In this work, Alain Berthoz examines the psychology of decision-making, based on his conception of the human brain not as a calculator or compiler but as a simulator of action. Instead of considering the process of decision-making as a rational one, based on logical tools, he regards it as the fundamental property of the nervous system, its goal being to prepare, command and control actions. It is within this framework that he describes the pathologies of decision-making (agnosia, aphasia, simultan-agnosia, obsessions, etc.). The primordial decision — to capture or flee — is vital, for it defines every living creature as both predator and prey. This decision involves the body — and others — as well as movement and balance. In a chapter that overturns much received knowledge, he describes the existence, within each one of us, of a double that often appears in dreams and that we constantly address, particularly to encourage or stimulate ourselves. Berthoz shows how perception is essentially a decision. Perceiving is not just a question of combining and pondering; it is also one of selecting and deciding, and of choosing — out of a mass of available information — what is pertinent, in function of the action envisaged. Moreover, it is a question of removing ambiguities, choosing between competing forms, and resolving conflicts of the senses. Berthoz concludes by proposing a “physiology of preference”. Not only is perceiving a form of decision-making, but so is memory. Memorising always concerns making a choice, and forgetfulness is always selective.
In this book, the author continues his enquiry into the brain as gambler — and shows that to decide is to predict.

Alain Berthoz teaches physiology of action and perception at the Collège de France. He is the author of The Sense of Movement.