My interest in perception started with the teaching of Professor Sir Frederic Bartlett, FRS, and was encouraged by Professor O. L. Zangwill, at Cambridge University.
I would like to thank particularly Dr Stuart Anstis, and my other colleagues and students who have discussed the problems of this book with me, pointed out errors, and helped with experiments. I have benefited by the personal generosity of many people in the United States, especially: the late H.-L. Teuber, the late Warren McCulloch, and F. Nowell Jones. The book was largely written during a visit to Professor Jones’s department at UCLA.
I would like to thank Mrs Audrey Besterman and Miss Mary Waldron for drawing the majority of the diagrams and the Illustrations Research Service, London, for collecting the colour plates used.
Acknowledgement is due to the following for illustrations: 1.3 C. E. Osgood and Oxford University Press; 2.3 The British Museum; 2.5, 7.1 The Royal Society; 2.6 The Bodleian Library; 3.1 G. L. Walls and Cranbrook Institute of Science Bulletin; 3.2 M. Rudwick; 3.3 V. B. Wigglesworth, Methuen & Co., Ltd, and John Wiley and Sons, Inc.; 3.4, 3.5 R. L. Gregory, H. E. Ross, N. Moray and Nature; 3.9 redrawn from J. G. Sivak (1976) Vision Research, Vol. 16, pp. 531–4, copyright 1976 Elsevier Science Ltd., The Boulevard, Langford Lane, Kidlington OX5 1GB, UK; 3.10 T. C. Ruch, J. F. Fulton, and W. B. Saunders Co.; 3.14 R. M. Pritchard and Quarterly Journal of Experimental Psychology; 4.2 W. Penfield, T. Rasmussen and The Macmillan Co., New York; 4.4 The British Broadcasting Corporation; 4.7, 4.8 D. H. Hubel, T. H. Wiesel and the Journal of Physiology; 5.6 H. K. Hartline and Academic Press, Inc.; 6.2, 10.19 The Mansell Collection; 6.4 R. L. Gregory, O. L. Zangwill, and Quarterly Journal of Experimental Psychology; 6.9 A. Michotte, Methuen & Co. Ltd., and Basic Books, Inc.; 7.3 W. D. Wright and Henry Kimpton; 7.4 S. Hecht, C. Murchisson, and Clark University Press; 8.4, 8.5 K. U. and W. M. Smith and W. B. Smith and W. B. Saunders Co.; 8.6 I. Kohler and Scientific American; 8.7 J. Allen Cash; 8.8, 8.9 R. L. Gregory, J. G. Wallace, and Experimental Psychology Society; 8.11 R. L. Franz and Scientific American, photo by David Linton; 8.13 William Vandivert and Scientific American; 9.3 John Freeman; 9.5 Bibliothèque de l’lnstitut de France; 9.6 by courtesy of the Trustees of the National Gallery, London; 9.7 Drawings Collection, Royal Institute of British Architects; 9.10, 9.11, 9.12 Punch; 9.13 Eastern Daily Press, Norwich; 9.16, 10.15 Derrick Witty; 9.18 J. J. Gibson, Allen & Unwin Ltd., and Houghton Mifflin Company; 10.14 Rania Massourides.
R.L.G.