The startle response (as a result of a sudden, loud noise, for instance) is a reflex that is wired into the brain at a very basic level. Although everybody will exhibit such a reflex, the strength and quickness of the startle response is modified by a subject's underlying psychoneurological state. Therefore, the nature of this modification is now seen as an accurate, objective measure of very deep neurological processes. This book is the first comprehensive volume devoted to startle modification. It offers a unique overview of the methods, measurement, physiology, and psychology of the phenomenon, particularly modification of the human startle eyeblink. Many of the world's leading investigators in the field have made contributions to this volume. Coverage includes elicitation and recording of startle blink; issues in measurement and quantification; the neurophysiological basis of the basic startle response and its modification by attentional and affective processes; psychological processes underlying short and long lead interval modification (including prepulse inhibition); applications of startle modification to the study of psychopathology, including schizophrenia, affective disorders, and psychopathy and developmental processes; and relationships with ERPs and behavioral measures of information processing.