This volume contains the proceedings of a symposium held in St. Vincent, Italy, on August 3-6,1976, entitled "Vigilance II: Relationships Among Theory, Physiological Correlates, and Opera tional Performance." The symposium was sponsored jointly by the Human Factors Panel of the Scientific Affairs Division of NATO and by the Physiology Programs Office of the U.S. Office of Naval Research (Contract N00014-76-C-0722). These sponsorships, and the helpful assistance of Dr. Donald P. Woodward and Dr. John A. Nagay, are gratefully acknowledged. Following the editor's introduction, the papers appear in the order they were given at St. Vincent. In general they are grouped according to the main topical themes of the symposium: keynote ad dress, vehicle operation, monitoring and inspection, physiological correlates, stress effects, individual differences, and theoretical considerations. I must point out, however, that individual papers often overlapped several of these topical areas and thus no defini tive partitioning of the proceedings has been attempted. I wish to acknowledge the many contributions of my colleague, Dr. James O'Hanlon, to both the planning of the symposium and the preparation of the manuscript, and the invaluable role of my wife, Shirley Jean, in making the symposium such a pleasant one for all. In addition, I wish to recognize the countless contributions of Lynda Lee Chilton and Katherine Peimann whose performance in compos ing, typing, and proofing the manuscript is certainly a tribute to human vigilance, and endurance as well.

The function of the vestibular system is not as obvious as those of vision, hearing, touch or smell. Vestibular dysfunction, however, is clearly apparent where lesions are present. It is probably for this reason that the vestibular sense was not discovered until the nineteenth century and that clinicians have continued to playa major role in basic vestibular research right up to the present. The relationship between basic and clinical research is certainly stronger in the vesti bular field than in that of tactile sensation, for instance, as testified by the work of clinicians as MENIERE, BREUER, BARANY, DEKLEIJN and FRENZEL. In this respect the situation is similar in vestibular physiology and in endocrinology, and for the same reason. This second part of the vestibular volume of the Handbook of Sensory Physio logy will be of interest to neurologists, otologists, neurosurgeons, ophthalmologists and physiotherapists on the one hand, and psychologists, physiologists, engineers and aviation specialists on the other. For a full understanding of Part 2, it is necessary to have assimilated the basic anatomy, physiology, and biochemistry of Part 1.

Information analysis centers were developed to help the scientist and practitioner cope with the ever increasing mass of published and unpublished information in a specific field. Their establishment resulted from a further extension of those pressures that had brought about the formation of the specialized primary journal and the abstracting services at the turn of the century. The information analysis center concept was greatly advanced by the 1963 report of the President's Science Advisory Committee Panel on Science Information. This report stated: " . . . scientific interpreters who can collect relevant data, review a field, and distill information in a manner that goes to the heart of a technical situation are more help to the overburdened specialist than is a mere pile of relevant docu ments. " Such specialized information centers are operated in closest possible contact with working scientists in the field. These centers not only furnish information about ongoing research and dis seminate and retrieve information but also create new information and develop new methods of infor mation analysis, synthesis, and dissemination. The continually expanding biomedical literature produced by scientists from the world's laboratories, research centers, and medical centers led the National Institute of Neurological Diseases and Stroke in 1964 to initiate a National Neurological Information Network of specialized centers for neurological information. The Centers are designed to bring under control and to promote ready access to important segments of the literature.

Human Factors in Simulation and Training: Application and Practice covers the latest applications and practical implementations of advanced technologies in the field of simulation and training. The text focuses on descriptions and discussions of current applications and the use of the latest technological advances in simulation and training. It covers topics including space adaptation syndrome and perceptual training, simulation for battle-ready command and control, healthcare simulation and training, human factors aspects of cybersecurity training and testing, design and development of algorithms for gesture-based control of semi-autonomous vehicles, and advances in the after-action review process for defence training. The text is an ideal read for professionals and graduate students in the fields of ergonomics, human factors, computer engineering, aerospace engineering, occupational health, and safety.