1,721,077 research outputs found
Les neurosciences au sein des sciences de la cognition – Vers un naturalisme situé
No full textSarti Alessandro, Monier Cyril. Les neurosciences au sein des sciences de la cognition – Vers un naturalisme situé. In: Intellectica. Revue de l'Association pour la Recherche Cognitive, n°69, 2018/1-2. Les Neurosciences au sein des Sciences de la Cognition entre Neuroenthousiasme et Neuroscepticisme. pp. 7-25
A Gauge Field Model of Modal Completion
No full textPerceptual completion of figures is a basic process revealing the deep architecture of low level vision. In this paper, a complete gauge field Lagrangian is proposed which couples the retinex equation with neurogeometrical models and solves the problem of modal completion, i.e. the pop up of the Kanizsa triangle. Euler–Lagrange equations are derived by variational calculus and numerically solved. Plausible neurophysiological implementations of the particle and field equations are discussed and a model of the interaction between LGN and visual cortex is proposed
The Cortical V1 Transform as a Heterogeneous Poisson Problem
Full text linkReceptive profiles of the primary visual cortex (V1) cortical cells are very heterogeneous and act by differentiating the stimulus image as operators changing from point to point. In this paper we aim to show that the distribution of cells in V1, although not complete to reconstruct the original image, is sufficient to reconstruct the perceived image with subjective constancy. We show that a color constancy image can be reconstructed as the solution of the associated inverse problem, which is a Poisson equation with heterogeneous differential operators. At the neural level the weights of short-range connectivity constitute the fundamental solution of the Poisson problem adapted point by point. A first demonstration of convergence of the result towards homogeneous reconstructions is proposed by means of homogenization techniques
Local and global gestalt laws: A neurally based spectral approach
Full text linkThis letter presents a mathematical model of figure-ground articulation that takes into account both local and global gestalt laws and is compatiblewith the functional architecture of the primary visual cortex (V1). The local gestalt law of good continuation is described by means of suitable connectivity kernels that are derived from Lie group theory and quantitatively compared with long-range connectivity in V1. Global gestalt constraints are then introduced in terms of spectral analysis of a connectivity matrix derived from these kernels. This analysis performs grouping of local features and individuates perceptual units with the highest salience. Numerical simulations are performed, and results are obtained by applying the technique to a number of stimuli
THE CONSTITUTION OF VISUAL PERCEPTUAL UNITS IN THE FUNCTIONAL ARCHITECTURE OF V1
No full textOne of the major challenges in neurobiology is understanding the relationship between spatially structured activity states and the underlying neural circuitry that supports them. From the geometrical point of view the first accurate models of the functiona
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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