Visual Memory Exp. Demo by R Sekuler

Visual memory --testing your ability to recognize things you've just seen.

Demos with gratings
Demos with synthetic faces

References
Robert Sekuler
http://people.brandeis.edu/~sekuler/

From Fragments to Objects

From Fragments to Objects : Segmentation and Grouping in Vision (Advances in Psychology (Amsterdam, Netherlands), 130,)-US-
ISBN:0444505067 (Hard cover book)
Shipley, Thomas F. (EDT) /Kellman, Philip J. (EDT) /Publisher:North-Holland Published 2001/12

Contents List
Philosophy and History of Perceptual Unit Formation"object" in perception and cognition, R. Schwartz; Balls of wax and cans of worms - the early history of object perception, M. Atherton; Development: Perceptual unit formation in infancy, M.E. Arterberry; Perceptual units and their mapping with language, B. Landau. Attention: An object substitution theory of visual masking, J.T. Enns, V. Di Lollo; Attention and unit formation - a biased competition account of object-based attention, S.P. Vecera, M. Behrmann. Models of Segmentation and Grouping: Geometric and neural models of object perception, P.J. Kellman et al; Varieties of grouping and its role in determining surface layout, B. Gillam; Amodal completion - a case study in grouping, A.B. Sekuler, R.F. Murray; Perceptual organization as generic object recognition, D.W. Jacobs; Simplicity, regularity, and perceptual interpretations - a structural information approach, R. Van Lier; Computational neural models of spatial integration in perceptual grouping, H. Neumann, E. Mingolla; Part-based representations of visual shape and implications for visual cognition, M. Singh, D.D. Hoffman. Spatiotemporal Segmentation and Grouping: Gaze control for face learning and recognition by humans and machines, J. Henderson et al; The visual interpretation of object and human movement, M. Shiffrar; Contours from apparent motion - a computational theory, W. Prophet et al; Breathing illusions and boundary formation in space-time, N. Bruno; Perception of occluding and occluded objects over time - spatiotemporal segmentation and unit formation, T.F. Shipley, D.W. Cunningham.

Murray, Gold, Bennett, Sekuler (2001)

ECVP 2001 abstract

Perceptually interpolated contours in shape discrimination
R F Murray, J M Gold, P J Bennett, A B Sekuler (Department of Psychology, University of Toronto, 100 St George Street, Toronto, Ontario M5S 3G3, Canada)

Observers use perceptually interpolated contours to perform some shape discrimination tasks, eg illusory and occluded contours to discriminate between Kanizsa squares (Murray et al, 2000 Perception 29 Supplement, 122). Do observers use contours defined only by perceptual grouping? We measured classification images in a task where observers discriminated between patterns made of four inward-facing Ls arranged as the corners of a square. The Ls were perceptually grouped as a square, but produced no illusory contours. Observers did not use whole sides of these grouping-defined squares. Rather, they mainly used the Ls, and were only slightly influenced by the empty regions between the Ls. This is in marked contrast to Murray et al's results with Kanizsa squares. Do observers use illusory contours that do not bound a region of illusory brightness? We measured classification images in a task where observers discriminated between Kanizsa squares defined by two white and two black inducers. These stimuli produced illusory contours, but the illusory square had the same brightness as the background. Observers did not use whole sides of the illusory square. Rather, they mainly used edges of the inducers. We conclude that different types of perceptually interpolated contours are not equally likely to be used to discriminate shapes.