ABSTRACT
The immediate texture discrimination of textures with isodipole statistics is one such attempt to study "bottom-up" processes free from the enigmatic problems of memory, semantics, and the many "top-down" processes that together are often called Gestalt organization and that interfere with the "bottom-up" processes in unknown ways. The existence of indistinguishable texture pairs with identical second-order statistics suggests that the preattentive texture discrimination system cannot globally compute statistical parameters of third or higher order! The fact that only the simplest first-order statistical parameters of textons contribute to texture discrimination points to a basically local process. Thus, preattentive texture discrimination is mediated either by local texton differences or by differences in the density of similar textons. Even though focal attention to local texture elements enables detection of the positional relationship between textons, preattentive attention during texture discrimination permits only detection of the presence of certain textons.
