What Is Memory?
Memory is the way your brain takes in and stores information so you can use it later on. Memories define who you are in a lot of ways. They help you recall things like important dates, facts, and even how you feel. Without memory, you’d have to relearn everything you know. Even the simplest tasks would be difficult.
As you age, some memory loss is normal. For instance, you might forget where you put your keys or neglect to pay a bill. But dementia, like Alzheimer’s, can really change the way your memory works. The memory problems dementia causes can have a big impact on your daily life.
There are several types of memory. Some types may be more affected than others by diseases like Alzheimer’s.
How many types of memory are there?
Memory is a complicated process. There are many theories and models about the different categories of memory. For years, experts have debated how many types of memory exist.
Most scientists agree that there are two main types of memory: explicit and implicit. Explicit memory is when you consciously remember something, like facts or events. You have to actively think about an explicit memory. On the other hand, implicit memory means recalling things without effort. An example would be tying your shoes. Your brain just knows how to do it subconsciously.
Within the categories of explicit and implicit memory, many scientists believe there are other stages, or subtypes, such as:
- Episodic memory
- Semantic memory
- Working memory
- Prospective memory
- Procedural memory
- Sensory memory
Episodic Memory
Episodic memory is a type of long-term, explicit memory. It’s your ability to consciously recall facts or details based on your firsthand experiences. These memories can be recent or old.
Episodic memories usually include detailed information, such as the time and place of a particular event. They’re unique to you and your own view. Often, they’re tied to feelings and emotions. You might think of episodic memory as your brain’s scrapbook of past moments.
Episodic memory examples
Some examples of episodic memories are when you remember:
- Who was there on your wedding day
- What happened on your first day of school
- What you felt at your high school graduation
- What you ate for breakfast this morning
- Where you were when a loved one died
How does dementia affect episodic memory?
Dementia can affect parts of the brain that control episodic memories. You may have trouble recalling past events. For example, you might forget where you parked your car. Or, you might overlook a friend’s birthday.
Semantic Memory
Semantic memory is your ability to remember facts about the world. It’s basically your long-term storage of knowledge. You use this type to remember faces, objects, and meanings.
It’s a type of explicit memory that doesn’t require you to think too much. You don’t need to remember when or where you learned a semantic memory. You just know it based on basic information you’ve picked up over time.
Semantic memory examples
Some examples of semantic memories are your ability to recall:
- State capitals
- Historical dates
- Math problems
- The alphabet
How does dementia affect semantic memory?
If dementia affects your semantic memory, you may not be able to recall basic facts. For example, you might forget the names of people or objects. Or, you could struggle to find the right words in a conversation.
Working Memory
Working memory is a form of short-term memory. It helps you hold onto information for a brief amount of time while you need it. It’s sort of like your brain’s notepad.
You need working memory to carry out many daily tasks. It’s what you use when you go through the steps of solving a math problem or follow directions. Once you’re done with the information, you usually forget it.
Working memory has been linked to intelligence and problem-solving. In other words, a good working memory is key to learning new concepts.
Working memory examples
You use working memory when you:
- Recall a phone number while you look for a pen to write it down
- Follow instructions
- Respond to someone in a conversation
- Remember a question long enough to answer it
How does dementia affect working memory?
When dementia affects working memory, you may struggle to figure things out. For example, you might need more time to add up your bill at the grocery store.
Prospective Memory
Prospective memory is the ability to remember to do something in the future. You temporarily store a prospective memory and then recall it later. It’s kind of like “remembering to remember” something.
You use prospective memory to remind yourself to do certain tasks. If prospective memory fails, it can sometimes be dangerous. For instance, if you forget to take essential medication, you could become very ill.
Prospective memory examples
You use prospective memory when you remember to:
- Take your medicine before bed
- Call a friend at a certain time
- Buy a gift for your anniversary
- Go to a doctor’s appointment
- Vote on election day
How does dementia affect prospective memory?
If dementia affects your prospective memory, you might forget to do something at a certain time. For instance, you may forget to attend a party or meeting that you’d planned to go to.
Procedural Memory
Procedural memory is a type of long-term implicit memory. It helps you automatically remember how to do things you’ve learned. You don’t need to think about what you’re doing because your brain is already trained to do it. These types of memories form very early in life.
You use procedural memory all the time, for many different tasks. When you call someone on your mobile phone, you use this form of memory. You don’t need to remind yourself how to operate the phone thanks to your procedural memory.
Procedural memory examples
Procedural memory is in use when you:
- Tie your shoes
- Ride a bike
- Drive a car
- Type on a keyboard
- Walk from one place to another
How does dementia affect procedural memory?
Early on, dementia is less likely to affect your procedural memory than other types of memory. But it does happen, especially in the later stages of the disease. You might struggle with simple tasks, like how to brush your teeth, if your procedural memory fails.
Sensory Memory
Sensory memory is a brief recall of a sensory encounter, such as something you’ve just seen. Some scientists think sensory memory lasts less than a second. It allows your brain to briefly process the sensations you take in. You use your five senses – sight, sound, touch, smell, and taste – to form sensory memories.
You can think of sensory memory like a filter. Most of what you take in via sensory memory is forgotten. But if you really pay attention to the information, it may turn into short-term memory.
Sensory memory examples
Some examples of a sensory memory are when you:
- Hear a bird sing
- See a flash of light
- Smell popcorn
- Taste a hot pepper
- Touch a pet’s fur
How does dementia affect sensory memory?
Dementia can make it harder for your brain to process information that comes through your senses. Some research suggests that sensory memory problems may lead to trouble understanding speech or hearing sounds.
Takeaways
You use different types of memory to remember various kinds of information. Experts don't agree on how to categorize them, but some of the main types include: episodic, semantic. working, prospective, procedural, and sensory. Conditions like Alzheimer's may affect the types of memory in different ways.
Types of Memory FAQs
What are the 4 types of memory?
Experts classify types of memory in several ways. More than four categories have been identified, but four commonly discussed types are:
- Working memory. This form of short-term memory helps you store information and solve problems.
- Episodic memory. You need it to remember past events.
- Semantic memory. It helps you recall facts.
- Prospective memory. These are memories you need for the future.
What are the 4 Cs of memory?
One textbook, The Cognitive Neuroscience of Memory: An Introduction, refers to the four Cs of memory. They include:
- Connection. Your memories are stored as connections between brain cells.
- Cognition. This refers to your brain’s processing of information.
- Compartmentalization. This is the way memories are classified – in other words, different types of memory.
- Consolidation. This refers to the way lasting memories are made in your brain.
