Educators educating Educators

Nov 19


Too little memory: The patient named H.M. (Henry Gustav Molaison, February 26, 1926 – December 2, 2008) who lost his ability to remember new things


Henry Molaison's, HM, high school graduation picture

For a fascinating discussion of memory, it is helpful to look at the famous patient referred to as H. M. who has been studied for more than 40 years by Brenda Milner, a psychologist.

H.M., born in 1926, suffered a severe head injury that left him with epileptic seizures, which got worse with age, culminating in one major seizure and 10 blackouts every 7 days. In 1942, H.M. at age 16 had his first major seizure, and by his late 20s, H.M. was dysfunctional, of great harm to himself, and in need of dramatic intervention.


Short YouTube video on H.M.: (3:06) Where Memories Go -- John Medina, author, Brain Rules, describes what was learned about memory from the removal of "H.M.'s" hippocampus

In 1953, the famed neurosurgeon William Scoville removed the inner surface of the temporal lobe (brain region located right behind eras) on both sides of the brain. This greatly helped the epilepsy, but left H.M. with catastrophic memory loss.

Following the surgery, H.M. lost the ability to convert a new short-term memory into a long-term memory. He could not encode new information. H.M. could meet you twice in two hours, with no recall of the first meeting. He lost the conversion ability Ebbinghaus described 50 years before.

Additionally, he could no longer recognize his own face in the mirror. Why? As he aged, the physical appearance of his face changed, but he could not process the new information and convert it into long-term memory. He was locked into a single idea about his appearance, and when he looked in the mirror, he could not identify to whom the aging image actually belonged.

H. M. brain


H.M.s’ brain after the operation by Dr. William Beecher Scoville. In 1953, the majority of H.M.'s hippocampus, along with some surrounding neuronal tissue, was surgically removed from both hemispheres of his brain (area in red). Because of H.M., it is known that memory function originates in this region.


H.M vs. normal brain

H. M. hippocampus



For additional insights into H.M.’s life, read the interesting October 2010 article in Esquire magazine

When a surgeon cut into Henry Molaison's skull to treat him for epilepsy, he inadvertently created the most important brain-research subject of our time — a man who could no longer remember, who taught us everything we know about memory.

Read more:




Clive Wearing:  Another person with too little memory

Imagine life without memory. View the link below of Clive Wearing, who lost his memory due to an infection of herpes encephalitis that wiped out his memory.Here’s a person whose life is a series of fragments without memory for 20 years of life, one night 20 years long with no dreams. There is no difference between day & night, no thoughts at all. In that sense, it has been totally painless, which is not something desirable, is it? Wearing shows us how memory is central to our existence. Without it, life is empty and meaningless.


There are two fundamental phenomena regarding memory that all educators should be quite attentive to as they directly affect memory and how well students remember information after initially presented.

By understanding these two essential factors affecting working memory detailed in November 2017 Ed Tip, educators will be able to drastically improve students’ retention of new information.