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Vision In Toads
The neural basis of prey detection, recognition, and orientation was studied in depth by Jörg-Peter Ewert in a series of experiments that made the toad visual system a model system in neuroethology (neural basis of natural behavior). He began by observing the natural prey catching behavior of the common European toad (''Bufo bufo''). Ewert's work with toads yielded several important discoveries (Ewert 1974, 2004). In general, his research revealed the specific neural circuits for recognition of complex visual stimuli. Specifically, he identified two main regions of the brain, the tectum and the thalamic-pretectal region, that were responsible for discriminating prey from non-prey and revealed the neural pathways that connected them. Furthermore, he found that the neural mechanisms are plastic and adaptable to varying environments and conditions (Carew 2000; Zupanc 2004). Natural toad behavior The common toad responds to a moving insect or worm with a series of prey-catching r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Eye Of Bufo Viridis
Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 nm. In subtractive color systems, used in painting and color printing, it is created by a combination of yellow and cyan; in the RGB color model, used on television and computer screens, it is one of the additive primary colors, along with red and blue, which are mixed in different combinations to create all other colors. By far the largest contributor to green in nature is chlorophyll, the chemical by which plants photosynthesize and convert sunlight into chemical energy. Many creatures have adapted to their green environments by taking on a green hue themselves as camouflage. Several minerals have a green color, including the emerald, which is colored green by its chromium content. During post-classical and early modern Europe, green was the color commonly associated with wealth, merchants, bankers, and the gentry, while red was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptive Field
The receptive field, or sensory space, is a delimited medium where some physiological stimuli can evoke a sensory neuronal response in specific organisms. Complexity of the receptive field ranges from the unidimensional chemical structure of odorants to the multidimensional spacetime of human visual field, through the bidimensional skin surface, being a receptive field for touch perception. Receptive fields can positively or negatively alter the membrane potential with or without affecting the rate of action potentials. A sensory space can be dependent of an animal's location. For a particular sound wave traveling in an appropriate transmission medium, by means of sound localization, an auditory space would amount to a reference system that continuously shifts as the animal moves (taking into consideration the space inside the ears as well). Conversely, receptive fields can be largely independent of the animal's location, as in the case of place cells. A sensory space can also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroethology
Neuroethology is the evolutionary and comparative approach to the study of animal behavior and its underlying mechanistic control by the nervous system. It is an interdisciplinary science that combines both neuroscience (study of the nervous system) and ethology (study of animal behavior in natural conditions). A central theme of neuroethology, which differentiates it from other branches of neuroscience, is its focus on behaviors that have been favored by natural selection (e.g., finding mates, navigation, locomotion, and predator avoidance) rather than on behaviors that are specific to a particular disease state or laboratory experiment. Neuroethologists hope to uncover general principles of the nervous system from the study of animals with exaggerated or specialized behaviors. They endeavor to understand how the nervous system translates biologically relevant stimuli into natural behavior. For example, many bats are capable of echolocation which is used for prey capture and navi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feature Detection (nervous System)
Feature detection is a process by which the nervous system sorts or filters complex natural stimuli in order to extract behaviorally relevant cues that have a high probability of being associated with important objects or organisms in their environment, as opposed to irrelevant background or noise. ''Feature detectors'' are individual neurons—or groups of neurons—in the brain which code for perceptually significant stimuli. Early in the sensory pathway feature detectors tend to have simple properties; later they become more and more complex as the features to which they respond become more and more specific. For example, simple cells in the visual cortex of the domestic cat (''Felis catus''), respond to edges—a feature which is more likely to occur in objects and organisms in the environment. By contrast, the background of a natural visual environment tends to be noisy—emphasizing high spatial frequencies but lacking in extended edges. Responding selectively to an extended ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artificial Neural Network
Artificial neural networks (ANNs), usually simply called neural networks (NNs) or neural nets, are computing systems inspired by the biological neural networks that constitute animal brains. An ANN is based on a collection of connected units or nodes called artificial neurons, which loosely model the neurons in a biological brain. Each connection, like the synapses in a biological brain, can transmit a signal to other neurons. An artificial neuron receives signals then processes them and can signal neurons connected to it. The "signal" at a connection is a real number, and the output of each neuron is computed by some non-linear function of the sum of its inputs. The connections are called ''edges''. Neurons and edges typically have a ''weight'' that adjusts as learning proceeds. The weight increases or decreases the strength of the signal at a connection. Neurons may have a threshold such that a signal is sent only if the aggregate signal crosses that threshold. Typically, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphodromantis Lineola
''Sphodromantis lineola'', common name African mantis or African praying mantis, is a species of praying mantis from Africa sometimes raised in captivity. ''S. lineola'' is often colored green, however they can also be colored different types of brown. The brown colored individuals have also been observed with purple colored eyes. It may be distinguished from '' S. baccettii'' by the absence of blue-black spots on its forearms. Visual System The visual system of the ''S. lineola'' is the most studied aspect of this species. In fact, this species is the most studied in this topic. Since ''S. lineola'' are sit and wait predators they have a well developed motion detection visual system. This species of mantis like most other species have apposition based compound eyes and mantises are the only invertebrates known to use stereoscopic vision. They use looming signals in order to detect and calculate other organisms or objects heading towards them using motion-in-depth perception. Us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periophthalmus
''Periophthalmus'' is a genus of fish in the family (biology), family Oxudercidae, native to coastal mangrove wood and shrubland in the Indo-Pacific region, except for ''P. barbarus'' from the Atlantic coast of Africa. It is one of the genera commonly known as mudskippers. All ''Periophthalmus'' species are aggressive and Territory (animal), territorial. Species There are currently 19 recognized species in this genus * ''Periophthalmus argentilineatus'' Achille Valenciennes, Valenciennes, 1837 (Barred mudskipper) * ''Periophthalmus barbarus'' (Carl Linnaeus, Linnaeus, 1766) (Atlantic mudskipper) * ''Periophthalmus chrysospilos'' Pieter Bleeker, Bleeker, 1852 * ''Periophthalmus darwini'' Helen Kay Larson, Larson & Toru Takita, Takita, 2004 (Darwin's mudskipper)Larson, H.K. & Takita, T. (2004): Two New Species of ''Periophthalmus'' (Teleostei: Gobiidae: Oxudercinae) from Northern Australia, and a re-diagnosis of ''Periophthalmus novaeguineaensis''. ''The Beagle: Records of the Muse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rana Esculenta
The edible frog (''Pelophylax'' kl. ''esculentus'') is a species of common European frog, also known as the common water frog or green frog (however, this latter term is also used for the North American species '' Rana clamitans''). It is used for food, particularly in France for the delicacy frog legs. Females are between 5 and 9 cm long, males between 6 and 11 cm. This widespread and common frog has many common names, including European dark-spotted frog, European black-spotted pond frog, and European black-spotted frog. Distribution ''Pelophylax esculentus'' is endemic to Europe. It naturally occurs from the northern half of France to western Russia, and from Estonia and Denmark to Bulgaria and northern Italy. The edible frog is introduced in Spain, Norway and the United Kingdom. The natural range is nearly identical to that of '' P. lessonae''. Hybridogenesis ''Pelophylax'' kl. ''esculentus'' is the fertile hybrid of the pool frog (''Pelophylax lessonae'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biotope
A biotope is an area of uniform environmental conditions providing a living place for a specific assemblage of plants and animals. ''Biotope'' is almost synonymous with the term "habitat", which is more commonly used in English-speaking countries. However, in some countries these two terms are distinguished: the subject of a habitat is a population, the subject of a biotope is a '' biocoenosis'' or "biological community". It is an English loanword derived from the German '' Biotop'', which in turn came from the Greek ''bios'' (meaning 'life') and ''topos'' ('place'). (The related word ''geotope'' has made its way into the English language by the same route, from the German '' Geotop''.) Ecology The concept of a biotope was first advocated by Ernst Haeckel (1834–1919), a German zoologist famous for the recapitulation theory. In his book ''General Morphology'' (1866), which defines the term " ecology", he stresses the importance of the concept of habitat as a prerequisite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Network
A neural network is a network or neural circuit, circuit of biological neurons, or, in a modern sense, an artificial neural network, composed of artificial neurons or nodes. Thus, a neural network is either a biological neural network, made up of biological neurons, or an artificial neural network, used for solving artificial intelligence (AI) problems. The connections of the biological neuron are modeled in artificial neural networks as weights between nodes. A positive weight reflects an excitatory connection, while negative values mean inhibitory connections. All inputs are modified by a weight and summed. This activity is referred to as a linear combination. Finally, an activation function controls the amplitude of the output. For example, an acceptable range of output is usually between 0 and 1, or it could be −1 and 1. These artificial networks may be used for predictive modeling, adaptive control and applications where they can be trained via a dataset. Self-learning re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapod
Tetrapods (; ) are four-limb (anatomy), limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant taxon, extant and extinct amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct therapsids and all extant mammals). Tetrapods evolved from a clade of primitive semiaquatic animals known as the Tetrapodomorpha which, in turn, evolved from ancient lobe-finned fish (sarcopterygians) around 390 million years ago in the Middle Devonian, Middle Devonian period; their forms were transitional between lobe-finned fishes and true four-limbed tetrapods. Limbed vertebrates (tetrapods in the broad sense of the word) are first known from Middle Devonian trackways, and body fossils became common near the end of the Late Devonian but these were all aquatic. The first crown group, crown-tetrapods (last common ancestors of extant tetrapods capable of terrestrial locomotion) appeared by the very early Mississippian ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diencephalon
The diencephalon (or interbrain) is a division of the forebrain (embryonic ''prosencephalon''). It is situated between the telencephalon and the midbrain The midbrain or mesencephalon is the forward-most portion of the brainstem and is associated with vision, hearing, motor control, sleep and wakefulness, arousal ( alertness), and temperature regulation. The name comes from the Greek ''mesos'', " ... (embryonic ''mesencephalon''). The diencephalon has also been known as the 'tweenbrain in older literature. It consists of structures that are on either side of the third ventricle, including the thalamus, the hypothalamus, the epithalamus and the subthalamus. The diencephalon is one of the main vesicles of the brain formed during embryogenesis. During the third week of development a neural tube is created from the ectoderm, one of the three primary germ layers. The tube forms three main vesicles during the third week of development: the prosencephalon, the mesencepha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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