If you’ve ever wondered how memory works, one of the first things you’ll want to understand is the difference between explicit vs implicit memory.
We’re often perplexed by how memory works, and why some things are etched into our memory while other events are quickly forgotten.
Why is memorizing a list of dates or scientific terms for school challenging, but the lyrics to a song we loved in highschool are impossible to forget? Why is it that appointments and grocery lists can slip out of our minds, but we can hold on vividly to memories of our childhood? Why do we remember how to do certain tasks so well that we can do them without even paying attention?
Creating memories is a complicated, 3-step process. The process involves encoding (how we take information in and alter it), storage, and recall. In clinical terms, our memories are nothing more than electrical and chemical signals. When we remember something, our brains are triggering cells to connect in a certain order, called a synapse. Certain sights, sounds, songs and especially smells can trigger vivid memories.
Short-Term and Long-Term Memories
In simple terms, our memories are divided into two categories: short-term and long-term. Our short-term memories are, obviously, a recall of events that happened a short time ago. A short-term memory could have happened a few minutes ago or a few days ago. Long-term memories can be held for months, years or even decades and, although these memories are subject to distortions, they are generally well preserved.
Long-term memories are especially well-preserved if the long-term memory involved an emotional response that caused it to become a core memory.
Core memories aren’t easily forgotten, and often shape who we are. Long-term memories can be divided even further into two more categories: explicit and implicit memories. The difference between explicit vs implicit memory, and the definitions of both, will be discussed below.
Explicit vs Implicit Memory: What is Implicit Memory?
Our implicit memories involve things we can remember how to do almost automatically or unconsciously, and therefore with little thought or focus. Therefore, implicit memory is often referred to as ‘automatic’ or ‘unconscious’ memory.
If you’ve ever completed a task on autopilot, it’s probably thanks to your implicit memory.
Dr. James Giordano, Professor of Neurology at Georgetown University Medical Center explains implicit memory as follows:
“Implicit memories are ‘non-declarative’ and are procedural or associative/comparative memories. These memories usually involve emotion in a process that links cognitive feelings to ideas, responses and skills. Implicit memory is unconscious and is more durable – often lasting a lifetime.”
There are 4 categories of implicit memories:
Procedural Memory is what you might call ‘muscle memory’. It involves recalling motor skills, like riding a bike or driving a car.
Associative Implicit Memory is the ability to recall a relationship between two seemingly unrelated things, like knowing someone’s name after seeing their face.
Non-Associative Memory requires being exposed to stimuli repeatedly to remember it implicitly.
Priming is the effect of our responses or behavior being influenced by exposure to a different stimulus, for example by picturing a banana or the sun after seeing the color yellow.
Some examples of implicit memory in action include:
- Buttoning a shirt
- Driving a car
- Riding a bike
- Following familiar routes
- Remembering the lyrics to a song
- Simple tasks like brushing your teeth or holding a pencil
How are Implicit Memories Stored in the Brain?
Dr. Giordano explains that there are two main structures involved in making implicit memories. He states,
“[Implicit memories] are formed through the networked activity of the auditory, visual and sensory cortex, and movement and coordinative regions including the basal ganglia and cerebellum, as well as areas involved in brain centers involved in emotion such as arousal, fear, pleasure or pain.”
The cerebellum is a region responsible for fine motor control, performing tasks such as typing, using a fork or holding a pencil.
The basal ganglia are involved in a wide range of tasks such as emotion, learning, processing rewards and forming habits. They also help us to coordinate larger movements like dancing. When a person falls victim to Parkinson’s disease, the basal ganglia are affected and their ability to move is gradually impaired.
Our amygdala attaches emotional gravity to our memory. It’s very easy for us to recall emotionally charged life events like our first love, painful breakups, being scared, graduating or being embarrassed.
What Is Explicit Memory?
When it comes to differentiating between explicit vs implicit memory, understand that explicit memory is any information we have to work or focus on in order to recall. It can also sometimes be referred to as conscious memory or declarative memory. Facts, learned information and autobiographical information are stored as explicit memories.
When comparing explicit vs implicit memory, if remembering how to play an instrument is implicit memory, remembering how to play a particular song you just started learning is explicit memory. Some other examples of explicit memory include:
- Remembering what’s on your grocery list
- Remembering dates of historical importance, including birthdays
- Phone numbers
- License plates
- Appointment times
- Past events
- Where you parked your car or left your wallet
If we think of memory as a filing cabinet, our brains keep the files of our memories organized by dividing our explicit memories even further into semantic memories and episodic memories.
Semantic memories are facts or factual information such as dates or math formulas.
Episodic memories are long-term memories of things that happen to us throughout the day or of past events. These are sometimes emotionally charged events like heartbreak, trauma or something that filled you with glee. That’s why music can trigger such vivid memories, especially when something emotional happened in your past, while a particular song was playing.
How Explicit Memories are Stored in the Brain
Dr. Giordano explains, “Explicit memories are formed and recalled through the networked activity of regions of the limbic system of the brain – most notably the hippocampus, fornix and septum, in coordination with areas of the cortex that contribute to rational thought, planning, and association of various modes of sensory information.”
When explicit memories are formed, the hippocampus creates links between neurons called synapses that tie together all the information pertaining to the memory such as sights or smells. Our explicit memory lives in the hippocampus for a little while, until we have recalled it enough times for it to be ‘transferred’ to the frontal cortex while we sleep. That’s why you might experience problems with your memory if you’re having trouble sleeping. In the frontal cortex, it becomes general knowledge.
What Happens to Our Memories as We Age?
There are plenty of healthy habits we can adopt that help preserve our memory as we age, like getting enough sleep, doing puzzles and learning new skills. You can read more about memory preservation techniques here.
However, memory loss is just part of getting older, and most of us will lose at least some of our memories. If the idea of losing precious memories gives you anxiety, try recording some of your favorite memories by writing them down in a journal.
Neurodegenerative diseases such as Alzheimer’s, Parkinson’s and dementia wreak havoc on our explicit memories. In the early stages, short-term memory is more affected, but as the disease progresses, our long-term memories slip away, too. Explicit memories like names, familiar faces, and events from our past become lost.
Our implicit memories, however, remain mostly intact. When it comes to explicit vs implicit memory, it’s very interesting that a musician with Alzheimer’s might not remember buying his piano or taking any lessons, but he can still sit down and play it. This is because the automatic memory of playing the piano is an implicit memory.
Aging does, however, impact our implicit memories. There is some evidence that suggests some parts of our implicit memory, specifically our priming memory and recognition, may in fact be subject to decline.
Are You Genetically More Likely to Have a Good or Bad Memory?
There are some genetic markers that can tell you whether or not you are genetically susceptible to neurodegenerative diseases. A DNA test from CircleDNA can reveal your genetic risk factors or genetic strengths when it comes to memory, including risks of neurodegenerative diseases. This DNA test can be performed at home and can answer your genes might influence your memories.