Undergraduate Research Internship Program in this laboratory.  For more information click Here

* What's this work about?  For more information click Here

* To view some neat demos of our experiments, click  Here

* Laboratory Web Site click on  Visual Attention Lab

* For a short description of the Multiple Object Tracking experiments click on:
            Zenon Pylyshyn (2007) Multiple Object Tracking. Scholarpedia, 2(10):3326.


Dr. Pylyshyn's research interests are in:

1) Visual attention and Preattention

The visual system does some things in parallel and some things serially. Not only does the eye move in rapid saccades several times each second, but attention also moves independent of any eye movements (so-called "covert attention scanning"). But a serial process which scans a display requires a mechanism to keep track of which things it has already visited and which things it should scan to. A number of people have referred to this process of keeping track of objects as "marking", but the marking metaphor is misleading because it suggests that we have a "picture" or some other display somewhere in our heads where we can place a marker. Since there are many reasons to refrain from hypothesizing such a pictorial display in the head, we have over the past decade developed an alternative view of how places in the visual field are "marked" or, to use our terminology, they are “FINSTed”.

The theory of indexing has motivated most of our experimental research over the past 8 years and has led to the exploration of a number of new phenomena (e.g. the ability to track several identical visual targets which move independently in random motion, weaving in and out among identical non-targets; the ability to visually separate a subset of items from others by brief location markers), and we have provided an new account of known phenomena, such as many of those arising from studies of "mental imagery" especially when they are superimposed onto visual percepts, of "subitizing" and of the visual stability of our percepts despite eye-movements. The theory has been described in (Pylyshyn, 1989) and a brief summary of the findings have been reported in (Pylyshyn, 1994).   For more on the FINST Visual Index theory and demos of the Multiple Object Tracking paradigm click The Visual Index Theory.

For a quicktime movie demo of Multiple Object Tracking (with occluders) M.O.T. DEMO
* {You need the Apple Quicktime Plugin to view this demo. If you don't have one you can get it free by clicking Download Quicktime}

2) Application of Visual Index Theory to saccadic integration. See lab notes at Chris Currie's ongoing FINSTs and eye movement research report.

3) Studies of Mental Imagery

A number of studies were done some years ago in our laboratory showing that many of the phenomena of mental imagery are a result of subjects' understanding of the imagery task and their tacit knowledge of what happens in real perceptual circumstances (Pylyshyn, 1981). We are now continuing these studies in order to show that the visual system is not involved in mental imagery and, in fact, that "imagery", in the pictorial sense in which it is understood by many psychologists, is not involved in vision either.  (see below for recent references)

4) Applied Research

Applications of spatial indexing theory in the design of interfaces to computers and to communications systems such as involved in teleconferencing and telelearning. This is based on the observation that space and 3D spatial location plays an important role in individuating ideas and in communicating complex ideas. Gestures and pointing (as well as indicating by other means such as acoustically) in order to keep track of separate ideas and relationships is common and aids communication. multimodalcommunication, including gestures, can help widen the psychological communication bandwidth.

5) Theoretical Research

Behind the research on attention, on mental imagery, and on the interaction of vision and cognition, lies a long standing interest in the nature of what is called the "cognitive architecture" of the human cognitive computer (Pylyshyn, 1991). Consequently another line of research has been on theoretical analyses of claims about architectures, whether they are so-called "connectionist" or "analogue" or symbolic. This also brings the empirical research into contact with hypotheses concerning thedecomposibility of the cognitive system or its "modularity". Much of our research bears on the question of whether vision or imagery processes are sensitive to knowledge_i.e. whether they are "cognitively penetrable". The connection of the research to issues of cognitive architecture is described in detail in my books (Pylyshyn, 1984; 2003).


Pylyshyn, Z.W. (1994). Some primitive mechanisms of spatial attention. Cognition, 50, 363-384.
Pylyshyn, Z.W. (1991). The role of cognitive architecture in theories of cognition. In K. VanLehn (Ed.), Architectures for Intelligence. Hillsdale: Lawrence Erlbaum Associates Inc.
Pylyshyn, Z.W. (1989). The role of location indexes in spatial perception: A sketch of the FINST spatial-index model. Cognition, 32, 65-97.
Pylyshyn, Z.W. (1984). Computation and Cognition: Towards a Foundation for Cognitive Science. MIT Press
Pylyshyn, Z.W. (1981). The imagery debate: Analogue media versus tacit knowledge. Psychological Review, 88, 16-45.