会性安排，它承载一种新的知识生产方式的载体，包含着我们理解学习的一种新范式，教师—学生学习共同体的构建不仅仅是简单的教与学的关系，它更是一种文化过程，但是当前学校教师文化与学生文化处于分离的状态，迫切需要共同的愿景以统合这两种文化，并创造一个师生共享的自然的批判性学习环境，以构建教师—学生学习共同体，使学习成为教师和学生共同的生活需求和方式。 相似文献
19.
The neural basis for learning of simple motor skills 总被引：7，自引：0，他引：7
S G Lisberger 《Science (New York, N.Y.)》1988,242(4879):728-735
The vestibulo-ocular reflex (VOR) is a simple movement that has been used to investigate the neural basis for motor learning in monkeys. The function of the VOR is to stabilize retinal images by generating smooth eye movements that are equal and opposite to each head movement. Learning occurs whenever image motion occurs persistently during head turns; as a result image stability is gradually restored. A hypothesis is proposed in which the output from the cerebellar cortex of the flocculus guides learning; the locus of learning is in the brain stem, in VOR pathways that are under inhibitory control from the flocculus. Other, parallel VOR pathways do not receive inputs from the flocculus and are not subject to learning. Similarities among the VOR and other motor systems suggest some organizing principles that may apply in many forms of motor learning. 相似文献
20.
为提高植物叶片识别的准确率及减少计算代价,在Pytorch框架下提出一种融合了深度卷积生成式对抗网络(DCGAN)和迁移学习(TL)的新型卷积神经网络叶片识别方法。首先,对植物叶片图像进行预处理,通过DCGAN对样本数据库扩充;其次,利用迁移学习将Inception v3模型应用于图像数据处理上,以提高植物叶片识别的准确率;最后,通过对比实验对该方法的有效性进行验证。结果表明:该方法可以获得96.57%的植物叶片识别精度,同时参数训练的迭代次数由4000次缩短到560次。 相似文献