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Artificial neuron

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851:– In a biological neuron, the dendrites act as the input vector. These dendrites allow the cell to receive signals from a large (>1000) number of neighboring neurons. As in the above mathematical treatment, each dendrite is able to perform "multiplication" by that dendrite's "weight value." The multiplication is accomplished by increasing or decreasing the ratio of synaptic neurotransmitters to signal chemicals introduced into the dendrite in response to the synaptic neurotransmitter. A negative multiplication effect can be achieved by transmitting signal inhibitors (i.e. oppositely charged ions) along the dendrite in response to the reception of synaptic neurotransmitters. 31: 872:
which an axon fires converts directly into the rate at which neighboring cells get signal ions introduced into them. The faster a biological neuron fires, the faster nearby neurons accumulate electrical potential (or lose electrical potential, depending on the "weighting" of the dendrite that connects to the neuron that fired). It is this conversion that allows computer scientists and mathematicians to simulate biological neural networks using artificial neurons which can output distinct values (often from −1 to 1).
867:– The axon gets its signal from the summation behavior which occurs inside the soma. The opening to the axon essentially samples the electrical potential of the solution inside the soma. Once the soma reaches a certain potential, the axon will transmit an all-in signal pulse down its length. In this regard, the axon behaves as the ability for us to connect our artificial neuron to other artificial neurons. 830: 859:– In a biological neuron, the soma acts as the summation function, seen in the above mathematical description. As positive and negative signals (exciting and inhibiting, respectively) arrive in the soma from the dendrites, the positive and negative ions are effectively added in summation, by simple virtue of being mixed together in the solution inside the cell's body. 958:, have been built into a robot, enabling it to learn sensorimotorically within the real world, rather than via simulations or virtually. Moreover, artificial spiking neurons made of soft matter (polymers) can operate in biologically relevant environments and enable the synergetic communication between the artificial and biological domains. 2301:
Wang, Ting; Wang, Ming; Wang, Jianwu; Yang, Le; Ren, Xueyang; Song, Gang; Chen, Shisheng; Yuan, Yuehui; Liu, Ruiqing; Pan, Liang; Li, Zheng; Leow, Wan Ru; Luo, Yifei; Ji, Shaobo; Cui, Zequn; He, Ke; Zhang, Feilong; Lv, Fengting; Tian, Yuanyuan; Cai, Kaiyu; Yang, Bowen; Niu, Jingyi; Zou, Haochen; Liu,
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such as the logistic function also has an easily calculated derivative, which can be important when calculating the weight updates in the network. It thus makes the network more easily manipulable mathematically, and was attractive to early computer scientists who needed to minimize the computational
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Unlike most artificial neurons, however, biological neurons fire in discrete pulses. Each time the electrical potential inside the soma reaches a certain threshold, a pulse is transmitted down the axon. This pulsing can be translated into continuous values. The rate (activations per second, etc.) at
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Krauhausen, Imke; Koutsouras, Dimitrios A.; Melianas, Armantas; Keene, Scott T.; Lieberth, Katharina; Ledanseur, Hadrien; Sheelamanthula, Rajendar; Giovannitti, Alexander; Torricelli, Fabrizio; Mcculloch, Iain; Blom, Paul W. M.; Salleo, Alberto; Burgt, Yoeri van de; Gkoupidenis, Paschalis (December
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Artificial neurons are designed to mimic aspects of their biological counterparts. However a significant performance gap exists between biological and artificial neural networks. In particular single biological neurons in the human brain with oscillating activation function capable of learning the
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Simple artificial neurons, such as the McCulloch–Pitts model, are sometimes described as "caricature models", since they are intended to reflect one or more neurophysiological observations, but without regard to realism. Artificial neurons can also refer to
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model is used. No method of training is defined, since several exist. If a purely functional model were used, the class TLU below would be replaced with a function TLU with input parameters threshold, weights, and inputs that returned a boolean value.
1253: 1584: 154:. Non-monotonic, unbounded and oscillating activation functions with multiple zeros that outperform sigmoidal and ReLU-like activation functions on many tasks have also been recently explored. The thresholding function has inspired building 2190:
Keene, Scott T.; Lubrano, Claudia; Kazemzadeh, Setareh; Melianas, Armantas; Tuchman, Yaakov; Polino, Giuseppina; Scognamiglio, Paola; Cinà, Lucio; Salleo, Alberto; van de Burgt, Yoeri; Santoro, Francesca (September 2020).
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In the late 1980s, when research on neural networks regained strength, neurons with more continuous shapes started to be considered. The possibility of differentiating the activation function allows the direct use of the
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term. A number of such linear neurons perform a linear transformation of the input vector. This is usually more useful in the first layers of a network. A number of analysis tools exist based on linear models, such as
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motivations and mathematical justifications. It has been demonstrated for the first time in 2011 to enable better training of deeper networks, compared to the widely used activation functions prior to 2011, i.e., the
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itself (that is, self-loops are possible). However, an output cannot connect more than once with a single neuron. Self-loops do not cause contradictions, since the network operates in synchronous discrete time-steps.
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production. The use of unary in biological networks is presumably due to the inherent simplicity of the coding. Another contributing factor could be that unary coding provides a certain degree of error correction.
978:. Initially, only a simple model was considered, with binary inputs and outputs, some restrictions on the possible weights, and a more flexible threshold value. Since the beginning it was already noticed that any 418: 1270:. It is specially useful in the last layer of a network intended to perform binary classification of the inputs. It can be approximated from other sigmoidal functions by assigning large values to the weights. 2802:
Hahnloser, Richard H. R.; Sarpeshkar, Rahul; Mahowald, Misha A.; Douglas, Rodney J.; Seung, H. Sebastian (2000). "Digital selection and analogue amplification coexist in a cortex-inspired silicon circuit".
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Fu, Tianda; Liu, Xiaomeng; Gao, Hongyan; Ward, Joy E.; Liu, Xiaorong; Yin, Bing; Wang, Zhongrui; Zhuo, Ye; Walker, David J. F.; Joshua Yang, J.; Chen, Jianhan; Lovley, Derek R.; Yao, Jun (April 20, 2020).
1009:. This model already considered more flexible weight values in the neurons, and was used in machines with adaptive capabilities. The representation of the threshold values as a bias term was introduced by 1353:
algorithm tend to diminish towards zero as activations propagate through layers of sigmoidal neurons, making it difficult to optimize neural networks using multiple layers of sigmoidal neurons.
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Sarkar, Tanmoy; Lieberth, Katharina; Pavlou, Aristea; Frank, Thomas; Mailaender, Volker; McCulloch, Iain; Blom, Paul W. M.; Torriccelli, Fabrizio; Gkoupidenis, Paschalis (7 November 2022).
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As a simple example, consider a single neuron with threshold 0, and a single inhibitory self-loop. Its output would oscillate between 0 and 1 at every step, acting as a "clock".
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in 1943. The model was specifically targeted as a computational model of the "nerve net" in the brain. As a transfer function, it employed a threshold, equivalent to using the
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of a biological neuron, and its value propagates to the input of the next layer, through a synapse. It may also exit the system, possibly as part of an output
1055:) of a neuron is chosen to have a number of properties which either enhance or simplify the network containing the neuron. Crucially, for instance, any 982:
could be implemented by networks of such devices, what is easily seen from the fact that one can implement the AND and OR functions, and use them in the
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transfer function has an equivalent single-layer network; a non-linear function is therefore necessary to gain the advantages of a multi-layer network.
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A commonly used variant of the ReLU activation function is the Leaky ReLU which allows a small, positive gradient when the unit is not active:
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A MCP neuron is a kind of restricted artificial neuron which operates in discrete time-steps. Each has zero or more inputs, and are written as
62:. The artificial neuron is a function that receives one or more inputs, applies weights to these inputs, and sums them to produce an output. 336: 1779:
Rami A. Alzahrani; Alice C. Parker. "Neuromorphic Circuits With Neural Modulation Enhancing the Information Content of Neural Signaling".
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through neurons, could define dynamical systems with memory, but most of the research concentrated (and still does) on strictly
2724: 2697: 1925: 1900: 1798: 2742:, Beyond Regression: New Tools for Prediction and Analysis in the Behavioral Sciences. PhD thesis, Harvard University, 1974 1025:
and other optimization algorithms for the adjustment of the weights. Neural networks also started to be used as a general
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It has no learning process as such. Its transfer function weights are calculated and threshold value are predetermined.
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Maan, A. K.; Jayadevi, D. A.; James, A. P. (1 January 2016). "A Survey of Memristive Threshold Logic Circuits".
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can be simulated by a MCP neural network. Furnished with an infinite tape, MCP neural networks can simulate any
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Songrui; Xu, Guoliang; Fan, Xing; Hu, Benhui; Loh, Xian Jun; Wang, Lianhui; Chen, Xiaodong (8 August 2022).
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The first artificial neuron was the Threshold Logic Unit (TLU), or Linear Threshold Unit, first proposed by
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One important and pioneering artificial neural network that used the linear threshold function was the
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was first introduced to a dynamical network by Hahnloser et al. in a 2000 paper in Nature with strong
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Samardak, A.; Nogaret, A.; Janson, N. B.; Balanov, A. G.; Farrer, I.; Ritchie, D. A. (2009-06-05).
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Neuron and myelinated axon, with signal flow from inputs at dendrites to outputs at axon terminals
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of this transfer function is binary, depending on whether the input meets a specified threshold,
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Gidon, Albert; Zolnik, Timothy Adam; Fidzinski, Pawel; Bolduan, Felix; Papoutsi, Athanasia;
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There is research and development into physical artificial neurons – organic and inorganic.
2993: 2812: 2521: 2435: 2204: 2089: 1997: 1841: 995: 808: 2583:"An organic artificial spiking neuron for in situ neuromorphic sensing and biointerfacing" 8: 1485: 1468: 1380: 1052: 684: 143: 119: 115: 111: 2997: 2900: 2816: 2525: 2510:"Organic neuromorphic electronics for sensorimotor integration and learning in robotics" 2439: 2208: 2093: 2001: 1845: 3017: 2844: 2784: 2668: 2622: 2563: 2550: 2509: 2458: 2423: 2343: 2236: 2136: 2112: 2077: 2023: 1873: 1831: 1804: 1489: 1481: 1033:
has been rediscovered several times but its first development goes back to the work of
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may enable construction of artificial neurons which function at voltages of biological
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In a MCP neural network, all the neurons operate in synchronous discrete time-steps of
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Potluri, Pushpa Sree (26 November 2014). "Error Correction Capacity of Unary Coding".
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The artificial neuron transfer function should not be confused with a linear system's
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refers in all cases to the weighted sum of all the inputs to the neuron, i.e. for
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if the number of firing excitatory inputs is at least equal to the threshold, and
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Squire, L.; Albright, T.; Bloom, F.; Gage, F.; Spitzer, N., eds. (October 2007).
1986:"Dendritic action potentials and computation in human layer 2/3 cortical neurons" 1617: 1350: 1030: 209: 88: 1596:
is a small positive constant (in the original paper the value 0.01 was used for
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inputs (true or false), and returns a single boolean output when activated. An
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In this case, the output unit is simply the weighted sum of its inputs plus a
30: 3054: 2878: 2832: 2780: 2664: 2618: 2339: 2224: 2078:"Motor pathway convergence predicts syllable repertoire size in oscine birds" 1966: 1861: 1759: 1460: 1319: 1303: 159: 2982:"Noise-Controlled Signal Transmission in a Multithread Semiconductor Neuron" 2102: 2010: 1985: 1789: 3013: 2956: 2840: 2559: 2533: 2467: 2232: 2121: 2019: 1869: 1345:. However, recent work has shown sigmoid neurons to be less effective than 1263: 971: 881: 839: 2905: 2752: 2739: 1034: 2981: 2959:(1943). "A logical calculus of the ideas immanent in nervous activity". 2876: 2609: 2541: 2330: 2972: 2901: 2277:"Artificial neuron swaps dopamine with rat brain cells like a real one" 1958: 1890: 1609: 1472: 1267: 1262:
and often shows up in many other models. It performs a division of the
1259: 1002: 913: 909: 473: 155: 2824: 2250:"Researchers develop artificial synapse that works with living cells" 1942: 936: 928: 847: 413:{\displaystyle y_{k}=\varphi \left(\sum _{j=0}^{m}w_{kj}x_{j}\right)} 163: 131: 103: 2772: 2756: 1781:
Proceedings of International Conference on Neuromorphic Systems 2020
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Permitted and Forbidden Sets in Symmetric Threshold-Linear Networks
1984:; Holtkamp, Martin; Vida, Imre; Larkum, Matthew Evan (2020-01-03). 1836: 991: 901: 885: 78: 2801: 2141: 2044:
Neural network models of birdsong production, learning, and coding
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have been extensively used to develop such logic in recent times.
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rather than electrical signals) and communicate with natural rat
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Each output can be the input to an arbitrary number of neurons,
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Rectifier Nonlinearities Improve Neural Network Acoustic Models
2362:"Scientists create tiny devices that work like the human brain" 2193:"A biohybrid synapse with neurotransmitter-mediated plasticity" 1783:. Art. 19. New York: Association for Computing Machinery. 955: 51: 2483:"Lego Robot with an Organic 'Brain' Learns to Navigate a Maze" 2189: 1943:"A logical calculus of the ideas immanent in nervous activity" 1341:
load of their simulations. It was previously commonly seen in
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resembling brain processing. For example, new devices such as
2757:"Backpropagation through time: what it does and how to do it" 2050:. New Encyclopedia of Neuroscience: Elservier. Archived from 900:
For example, some artificial neurons can receive and release
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neurons. The reason is that the gradients computed by the
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IEEE Transactions on Neural Networks and Learning Systems
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Discrete Mathematics of Neural Networks: Selected Topics
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referred to as threshold logic; applicable to building
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Andrew L. Maas, Awni Y. Hannun, Andrew Y. Ng (2014).
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The design of the artificial neuron was inspired by
2303: 1941:McCulloch, Warren S.; Pitts, Walter (1943-12-01). 1578: 1459:is the input to a neuron. This is also known as a 1444: 1247: 1133: 785: 740: 699: 673: 614: 542: 522: 435: 412: 106:, and the sum is often added to a term known as a 2712: 2158:"Making computer chips act more like brain cells" 1821: 280:input is assigned the value +1, which makes it a 58:. Artificial neurons are the elementary units of 3052: 2716:Data Classification: Algorithms and Applications 2300: 1891:F. C. Hoppensteadt and E. M. Izhikevich (1997). 1421: 1029:model. The best known training algorithm called 998:because of the smaller difficulty they present. 223:) that are similar to natural physical neurons. 27:Mathematical function conceived as a crude model 884:is used in the neural circuits responsible for 467: 2951: 2685: 1940: 1383:defined as the positive part of its argument: 1040: 231:For a given artificial neuron k, let there be 219: 2855: 2795: 176:An artificial neuron may be referred to as a 3041:] neuron mimicks function of human cells 2706: 2420: 945:direct communication with biological neurons 892: 609: 579: 91:, and its output is analogous to a neuron's 2679: 1612:implementation of a single TLU which takes 1134:{\displaystyle u=\sum _{i=1}^{n}w_{i}x_{i}} 2870: 1488:) and its more practical counterpart, the 950:Organic neuromorphic circuits made out of 2608: 2598: 2549: 2457: 2447: 2329: 2305:"A chemically mediated artificial neuron" 2254:Stanford University via medicalxpress.com 2140: 2111: 2101: 2009: 1918:Computation: Finite and Infinite Machines 1835: 1788: 1336:A fairly simple non-linear function, the 2927: 828: 126:. The transfer functions usually have a 29: 2155: 2134: 1947:The Bulletin of Mathematical Biophysics 1603: 14: 3053: 2751: 2474: 1915: 935:and could be used to directly process 2884:Deep sparse rectifier neural networks 2075: 1445:{\displaystyle f(x)=x^{+}=\max(0,x),} 1273: 566:. An MCP neuron also has a threshold 2921:Neural Networks: Tricks of the Trade 2424:"Bioinspired bio-voltage memristors" 818: 2961:Bulletin of Mathematical Biophysics 2480: 2372:from the original on April 24, 2020 235: + 1 inputs with signals 204:, depending on the structure used. 24: 3046:McCulloch-Pitts Neurons (Overview) 2944: 2713:Charu C. Aggarwal (25 July 2014). 2162:Knowable Magazine | Annual Reviews 615:{\displaystyle b\in \{0,1,2,...\}} 307:actual inputs to the neuron: from 226: 135: 102:Usually, each input is separately 75:inhibitory postsynaptic potentials 71:excitatory postsynaptic potentials 25: 3082: 3030: 2651:(11): 721–722. 10 November 2022. 2402:from the original on May 28, 2020 2076:Moore, J.M.; et al. (2011). 1916:Minsky, Marvin Lee (1967-01-01). 1909: 114:), before being passed through a 2862:R Hahnloser; H.S. Seung (2001). 2156:Kleiner, Kurt (25 August 2022). 1893:Weakly connected neural networks 1467:in electrical engineering. This 1159: 530:. It has one output, written as 446: 2919:. In G. Orr; K. Müller (eds.). 2894: 2877:Xavier Glorot; Antoine Bordes; 2745: 2733: 2686:Martin Anthony (January 2001). 2633: 2574: 2500: 2414: 2384: 2354: 2294: 2269: 2183: 1592:is the input to the neuron and 523:{\displaystyle x_{1},...,x_{n}} 453:The output is analogous to the 95:which is transmitted along its 87:, its weights are analogous to 3006:10.1103/physrevlett.102.226802 2128: 2069: 2034: 1973: 1934: 1884: 1815: 1772: 1513: 1507: 1436: 1424: 1402: 1396: 1316:Independent component analysis 774: 762: 752:inhibitory inputs are firing; 729: 717: 707:, the output of the neuron is 110:(loosely corresponding to the 69:. Its inputs are analogous to 13: 1: 1765: 674:{\displaystyle t=0,1,2,3,...} 2719:. CRC Press. pp. 209–. 1377:ReLU (Rectified Linear Unit) 1356: 1312:Principal component analysis 916:, with potential for use in 468:McCulloch–Pitts (MCP) neuron 7: 1748: 1712:T + weights(i) 1363:Rectifier (neural networks) 1041:Types of transfer functions 875: 558:. The output can either be 550:. Each input can be either 217: 34:Artificial neuron structure 10: 3087: 3061:Artificial neural networks 2657:10.1038/s41928-022-00862-3 2600:10.1038/s41928-022-00859-y 2449:10.1038/s41467-020-15759-y 2322:10.1038/s41928-022-00803-0 2247:University press release: 2082:Proc. Natl. Acad. Sci. USA 1854:10.1109/TNNLS.2016.2547842 1608:The following is a simple 1369:artificial neural networks 1360: 1329: 1325: 1044: 961: 822: 471: 60:artificial neural networks 2217:10.1038/s41563-020-0703-y 2170:10.1146/knowable-082422-1 1258:This function is used in 893:Physical artificial cells 190:linear threshold function 927:Low-power biocompatible 880:Research has shown that 786:{\displaystyle y(t+1)=0} 741:{\displaystyle y(t+1)=1} 436:{\displaystyle \varphi } 214:neuromorphic engineering 140:monotonically increasing 2986:Physical Review Letters 2761:Proceedings of the IEEE 2103:10.1073/pnas.1102077108 2011:10.1126/science.aax6239 1895:. Springer. p. 4. 1790:10.1145/3407197.3407204 1465:half-wave rectification 1156:is a vector of inputs. 1051:The transfer function ( 988:conjunctive normal form 976:Heaviside step function 842:have been discovered. 825:Biological neuron model 2534:10.1126/sciadv.abl5068 1580: 1480:(which is inspired by 1446: 1343:multilayer perceptrons 1289:affine transformations 1249: 1135: 1110: 1027:function approximation 941:neuromorphic computing 834: 787: 742: 701: 675: 616: 544: 524: 437: 414: 381: 138:. They are also often 35: 18:McCulloch–Pitts neuron 2692:. SIAM. pp. 3–. 2428:Nature Communications 1581: 1447: 1296:Linear transformation 1250: 1136: 1090: 1057:multilayer perceptron 996:feed-forward networks 832: 788: 743: 702: 676: 617: 545: 525: 438: 415: 361: 134:linear functions, or 44:mathematical function 33: 2953:McCulloch, Warren S. 2914:"Efficient BackProp" 2908:; Genevieve B. Orr; 1604:Pseudocode algorithm 1501: 1463:and is analogous to 1390: 1179: 1081: 809:finite state machine 756: 711: 685: 629: 570: 534: 482: 427: 337: 3066:American inventions 3037:Artifical [ 2998:2009PhRvL.102v6802S 2910:Klaus-Robert Müller 2817:2000Natur.405..947H 2526:2021SciA....7.5068K 2487:Scientific American 2440:2020NatCo..11.1861F 2209:2020NatMa..19..969K 2094:2011PNAS..10816440M 2088:(39): 16440–16445. 2002:2020Sci...367...83G 1846:2016arXiv160407121M 1486:logistic regression 1469:activation function 1381:activation function 1053:activation function 700:{\displaystyle t+1} 303:. This leaves only 120:activation function 116:non-linear function 112:threshold potential 2973:10.1007/bf02478259 2645:Nature Electronics 2587:Nature Electronics 2368:. April 20, 2020. 2310:Nature Electronics 1982:Poirazi, Panayiota 1959:10.1007/BF02478259 1576: 1571: 1490:hyperbolic tangent 1482:probability theory 1442: 1367:In the context of 1274:Linear combination 1245: 1240: 1131: 937:biosensing signals 835: 783: 738: 697: 671: 612: 540: 520: 433: 410: 326:The output of the 36: 2811:(6789): 947–951. 2767:(10): 1550–1560. 2726:978-1-4665-8674-1 2699:978-0-89871-480-7 2481:Bolakhe, Saugat. 1927:978-0-13-165563-8 1920:. Prentice Hall. 1902:978-0-387-94948-2 1830:(99): 1734–1746. 1800:978-1-4503-8851-1 1722:T > threshold 1677:number T 1564: 1535: 1300:Harmonic analysis 1285:harmonic analysis 1227: 1204: 1047:Transfer function 933:action potentials 819:Biological models 543:{\displaystyle y} 171:transfer function 124:transfer function 40:artificial neuron 16:(Redirected from 3078: 3025: 2976: 2938: 2931: 2925: 2924: 2918: 2898: 2892: 2891: 2889: 2874: 2868: 2867: 2859: 2853: 2852: 2825:10.1038/35016072 2799: 2793: 2792: 2749: 2743: 2737: 2731: 2730: 2710: 2704: 2703: 2683: 2677: 2676: 2637: 2631: 2630: 2612: 2602: 2578: 2572: 2571: 2553: 2520:(50): eabl5068. 2514:Science Advances 2504: 2498: 2497: 2495: 2493: 2478: 2472: 2471: 2461: 2451: 2418: 2412: 2411: 2409: 2407: 2388: 2382: 2381: 2379: 2377: 2358: 2352: 2351: 2333: 2307: 2298: 2292: 2291: 2289: 2287: 2273: 2267: 2264: 2262: 2260: 2244: 2197:Nature Materials 2187: 2181: 2180: 2178: 2176: 2153: 2147: 2146: 2144: 2132: 2126: 2125: 2115: 2105: 2073: 2067: 2066: 2064: 2062: 2056: 2049: 2038: 2032: 2031: 2013: 1977: 1971: 1970: 1938: 1932: 1931: 1913: 1907: 1906: 1888: 1882: 1881: 1839: 1819: 1813: 1812: 1792: 1776: 1585: 1583: 1582: 1577: 1575: 1574: 1565: 1562: 1536: 1533: 1478:logistic sigmoid 1451: 1449: 1448: 1443: 1417: 1416: 1347:rectified linear 1338:sigmoid function 1332:Sigmoid function 1254: 1252: 1251: 1246: 1244: 1243: 1228: 1225: 1205: 1202: 1150:synaptic weights 1140: 1138: 1137: 1132: 1130: 1129: 1120: 1119: 1109: 1104: 1023:gradient descent 1007:Frank Rosenblatt 980:boolean function 968:Warren McCulloch 906:chemical signals 792: 790: 789: 784: 747: 745: 744: 739: 706: 704: 703: 698: 680: 678: 677: 672: 621: 619: 618: 613: 549: 547: 546: 541: 529: 527: 526: 521: 519: 518: 494: 493: 450: 442: 440: 439: 434: 419: 417: 416: 411: 409: 405: 404: 403: 394: 393: 380: 375: 349: 348: 222: 210:artificial cells 178:semi-linear unit 93:action potential 86: 85: 67:neural circuitry 21: 3086: 3085: 3081: 3080: 3079: 3077: 3076: 3075: 3051: 3050: 3033: 3028: 2947: 2945:Further reading 2942: 2941: 2932: 2928: 2916: 2899: 2895: 2887: 2875: 2871: 2860: 2856: 2800: 2796: 2773:10.1109/5.58337 2750: 2746: 2738: 2734: 2727: 2711: 2707: 2700: 2684: 2680: 2639: 2638: 2634: 2593:(11): 774–783. 2579: 2575: 2505: 2501: 2491: 2489: 2479: 2475: 2419: 2415: 2405: 2403: 2390: 2389: 2385: 2375: 2373: 2366:The Independent 2360: 2359: 2355: 2299: 2295: 2285: 2283: 2275: 2274: 2270: 2258: 2256: 2248: 2188: 2184: 2174: 2172: 2154: 2150: 2133: 2129: 2074: 2070: 2060: 2058: 2054: 2047: 2039: 2035: 1996:(6473): 83–87. 1978: 1974: 1939: 1935: 1928: 1914: 1910: 1903: 1889: 1885: 1820: 1816: 1801: 1777: 1773: 1768: 1751: 1746: 1652:function member 1618:object-oriented 1606: 1570: 1569: 1561: 1559: 1550: 1549: 1532: 1530: 1520: 1519: 1502: 1499: 1498: 1412: 1408: 1391: 1388: 1387: 1365: 1359: 1351:backpropagation 1334: 1328: 1276: 1266:of inputs by a 1239: 1238: 1224: 1222: 1216: 1215: 1201: 1199: 1189: 1188: 1180: 1177: 1176: 1162: 1148:is a vector of 1125: 1121: 1115: 1111: 1105: 1094: 1082: 1079: 1078: 1049: 1043: 1031:backpropagation 1005:, developed by 964: 895: 878: 827: 821: 757: 754: 753: 712: 709: 708: 686: 683: 682: 630: 627: 626: 571: 568: 567: 535: 532: 531: 514: 510: 489: 485: 483: 480: 479: 476: 470: 428: 425: 424: 399: 395: 386: 382: 376: 365: 360: 356: 344: 340: 338: 335: 334: 322: 313: 302: 293: 279: 273:. Usually, the 272: 266: 260: 256: 250: 241: 229: 227:Basic structure 194:McCulloch–Pitts 89:synaptic weight 83: 82: 46:conceived as a 28: 23: 22: 15: 12: 11: 5: 3084: 3074: 3073: 3071:Bioinspiration 3068: 3063: 3049: 3048: 3043: 3032: 3031:External links 3029: 3027: 3026: 2992:(22): 226802. 2977: 2967:(4): 115–133. 2948: 2946: 2943: 2940: 2939: 2926: 2893: 2869: 2854: 2794: 2744: 2732: 2725: 2705: 2698: 2678: 2632: 2573: 2499: 2473: 2413: 2383: 2353: 2316:(9): 586–595. 2293: 2268: 2266: 2265: 2203:(9): 969–973. 2182: 2148: 2127: 2068: 2033: 1972: 1953:(4): 115–133. 1933: 1926: 1908: 1901: 1883: 1814: 1799: 1770: 1769: 1767: 1764: 1763: 1762: 1757: 1755:Binding neuron 1750: 1747: 1736:false 1623: 1605: 1602: 1573: 1568: 1560: 1558: 1555: 1552: 1551: 1548: 1545: 1542: 1539: 1531: 1529: 1526: 1525: 1523: 1518: 1515: 1512: 1509: 1506: 1453: 1452: 1441: 1438: 1435: 1432: 1429: 1426: 1423: 1420: 1415: 1411: 1407: 1404: 1401: 1398: 1395: 1358: 1355: 1327: 1324: 1275: 1272: 1256: 1255: 1242: 1237: 1234: 1231: 1223: 1221: 1218: 1217: 1214: 1211: 1208: 1200: 1198: 1195: 1194: 1192: 1187: 1184: 1161: 1158: 1142: 1141: 1128: 1124: 1118: 1114: 1108: 1103: 1100: 1097: 1093: 1089: 1086: 1045:Main article: 1042: 1039: 1013:in 1960 – see 1011:Bernard Widrow 963: 960: 894: 891: 877: 874: 869: 868: 860: 852: 823:Main article: 820: 817: 813:Turing machine 782: 779: 776: 773: 770: 767: 764: 761: 737: 734: 731: 728: 725: 722: 719: 716: 696: 693: 690: 670: 667: 664: 661: 658: 655: 652: 649: 646: 643: 640: 637: 634: 611: 608: 605: 602: 599: 596: 593: 590: 587: 584: 581: 578: 575: 539: 517: 513: 509: 506: 503: 500: 497: 492: 488: 469: 466: 432: 421: 420: 408: 402: 398: 392: 389: 385: 379: 374: 371: 368: 364: 359: 355: 352: 347: 343: 330:th neuron is: 318: 311: 298: 288: 277: 268: 264: 258: 254: 246: 239: 228: 225: 160:logic circuits 148:differentiable 136:step functions 56:neural network 50:of biological 26: 9: 6: 4: 3: 2: 3083: 3072: 3069: 3067: 3064: 3062: 3059: 3058: 3056: 3047: 3044: 3042: 3040: 3035: 3034: 3023: 3019: 3015: 3011: 3007: 3003: 2999: 2995: 2991: 2987: 2983: 2978: 2974: 2970: 2966: 2962: 2958: 2957:Pitts, Walter 2954: 2950: 2949: 2936: 2930: 2922: 2915: 2911: 2907: 2903: 2897: 2886: 2885: 2880: 2879:Yoshua Bengio 2873: 2865: 2858: 2850: 2846: 2842: 2838: 2834: 2830: 2826: 2822: 2818: 2814: 2810: 2806: 2798: 2790: 2786: 2782: 2778: 2774: 2770: 2766: 2762: 2758: 2754: 2748: 2741: 2736: 2728: 2722: 2718: 2717: 2709: 2701: 2695: 2691: 2690: 2682: 2674: 2670: 2666: 2662: 2658: 2654: 2650: 2646: 2642: 2636: 2628: 2624: 2620: 2616: 2611: 2606: 2601: 2596: 2592: 2588: 2584: 2577: 2569: 2565: 2561: 2557: 2552: 2547: 2543: 2539: 2535: 2531: 2527: 2523: 2519: 2515: 2511: 2503: 2488: 2484: 2477: 2469: 2465: 2460: 2455: 2450: 2445: 2441: 2437: 2433: 2429: 2425: 2417: 2401: 2397: 2393: 2387: 2371: 2367: 2363: 2357: 2349: 2345: 2341: 2337: 2332: 2327: 2323: 2319: 2315: 2311: 2306: 2297: 2282: 2281:New Scientist 2278: 2272: 2255: 2251: 2246: 2245: 2242: 2238: 2234: 2230: 2226: 2222: 2218: 2214: 2210: 2206: 2202: 2198: 2194: 2186: 2171: 2167: 2163: 2159: 2152: 2143: 2138: 2131: 2123: 2119: 2114: 2109: 2104: 2099: 2095: 2091: 2087: 2083: 2079: 2072: 2057:on 2015-04-12 2053: 2046: 2045: 2037: 2029: 2025: 2021: 2017: 2012: 2007: 2003: 1999: 1995: 1991: 1987: 1983: 1976: 1968: 1964: 1960: 1956: 1952: 1948: 1944: 1937: 1929: 1923: 1919: 1912: 1904: 1898: 1894: 1887: 1879: 1875: 1871: 1867: 1863: 1859: 1855: 1851: 1847: 1843: 1838: 1833: 1829: 1825: 1818: 1810: 1806: 1802: 1796: 1791: 1786: 1782: 1775: 1771: 1761: 1760:Connectionism 1758: 1756: 1753: 1752: 1745: 1742: 1739: 1735: 1732: 1729:true 1728: 1725: 1721: 1718: 1715: 1711: 1707: 1703: 1699: 1696: 1692: 1688: 1684: 1680: 1676: 1672: 1669: 1665: 1661: 1657: 1653: 1649: 1645: 1641: 1637: 1633: 1630: 1626: 1622: 1619: 1615: 1611: 1601: 1599: 1595: 1591: 1586: 1566: 1556: 1553: 1546: 1543: 1540: 1537: 1527: 1521: 1516: 1510: 1504: 1496: 1493: 1491: 1487: 1483: 1479: 1474: 1470: 1466: 1462: 1461:ramp function 1458: 1439: 1433: 1430: 1427: 1418: 1413: 1409: 1405: 1399: 1393: 1386: 1385: 1384: 1382: 1378: 1374: 1370: 1364: 1354: 1352: 1348: 1344: 1339: 1333: 1323: 1321: 1320:Deconvolution 1317: 1313: 1309: 1305: 1304:Linear filter 1301: 1297: 1292: 1291:to the data. 1290: 1286: 1281: 1271: 1269: 1265: 1261: 1235: 1232: 1229: 1219: 1212: 1209: 1206: 1196: 1190: 1185: 1182: 1175: 1174: 1173: 1171: 1167: 1160:Step function 1157: 1155: 1151: 1147: 1126: 1122: 1116: 1112: 1106: 1101: 1098: 1095: 1091: 1087: 1084: 1077: 1076: 1075: 1073: 1069: 1064: 1062: 1058: 1054: 1048: 1038: 1036: 1032: 1028: 1024: 1018: 1016: 1012: 1008: 1004: 999: 997: 993: 989: 985: 981: 977: 973: 969: 959: 957: 953: 948: 946: 942: 938: 934: 930: 925: 923: 919: 915: 911: 907: 903: 898: 890: 887: 883: 873: 866: 865: 861: 858: 857: 853: 850: 849: 845: 844: 843: 841: 831: 826: 816: 814: 810: 805: 802: 799: 794: 780: 777: 771: 768: 765: 759: 751: 735: 732: 726: 723: 720: 714: 694: 691: 688: 668: 665: 662: 659: 656: 653: 650: 647: 644: 641: 638: 635: 632: 623: 606: 603: 600: 597: 594: 591: 588: 585: 582: 576: 573: 565: 561: 557: 553: 537: 515: 511: 507: 504: 501: 498: 495: 490: 486: 475: 465: 462: 460: 456: 451: 449: 444: 430: 406: 400: 396: 390: 387: 383: 377: 372: 369: 366: 362: 357: 353: 350: 345: 341: 333: 332: 331: 329: 324: 321: 317: 310: 306: 301: 297: 294: =  291: 287: 283: 276: 271: 267: 257: 249: 245: 238: 234: 224: 221: 215: 211: 205: 203: 199: 195: 191: 187: 186:binary neuron 183: 179: 174: 172: 167: 165: 161: 157: 153: 149: 145: 141: 137: 133: 129: 128:sigmoid shape 125: 121: 117: 113: 109: 105: 100: 98: 94: 90: 80: 76: 72: 68: 63: 61: 57: 53: 49: 45: 41: 32: 19: 3038: 2989: 2985: 2964: 2960: 2929: 2920: 2896: 2883: 2872: 2866:. NIPS 2001. 2863: 2857: 2808: 2804: 2797: 2764: 2760: 2753:Werbos, P.J. 2747: 2735: 2715: 2708: 2688: 2681: 2648: 2644: 2635: 2610:10754/686016 2590: 2586: 2576: 2542:10754/673986 2517: 2513: 2502: 2490:. Retrieved 2486: 2476: 2431: 2427: 2416: 2404:. Retrieved 2395: 2386: 2374:. Retrieved 2365: 2356: 2331:10356/163240 2313: 2309: 2296: 2286:16 September 2284:. Retrieved 2280: 2271: 2259:23 September 2257:. Retrieved 2253: 2200: 2196: 2185: 2175:23 September 2173:. Retrieved 2161: 2151: 2130: 2085: 2081: 2071: 2059:. Retrieved 2052:the original 2043: 2036: 1993: 1989: 1975: 1950: 1946: 1936: 1917: 1911: 1892: 1886: 1827: 1823: 1817: 1780: 1774: 1743: 1741:end function 1740: 1737: 1733: 1730: 1726: 1723: 1719: 1717:end for each 1716: 1713: 1709: 1705: 1701: 1697: 1694: 1690: 1686: 1682: 1678: 1674: 1670: 1667: 1663: 1659: 1655: 1654:fire(inputs 1651: 1647: 1643: 1639: 1635: 1631: 1628: 1624: 1607: 1597: 1593: 1589: 1587: 1497: 1494: 1456: 1454: 1376: 1372: 1366: 1335: 1293: 1279: 1277: 1257: 1169: 1165: 1163: 1153: 1149: 1145: 1143: 1071: 1067: 1065: 1060: 1050: 1019: 1000: 972:Walter Pitts 965: 956:real neurons 949: 926: 899: 896: 882:unary coding 879: 870: 862: 854: 846: 840:XOR function 836: 806: 803: 797: 795: 749: 624: 563: 559: 555: 551: 477: 463: 452: 445: 422: 327: 325: 319: 315: 308: 304: 299: 295: 289: 285: 281: 274: 269: 262: 252: 251:and weights 247: 243: 236: 232: 230: 206: 201: 197: 193: 189: 185: 181: 177: 175: 168: 118:known as an 107: 101: 64: 39: 37: 2923:. Springer. 2906:Leon Bottou 2740:Paul Werbos 2434:(1): 1861. 1668:defined as: 1640:data member 1638:number 1632:data member 1629:defined as: 1260:perceptrons 1164:The output 1035:Paul Werbos 984:disjunctive 922:prosthetics 914:brain cells 793:otherwise. 284:input with 156:logic gates 3055:Categories 2902:Yann LeCun 2890:. AISTATS. 2492:1 February 1837:1604.07121 1766:References 1700:inputs(i) 1681:0 1634:threshold 1610:pseudocode 1473:biological 1361:See also: 1330:See also: 1268:hyperplane 1003:perceptron 929:memristors 681:. At time 556:inhibitory 552:excitatory 474:Perceptron 472:See also: 164:memristors 144:continuous 84:activation 77:at neural 2833:0028-0836 2781:0018-9219 2673:253469402 2665:2520-1131 2627:253413801 2619:2520-1131 2568:245046482 2348:251464760 2340:2520-1131 2241:219691307 2225:1476-4660 2142:1411.7406 2028:209676937 1967:1522-9602 1862:2162-237X 1809:220794387 1744:end class 1658:booleans 1656:: list of 1644:: list of 1563:otherwise 1373:rectifier 1357:Rectifier 1236:θ 1213:θ 1210:≥ 1092:∑ 992:feedbacks 848:Dendrites 798:including 577:∈ 431:φ 363:∑ 354:φ 182:Nv neuron 132:piecewise 79:dendrites 3022:11211062 3014:19658886 2912:(1998). 2881:(2011). 2841:10879535 2789:18470994 2755:(1990). 2560:34890232 2468:32313096 2400:Archived 2396:phys.org 2370:Archived 2233:32541935 2122:21918109 2061:12 April 2020:31896716 1870:27164608 1749:See also 1683:for each 1671:variable 1666:boolean 1646:numbers 1642:weights 1534:if  1226:if  1203:if  1074:inputs, 1059:using a 952:polymers 902:dopamine 886:birdsong 876:Encoding 261:through 242:through 104:weighted 2994:Bibcode 2849:4399014 2813:Bibcode 2551:8664264 2522:Bibcode 2508:2021). 2459:7171104 2436:Bibcode 2406:May 17, 2376:May 17, 2205:Bibcode 2113:3182746 2090:Bibcode 1998:Bibcode 1990:Science 1878:1798273 1842:Bibcode 1660:of size 1648:of size 1614:boolean 1326:Sigmoid 1308:Wavelet 1066:Below, 1015:ADALINE 986:or the 962:History 943:and/or 152:bounded 52:neurons 3020:  3012:  2847:  2839:  2831:  2805:Nature 2787:  2779:  2723:  2696:  2671:  2663:  2625:  2617:  2566:  2558:  2548:  2466:  2456:  2346:  2338:  2239:  2231:  2223:  2120:  2110:  2026:  2018:  1965:  1924:  1899:  1876:  1868:  1860:  1807:  1797:  1738:end if 1734:return 1727:return 1714:end if 1650:X 1588:where 1484:; see 1455:where 1379:is an 1371:, the 1144:where 1061:linear 939:, for 910:muscle 564:firing 459:vector 423:Where 202:neuron 3018:S2CID 2917:(PDF) 2888:(PDF) 2845:S2CID 2785:S2CID 2669:S2CID 2623:S2CID 2564:S2CID 2344:S2CID 2237:S2CID 2137:arXiv 2055:(PDF) 2048:(PDF) 2024:S2CID 1874:S2CID 1832:arXiv 1805:S2CID 1731:else: 1704:true 1625:class 1294:See: 1264:space 560:quiet 220:below 192:, or 81:, or 54:in a 48:model 42:is a 3010:PMID 2837:PMID 2829:ISSN 2777:ISSN 2721:ISBN 2694:ISBN 2661:ISSN 2615:ISSN 2556:PMID 2494:2022 2464:PMID 2408:2020 2378:2020 2336:ISSN 2288:2022 2261:2022 2229:PMID 2221:ISSN 2177:2022 2118:PMID 2063:2015 2016:PMID 1963:ISSN 1922:ISBN 1897:ISBN 1866:PMID 1858:ISSN 1795:ISBN 1724:then 1706:then 1627:TLU 1541:> 1280:bias 1233:< 1152:and 970:and 918:BCIs 912:and 864:Axon 856:Soma 807:Any 455:axon 282:bias 218:see 150:and 108:bias 97:axon 73:and 3039:sic 3002:doi 2990:102 2969:doi 2821:doi 2809:405 2769:doi 2653:doi 2605:hdl 2595:doi 2546:PMC 2538:hdl 2530:doi 2454:PMC 2444:doi 2326:hdl 2318:doi 2213:doi 2166:doi 2108:PMC 2098:doi 2086:108 2006:doi 1994:367 1955:doi 1850:doi 1785:doi 1662:X) 1600:). 1422:max 1375:or 562:or 554:or 314:to 212:in 198:MCP 122:or 38:An 3057:: 3016:. 3008:. 3000:. 2988:. 2984:. 2963:. 2955:; 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Index

McCulloch–Pitts neuron
Artificial neuron structure
mathematical function
model
neurons
neural network
artificial neural networks
neural circuitry
excitatory postsynaptic potentials
inhibitory postsynaptic potentials
dendrites
synaptic weight
action potential
axon
weighted
threshold potential
non-linear function
activation function
transfer function
sigmoid shape
piecewise
step functions
monotonically increasing
continuous
differentiable
bounded
logic gates
logic circuits
memristors
transfer function

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