4 Castelo-Branco, M. et al. (2000) Neural synchrony correlates with surface segregation rules. Nature 405, 685-689 5 Singer, W. (2001) Consciousness and the binding problem. Ann. N. Y. Acad. Sci. 929, 123-146 6 Singer, W. (2003) Synchronization, binding and expectancy. In The Handbook of Brain Theory and Neural Networks (Arbib, M. A., ed. ), pp. 1136-1143, MIT Press 7 Robertson, L. C. (2003) Binding, spatial attention and perceptual awareness. Nat. Rev. Neurosci. 4, 93-102 8 Humphreys, G. W. (2003) Conscious visual representations built from multiple binding processes: evidence from neurophysiology. Prog. Brain Res. 142, 243-255 9 Ursino, M. et al. (2003) Binding and segmentation of multiple objects through neural oscillators inhibited by contour information. Biol. Cybern. 89, 56-70 10 Bertrand, O. and Tallon-Baudry, C. (2000) Oscillatory gamma activity in humans: a possible role for object representation. Int. J. Psychophysiol. 38, 21 1-223 11 Muller, M. M. et al. (2000) Modulation of induced gamma band activity in the human EEG by attention and visual information processing. Int. J. Psychophysiol. 38, 283-299 12 Gruber, T. et al. (2002) Modulation of induced gamma band responses in a perceptual learning task in the human EEG. J. Cogn. Neurosci. 14, 732-744 13 Billock, V. A. et al. (2001) Perception of forbidden colors in retinally stabilized equiluminant images: an indication of softwired cortical color opponency? J. Opt. Soc. Am. A. Opt. Image Sci. Vis. 18, 2398-2403 14 Crane, H. D. (1994) The Purkinje image eyetracker, image stabiliz-ation, and related forms of stimulus manipulation. In Visual Science and Engineering (Kelly, D. H., ed. ), pp. 15-89, Dekker 15 Grossberg, S. and Wyse, L. (1992) Figure-ground separation of connected scenic ﬁgures: boundaries, ﬁlling-in and opponent proces-sing. In Neural Networks for Vision and Image Processing (Carpenter, G. A. and Grossberg, S., eds), pp. 161-194, MIT Press 16 Levine, D. S. (2000) Introduction to Neural and Cognitive Modeling, Erlbaum 17 Terman, D. and Wang, D. L. (1995) Global competition and local cooperation in a network of neural oscillators. Physica D. 81, 148-176 18 Marr, D. et al. (1978) Analysis of a cooperative stereo algorithm. Biol. Cybern. 28, 223-239 19 Ditchburn, R. W. (1973) Eye movements and Visual Perception, Clarendon 20 Ingling, C. R. Jr and Martinez-Uriegas, E. (1985) The spatiotemporal properties of the r-g X-cell channel. Vision Res. 25, 33-38 21 Merigan, W. H. and Maunsell, J. H. R. (1993) How parallel are the primate visual pathways? Annu. Rev. Neurosci. 16, 369-402 22 Ingling, C. R. Jr and Grigsby, S. S. (1990) Perceptual correlates of magnocellular and parvocellular channels: seeing form and depthin afterimages. Vision Res. 30, 823-828 23 Benardete, E. A. et al. (1992) Contrast gain control in the primate retina: P cells are not X-like, some M-cells are. Vis. Neurosci. 8, 483-486 24 Coppola, D. and Purves, D. (1996) The extraordinarily rapid disappearance of entopic images. Proc. Natl. Acad. Sci. U. S. A. 93, 8001-800425 Weintraub, D. J. (1964) Successive contrast involving luminance and purity alterations of the Ganzfeld. J. Exp. Psychol. 68, 555-562 26 Kelly, D. H. (1981) Disappearance of stabilized chromatic gratings. Science 214, 1257-1258 27 Cohen, H. B. (1961) The effect of contralateral visual stimulation on visibility with stabilized retinal images. Can. J. Psychol. 15, 212-219 28 Pritchard, R. M. et al. (1960) Visual perception approached by the method of stabilized images. Can. J. Psychol. 14, 67-77 29 Pritchard, R. M. (1961) Stabilized images on the retina. Sci. Am. 204, 72-78 30 Davies, P. (1973) The role of central processes in the perception of visual after-images. Br. J. Psychol. 64, 325-338 31 Evans, C. R. (1965) Some studies of pattern perception using a stabilized retinal image. Br. J. Psychol. 56, 121-133 32 Evans, C. R. (1967) Further studies of pattern perception and a stabilized retinal image. Br. J. Psychol. 58, 315-327 33 Cardu, B. et al. (1971) The inﬂuence of peripheral and central factors on the way that stabilized images disappeared. Vision Res. 11, 1337-1343 34 Evans, C. R. and Wells, A. M. (1967) Fragmentation phenomena associated with binocular stabilization. Br. J. Physiol. Opt. 24, 45-50 35 Sacks, O. (1999) Migraine, Vintage Books 36 Hess, R. F. et al. (1990) The puzzle of amblyopia. In Vision: Coding and Efﬁciency (Blakemore, C., ed. ), pp. 267-280, Cambridge University Press 37 Roelfsema, P. R. et al. (1994) Reduced synchronization in the visual cortex of cats with strabismic amblyopia. Eur. J. Neurosci. 6, 1645-1655 38 Lehmann, D. et al. (1965) Changes in patterns of the human electroencephalogram during ﬂuctuations of perception of stabilizedretinal images. Electroencephalogr. Clin. Neurophysiol. 19, 336-343 39 Keesey, U. T. and Nichols, D. J. (1967) Fluctuations in target visibility as related to the occurrence of the alpha component of theelectroencephalogram. Vision Res. 7, 959-977 40 Gregory, R. L. (1977) Vision with isoluminant colour contrast. Perception 6, 113-119 41 Livingstone, M. S. and Hubel, D. H. (1987) Psychophysical evidence for separate channels for perception of form, color, movement and depth. J. Neurosci. 7, 3416-3468 42 Cavanagh, P. (1991) Vision at equiluminance. In Limits of Vision (Kulikowski, J. J. et al., eds), pp. 234-250, CRC Press 43 Mullen, K. T. and Kingdom, F. A. A. (1991) Colour contrast in form perception. In The Perception of Colour (Gouras, P., ed. ), pp. 198-217, CRC Press 44 Buck, S. L. et al. (1977) Initial distinctness and subsequent fading of minimally distinct borders. J. Opt. Soc. Am. 67, 1126-1128 45 Finkel, L. H. and Edelman, G. M. (1989) Integration of distributed cortical systems by reentry: a computer simulation of interactivefunctionally segregated visual areas. J. Neurosci. 9, 3188-3208 46 Schillen, T. B. and Ko ¨nig, P. (1994) Binding by temporal structure in multiple feature domains of an oscillatory neuronal network. Biol. Cybern. 70, 397-405 47 Poggio, T. et al. (1988) Parallel integration in visual modules. Science 242, 436-440 48 Niebur, E. et al. (1993) An oscillation-based model for the neuronal basis of attention. Vision Res. 33, 2789-2802Opinion TRENDS in Neurosciences Vol. 27 No. 2 February 2004 89 www. sciencedirect. com