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DeepDream is a computer vision program created by Google engineer Alexander Mordvintsev that uses a convolutional neural network to find and enhance patterns in images via algorithmic pareidolia , thus creating a dream -like appearance reminiscent of a psychedelic experience in the deliberately overprocessed images.

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108-673: Google's program popularized the term (deep) "dreaming" to refer to the generation of images that produce desired activations in a trained deep network , and the term now refers to a collection of related approaches. The DeepDream software, originated in a deep convolutional network codenamed "Inception" after the film of the same name , was developed for the ImageNet Large-Scale Visual Recognition Challenge (ILSVRC) in 2014 and released in July 2015. The dreaming idea and name became popular on

216-420: A x otherwise . {\displaystyle f(x)={\begin{cases}x&{\text{if }}x>0,\\ax&{\text{otherwise}}.\end{cases}}} where x {\displaystyle x} is the input to the neuron and a {\displaystyle a} is a small positive constant (set to 0.01 in the original paper). The following is a simple pseudocode implementation of

324-414: A collective consciousness . Art historians do not commonly commit to any one particular brand of semiotics but rather construct an amalgamated version which they incorporate into their collection of analytical tools. For example, Meyer Schapiro borrowed Saussure 's differential meaning in effort to read signs as they exist within a system. According to Schapiro, to understand the meaning of frontality in

432-465: A decade, scores of papers, articles, and essays sustained a growing momentum, fueled by the Second-wave feminist movement , of critical discourse surrounding women's interactions with the arts as both artists and subjects. In her pioneering essay, Nochlin applies a feminist critical framework to show systematic exclusion of women from art training, arguing that exclusion from practicing art as well as

540-501: A full-blown art-historical methodology. Sedlmayr, in particular, rejected the minute study of iconography, patronage, and other approaches grounded in historical context, preferring instead to concentrate on the aesthetic qualities of a work of art. As a result, the Second Vienna School gained a reputation for unrestrained and irresponsible formalism , and was furthermore colored by Sedlmayr's overt racism and membership in

648-410: A general function approximation model. The best known training algorithm called backpropagation has been rediscovered several times but its first development goes back to the work of Paul Werbos . The activation function 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 multilayer perceptron using

756-465: A given artificial neuron k {\displaystyle k} , let there be m + 1 {\displaystyle m+1} inputs with signals x 0 {\displaystyle x_{0}} through x m {\displaystyle x_{m}} and weights w k 0 {\displaystyle w_{k0}} through w k m {\displaystyle w_{km}} . Usually,

864-402: A linear activation function has an equivalent single-layer network; a non -linear function is therefore necessary to gain the advantages of a multi-layer network. Below, u {\displaystyle u} refers in all cases to the weighted sum of all the inputs to the neuron, i.e. for n {\displaystyle n} inputs, where w {\displaystyle w}

972-656: A linear system's transfer function . An artificial neuron may be referred to as a semi-linear unit , Nv neuron , binary neuron , linear threshold function , or McCulloch–Pitts ( MCP ) neuron , depending on the structure used. 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 artificial cells in neuromorphic engineering that are similar to natural physical neurons. For

1080-400: A linear transformation of the input vector. This is usually more useful in the early layers of a network. A number of analysis tools exist based on linear models, such as harmonic analysis , and they can all be used in neural networks with this linear neuron. The bias term allows us to make affine transformations to the data. A fairly simple nonlinear function, the sigmoid function such as

1188-433: A material to carry an electric charge like real neurons , 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. The first artificial neuron

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1296-514: A more affirmative notion of leftover materials of capitalist culture. Greenberg now is well known for examining and criticizing the formal properties of modern art. [3] Meyer Schapiro is one of the best-remembered Marxist art historians of the mid-20th century. After his graduation from Columbia University in 1924, he returned to his alma mater to teach Byzantine, Early Christian, and medieval art along with art-historical theory. [4] Although he wrote about numerous time periods and themes in art, he

1404-537: A pre-recorded panoramic video, allowing users to explore virtual reality environments to mimic the experience of psychoactive substances and/or psychopathological conditions. They were able to demonstrate that the subjective experiences induced by the Hallucination Machine differed significantly from control (non-‘hallucinogenic’) videos, while bearing phenomenological similarities to the psychedelic state (following administration of psilocybin). In 2021,

1512-411: A pulse is transmitted down the axon. This pulsing can be translated into continuous values. The rate (activations per second, etc.) at 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

1620-402: A reorganization in the cognitive dynamics that facilitates the exploration of uncommon decision strategies and inhibits automated choices." Activation (neural network) An artificial neuron is a mathematical function conceived as a model of a biological neuron in a neural network . The artificial neuron is the elementary unit of an artificial neural network . The design of

1728-573: A research group coordinated by the University of Trento "measure[d] participants’ cognitive flexibility and creativity after the exposure to virtual reality panoramic videos and their hallucinatory-like counterparts generated by the DeepDream algorithm ... following the simulated psychedelic exposure, individuals exhibited ... an attenuated contribution of the automatic process and chaotic dynamics underlying their decision processes, presumably due to

1836-460: 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 XOR function have been discovered. Unlike most artificial neurons, however, biological neurons fire in discrete pulses. Each time the electrical potential inside the soma reaches a certain threshold,

1944-465: A similar work by Franz Theodor Kugler . Heinrich Wölfflin (1864–1945), who studied under Burckhardt in Basel, is the "father" of modern art history. Wölfflin taught at the universities of Berlin, Basel, Munich, and Zurich. A number of students went on to distinguished careers in art history, including Jakob Rosenberg and Frida Schottmüller  [ de ] . He introduced a scientific approach to

2052-606: 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 Boolean function 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 disjunctive or the conjunctive normal form . Researchers also soon realized that cyclic networks, with feedbacks through neurons, could define dynamical systems with memory, but most of

2160-456: A single Threshold Logic Unit (TLU) which takes Boolean inputs (true or false), and returns a single Boolean output when activated. An object-oriented 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. Art history Art history is, briefly,

2268-554: A single neuron. Self-loops do not cause contradictions, since the network operates in synchronous discrete time-steps. 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". Any finite state machine can be simulated by a MCP neural network. Furnished with an infinite tape, MCP neural networks can simulate any Turing machine . Artificial neurons are designed to mimic aspects of their biological counterparts. However

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2376-426: A specific pictorial context, it must be differentiated from, or viewed in relation to, alternate possibilities such as a profile , or a three-quarter view . Schapiro combined this method with the work of Charles Sanders Peirce whose object, sign, and interpretant provided a structure for his approach. Alex Potts demonstrates the application of Peirce's concepts to visual representation by examining them in relation to

2484-581: A study published in the journal Entropy demonstrated the similarity between DeepDream and actual psychedelic experience with neuroscientific evidence. The authors recorded Electroencephalography ( EEG ) of human participants during passive vision of a movie clip and its DeepDream-generated counterpart. They found that DeepDream video triggered a higher entropy in the EEG signal and a higher level of functional connectivity between brain areas, both well-known biomarkers of actual psychedelic experience. In 2022,

2592-419: A threshold b ∈ { 0 , 1 , 2 , . . . } {\displaystyle b\in \{0,1,2,...\}} . In an MCP neural network, all the neurons operate in synchronous discrete time-steps of t = 0 , 1 , 2 , 3 , . . . {\displaystyle t=0,1,2,3,...} . At time t + 1 {\displaystyle t+1} ,

2700-412: A work of art. Art historians employ a number of methods in their research into the ontology and history of objects. Art historians often examine work in the context of its time. At best, this is done in a manner which respects its creator's motivations and imperatives; with consideration of the desires and prejudices of its patrons and sponsors; with a comparative analysis of themes and approaches of

2808-417: Is a vector of synaptic weights and x {\displaystyle x} is a vector of inputs. The output y {\displaystyle y} of this activation function is binary, depending on whether the input meets a specified threshold, θ {\displaystyle \theta } (theta). The "signal" is sent, i.e. the output is set to 1, if the activation meets or exceeds

2916-454: Is an especially good example of this, as the Russian avant-garde and later Soviet art were attempts to define that country's identity. Napoleon Bonaparte was also well known for commissioning works that emphasized the strength of France with him as ruler. Western Romanticism provided a new appreciation for one's home country, or new home country. Caspar David Friedrich 's, Monk by

3024-401: Is an icon for all of womankind. This chain of interpretation, or "unlimited semiosis" is endless; the art historian's job is to place boundaries on possible interpretations as much as it is to reveal new possibilities. Semiotics operates under the theory that an image can only be understood from the viewer's perspective. The artist is supplanted by the viewer as the purveyor of meaning, even to

3132-455: Is best remembered for his commentary on sculpture from the late Middle Ages and early Renaissance. Arnold Hauser wrote the first Marxist survey of Western Art, entitled The Social History of Art . He attempted to show how class consciousness was reflected in major art periods. The book was controversial when published in 1951 because of its generalizations about entire eras, a strategy now called " vulgar Marxism ". [5] Marxist art history

3240-414: Is concerned with the fundamental nature of art. One branch of this area of study is aesthetics , which includes investigating the enigma of the sublime and determining the essence of beauty. Technically, art history is not these things, because the art historian uses historical method to answer the questions: How did the artist come to create the work?, Who were the patrons?, Who were their teachers?, Who

3348-471: Is non-representational or a work of expressionism . An iconographical analysis is one which focuses on particular design elements of an object. Through a close reading of such elements, it is possible to trace their lineage, and with it draw conclusions regarding the origins and trajectory of these motifs . In turn, it is possible to make any number of observations regarding the social, cultural, economic and aesthetic values of those responsible for producing

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3456-482: Is possible to trace the ideas of Xenokrates of Sicyon ( c.  280 BC ), a Greek sculptor who was perhaps the first art historian. Pliny's work, while mainly an encyclopaedia of the sciences, has thus been influential from the Renaissance onwards. (Passages about techniques used by the painter Apelles c. (332–329 BC), have been especially well-known.) Similar, though independent, developments occurred in

3564-481: Is predetermined. An 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 x 1 , . . . , x n {\displaystyle x_{1},...,x_{n}} . It has one output, written as y {\displaystyle y} . Each input can be either excitatory or inhibitory . The output can either be quiet or firing . An MCP neuron also has

3672-469: Is that the gradients computed by the backpropagation 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. In the context of artificial neural networks , the rectifier or ReLU (Rectified Linear Unit) is an activation function defined as the positive part of its argument: where x {\displaystyle x}

3780-493: Is the input to a neuron. This is also known as a ramp function and is analogous to half-wave rectification in electrical engineering. This activation function was first introduced to a dynamical network by Hahnloser et al. in a 2000 paper in Nature with strong biological motivations and mathematical justifications. It has been demonstrated for the first time in 2011 to enable better training of deeper networks, compared to

3888-505: The k {\displaystyle k} -th neuron is: where φ {\displaystyle \varphi } (phi) is the activation function. [REDACTED] The output is analogous to the axon 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 vector . It has no learning process as such. Its activation function weights are calculated, and its threshold value

3996-599: The Mona Lisa . By seeing the Mona Lisa , for example, as something beyond its materiality is to identify it as a sign. It is then recognized as referring to an object outside of itself, a woman, or Mona Lisa . The image does not seem to denote religious meaning and can therefore be assumed to be a portrait. This interpretation leads to a chain of possible interpretations: who was the sitter in relation to Leonardo da Vinci ? What significance did she have to him? Or, maybe she

4104-525: The psyche through exploring the worlds of dreams , art, mythology , world religion and philosophy . Much of his life's work was spent exploring Eastern and Western philosophy, alchemy , astrology , sociology , as well as literature and the arts. His most notable contributions include his concept of the psychological archetype , the collective unconscious , and his theory of synchronicity . Jung believed that many experiences perceived as coincidence were not merely due to chance but, instead, suggested

4212-532: The three dimensions of sculptural or architectural space to create their art. The way these individual elements are employed results in representational or non-representational art. Is the artist imitating an object or can the image be found in nature? If so, it is representational. The closer the art hews to perfect imitation, the more the art is realistic . Is the artist not imitating, but instead relying on symbolism or in an important way striving to capture nature's essence, rather than copy it directly? If so

4320-473: The 6th century China, where a canon of worthy artists was established by writers in the scholar-official class. These writers, being necessarily proficient in calligraphy, were artists themselves. The artists are described in the Six Principles of Painting formulated by Xie He . While personal reminiscences of art and artists have long been written and read (see Lorenzo Ghiberti Commentarii , for

4428-485: The English-speaking academy in the 1930s. These scholars were largely responsible for establishing art history as a legitimate field of study in the English-speaking world, and the influence of Panofsky's methodology, in particular, determined the course of American art history for a generation. Heinrich Wölfflin was not the only scholar to invoke psychological theories in the study of art. An unexpected turn in

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4536-692: The Litany , The Expanding Discourse: Feminism and Art History , and Reclaiming Feminist Agency: Feminist Art History After Postmodernism are substantial efforts to bring feminist perspectives into the discourse of art history. The pair also co-founded the Feminist Art History Conference. As opposed to iconography which seeks to identify meaning, semiotics is concerned with how meaning is created. Roland Barthes 's connoted and denoted meanings are paramount to this examination. In any particular work of art, an interpretation depends on

4644-528: The Modern era. Some of this scholarship centers on the feminist art movement , which referred specifically to the experience of women. Often, feminist art history offers a critical "re-reading" of the Western art canon, such as Carol Duncan 's re-interpretation of Les Demoiselles d'Avignon . Two pioneers of the field are Mary Garrard and Norma Broude . Their anthologies Feminism and Art History: Questioning

4752-613: The Nazi party. This latter tendency was, however, by no means shared by all members of the school; Pächt, for example, was himself Jewish, and was forced to leave Vienna in the 1930s. Our 21st-century understanding of the symbolic content of art comes from a group of scholars who gathered in Hamburg in the 1920s. The most prominent among them were Erwin Panofsky , Aby Warburg , Fritz Saxl and Gertrud Bing . Together they developed much of

4860-499: The Russian Revolution and the communist ideals. Artist Isaak Brodsky 's work of art Shock Workers from Dnieprostroi in 1932 shows his political involvement within art. This piece of art can be analysed to show the internal troubles Soviet Russia was experiencing at the time. Perhaps the best-known Marxist was Clement Greenberg , who came to prominence during the late 1930s with his essay " Avant-Garde and Kitsch ". In

4968-534: The World War in 1914, wanted to create artworks which were nonconforming and aimed to destroy traditional art styles. [2] These two movements helped other artists to create pieces that were not viewed as traditional art. Some examples of styles that branched off the anti-art movement would be Neo-Dadaism, Surrealism, and Constructivism. These styles and artists did not want to surrender to traditional ways of art. This way of thinking provoked political movements such as

5076-403: The art is non-representational—also called abstract . Realism and abstraction exist on a continuum. Impressionism is an example of a representational style that was not directly imitative, but strove to create an "impression" of nature. If the work is not representational and is an expression of the artist's feelings, longings and aspirations or is a search for ideals of beauty and form, the work

5184-457: The article anonymously. Though the use of posthumous material to perform psychoanalysis is controversial among art historians, especially as the sexual mores of Michelangelo's and Leonardo's time and Freud's are different, it is often attempted. Carl Jung also applied psychoanalytic theory to art. Jung was a Swiss psychiatrist , an influential thinker, and founder of analytical psychology . Jung's approach to psychology emphasized understanding

5292-417: The artificial neuron was inspired by biological neural circuitry . Its inputs are analogous to excitatory postsynaptic potentials and inhibitory postsynaptic potentials at neural dendrites , or activation . Its weights are analogous to synaptic weights , and its output is analogous to a neuron's action potential which is transmitted along its axon . Usually, each input is separately weighted , and

5400-663: The best early example), it was Giorgio Vasari, the Tuscan painter, sculptor and author of the Lives of the Most Excellent Painters, Sculptors, and Architects , who wrote the first true history of art. He emphasized art's progression and development, which was a milestone in this field. His was a personal and a historical account, featuring biographies of individual Italian artists, many of whom were his contemporaries and personal acquaintances. The most renowned of these

5508-462: The canonical history of art was the consequence of cultural conditions which curtailed and restricted women from art producing fields. The few who did succeed were treated as anomalies and did not provide a model for subsequent success. Griselda Pollock is another prominent feminist art historian, whose use of psychoanalytic theory is described above. While feminist art history can focus on any time period and location, much attention has been given to

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5616-432: The creator's colleagues and teachers; and with consideration of iconography and symbolism . In short, this approach examines the work of art in the context of the world within which it was created. Art historians also often examine work through an analysis of form; that is, the creator's use of line , shape , color , texture and composition. This approach examines how the artist uses a two-dimensional picture plane or

5724-419: 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). Research has shown that unary coding is used in the neural circuits responsible for birdsong production. The use of unary in biological networks is presumably due to

5832-560: The direct inspiration for Karl Schnaase 's work. Schnaase's Niederländische Briefe established the theoretical foundations for art history as an autonomous discipline, and his Geschichte der bildenden Künste , one of the first historical surveys of the history of art from antiquity to the Renaissance, facilitated the teaching of art history in German-speaking universities. Schnaase's survey was published contemporaneously with

5940-532: The discipline. As in literary studies, there is an interest among scholars in nature and the environment, but the direction that this will take in the discipline has yet to be determined. The earliest surviving writing on art that can be classified as art history are the passages in Pliny the Elder 's Natural History ( c.  AD 77 –79), concerning the development of Greek sculpture and painting . From them it

6048-515: The emergent structure of the neural network better, and is the basis for the DeepDream concept. This reversal procedure is never perfectly clear and unambiguous because it utilizes a one-to-many mapping process. However, after enough reiterations, even imagery initially devoid of the sought features will be adjusted enough that a form of pareidolia results, by which psychedelic and surreal images are generated algorithmically. The optimization resembles backpropagation ; however, instead of adjusting

6156-524: The essay Greenberg claimed that the avant-garde arose in order to defend aesthetic standards from the decline of taste involved in consumer society , and seeing kitsch and art as opposites. Greenberg further claimed that avant-garde and Modernist art was a means to resist the leveling of culture produced by capitalist propaganda . Greenberg appropriated the German word ' kitsch ' to describe this consumerism, although its connotations have since changed to

6264-463: The extent that an interpretation is still valid regardless of whether the creator had intended it. Rosalind Krauss espoused this concept in her essay "In the Name of Picasso." She denounced the artist's monopoly on meaning and insisted that meaning can only be derived after the work has been removed from its historical and social context. Mieke Bal argued similarly that meaning does not even exist until

6372-411: The founders of art history, noted that Winckelmann was 'the first to distinguish between the periods of ancient art and to link the history of style with world history'. From Winckelmann until the mid-20th century, the field of art history was dominated by German-speaking academics. Winckelmann's work thus marked the entry of art history into the high-philosophical discourse of German culture. Winckelmann

6480-402: The function of the serotonergic system which is present within the layers of the visual cortex. Neural networks are trained on input vectors and are altered by internal variations during the training process. The input and internal modifications represent the processing of exogenous and endogenous signals respectively in the visual cortex. As internal variations are modified in deep neural networks

6588-529: The history of art criticism came in 1910 when psychoanalyst Sigmund Freud published a book on the artist Leonardo da Vinci , in which he used Leonardo's paintings to interrogate the artist's psyche and sexual orientation. Freud inferred from his analysis that Leonardo was probably homosexual . In 1914 Freud published a psychoanalytical interpretation of Michelangelo's Moses ( Der Moses des Michelangelo ). He published this work shortly after reading Vasari's Lives . For unknown reasons, he originally published

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6696-442: The history of art, focusing on three concepts. Firstly, he attempted to study art using psychology, particularly by applying the work of Wilhelm Wundt . He argued, among other things, that art and architecture are good if they resemble the human body. For example, houses were good if their façades looked like faces. Secondly, he introduced the idea of studying art through comparison. By comparing individual paintings to each other, he

6804-410: The history of art—or the study of a specific type of objects created in the past. Traditionally, the discipline of art history emphasized painting, drawing, sculpture, architecture, ceramics and decorative arts; yet today, art history examines broader aspects of visual culture , including the various visual and conceptual outcomes related to an ever-evolving definition of art. Art history encompasses

6912-406: The identification of denoted meaning —the recognition of a visual sign, and the connoted meaning —the instant cultural associations that come with recognition. The main concern of the semiotic art historian is to come up with ways to navigate and interpret connoted meaning. Semiotic art history seeks to uncover the codified meaning or meanings in an aesthetic object by examining its connectedness to

7020-580: The image has too much high frequency information. The generated images can be greatly improved by including a prior or regularizer that prefers inputs that have natural image statistics (without a preference for any particular image), or are simply smooth. For example, Mahendran et al. used the total variation regularizer that prefers images that are piecewise constant. Various regularizers are discussed further in Yosinski et al. An in-depth, visual exploration of feature visualization and regularization techniques

7128-427: The image is observed by the viewer. It is only after acknowledging this that meaning can become opened up to other possibilities such as feminism or psychoanalysis. Aspects of the subject which have come to the fore in recent decades include interest in the patronage and consumption of art, including the economics of the art market, the role of collectors, the intentions and aspirations of those commissioning works, and

7236-911: The inherent simplicity of the coding. Another contributing factor could be that unary coding provides a certain degree of error correction. There is research and development into physical artificial neurons – organic and inorganic. For example, some artificial neurons can receive and release dopamine ( chemical signals rather than electrical signals) and communicate with natural rat muscle and brain cells , with potential for use in BCIs / prosthetics . Low-power biocompatible memristors may enable construction of artificial neurons which function at voltages of biological action potentials and could be used to directly process biosensing signals , for neuromorphic computing and/or direct communication with biological neurons . Organic neuromorphic circuits made out of polymers , coated with an ion-rich gel to enable

7344-468: The input x 0 {\displaystyle x_{0}} is assigned the value +1, which makes it a bias input with w k 0 = b k {\displaystyle w_{k0}=b_{k}} . This leaves only m {\displaystyle m} actual inputs to the neuron: x 1 {\displaystyle x_{1}} to x m {\displaystyle x_{m}} . The output of

7452-460: The internet in 2015 thanks to Google's DeepDream program. The idea dates from early in the history of neural networks, and similar methods have been used to synthesize visual textures. Related visualization ideas were developed (prior to Google's work) by several research groups. After Google published their techniques and made their code open-source , a number of tools in the form of web services, mobile applications, and desktop software appeared on

7560-413: The internet or by other means, has transformed the study of many types of art, especially those covering objects existing in large numbers which are widely dispersed among collections, such as illuminated manuscripts and Persian miniatures , and many types of archaeological artworks. Concurrent to those technological advances, art historians have shown increasing interest in new theoretical approaches to

7668-493: 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 load of their simulations. It was previously commonly seen in multilayer perceptrons . However, recent work has shown sigmoid neurons to be less effective than rectified linear neurons. The reason

7776-570: The manifestation of parallel events or circumstances reflecting this governing dynamic. He argued that a collective unconscious and archetypal imagery were detectable in art. His ideas were particularly popular among American Abstract expressionists in the 1940s and 1950s. His work inspired the surrealist concept of drawing imagery from dreams and the unconscious. Jung emphasized the importance of balance and harmony. He cautioned that modern humans rely too heavily on science and logic and would benefit from integrating spirituality and appreciation of

7884-453: The market to enable users to transform their own photos. The software is designed to detect faces and other patterns in images, with the aim of automatically classifying images. However, once trained, the network can also be run in reverse, being asked to adjust the original image slightly so that a given output neuron (e.g. the one for faces or certain animals) yields a higher confidence score. This can be used for visualizations to understand

7992-492: The most important twentieth-century art historians, including Ernst Gombrich , received their degrees at Vienna at this time. The term "Second Vienna School" (or "New Vienna School") usually refers to the following generation of Viennese scholars, including Hans Sedlmayr , Otto Pächt, and Guido Kaschnitz von Weinberg. These scholars began in the 1930s to return to the work of the first generation, particularly to Riegl and his concept of Kunstwollen , and attempted to develop it into

8100-455: The nature of artworks as objects. Thing theory , actor–network theory , and object-oriented ontology have played an increasing role in art historical literature. The making of art, the academic history of art, and the history of art museums are closely intertwined with the rise of nationalism. Art created in the modern era, in fact, has often been an attempt to generate feelings of national superiority or love of one's country . Russian art

8208-449: The network weights, the weights are held fixed and the input is adjusted. For example, an existing image can be altered so that it is "more cat-like", and the resulting enhanced image can be again input to the procedure. This usage resembles the activity of looking for animals or other patterns in clouds. Applying gradient descent independently to each pixel of the input produces images in which adjacent pixels have little relation and thus

8316-478: The object. Many art historians use critical theory to frame their inquiries into objects. Theory is most often used when dealing with more recent objects, those from the late 19th century onward. Critical theory in art history is often borrowed from literary scholars and it involves the application of a non-artistic analytical framework to the study of art objects. Feminist , Marxist , critical race , queer and postcolonial theories are all well established in

8424-423: The output image reflect these changes. This specific manipulation demonstrates how inner brain mechanisms are analogous to internal layers of neural networks. Internal noise level modifications represent how hallucinogens omit external sensory information leading internal preconceived conceptions to strongly influence visual perception. The dreaming idea can be applied to hidden (internal) neurons other than those in

8532-499: The output of the neuron is y ( t + 1 ) = 1 {\displaystyle y(t+1)=1} if the number of firing excitatory inputs is at least equal to the threshold, and no inhibitory inputs are firing; y ( t + 1 ) = 0 {\displaystyle y(t+1)=0} otherwise. Each output can be the input to an arbitrary number of neurons, including itself (i.e., self-loops are possible). However, an output cannot connect more than once with

8640-415: The output, which allows exploration of the roles and representations of various parts of the network. It is also possible to optimize the input to satisfy either a single neuron (this usage is sometimes called Activity Maximization) or an entire layer of neurons. While dreaming is most often used for visualizing networks or producing computer art, it has recently been proposed that adding "dreamed" inputs to

8748-497: The philosophy of art (aesthetics) often hinders this inquiry. Art of Central Asia Art of East Asia Art of South Asia Art of Southeast Asia Art of Europe Art of Africa Art of the Americas Art of Oceania Art history is an interdisciplinary practice that analyzes the various factors—cultural, political, religious, economic or artistic—which contribute to visual appearance of

8856-422: The piece. Proper analysis of pigments used in paint is now possible, which has upset many attributions. Dendrochronology for panel paintings and radio-carbon dating for old objects in organic materials have allowed scientific methods of dating objects to confirm or upset dates derived from stylistic analysis or documentary evidence. The development of good color photography, now held digitally and available on

8964-555: The political and economic climates in which the art was created. Linda Nochlin 's essay " Why Have There Been No Great Women Artists? " helped to ignite feminist art history during the 1970s and remains one of the most widely read essays about female artists. This was then followed by a 1972 College Art Association Panel, chaired by Nochlin, entitled "Eroticism and the Image of Woman in Nineteenth-Century Art". Within

9072-504: The reactions of contemporary and later viewers and owners. Museum studies , including the history of museum collecting and display, is now a specialized field of study, as is the history of collecting. Scientific advances have made possible much more accurate investigation of the materials and techniques used to create works, especially infra-red and x-ray photographic techniques which have allowed many underdrawings of paintings to be seen again, including figures that had been removed from

9180-461: The real emphasis in the study of art should be the views of the learned beholder and not the viewpoint of the artist. Winckelmann's writings thus were the beginnings of art criticism. His two most notable works that introduced the concept of art criticism were Gedanken über die Nachahmung der griechischen Werke in der Malerei und Bildhauerkunst , published in 1755, shortly before he left for Rome ( Fuseli published an English translation in 1765 under

9288-427: The research concentrated (and still does) on strictly feed-forward networks because of the smaller difficulty they present. One important and pioneering artificial neural network that used the linear threshold function was the perceptron , developed by Frank Rosenblatt . This model already considered more flexible weight values in the neurons, and was used in machines with adaptive capabilities. The representation of

9396-472: The study of objects created by different cultures around the world and throughout history that convey meaning, importance or serve usefulness primarily through visual representations. As a discipline, art history is distinguished from art criticism , which is concerned with establishing a relative artistic value for individual works with respect to others of comparable style or sanctioning an entire style or movement; and art theory or " philosophy of art ", which

9504-1025: The sum is often added to a term known as a bias (loosely corresponding to the threshold potential ), before being passed through a nonlinear function known as an activation function . Depending on the task, these functions could have a sigmoid shape (e.g. for binary classification ), but they may also take the form of other nonlinear functions, piecewise linear functions, or step functions . They are also often monotonically increasing , continuous , differentiable , and bounded . 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 threshold function has inspired building logic gates referred to as threshold logic; applicable to building logic circuits resembling brain processing. For example, new devices such as memristors have been extensively used to develop such logic. The artificial neuron activation function should not be confused with

9612-552: The theories of Riegl, but became eventually more preoccupied with iconography, and in particular with the transmission of themes related to classical antiquity in the Middle Ages and Renaissance. In this respect his interests coincided with those of Warburg, the son of a wealthy family who had assembled a library in Hamburg, devoted to the study of the classical tradition in later art and culture. Under Saxl's auspices, this library

9720-449: The threshold values as a bias term was introduced by Bernard Widrow in 1960 – see ADALINE . 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 gradient descent and other optimization algorithms for the adjustment of the weights. Neural networks also started to be used as

9828-413: The threshold. This function is used in perceptrons , and appears in many other models. It performs a division of the space of inputs by a hyperplane . It is specially useful in the last layer of a network, intended for example to perform binary classification of the inputs. In this case, the output unit is simply the weighted sum of its inputs, plus a bias term. A number of such linear neurons perform

9936-617: The title Reflections on the Painting and Sculpture of the Greeks ), and Geschichte der Kunst des Altertums ( History of Art in Antiquity ), published in 1764 (this is the first occurrence of the phrase 'history of art' in the title of a book). Winckelmann critiqued the artistic excesses of Baroque and Rococo forms, and was instrumental in reforming taste in favor of the more sober Neoclassicism . Jacob Burckhardt (1818–1897), one of

10044-584: The training set can improve training times for abstractions in Computer Science. The DeepDream model has also been demonstrated to have application in the field of art history . DeepDream was used for Foster the People 's music video for the song " Doing It for the Money ". In 2017, a research group out of the University of Sussex created a Hallucination Machine , applying the DeepDream algorithm to

10152-803: The unconscious realm. His work not only triggered analytical work by art historians but became an integral part of art-making. Jackson Pollock , for example, famously created a series of drawings to accompany his sessions with his Jungian analyst, Joseph Henderson. Henderson, who later published the drawings in a text devoted to Pollock's sessions, realized how powerful the drawings were as a therapeutic tool. The legacy of psychoanalysis and analytical psychology in art history has been profound, and extends beyond Freud and Jung. The prominent feminist art historian Griselda Pollock, for example, draws upon psychoanalysis both in her reading into contemporary art and in her rereading of modernist art. With Griselda Pollock 's reading of French feminist psychoanalysis and in particular

10260-449: The vocabulary that continues to be used in the 21st century by art historians. "Iconography"—with roots meaning "symbols from writing" refers to subject matter of art derived from written sources—especially scripture and mythology. "Iconology" is a broader term that referred to all symbolism, whether derived from a specific text or not. Today art historians sometimes use these terms interchangeably. Panofsky, in his early work, also developed

10368-567: The widely used activation functions prior to 2011, i.e., the logistic sigmoid (which is inspired by probability theory ; see logistic regression ) and its more practical counterpart, the hyperbolic tangent . 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: f ( x ) = { x if  x > 0 ,

10476-468: The writings of Julia Kristeva and Bracha L. Ettinger , as with Rosalind Krauss's readings of Jacques Lacan and Jean-François Lyotard and Catherine de Zegher's curatorial rereading of art, Feminist theory written in the fields of French feminism and Psychoanalysis has strongly informed the reframing of both men and women artists in art history. During the mid-20th century, art historians embraced social history by using critical approaches. The goal

10584-484: Was Michelangelo . Vasari's ideas about art were enormously influential, and served as a model for many, including in the north of Europe Karel van Mander 's Schilder-boeck and Joachim von Sandrart 's Teutsche Akademie . Vasari's approach held sway until the 18th century, when criticism was leveled at his biographical account of history. Scholars such as Johann Joachim Winckelmann (1717–1768) criticized Vasari's "cult" of artistic personality, and they argued that

10692-442: Was able to make distinctions of style. His book Renaissance and Baroque developed this idea, and was the first to show how these stylistic periods differed from one another. In contrast to Giorgio Vasari , Wölfflin was uninterested in the biographies of artists. In fact he proposed the creation of an "art history without names." Finally, he studied art based on ideas of nationhood . He was particularly interested in whether there

10800-545: Was an inherently "Italian" and an inherently " German " style. This last interest was most fully articulated in his monograph on the German artist Albrecht Dürer . Contemporaneous with Wölfflin's career, a major school of art-historical thought developed at the University of Vienna . The first generation of the Vienna School was dominated by Alois Riegl and Franz Wickhoff , both students of Moritz Thausing , and

10908-535: Was characterized by a tendency to reassess neglected or disparaged periods in the history of art. Riegl and Wickhoff both wrote extensively on the art of late antiquity , which before them had been considered as a period of decline from the classical ideal. Riegl also contributed to the revaluation of the Baroque. The next generation of professors at Vienna included Max Dvořák , Julius von Schlosser , Hans Tietze, Karl Maria Swoboda, and Josef Strzygowski . A number of

11016-703: Was developed into a research institute, affiliated with the University of Hamburg , where Panofsky taught. Warburg died in 1929, and in the 1930s Saxl and Panofsky, both Jewish, were forced to leave Hamburg. Saxl settled in London, bringing Warburg's library with him and establishing the Warburg Institute . Panofsky settled in Princeton at the Institute for Advanced Study . In this respect they were part of an extraordinary influx of German art historians into

11124-408: Was published more recently. The cited resemblance of the imagery to LSD - and psilocybin -induced hallucinations is suggestive of a functional resemblance between artificial neural networks and particular layers of the visual cortex. Neural networks such as DeepDream have biological analogies providing insight into brain processing and the formation of consciousness. Hallucinogens such as DMT alter

11232-496: Was read avidly by Johann Wolfgang von Goethe and Friedrich Schiller , both of whom began to write on the history of art, and his account of the Laocoön group occasioned a response by Lessing . The emergence of art as a major subject of philosophical speculation was solidified by the appearance of Immanuel Kant 's Critique of Judgment in 1790, and was furthered by Hegel 's Lectures on Aesthetics . Hegel's philosophy served as

11340-416: Was refined by scholars such as T. J. Clark , Otto Karl Werckmeister  [ de ] , David Kunzle, Theodor W. Adorno , and Max Horkheimer . T. J. Clark was the first art historian writing from a Marxist perspective to abandon vulgar Marxism . He wrote Marxist art histories of several impressionist and realist artists, including Gustave Courbet and Édouard Manet . These books focused closely on

11448-537: Was the Threshold Logic Unit (TLU), or Linear Threshold Unit, first proposed by Warren McCulloch and Walter Pitts in 1943 in A logical calculus of the ideas immanent in nervous activity . The model was specifically targeted as a computational model of the "nerve net" in the brain. As an activation function, it employed a threshold, equivalent to using the Heaviside step function . Initially, only

11556-419: Was the audience?, Who were their disciples?, What historical forces shaped the artist's oeuvre and how did he or she and the creation, in turn, affect the course of artistic, political and social events? It is, however, questionable whether many questions of this kind can be answered satisfactorily without also considering basic questions about the nature of art. The current disciplinary gap between art history and

11664-462: Was to show how art interacts with power structures in society. One such critical approach was Marxism. Marxist art history attempted to show how art was tied to specific classes, how images contain information about the economy, and how images can make the status quo seem natural ( ideology ). [1] Marcel Duchamp and the Dada Movement jump-started the anti-art style. German artists, upset by

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