L'iperbole e il sombrero

Of Hyperboles and Mexican Hats This paper presents three examples from experimental psychology, which show how all human psychological functioning is intrinsically pervaded by “hyperbolic” mechanisms. The starting point is the neuronal wiring of the retina, which wonderfully implements the filtering device imagined by David Marr, a mathematician who argued that the Laplacian operator of a two-dimensional Gaussian is the most satisfactory operator to efficiently detect intensity changes of light (i.e., the “contours of things” in a visual representation, indeed a basic element for our interpretation of the world). This filter is called a “Mexican hat” filter. The second example comes from the segmentation of human speech performed by newborns, and the third concerns processes of social categorization. In all these fields, which represent a cross-section of all human behavior (from very basic perception to social functioning), we find similar processes, aimed at functionally exaggerating differences in order to “make sense” in an otherwise fluctuating world. Results are interpreted as good empirical reasons to consider “hyperbolic” mechanisms as the foundations of all perceptive and interpretative acts