''People have said that what is being passed from God to man in the painting is the spark of life,'' Dr. Meshberger said in a telephone interview. ''But Adam is already alive. I think what God is giving to Adam here is intellect.''

Dr. Meshberger's theory appears in today's issue of The Journal of the American Medical Association.

Other physicians and scholars familiar with the report say while the notion is intriguing, they are skeptical.

'More Than a Flying Brain'

''I certainly see how he had the idea, but I think it is a retrofit of his own modern knowledge onto Renaissance culture,'' said Dr. Kathleen Weil-Garris Brandt, a professor of fine arts at New York University and a consultant for Renaissance art at the Vatican Museum.

''All the elements in the image have profound traditional roots in the visual culture of the Renaissance and Middle Ages. God is more than a flying brain.'' But other art historians do not entirely dismiss the theory. ''There are drawings by Leonardo that showed details of the brain, and it seems scientists at the time were trying to establish the sections of the brain and their function in intelligence,'' said Dr. Graham Smith, an authority on 16th-century art at the University of Michigan in Ann Arbor. ''The idea of God being equated with the mind is quite attractive.''