Let’s play a quick memory game! I’m going to show you a series of numbers, and your job is to remember them when I ask later. Ready? Here they are: 6, 3, 4, 7, 1, 5, 2. Now, here’s a picture of my dog. Isn’t she adorable? Okay, back to the numbers. Can you recall them in the right order? If you can, your working memory is doing great!
Now, let’s talk about someone who had a really tough time with memory. His name was Henry Molaison, but he’s better known as Patient H.M. He’s one of the most famous people in brain science. When H.M. was a child, he hit his head and started having seizures. These seizures got worse as he grew older. At the age of 27, he had surgery to help stop the seizures. During the surgery, doctors removed part of his brain called the temporal lobe, which included the hippocampus. This happened in the early 1950s, and back then, doctors weren’t sure what the outcome would be.
After the surgery, H.M.’s seizures stopped, but he became very forgetful. He couldn’t remember some things and even forgot events from a few years before the surgery. Scientists were curious about why he remembered some things but not others, so they studied him closely. They found out that without his hippocampus, H.M. couldn’t store declarative memories. These are memories for facts, like a phone number or the name of a dog breed. However, he could still learn new skills, which are called procedural memories, like riding a bike.
H.M. took part in an interesting experiment. He had to draw a shape between two lines using only a mirror to see his hand’s reflection. Even though he didn’t remember doing the task before, his motor skills improved each time. This showed researchers that different types of memory rely on different parts of the brain. Declarative memories need the hippocampus to be stored permanently, while procedural memories use other brain areas like the cerebellum and basal ganglia.
H.M.’s case taught us a lot about how memory works and how different parts of the brain are involved. His brain was so important to science that after he passed away in 2009, it was sliced into 2,401 thin sections and turned into a 3D model for further study. Even after more than 60 years since his surgery, we are still learning from H.M.’s experiences.
Oh, and about those numbers I asked you to remember earlier—did you get them right? If you forgot, they were 6, 3, 4, 7, 1, 5, 2. Don’t worry if you didn’t remember; H.M. wouldn’t have remembered being asked either!
Here’s another picture of my dog, just in case you wanted to see her again. She’s quite the looker! And if you enjoy learning about the brain, make sure to check out BrainCraft for a new video every Thursday!
Try to remember a sequence of numbers that your teacher will show you for 30 seconds. Afterward, write down as many numbers as you can recall in the correct order. Discuss with your classmates how you remembered the numbers and what strategies worked best for you.
Work in small groups to research more about Henry Molaison’s life and the impact of his case on neuroscience. Create a short presentation to share with the class, highlighting key findings and how they relate to the understanding of memory.
Recreate the mirror drawing experiment that H.M. participated in. Use a mirror to trace a simple shape while only looking at the reflection. Record your progress over several attempts and discuss how your procedural memory improves even if you don’t consciously remember each attempt.
Draw a diagram of the brain and label the parts involved in different types of memory, such as the hippocampus for declarative memory and the cerebellum for procedural memory. Use colors and symbols to make your map engaging and easy to understand.
Conduct an experiment to see how distractions affect memory. Have a classmate read a list of words to you while you are distracted by background noise or a visual distraction. Then, try to recall the words. Compare your results with those of your classmates and discuss the effects of distractions on memory retention.
I’m going to show you a series of numbers, and you need to recall them when I ask. Ready? 6, 3, 4, 7, 1, 5, 2. This is a picture of my dog, who I think is very good looking. Do you remember the series of numbers? If you got all 7 in the right order, your working memory is functioning well.
However, there’s someone who would have trouble repeating those numbers. He is known for having a poor memory. This is Henry Molaison, also known as Patient H.M., one of the most famous patients in brain science. As a child, H.M. hit his head and began having seizures, which worsened as he got older. When he was 27, H.M. underwent surgery, and part of his temporal lobe, including his hippocampus, was removed. It was the early 1950s, and no one was certain what would happen next.
H.M.’s seizures stopped, but he became forgetful. He couldn’t retain some information and couldn’t recall the few years before the surgery. Researchers were puzzled—he remembered some things, but not others. So they studied H.M. to try to understand his behavior. Without his hippocampus, H.M. couldn’t store declarative memories—our memories for facts like a phone number or dog breed. However, he could retain procedural memories—those for learning a skill, like riding a bike.
H.M. repeatedly performed a task where, using only a mirror to see the reflection of his hand, he’d draw a shape between two lines. His motor skills improved with the task, even though he had no memory of completing it before. Researchers discovered that there are different types of memory that rely on different areas of our brain. When we form declarative memories, the information travels to the hippocampus before it’s consolidated and permanently stored. In contrast, procedural memories rely on other areas, such as the cerebellum and basal ganglia.
Without a hippocampus, H.M. was missing a crucial part of the memory process. The case of H.M. helped us understand the nature of memory and that there are different types that rely on different parts of the brain. His brain was so significant that in 2009, after he passed away, it was sliced into 2,401 paper-thin sections and reconstructed into a 3D model.
It’s been over 60 years since he first had his hippocampus removed, and we’re still learning from H.M. And one last thing! Do you remember that series of numbers? If you forgot, it was 6, 3, 4, 7, 1, 5, 2. And don’t worry—H.M. wouldn’t even remember being asked in the first place.
Here’s another picture of my dog, in case you wanted to see her again. She’s very good looking. If you don’t already, subscribe to BrainCraft for a new brainy video every Thursday!
Memory – The ability of the brain to store and recall information and past experiences. – Example sentence: Studying regularly can help improve your memory and make it easier to remember important facts during exams.
Hippocampus – A part of the brain involved in forming, organizing, and storing memories. – Example sentence: Damage to the hippocampus can lead to difficulties in forming new memories.
Brain – The organ in the head that controls thoughts, memory, emotions, and actions. – Example sentence: The brain is constantly processing information from our senses to help us understand the world around us.
Declarative – Relating to memories that can be consciously recalled, such as facts and events. – Example sentence: Knowing the capital of France is an example of declarative memory.
Procedural – Relating to memories of how to perform tasks and actions, often without conscious awareness. – Example sentence: Riding a bicycle is a skill stored in procedural memory.
Skills – The abilities acquired through practice and learning, enabling one to perform tasks effectively. – Example sentence: Developing good study skills can help students succeed in their academic pursuits.
Seizures – Sudden, uncontrolled electrical disturbances in the brain that can cause changes in behavior, movements, or feelings. – Example sentence: Epilepsy is a condition that can cause frequent seizures, affecting a person’s daily life.
Science – The systematic study of the structure and behavior of the physical and natural world through observation and experiment. – Example sentence: Science helps us understand how the brain works and how it affects our behavior.
Learning – The process of acquiring new knowledge, behaviors, skills, values, or preferences. – Example sentence: Learning a new language can be challenging but rewarding as it opens up new ways to communicate.
Forgetful – Having a tendency to forget things easily or often. – Example sentence: Being forgetful can be frustrating, but using a planner can help keep track of important tasks and dates.
