Henry M.: Episodic Memory

Henry M. grew up just outside of Hartford, Connecticut and was known as a young man with an above average intelligence. Some of his favorite activities were ice-skating, listening to detective shows on the radio, and he enjoyed figuring out what would happen in the detective shows before it was released. On his sixteen birthday, Henry had his very first grand mal seizure. Then after that day, the seizures started appearing more often. In 1953, he was experiencing up to as many as eleven seizures a week. At this point Henry could not hold a job and he was unable to live the independent life he wanted. During this time there was not very many solutions or treatments that were available for epilepsy. With a combination of hope and determination, …show more content…
This will cause previously consolidated memories to become lost and unable to be retrieved. Retrograde memories are the events that patient H.M. could remember before the surgery had taken place. H.M. lost his ability to convert new experiences into explicit memories, but he was able to retain a lot of his procedural or implicit memories. An explicit memory is a memory that people are aware of and it can be verbally described. This means that it is declarative and people can describe what they have learned easily to others. There are two types of explicit memories and they are episodic and semantic. Episodic memories are records of life experiences and semantic memories consist of data, facts, and vocabulary. The hippocampus plays a key role in explicit memories. The hippocampus is a part of the limbic system and it is located in the temporal lobe. When the hippocampus is destroyed, a person can remember the events that lead up to the accident or surgery, but are now unable to produce new memories. An implicit memory is a memory that people have a hard time verbally describing. These memories can include certain actions like riding a bike, walking, or swimming. This means that implicit memories are procedural …show more content…
William Scoville began the surgery by removing large chunks of H.M.’s left and right temporal lobes from his brain. The hippocampus is a section of the temporal lobe that deals with the storage of memories. Since the doctor took a chunk of the hippocampus out of H.M.’s brain, he became frozen in the year 1953. H.M. could only remember events that had taken place before his operation. This meant that his retrograde memory was intact, but he will no longer be able to create new memories. H.M. is suffering from the condition called anterograde amnesia for explicit memories. Which is when a person is unable to form new long-term memories for different events that occur after a specific time. H.M.’s working short-term and long-term memory stayed intact after the operation. The biggest problem that H.M. had developed is that he can no longer convert short-term memories into permanent storage long-term memories, which is a process called consolidation. H.M. can preform normal skill learning activities and that meant that his implicit memories were intact. On the other hand, his explicit memories were not because he was unable to learn new data, facts, vocabulary, and was unable to remember his life experiences after the surgery. To this day, H.M. has been called the most important patient in the history of brain science and he has been studied for more than fifty years. After H.M.’s death, his brain was removed and scanned multiple times using an MRI. Lastly, his brain was