is this one of those studies that we should be excited about immediately? or -- >> immediately is the key word, craig. this is very exciting. but we have to remember that it is an early, small-stage trial. . >> what we're going to do is i'm going to demonstrate for you -- >> reporter: it could be a dramatic new treatment for alzheimer's disease. >> very promising. we're very excited about it. we'd like to see it move forward into a larger trial. >> reporter: dr. suzanne kraft and her team gave volunteers a daily dose of a special insulin nasal spray, or a placebo. >> relax your leg. >> reporter: the 104 participants had alzheimer's or like john martin, pre-alzheimer's memory problems. after four months. three quarters of the people getting the insulin spray did better on memory tests. >> children saw lions. >> reporter: and on scans showing brain changes that signal memory loss. >> we were surprised by how many of the participants benefited.