The investigation reported here was supported by Research Grant RG-5786 to Michigan State University from the Division of General Medical Sciences, Public Health Service, U. S. Department of Health, Education and Welfare. It was conducted under the joint auspices of the Audio-Visual Center and the Highway Traffic Safety Center of the University. Dr. Merrill, who was on the staff of the Highway Traffic Safety Center as the principal investigator under the research grant, is now director of television research at the University of California, San Francisco Medical Center.