The Mind of Mr. Soames can be described as a melodramatic Charly. John Soames (Terence Stamp) is a hospital patient who has been in a coma for 30 years. Doctor Bergen (Robert Vaughn) attempts to revitalize Soames by transplanting an infant's brain in the patient's head. When Soames awakens, he has the mental capacity of a baby, but Dr. Bergen is certain that he can accelerate the maturation process, which he does in a matter of weeks. But the pressure on Soames' emotional stability is such that he tragically snaps during a live TV broadcast. Adapted from a novel by Charles Eric Maine, The Mind of Mr. Soames raises more questions than it can possibly answer, but works well on the level of solid science fiction.
~ Hal Erickson, All Movie Guide