|
Face Space
Face space is a theoretical idea in psychology such that it is a multidimensional space in which recognizable faces are stored. The representation of faces within this space are according to invariant features of the face itself.Valentine, T. (1991). A unified account of the effects of distinctiveness, inversion, and race in face recognition. The Quarterly Journal of Experimental Psychology, 43(2), 161-204. However, recently it was theoretically demonstrated that faces can be stored in the face space according to their dynamic features as well, and that in this case the resulting space exhibits a twofold structure. The face space framework has been highly influential in recent face processing theory; cited in almost 1000 scientific articles and recently revisited in a special edition of the journal '' Quarterly Journal of Experimental Psychology'' featuring the top 10 ideas that have appeared in the journal's pages.Valentine, T., Lewis, M. B., & Hills, P. J. (2015). Face-space: A un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychology
Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries between the natural and social sciences. Psychologists seek an understanding of the emergent properties of brains, linking the discipline to neuroscience. As social scientists, psychologists aim to understand the behavior of individuals and groups.Fernald LD (2008)''Psychology: Six perspectives'' (pp.12–15). Thousand Oaks, CA: Sage Publications.Hockenbury & Hockenbury. Psychology. Worth Publishers, 2010. Ψ (''psi''), the first letter of the Greek word ''psyche'' from which the term psychology is derived (see below), is commonly associated with the science. A professional practitioner or researcher involved in the discipline is called a psychologist. Some psychologists can also be classified as behavioral or cognitive scientists. Some ps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Face Inversion Effect
The face inversion effect is a phenomenon where identifying inverted (upside-down) faces compared to upright faces is much more difficult than doing the same for non-facial objects. A typical study examining the face inversion effect would have images of the inverted and upright object presented to participants and time how long it takes them to recognise that object as what it actually is (i.e. a picture of a face as a face). The face inversion effect occurs when, compared to other objects, it takes a disproportionately longer time to recognise faces when they are inverted as opposed to upright. Faces are normally processed in the special face-selective regions of the brain, such as the fusiform face area. However, processing inverted faces involves both face-selective regions and additional visual areas such as mid-level visual areas and high-level scene-sensitive and object-sensitive regions of the parahippocampal place area and lateral occipital cortex. There seems to be s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conceptual Space
A conceptual space is a geometric structure that represents a number of quality dimensions, which denote basic features by which concepts and objects can be compared, such as weight, color, taste, temperature, pitch, and the three ordinary spatial dimensions.Kriegeskorte, N., & Kievit, R. A. (2013). Representational geometry: Integrating cognition, computation, and the brain. ''Trends in Cognitive Sciences, 17''(8), 401–412. http://doi.org/10.1016/j.tics.2013.06.007 In a conceptual space, ''points'' denote objects, and ''regions'' denote concepts. The theory of conceptual spaces is a theory about concept learning first proposed by Peter Gärdenfors.Foo, N. (2001). Conceptual Spaces—The Geometry of Thought. ''AI Magazine, 22''(1), 139–140. Retrieved fro/ref> It is motivated by notions such as conceptual Similarity (psychology), similarity and prototype theory. The theory also puts forward the notion that ''natural'' categories are convex regions in conceptual spaces. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eigenface
An eigenface () is the name given to a set of eigenvectors when used in the computer vision problem of human face recognition. The approach of using eigenfaces for recognition was developed by Sirovich and Kirby and used by Matthew Turk and Alex Pentland in face classification. The eigenvectors are derived from the covariance matrix of the probability distribution over the high-dimensional vector space of face images. The eigenfaces themselves form a basis set of all images used to construct the covariance matrix. This produces dimension reduction by allowing the smaller set of basis images to represent the original training images. Classification can be achieved by comparing how faces are represented by the basis set. History The eigenface approach began with a search for a low-dimensional representation of face images. Sirovich and Kirby showed that principal component analysis could be used on a collection of face images to form a set of basis features. These basis image ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principal Component Analysis
Principal component analysis (PCA) is a popular technique for analyzing large datasets containing a high number of dimensions/features per observation, increasing the interpretability of data while preserving the maximum amount of information, and enabling the visualization of multidimensional data. Formally, PCA is a statistical technique for reducing the dimensionality of a dataset. This is accomplished by linearly transforming the data into a new coordinate system where (most of) the variation in the data can be described with fewer dimensions than the initial data. Many studies use the first two principal components in order to plot the data in two dimensions and to visually identify clusters of closely related data points. Principal component analysis has applications in many fields such as population genetics, microbiome studies, and atmospheric science. The principal components of a collection of points in a real coordinate space are a sequence of p unit vectors, where the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multidimensional Scaling
Multidimensional scaling (MDS) is a means of visualizing the level of similarity of individual cases of a dataset. MDS is used to translate "information about the pairwise 'distances' among a set of n objects or individuals" into a configuration of n points mapped into an abstract Cartesian space. More technically, MDS refers to a set of related ordination techniques used in information visualization, in particular to display the information contained in a distance matrix. It is a form of non-linear dimensionality reduction. Given a distance matrix with the distances between each pair of objects in a set, and a chosen number of dimensions, ''N'', an MDS algorithm places each object into ''N''-dimensional space (a lower-dimensional representation) such that the between-object distances are preserved as well as possible. For ''N'' = 1, 2, and 3, the resulting points can be visualized on a scatter plot. Core theoretical contributions to MDS were made by James O. Ramsay of M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caricature
A caricature is a rendered image showing the features of its subject in a simplified or exaggerated way through sketching, pencil strokes, or other artistic drawings (compare to: cartoon). Caricatures can be either insulting or complimentary, and can serve a political purpose, be drawn solely for entertainment, or for a combination of both. Caricatures of politicians are commonly used in editorial cartoons, while caricatures of movie stars are often found in entertainment magazines. In literature, a ''caricature'' is a distorted representation of a person in a way that exaggerates some characteristics and oversimplifies others. Etymology The term is derived for the Italian ''caricare''—to charge or load. An early definition occurs in the English doctor Thomas Browne's ''Christian Morals'', published posthumously in 1716. with the footnote: Thus, the word "caricature" essentially means a "loaded portrait". Until the mid 19th century, it was commonly and mistakenly beli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euclidean Vector
In mathematics, physics, and engineering, a Euclidean vector or simply a vector (sometimes called a geometric vector or spatial vector) is a geometric object that has magnitude (or length) and direction. Vectors can be added to other vectors according to vector algebra. A Euclidean vector is frequently represented by a ''directed line segment'', or graphically as an arrow connecting an ''initial point'' ''A'' with a ''terminal point'' ''B'', and denoted by \overrightarrow . A vector is what is needed to "carry" the point ''A'' to the point ''B''; the Latin word ''vector'' means "carrier". It was first used by 18th century astronomers investigating planetary revolution around the Sun. The magnitude of the vector is the distance between the two points, and the direction refers to the direction of displacement from ''A'' to ''B''. Many algebraic operations on real numbers such as addition, subtraction, multiplication, and negation have close analogues for vectors, operation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative (photography)
In photography, a negative is an image, usually on a strip or sheet of transparent plastic film, in which the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest. This reversed order occurs because the extremely light-sensitive chemicals a camera film must use to capture an image quickly enough for ordinary picture-taking are darkened, rather than bleached, by exposure to light and subsequent photographic processing. In the case of color negatives, the colors are also reversed into their respective complementary colors. Typical color negatives have an overall dull orange tint due to an automatic color-masking feature that ultimately results in improved color reproduction. Negatives are normally used to make positive prints on photographic paper by projecting the negative onto the paper with a photographic enlarger or making a contact print. The paper is also darkened in proportion to its exposure to light, so a second reversal resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conceptual Space
A conceptual space is a geometric structure that represents a number of quality dimensions, which denote basic features by which concepts and objects can be compared, such as weight, color, taste, temperature, pitch, and the three ordinary spatial dimensions.Kriegeskorte, N., & Kievit, R. A. (2013). Representational geometry: Integrating cognition, computation, and the brain. ''Trends in Cognitive Sciences, 17''(8), 401–412. http://doi.org/10.1016/j.tics.2013.06.007 In a conceptual space, ''points'' denote objects, and ''regions'' denote concepts. The theory of conceptual spaces is a theory about concept learning first proposed by Peter Gärdenfors.Foo, N. (2001). Conceptual Spaces—The Geometry of Thought. ''AI Magazine, 22''(1), 139–140. Retrieved fro/ref> It is motivated by notions such as conceptual Similarity (psychology), similarity and prototype theory. The theory also puts forward the notion that ''natural'' categories are convex regions in conceptual spaces. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Distribution
In statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is : f(x) = \frac e^ The parameter \mu is the mean or expectation of the distribution (and also its median and mode), while the parameter \sigma is its standard deviation. The variance of the distribution is \sigma^2. A random variable with a Gaussian distribution is said to be normally distributed, and is called a normal deviate. Normal distributions are important in statistics and are often used in the natural and social sciences to represent real-valued random variables whose distributions are not known. Their importance is partly due to the central limit theorem. It states that, under some conditions, the average of many samples (observations) of a random variable with finite mean and variance is itself a random variable—whose distribution converges to a normal dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Tendency
In statistics, a central tendency (or measure of central tendency) is a central or typical value for a probability distribution.Weisberg H.F (1992) ''Central Tendency and Variability'', Sage University Paper Series on Quantitative Applications in the Social Sciences, p.2 Colloquially, measures of central tendency are often called '' averages.'' The term ''central tendency'' dates from the late 1920s. The most common measures of central tendency are the arithmetic mean, the median, and the mode. A middle tendency can be calculated for either a finite set of values or for a theoretical distribution, such as the normal distribution. Occasionally authors use central tendency to denote "the tendency of quantitative data to cluster around some central value."Upton, G.; Cook, I. (2008) ''Oxford Dictionary of Statistics'', OUP (entry for "central tendency")Dodge, Y. (2003) ''The Oxford Dictionary of Statistical Terms'', OUP for International Statistical Institute. (entry for "c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
