Pylyshyn on Vision & Cognition: BBS Call for Commentators

Below is the abstract of a forthcoming BBS target article on: IS VISION CONTINUOUS WITH COGNITION? THE CASE FOR COGNITIVE IMPENETRABILITY OF VISUAL PERCEPTION by Zenon Pylyshyn This article has been accepted for publication in Behavioral and Brain Sciences (BBS), an international, interdisciplinary journal providing Open Peer Commentary on important and controversial current research in the biobehavioral and cognitive sciences. Commentators must be BBS Associates or nominated by a BBS Associate. To be considered as a commentator for this article, to suggest other appropriate commentators, or for information about how to become a BBS Associate, please send EMAIL to: bbs(a)cogsci.soton.ac.uk or write to: Behavioral and Brain Sciences Department of Psychology University of Southampton Highfield, Southampton SO17 1BJ UNITED KINGDOM http://www.princeton.edu/~harnad/bbs/ http://www.cogsci.soton.ac.uk/bbs/ ftp://ftp.princeton.edu/pub/harnad/BBS/ ftp://ftp.cogsci.soton.ac.uk/pub/bbs/ gopher://gopher.princeton.edu:70/11/.libraries/.pujournals If you are not a BBS Associate, please send your CV and the name of a BBS Associate (there are currently over 10,000 worldwide) who is familiar with your work. All past BBS authors, referees and commentators are eligible to become BBS Associates. To help us put together a balanced list of commentators, please give some indication of the aspects of the topic on which you would bring your areas of expertise to bear if you were selected as a commentator. An electronic draft of the full text is available for inspection with a WWW browser, anonymous ftp or gopher according to the instructions that follow after the abstract. ____________________________________________________________________ IS VISION CONTINUOUS WITH COGNITION? THE CASE FOR COGNITIVE IMPENETRABILITY OF VISUAL PERCEPTION Zenon Pylyshyn Rutgers Center for Cognitive Science Rutgers University Psychology Addition, Busch Campus, New Brunswick, NJ 08903 zenon(a)ruccs.rutgers.edu KEYWORDS: visual processing, modularity, cognitive penatrability, early vision context effects, top down processes, signal detection theory, attention expert perception, perceptual learning, knowledge-based vision, visual agnosia, categorical perception. ABSTRACT: Although the study of visual perception has made more progress in the past 40 years than any other area of cognitive science, there remain major disagreements as to how closely vision is tied to cognition. This paper sets out some of the arguments for both sides (arguments from computer vision, neuroscience, Psychophysics, perceptual learning and other areas of vision science) and defends the position that an important part of visual perception, corresponding to what some people have called early vision, is prohibited from accessing relevant expectations, knowledge and utilities in determining the function it computes - in other words it is cognitively impenetrable. That part of vision is complex and involves top-down interactions that are internal to the early vision system. Its function is to provide a structured representation of the 3-D surfaces of objects sufficient to serve as an index into memory, with somewhat different outputs being made available to other systems such as those dealing with motor control. The paper also addresses certain conceptual and methodological issues raised by this claim, including the use of signal detection theory and event-related potentials to assess cognitive penetration of vision. A distinction is made among several stages in visual processing. These include, in addition to the inflexible early-vision stage, a pre-perceptual attention-allocation stage and a post-perceptual evaluation, selection, and inference stage which accesses long-term memory. These two stages provide the primary ways in which cognition can affect the outcome of visual perception. The paper discusses arguments that have been presented in both computer vision and psychology showing that vision is "intelligent" and involves elements of "problem solving". It is suggested that the cases of apparently intelligent interpretation that are sometimes cited in support of this claim do not show cognitive penetration, but rather they show that certain natural constraints on interpretation, concerned primarily with optical and geometrical properties of the world, have been compiled into the visual system. The paper also examines a number of examples where instructions and "hints" are alleged to affect what is seen. In each case it is concluded that the evidence is more readily assimilated to the view that when cognitive effects are found, they have a locus outside early vision, in such processes as the allocation of focal attention and identification of the stimulus. -------------------------------------------------------------- To help you decide whether you would be an appropriate commentator for this article, an electronic draft is retrievable from the World Wide Web or by anonymous ftp or gopher from the US or UK BBS Archive. Ftp instructions follow below. Please do not prepare a commentary on this draft. Just let us know, after having inspected it, what relevant expertise you feel you would bring to bear on what aspect of the article. The URLs you can use to get to the BBS Archive: http://www.princeton.edu/~harnad/bbs/ http://www.cogsci.soton.ac.uk/bbs/Archive/bbs.pylyshyn.html ftp://ftp.princeton.edu/pub/harnad/BBS/bbs.pylyshyn ftp://ftp.cogsci.soton.ac.uk/pub/bbs/Archive/bbs.pylyshyn gopher://gopher.princeton.edu:70/11/.libraries/.pujournals To retrieve a file by ftp from an Internet site, type either: ftp ftp.princeton.edu or ftp 128.112.128.1 When you are asked for your login, type: anonymous Enter password as queried (your password is your actual userid: yourlogin(a)yourhost.whatever.whatever - be sure to include the "@") cd /pub/harnad/BBS To show the available files, type: ls Next, retrieve the file you want with (for example): get bbs.pylyshyn When you have the file(s) you want, type: quit