Not Completeley Brainless
When millionaire businessman Max Holt's private plane crashes, Dr Peter Corrie (Peter van Eyck) rushes to the crash sight where upon knowing he hasn't a chance of getting Holt to hospital in time removes his brain in order to keep it alive in his own laboratory. But soon after Corrie starts to change as the brain seems to have some strange power over him and is using Corrie to look into his death as he believes his business partners or family may have murdered him.
If you look through the credits of "The Brain" you will come across the name Curt Siodmak which may not mean anything to you but he wrote a novel called "Donovan's Brain" about a scientist who becomes controlled by a brain he is doing experiments on. That novel has so far been used in three movies "The Brain" alongside the earlier "The Lady and the Monster" and "Donovan's Brain". But unfortunately "The Brain" doesn't stick to Siodmak's ideas and in many ways that is the movie's undoing because it turns science fiction into crime drama.
What that means is that initially we have the build up which sees Dr. Corrie trying to unlock the mysteries of the mind and ending up under the control of Holt's brain when all of a sudden he finds himself becoming left handed. But then instead of focussing on the fear factor of Dr. Corrie becoming controlled by Holt's brain it switches to a crime story with Corrie trying to investigate who may have killed Holt. It sadly makes "The Brain" both ordinary and forgettable. In fairness the characters and to a certain extent the performances are not great and I doubt that if it had stayed true to Siodmak's novel it would have ended up any more memorable.
What this all boils down to is that "The Brain" whilst not terrible is now just a pieces of early 60s film making which once watched you won't feel a need to watch again although it may lead you to track down the earlier versions of Siodmak's novels.