The Life and Legacy of Henry Molaison


Henry Molaison, commonly known as H.M. to researchers studying memory, was a patient who revolutionized our understanding of the human brain and memory. He suffered from a type of amnesia that left him unable to form new memories, yet he retained many of his childhood memories. In this blog post, we will explore the life of Henry Molaison and his legacy, including what H.M. taught us about the brain and memory.

What Was Henry Molaison Known For?

Henry Molaison was a patient best known for his contribution to the field of psychology and neuroscience. He suffered from a unique type of amnesia that affected his ability to form new memories, yet he could remember events that occurred before his brain surgery. H.M.’s contribution to psychology was immense, and he became the most studied patient in the history of neuroscience.

What Type of Amnesia did H.M. have?

Henry Molaison’s amnesia was caused by the removal of parts of his medial temporal lobe, including his hippocampus. This brain surgery was performed by Dr. William Scoville in an attempt to control Molaison’s severe epilepsy. The surgery was successful in reducing his seizures, but it also had significant implications for H.M.’s memory.

What Impact did Henry Molaison have on Psychology?

Henry Molaison had a profound impact on psychology by allowing researchers to understand the role of the hippocampus in memory consolidation. The hippocampus is a crucial area of the brain responsible for the formation of new memories. H.M.’s surgery helped researchers understand the importance of the hippocampus for the ability to encode, store, and retrieve information.

What Part of the Brain did Henry Molaison have Cut Out?

Henry Molaison had parts of his medial temporal lobe, including his hippocampus, removed. The removal of these areas had significant consequences on his memory abilities. Specifically, he could not form new memories after the surgery but could remember events from before the surgery.

What Was Intact After H.M.’s Initial Brain Surgery?

After H.M.’s initial brain surgery, some aspects of his memory abilities were still intact, such as his ability to learn new procedural and motor tasks. This led researchers to conclude that there are different forms of memory that are stored in different parts of the brain.

When H.M. had his Hippocampus Removed, He was…

When Henry Molaison had his hippocampus removed, he was left unable to form new long-term memories, leading to him constantly living in the past. He could remember who he was and basic information, but he could not recall events that occurred after his surgery.

Was Henry Molaison Married?

Henry Molaison was not married and had no children. He lived in a care facility in Windsor Locks, Connecticut, until his death in 2008.

Why did H.M. have his Hippocampus Removed?

Henry Molaison had his hippocampus removed to control his severe epilepsy. The surgery was performed by Dr. William Scoville in 1953. The result was a reduction in seizures but also a significant impact on H.M.’s memory.

What Did Henry Molaison Teach Us?

Henry Molaison taught us a great deal about the brain and memory. His case helped researchers understand the different forms of memory and the critical role that the hippocampus plays in memory consolidation. His legacy continues to inspire the field of neuroscience and our understanding of the human brain.

HM Psychology Quizlet

If you want to learn more about Henry Molaison’s case and the implications it had for psychology, you can use the HM Psychology Quizlet. This resource features key terms and concepts related to H.M.’s case, including the different memory systems and their roles in memory consolidation.


Henry Molaison’s story is a unique one, inspiring countless researchers to dedicate their lives to studying memory and the brain. His life and legacy remain important to this day, reminding us of the incredible complexity and fragility of the human brain. H.M. will continue to be remembered as a patient who revolutionized our understanding of the brain and memory.