It’s the morning of a big presentation and you’re stressed out. You’ve gone over your slides a thousand times and you think you’ve memorized them all. While you’re in the shower, an old song comes on the radio and you hum along.
As you’re making breakfast, you sing the song to yourself, amazed that you still know every single word. When the time comes to do your presentation, you pull up your slides and suddenly your mind blanks. All you can hear are the lyrics to that old song, which are so not important. But you studied your presentation for hours the night before. What gives?
It all comes down to differences in your long-term memory. The content of your presentation is an example of explicit memory, while the old song is an example of implicit memory—so is how to shampoo your hair, make coffee, and get dressed. Explicit memory refers to the conscious retrieval of past information or experiences, whereas implicit memory refers to an unintentional or unconscious form of retrieval.
Our experiences are intertwined with both explicit and implicit memory, influencing how we perceive the world, form habits, and navigate the intricacies of our relationships. So how does that play out in our brains?
Also known as declarative memory, explicit memory is our mental filing cabinet, storing facts, experiences, and details with a deliberate and conscious effort (like your presentation). Whether it's the memory of a cherished moment, a historical fact, or the name of a dear friend, explicit memory allows us to navigate the world with a sense of continuity and coherence. Explicit memory is divided into two main sub-categories.
Episodic memories are long-term memories of specific, personal events that can be recalled, such as what you had for breakfast or where you stayed for your last vacation.
Semantic memories are long-term memories of facts and figures like names, dates, and other general knowledge such as your best friend’s birthday or state capitals.
A semantic memory might be that London is the capital of England while an episodic memory would be that you rented a car for your last trip instead of flying. Other examples of explicit memories are:
In other words, explicit memories are about “knowing that.”
Nestled within the brain's temporal lobe, the hippocampus plays a pivotal role in the formation and retrieval of explicit memories. It acts as a sort of neural librarian, cataloging information and experiences for easy retrieval when needed. Understanding the relationship between the hippocampus and explicit memory sheds light on how we construct our personal narratives.
Implicit memories are our unconscious and automatic memories. We do not have to actively recall implicit memories (like you might struggle to remember the capital of Lithuania with your explicit memory). We sometimes refer to implicit memory as non-declarative memory since it can’t consciously be brought into awareness.
For example, I’ve been typing on computers for about twenty-five years. I can type over seventy words a minute, and I don’t have to look at my keyboard to type. Knowing how to type is an implicit memory; I don’t think about it consciously, I just do it. I know exactly where the keys are.
However, if someone pulled up a picture of a blank keyboard and asked me to fill it in, I couldn’t do it. That would be an explicit memory, and I don’t have that information available for recall.
From the muscle memory that allows us to ride a bike to the emotional associations tied to certain scents, implicit memory silently influences our daily lives. Implicit memory is also divided into subcategories.
Priming has to do with the perceptual identification of objects and words and means that past experiences increase the rapidity and accuracy of your response. For example, if you saw the word “money,” you would be more likely to think of the words “bank” or “work.” If you met someone who went to a rival college of yours, you might be more likely to feel competitive because you have been primed to do so.
Procedural memory is responsible for knowing how to perform repetition-induced motor memories. These can be basic, like brushing your teeth, or complex, like driving a car. We often describe these activities as “second nature” or “autopilot” because we can combine our cognitive and motor skills to complete tasks without consciously thinking about them or paying attention to what we’re doing.
Classical conditioning is where we link unrelated stimuli and responses or associate one thing with another without realizing it. You may have learned about Pavlov’s dogs in high school; when he rang a bell, the dogs salivated. That’s an example of classical conditioning. The same thing happens when your phone dings with a text message. It doesn’t say “text message” to you, but you’re conditioned to know that a particular ding means you got a text (and it makes you eager to check your phone!).
Riding a bike is a popular example of implicit memory—even if you don’t ride a bike for years, if you learned how as a child, you’ll be able to hop on and ride years later without much effort. When we use our implicit memory, we have little to no awareness of the skills involved; they’re automatic. Some other examples of implicit memory include:
In other words, implicit memories are about “knowing how.”
The reason I can type seventy words a minute without looking at the keyboard but can’t fill in a blank picture of a computer keyboard accurately is that our implicit and explicit memories are distinct forms of memory mediated by different parts of the brain.
The hippocampus is important for explicit memory while the basal ganglia, cerebellum, and neocortex are responsible for implicit memory. The amygdala is involved in both. These subconscious architects collaborate seamlessly, forming associations and patterns that influence our actions and reactions.
For humans, dual processing is constantly at play. Consider a familiar scenario: learning to ride a bike. The explicit memory catalogs the instructions, the feel of the handlebars, and the act of pedaling consciously. Yet, as we ride, implicit memory takes the lead, fine-tuning our balance and coordinating the motor skills required. This intricate dance of dual processing encapsulates the synergy between explicit and implicit memory, showcasing how these two facets collaborate in our daily lives.
Still, the full relationship between implicit and explicit memory is still not fully understood, and the two systems are believed to be independent with their own ways of operating. This can be seen most clearly when it comes to diseases like Alzheimer’s. Because the hippocampus is not necessary for implicit memory, Alzheimer's patients are able to remember how to read, write, walk, and talk even after they are no longer able to recognize loved ones.
The implicit vs explicit memory divide came out of the treatment of Henry Gustav Molaison, better known as HM, in the 1950s. After an attempt to cure his epilepsy damaged his brain, he suffered from amnesia. After the surgery, he was still able to form short-term memories but his long-term memory was impaired. For example, one exercise asked HM to draw a figure while looking at its reflection in a mirror. Every time he was asked to do this task, he improved. However, when asked if he had done the task before, he could not remember. This showed that while HM’s explicit memory was damaged and he could not recall the fact that he had done the task before (episodic explicit memory), his implicit (procedural) memory remained intact as his motor skills to actually complete the task improved.
When you grasp the harmony between explicit and implicit memory, you can optimize your learning strategies, improve your memory recall, and even develop better habits.
When learning something new, blend intentional practice (explicit) with routine application (implicit). This dual approach helps solidify both your conscious understanding and automatic execution.
Repetition is key for both memory systems. Whether you're memorizing facts or trying to acquire a new skill, repeated exposure strengthens both explicit and implicit memory.
Both memory systems thrive on sensory input. When trying to remember something, engage as many senses as possible – visualize, touch, or even associate a scent. This multisensory approach enhances both conscious and automatic recall.
Neither implicit nor explicit memory is more important than the other! We need to be able to cook dinner and remember friends’ birthdays, drive a car or navigate public transportation and remember the facts and figures we need to do our jobs. To lead fully functional lives, we need both implicit and explicit memory—even if the lyrics to old songs seem less than important sometimes.
Our memory is intricately connected to our mental health. It serves as a barometer, reflecting the state of our cognitive well-being. Persistent memory lapses, forgetfulness, or difficulties in retaining information can be early indicators of underlying mental health conditions, such as depression, anxiety, or even neurodegenerative disorders like Alzheimer's disease.
Exploring therapy for memory concerns is not only about identifying potential issues but also about fostering a collaborative approach to memory wellness. Mental health professionals work in tandem with other healthcare providers, such as neurologists or geriatric specialists, to ensure a comprehensive and holistic evaluation. This collaborative effort maximizes the chances of early detection, accurate diagnosis, and the implementation of effective interventions.
Caitlin is an organizational change strategist, advisor, writer, and the founder of Commcoterie, a change management communication consultancy. She helps leaders and the consultants who work with them communicate change for long-lasting impact. Caitlin is a frequent speaker, workshop facilitator, panelist, and podcast guest on topics such as organizational change, internal communication strategy, DEIBA, leadership and learning, management and coaching, women in the workplace, mental health and wellness at work, and company culture. Find out more, including how to work with her, at www.commcoterie.com.