In the 1960s, an era in which research into memory and its process was growing gradually, Brenda Milner studied the case of a patient named HM, whose identity was later revealed as Henry Molaison. HM had undergone surgery to help treat epileptic seizures, but in the process, he lost the ability to create new memories.
The following clip shows Brenda Milner discussing her career and how HM affected it: