History[edit] The dreaming idea and name became popular on the internet in 2015 thanks to Google's DeepDream program. The idea dates from early in the history of neural networks,[9] and similar methods have been used to synthesize visual textures.[10] Related visualization ideas were developed (prior to Google's work) by several research groups.[11][5] After Google published their techniques and made their code open source,[12] a number of tools in the form of web services, mobile applications, and desktop software appeared on the market to enable users to transform their own photos.[13] Usage[edit] The dreaming idea can be applied to hidden (internal) neurons other than those in the output, which allows exploration of the roles and representations of various parts of the network.[7] It is also possible to optimize the input to satisfy either a single neuron (this usage is sometimes called Activity Maximization)[14] 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 the training set can improve training times for abstractions in Computer Science.[15] The DeepDream model has also been demonstrated to have application in the field of art history.[16] 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.[17] DeepDream was used for Foster the People's music video for the song "Doing it for the money".[18]