How Long Term Memory Works

Have you ever wondered why some memories last a lifetime while others disappear as soon as you walk into another room? For example, you might remember your childhood home in detail but struggle to recall what you had for breakfast this morning. The reason why some memories are so enduring is because they are part of long-term memory, the mental storage system you use to archive important details, moments, skills, and information you need to hold onto for years and years.

Long-term memory refers to the transfer of information from short-term memory into long-term storage to create lasting memories. It's information we need to keep, so it's good that this type of memory is essentially unlimited and stable—lasting for years or even a lifetime. Short-term memories can become long-term memories through a process known as consolidation.

Long-term memory can be subdivided into explicit (conscious) and implicit (unconscious). It is long-term memory if you can remember something that happened more than just a few moments ago, whether just hours ago or decades earlier.

Long-term memory is crucial because it helps us recall significant life events. It shapes who we are, influences our decisions, and allows us to learn and grow. We also use long-term memory to access the skills and behaviors we've learned, which helps us survive and thrive.

Keep reading to learn more about how long-term memory works, how it forms, and why it can be prone to error.

Types of Long-Term Memory

Long-term memory is usually divided into two types—explicit and implicit.

Explicit Memory

Explicit memories, also known as declarative memories, include all of the memories that are available in consciousness. Explicit memory can be further divided into episodic memory (specific events) and semantic memory (knowledge about the world).

Examples of this type of long-term memory include being able to recall your high school graduation or remembering the year that the U.S. declared its independence.

Implicit Memory

Implicit memories are those that are mostly unconscious. This type of memory includes procedural memory, which involves memories of body movement and how to use objects in the environment. Knowing how to drive a car or use a computer are examples of procedural memories. These memories tend to be more durable and resistant to loss than others.

Most of the time, we aren't aware of what's in our long-term memories. While this information is largely outside our awareness, we can call it into working memory for use when needed. As you've probably already realized, some memories are relatively easy to recall, while others are much harder to access.

How Long Is Long-Term Memory?

Through association and rehearsal, the content of short-term memory can become long-term memory. When we say these memories are long, we mean it. Long-term memories can last from days to decades to a whole lifetime.

How long these memories last can be influenced by a variety of factors, including:

• How the memory was encoded in the first place can play a significant role. If you were very aware and alert when you had the experience, then the memory will probably be much more vivid.
• How many times you access a memory can also play a role in how strong and durable the memory is over time. Not surprisingly, memories you recall often tend to stick around and become much stronger.

The more important the information, the easier it is to remember. Typically, you can recall significant events, like your wedding day, with far greater clarity and detail than everyday occurrences.

How Long-Term Memory Forms

The information-processing model of memory characterizes human memory as being like a computer. Information enters short-term memory (a temporary store), then some of this information is transferred into long-term memory (a relatively permanent store), much like information being saved to the hard disk of a computer.

Each time you access these memories, you help strengthen the neural networks where your information is stored. With those neural pathways becoming stronger, your brain can effortlessly retrieve that information when you need it.

When information is needed, it is retrieved from long-term storage using environmental cues, similar to accessing a saved folder on your computer. However, these saved memories can be changed or sometimes even lost altogether.

Memories that you rarely access often weaken or be replaced by other information. You might still be able to access them with the right cues, but you might be a little foggy about the details.

Long-Term Memory Changes

While we might like to think that we have perfect memory, the evidence suggests that's just not the case. Studies suggest that memories are not saved in a static state, then pulled up with perfect clarity. Instead, researchers have found that memories are transformed or changed every single time they are accessed.

Neurons first encode memories in the cortex and hippocampus. Each time a memory is recalled, it is *re-encoded* by a similar, but not identical, set of neurons.

Accessing memories often helps make them stronger, yet the research has found that this re-encoding can impact how the information is remembered. Subtle details may change, and certain aspects of the memory may be strengthened, weakened, or even lost altogether, depending on which neurons are activated.

Fragility of Long-Term Memory

Long-term memory can be durable, but decades of research have also shown that it can be surprisingly fragile and susceptible to change, misinformation, and interference.

Memory expert Elizabeth Loftus has demonstrated how easily false memories can be triggered. In one of her most famous experiments, she was able to get 25% of her participants to believe in a false memory that they had once been lost in a shopping mall as a child. While the participants could vividly recall details of their experience, it never actually happened.

Why is long-term memory so susceptible to these inaccuracies? In some cases, people miss important details about events. But our brains crave consistency and cohesiveness. So, to fill in these missing gaps in information, it sometimes fabricates details that *seem* to make sense.

It helps create a cohesive narrative and adds the details that help your brain make sense of your experiences, but this tendency to "make up" key information can lead to imperfect memories.

How Can I Improve My Long-Term Memory?

Strategies that may help improve your long-term memory include exercising regularly, getting plenty of sleep, and using cognitive training to strengthen your memory skills.

Takeaways

Long-term memory plays a vital role in daily life. It gives you the base you need to build a foundation of information so you can live your life. While it is easy to think of memories as something similar to files in a computer, research has shown that long-term memory is enduring—and susceptible to error.