PREATTENTIVE OBJECT FILES - SHAPELESS BUNDLES OF BASIC FEATURES

A considerable body of recent evidence shows that preattentive process es can carve visual input into candidate objects. Borrowing and modify ing terminology from Kahneman & Treisman (1984), this paper investigat es the properties of these preattentive object files. Experiments 1-3 show that preattentive object files are loose collections of basic fea tures. Thus, we can know preattentively that an object has the attribu tes ''red'' and ''vertical'' and yet have no idea if any part of the o bject is red ann vertical. Experiment 4 shows that some information ab out the structure of an object is available preattentively, but Experi ments 5-12 search for and fail to find any preattentive representation of overall shape. Appreciation of the overall shape of an object appe ars to require the binding together of local form features-a process t hat requires attention. Copyright (C) 1996 Elsevier Science Ltd