Traditional theories of associative learning have found no place for the possibility that an individual's perception of events might change as a result of experience. Evidence for the reality of perceptual learning has come from procedures unlike those studied by learning theorists. The work reviewed in this book shows that learned changes in perceptual organization can in fact be demonstrated, even in experiments using procedures (such as conditioning and simple discrimination learning) which form the basis of associative theories. These results come from procedures that have been the focus of detailed theoretical and empirical analysis; and from this analysis emerges an outline of the mechanisms responsible. Some of these are associative, others require the addition of nonassociative mechanisms to the traditional theory. The result is an extended version of associative theory which, it is argued, will be relevant not only to the experimental procedures discussed in this book but to the entire range of instances of perceptual learning. For psychologists interested in the basic mechanisms of conditioning, perception, and learning, this volume provides an up-to-date, critical review of the field.

Rather than focusing on the contributions of theoretical physicists to the understanding of the subatomic world and of the beginning of the universe - as most popular science books on particle physics do - this book is different in that, firstly, the main focus is on machine inventors and builders and, secondly, particle accelerators are not only described as discovery tools but also for their contributions to tumour diagnosis and therapy. The characters of well-known (e.g. Ernest Lawrence) and mostly unknown actors (e.g. Nicholas Christofilos) are outlined, including many colourful quotations. The overall picture supports the author's motto: "Physics is beautiful and useful". Advance appraisal: "Accelerators go all the way from the unique and gargantuan Large Hadron Collider to thousands of smaller versions in hospitals and industry. Ugo Amaldi has experience across the range. He has worked at CERN and has for many years been driving the application of accelerators in medicine. This is a must-read introduction to this frontier of modern technology, written beautifully by a world expert." Frank Close, Professor of Physics at Oxford University author of "The Infinity Puzzle" "This book should be read by school teachers and all those interested in the exploration of the microcosm and its relation to cosmology, and in the use of accelerators for medical applications. With a light hand and without formulae the autho r easily explains complicated matters, spicing up the text with amusing historical anecdotes. His reputation as an outstanding scientist in all the fields treated guarantees high standards." Herwig Schopper, former CERN Director General author of "LEP - The Lord of the Collider Rings at CERN" "This book tells the story of modern physics with an unusual emphasis on the machine-builders who made it all possible, and their machines. Learning to accelerate particles has enabled physicists to probe the subatomic world and gain a deeper understanding of the cosmos. It has also brought numerous benefits to medicine, from the primitive X-ray machines of over a century ago to today's developments in hadron therapy for cancer. Amaldi tells this story in a most fascinating way." Edward Witten, Professor of Mathematical Physics at the Institute for Advanced Study in Princeton; Fields Medal (1990)