与笼养虎皮鹦鹉认知相关的因素

越来越多的证据表明,动物的认知表现在物种之间和物种内部均存在差异,然而与这种认知差异相关的因素却不一致。本研究以笼养虎皮鹦鹉（Melopsittacus undulatus）为研究对象,通过测量其在一般认知任务和问题解决任务中的表现,探讨性别、跗跖长度、头体积和个性特征与认知能力之间的关系。结果发现,头体积较小的个体在自我控制任务中得分更高,在联想学习任务中得分更低。雄性个体在自我控制任务中的得分更高。雄性个体在联想学习任务中的得分低于雌性。在较容易的问题解决任务中,雌性、跗跖较长的个体以及探索性得分较高的个体更倾向于解决问题。在较难的问题解决任务中,雌性比雄性更倾向于解决问题。在成功解决较难问题的虎皮鹦鹉中,雌性个体的尝试次数高于雄性。本研究结果表明,不同认知任务的个体表现与多维因素相关,并且同一因素在不同的认知任务中所起的作用也各不相同。     

关联理论视角下的翻译

本文从关联理论的视角探讨翻译是一个双重明示推理的过程,译者在翻译过程中要分析不同文化读者认知语境的不同,根据最佳关联的原则,选择合适翻译方法构建译本。     

社会性蜂类昆虫认知行为研究进展

关于动物认知研究主要侧重于大脑相对较大的脊椎动物,如灵长类和鸟类。本文综述了社会性蜂类个体、群体水平认知相关的研究工作。研究表明蜂类昆虫也具有复杂的个体认知能力,包括联想学习、自我认知、工具使用和空间导航等。蜂类昆虫表现出基于多巴胺的情绪状态,这种情绪是由对食物的欲望和个体经历引起的。蜂类昆虫同样还具有复杂的社会认知行为,蜂群中不同个体间能够进行个体识别,这是蜂群内部进行社会互动的基础。此外,部分蜂类被证实通过训练之后能解决一些非自然任务的能力,这些行为可以通过社会学习在不同个体间传播,最终在整个种群中保留下来。本文最后讨论了蜂类昆虫认知行为的神经基础,越来越多的证据表明蜂类昆虫具备认知能力的神经细胞基础,这取决于神经元之间的复杂连接。本文回顾了蜂类昆虫认知行为的最新进展,这有助于为动物行为和认知演化提供独特的视野。     

蚂蚁个体与社会认知研究进展

蚁科昆虫是具有精密分工系统的社会性昆虫。蚂蚁表现出复杂认知和群体行为,如工具使用、空间导航、价值认知、联想学习、信息传递、情绪意识、自我组装和集体运输等。在使用工具时,工蚁会根据不同场景选择匹配的工具,并能够优化工具使用效率。工蚁具备复杂的导航能力,同时依赖于内部信息和外部视觉与嗅觉等信号。工蚁个体具备对不同信息的价值判断,能够通过联想学习形成对这些信息的记忆。当同巢的其他个体处于困境中时,工蚁个体表现出对巢友的共情能力。蚁科昆虫能够组装自己身体为同伴提供益处,平衡能量消耗,以优化蚁群的整体效益。在遇到较大的食物时,多个工蚁个体能够通过高效协作的方式将食物运输回蚁巢。蚂蚁具备多种认知能力,但这种能力的神经基础亟待回答。本文回顾了蚁科昆虫认知行为的最新进展,有助于加深对动物认知的理解。     

不同生长发育期的虎皮鹦鹉发声行为与发声控制神经核团的研究

鸟类的鸣叫依赖于发育完善的鸣管并接受各级发声中枢组成的机能控制系统的调控,善鸣唱的鸟类前脑控制发声的神经核团发达.用石蜡切片法和生物信号采集处理系统对不同生长发育期的虎皮鹦鹉的发声控制神经核团的体积和声音进行了比较性研究.结果发现:(1)随着虎皮鹦鹉的成长,核团体积逐渐增大,核团轮廓逐渐清晰,而且雄鸟的核团明显大于雌鸟;(2)在鸟类成长的过程中,鸟的叫声越来越复杂,幅度越来越高,雄鸟的叫声比雌鸟更复杂,雌鸟的叫声比雄鸟的叫声幅度更高;(3)鸟类鸣叫的复杂程度和发声控制神经核团的体积呈相关性.     

虎皮鹦鹉(Melopsittacus undulatfus)的振动敏感性研究

本文研究了虎皮鹦鹉对正弦振动的敏感性,旨在探索其腿部存在赫氏小体,和阐明其震前声行为反应与地面振动的关系提供依据。虎皮鹦鹉对５０－８０Ｈｚ的正弦振动不敏感,振动位移约２００－５０μｍ才可能激起声行为反应．但对１００－２５０Ｈｚ的正弦振动具有显著的敏感性,反应阈值约１０－２μｍ。对１３０－１７０Ｈｚ和２００－２５０Ｈｚ阈值反应,约７０％的潜伏期（ＬＰ）分别为ＬＰ＜３０５和ＬＰ＜１５ｓ。     

虎皮鹦鹉耳蜗感觉细胞的发育与听觉的关系

选用18d、38d、成鸟(3月以上)三种年龄的雄性虎皮鹦鹉作为实验材料,采用测量脑干听觉诱发电位和制作内耳的石蜡切片两种方法,研究了鸟类在发育时期耳蜗感觉上皮细胞的变化以及听觉功能的发育状况。鸟的听觉能力在出生后不断得到提高,38d基本达到成鸟的水平;耳蜗毛细胞的形态、内部结构逐渐趋于成熟,其灵敏度不断提高,感受听觉的能力也在增强,38d基本与成鸟的发育程度相同。耳蜗感觉上皮细胞的发育对听觉行为产生的时间和发展具有极为重要的影响。     

人类认知功能的新发现：右脑在自我认知中发挥着主导作用

自我认知是高度有序之意识活动的重要标志。动物的认知功能差异很大。属于灵长类的猴子虽能察觉到对其面部的复杂刺激 ,但只有进化水平更高的类人猿才能认出镜中自己的面孔。那么 ,作为万物之灵的人类又是怎么进行其自我认知的呢 ?这个问题一直不清。最近 ,美国学者通过对人类左右半球对面部认知的研究 ,得出了令人信服的结果 :是右脑而不是左脑控制着自我认知。他们提供了以下 5个方面的证据 :(1)和田试验 (Ｗａｄａｔｅｓｔ:用于检测言语功能和其它认知现象的优势半球 )显示 ,准备接受癫痫手术治疗的 5个病人 ,左脑麻醉不影响他们对面部的…     

内侧前额叶与社会认知

早期的研究表明杏仁核、前额叶、颞上沟、前扣带回等与人类的社会认知活动有关;随着多种新技术的应用。越来越多的研究发现其它一些脑区结构(如岛叶、基底节、白质等)也与社会认知和行为有关。本文综述了内侧前额叶在社会认知中的作用,重点介绍了内侧前额叶在心灵理论、情绪认知、社会推理与决策、道德判断、自我认知等社会认知活动中的作用。未来研究希望能从整体和动态上认识内侧前额叶在社会认知活动中的作用。     

虎皮鹦鹉腿部的赫氏小体及切断传入神经前后振动敏感性的比较研究

虎皮鹦鹉（Ｍｅｌｏｐｓｉｔａｃｕｓｕｎｄｕｌａｔｕｓ）腿部的赫氏小体（Ｈｅｒｂｓｔ）的分布长度约６５～８０ｍｍ,平均含１２５个感受单元。感受单元的宽度较均一,平均为３６μｍ。但感受单元的长度呈不规则分布,前、中和后段内感受单元的长度分别平均为１７３±１３μｍ、２３２±６μｍ和２５３±２７μｍ。在前兆地声优势频段内振幅３～１０μｍ的１００、１３０、１７０和２００～２５０Ｈｚ正弦振动刺激下,腿部赫氏小体传入神经切断动物的反应率比正常动物下降约７５％,基本上失去对该频段内振动刺激的敏感反应。     

Benefits and costs of increased levels of corticosterone in seabird chicks

Seabird chicks respond to food shortages by increasing corticosterone (cort) secretion, which is probably associated with fitness benefits and costs. To examine this, we experimentally increased levels of circulating cort in captive black-legged kittiwake chicks fed ad libitum. We found that cort-implanted chicks begged more frequently and were more aggressive compared to controls. These behavioral modifications must be beneficial to chicks as they facilitate acquisition of food from the parents and might trigger brood reduction and reduced competition for food. Cort-implanted chicks also increased food intake; however, their growth rates were similar to controls. To examine the costs of chronically increased circulating levels of cort, we removed cort implants and, after a 10-day recovery period, tested cognitive abilities of young kittiwakes. We found that the ability of kittiwakes to associate a visual cue with the presence of food in a choice situation was compromised by the experimental elevation of cort during development. To examine the long-term costs of increased levels of cort, 8 months later we tested the performance of the same individuals in a spatial task requiring them to make a detour around a barrier in order to escape from an enclosure. Individuals treated with cort during development took significantly more time to solve this task compared to controls. The results of this study suggest that the adrenocortical response of a developing bird to environmental stressors is associated with both benefits (increased food intake, foraging behavior, and aggression) and costs (low growth efficiency and compromised cognitive abilities later in life). This provides an evolutionary framework for relating juvenile physiological traits to fitness of birds in subsequent life-history stages.     

Associative learning in biochemical networks

It has been recently suggested that there are likely generic features characterizing the emergence of systems constructed from the self-organization of self-replicating agents acting under one or more selection pressures. Therefore, structures and behaviors at one length scale may be used to infer analogous structures and behaviors at other length scales. Motivated by this suggestion, we seek to characterize various "animate" behaviors in biochemical networks, and the influence that these behaviors have on genomic evolution. Specifically, in this paper, we develop a simple, chemostat-based model illustrating how a process analogous to associative learning can occur in a biochemical network. Associative learning is a form of learning whereby a system "learns" to associate two stimuli with one another. Associative learning, also known as conditioning, is believed to be a powerful learning process at work in the brain (associative learning is essentially "learning by analogy"). In our model, two types of replicating molecules, denoted as A and B, are present in some initial concentration in the chemostat. Molecules A and B are stimulated to replicate by some growth factors, denoted as G(A) and G(B), respectively. It is also assumed that A and B can covalently link, and that the conjugated molecule can be stimulated by either the G(A) or G(B) growth factors (and can be degraded). We show that, if the chemostat is stimulated by both growth factors for a certain time, followed by a time gap during which the chemostat is not stimulated at all, and if the chemostat is then stimulated again by only one of the growth factors, then there will be a transient increase in the number of molecules activated by the other growth factor. Therefore, the chemostat bears the imprint of earlier, simultaneous stimulation with both growth factors, which is indicative of associative learning. It is interesting to note that the dynamics of our model is consistent with certain aspects of Pavlov's original series of conditioning experiments in dogs. We discuss how associative learning can potentially be performed in vitro within RNA, DNA, or peptide networks. We also describe how such a mechanism could be involved in genomic evolution, and suggest relevant bioinformatics studies that could potentially resolve these issues.     

Evidence against the presence of NMDA receptors at a central glutamatergic synapse in leeches

The N-methyl-D-aspartate (NMDA) receptor, able to detect the coincidence of pre- and postsynaptic events, is considered to be the molecular analogue of associative learning. Associative learning is well known in leeches, particularly for reflexive shortening. The neuronal circuits underlying shortening have been documented and include neurons that release glutamate. Is this type of learning in leeches also mediated by NMDA receptors? The synapse between the P sensory neuron and the motoneuron-like AP cell was examined and: (1) NMDA failed to elicit a response in the AP cell, (2) the NMDA receptor antagonist 2-amino-5-phosphopentanoic acid affected synaptic transmission only at high, non-specific levels, and (3) the antagonist for the glycine-binding site 7-chloro-kynurenic acid at 20 μM did not inhibit transmission. Therefore, there are evidently no NMDA receptors at the P to AP synapse, suggesting other mechanisms of associative learning in leeches. Electronic Publication     

Precedence of spatial pattern learning revealed by immediate reversal performance

Human participants learned to choose eight correct locations in a 4 × 4 matrix on a computer display. The locations were arranged either in a structured spatial pattern or an unstructured but consistent spatial arrangement. When the assignment of correct and incorrect locations was reversed after initial learning, participants in the spatial pattern condition demonstrated reversal performance immediately (i.e., following the first choice after reversal of the contingencies). Follow-up experiments confirmed that immediate reversal performance depends on a structured spatial pattern among the locations and that a learned motor pattern cannot explain the immediate reversal performance. This pattern of results shows that learning the spatial relations among locations has precedence over learning about the individual locations, even when the individual locations are completely valid predictive cues.     

A new paradigm for operant conditioning of Drosophila melanogaster

A freely walking single fly (Drosophila melanogaster) can be conditioned to avoid one side of a small test chamber if the chamber is heated whenever the fly enters this side. In a subsequent memory test without heat it keeps avoiding the heat-associated side. The memory mutants dunce ¹ and rutabaga ¹ successfully avoid the heated side but show no avoidance in the memory test. Wildtype flies can be trained to successively avoid alternating sides in a reversal conditioning experiment. Every single fly shows strong avoidance and a positive memory score. The new conditioning apparatus has several advantages: (1) Statistically significant learning scores can be obtained for individual flies. (2) Learning scores are obtained fully automatically without interference of the experimenter. (3) The procedure is fast, robust and requires little handling. Therefore the apparatus is suitable for largescale mutant screening. (4) Animals are not attached to a hook and thus can easily be used for breeding.Abbreviations dnc dunce gene - PI performance Index - rut rutabaga gene - S.E.M. standard error of mean     

The effects of hippocampal lesions in homing pigeons on a one-trial food association task

The role of the avian hippocampal formation in a one-trial food association task was investigated across various retention intervals. Control pigeons, lesioned controls, and pigeons with hippocampal formation lesions were allowed to find food hidden in one of four uniquely decorated bowls in a specific location in a room. After retention intervals of 10 min, 1 h, 7 h, and 24 h, pigeons were placed back in the room with the same bowl in the same location (unmanipulated trials) or with the previously rewarding bowl in a new location and a different bowl in the previously rewarding location (test trials). Although all groups chose the correct bowl during unmanipulated trials, hippocampal formation lesioned birds' choices to the bowl in the correct location decreased compared to the combined controls during the test trials. The results suggest that hippocampal formation lesions do not impair long-term memory of a goal after one experience but significantly decrease the use of spatial information to return to that goal. Accepted: 18 September 1999     

Salience modulation and associative inhibition interaction: Short but not long exposure to similar stimuli protects the salience of the unique elements

In three experiments, rats were given preexposure to two similar flavour compounds, AX and BX. Following preexposure, conditioning trials took place in which AX was paired with an illness-induced unconditioned stimulus. Animals that were given short alternated preexposure to AX and BX, showed higher generalization of conditioned aversion to AX to a new compound, AN, than animals that were given blocked preexposure (short and long) and long alternated preexposure (Experiments 1 and 2); and showed less preference for A when they were given a choice between A and X (Experiment 3). These results have been taken to indicate that the salience of the A element is well preserved after short alternated preexposure, but declines when preexposure goes on for some more trials. The results reported support the notion that perceptual learning is a multi-determined phenomenon that depends on salience modulation processes after relatively short preexposure, and on an associative inhibition mechanism after prolonged preexposure.