In a compelling and at times disturbing series, Dr Michael Mosley explores the brutal history of experimental psychology.

Mosley embarks on three journeys to understand science's last great frontier - the human mind - as he traces the history of the attempts to understand and manipulate the brain. Experiments on the human mind have led to profound insights into how our brain works - but have also involved great cruelty and posed some terrible ethical dilemmas.

Mind Control. To begin, Michael traces the sinister ways this science has been used to try to control our minds. He finds that the pursuit of mind control has led to some truly horrific experiments and left many casualties in its wake. Extraordinary archive captures what happened - scientists systematically change the behavior of children; law abiding citizens give fatal electric shocks; a gay man has electrodes implanted in his head in an attempt to turn his sexuality.

Emotions. In this film, Michael investigates how scientists have struggled to understand that most irrational and deeply complex part of our minds - our emotions. Michael meets survivors - both participants and scientists - of some of the key historical experiments. Many of these extraordinary research projects were captured on film - an eight-month-old boy is taught to fear random objects, baby monkeys are given mothers made from wire and cloth, and an adult is deliberately violent before a group of toddlers.

Broken Brains. Dr Michael Mosley concludes his series exploring the brutal history of experimental psychology by looking at how experiments on abnormal brains have revealed the workings of the normal brain. He meets remarkable individuals like Karen, who suffered from a rare condition - alien hand syndrome - which meant that one of her hands constantly attacked her. And Julia, who seems to have recovered from her stroke - until experiments reveal she is unable to recall the name of any object.