Few years later, Brenda started going to interesting classes on psychology by Donald Hebb at McGill. Brenda became very interested in what Hebb talked about. In the meanwhile, a brain surgeon Dr. Penfield was thinking about taking in one student of Hebb to test his patients. Hebb asked Brenda and she was very honoured and decided to go to the MNI.
Dr. Penfield was treating patients who had epilepsy by removing a piece of brain called hippocampus. But in one case, the patient lost his memory after the surgery. This surprised Dr. Penfield greatly because he had done this surgery so many times and yet it had never damaged the memory. Dr. Penfield then had another patient and it happened again. That frightened him! Brenda had to find out what caused it. She figured out that hippocampus is important for creating memories like what you ate today, what game you played and what you learned in class. This memory is called declarative.
Dr. Penfield and Brenda wrote a paper about what had been happening with his patients. In Hartford, Dr. Scoville read this paper and became soon interested because something similar happened to one of his patients, H.M.. When he was 23, Scoville treated his epilepsy by taking out the hippocampus on both sides of the brain. After surgery, H.M lost declarative memory. He could still remember things from before the surgery because it was saved on the surface of the brain. If you would tell H.M your name and who you are and then go away for 5 minutes H.M would not remember you. Brenda went to study H.M. to learn more about the hippocampus and declarative memory. She tried out different memory tests with him. Unfortunately, H.M could not go to her to Montreal all the way from Hartford so instead Brenda made the trip. Brenda had done a lot of tests with him but realized she wanted something new. So she thought she would try the mirror drawing with him. In this test, you ask the patient to trace the outline of a star while looking at what you are doing only in a mirror. At first, you would do terribly but with practice it gets better. She tried the mirror drawing because it was something that was not used a lot and because it was easy to carry all the way to Hartford. When she first tried it with him he started out the same way as any of us would. But then later on she discovered something very amazing. Even though he did not remember he had been doing the mirror drawing yesterday she saw that he was getting better and better. Brenda Milner had proved that hippocampus is not important for all kinds of memory. What H.M. could still do was to learn new skills. Like riding a bike, playing basketball, skating, skiing, tennis, and mirror drawing! But he could never remember learning those skills. For that, he needed his hippocampus.
You see that I have not been using H.M.'s full name. That is because scientists do not want to harm the patients' feelings by being known as the patient who lost his memory, etc.
For Brenda Milner, her most interesting time at the MNI so far was in the 1950's. That was when most of scientific discoveries in psychology were made.
At the end of my interview with Brenda, I asked her what is the best thing about being a scientist. She said that if you look at poetry, music or story writing you will notice that it can be all as good a hundred years ago as it is now. But in science, the discoveries made now all always more advanced and better that the ones a hundred years ago. Science is always new and is meant to make our lives more interesting and understandable.