EEG machines had been used on humans for around 30 years, when this mixed up little film was made. I'm sure they weren't that well-known then and thus for many, a futuristic concept, through which a convoluted thriller might just have its genesis. With the benefit of almost 65 years of hindsight, the whole thing now does look somewhat dated and a bit silly.
For the first half of this film, I had high hopes the Elizabeth Allan female doctor would surprisingly prove to be the dominant character and a heroine in her own right. But half way through, she sadly just becomes another damsel in distress who needs to be rescued by her estranged and rather boring husband. For this to occur, we have to suspend disbelief, that: (a) He wouldn't share any of the information he receives about his wife's kidnapping with the police (Even though another character asks him this question, which he essentially ignores). (b) The police with their resources wouldn't get that information any way.
It's a movie like that; starting out somewhat intriguingly in the first act, but rapidly running out of any original ideas and common sense and happy to slip back into very pedestrian predictability, from which it never recovers. Overall, we are left feeling that The Brain Machine has short circuited out well before the intended climax.