What Is Nondeclarative Memory? 3 Ways It Works in Real Life

7:00 AM!

Gotta rush, or else I’ll miss my skating practice. Tying my shoelaces, I munch a sandwich on my way out and pedal away on my bicycle.

The session is in full swing as I reach the rink. I put on my skating gear as I observe the rest of the class. In five minutes, I’m ready for the maneuvers.

I’m skilled at this now. I don’t even need to think — I just need the skating rink to perform!

That was 14-year-old Russell.

And almost everything he did that morning involved nondeclarative memory.

Nondeclarative memory is the part of long-term memory involved in learned skills, habits, priming and conditioned responses that can operate without deliberate conscious recall.

It’s one reason you can ride a bike without explaining every movement to yourself.

But nondeclarative memory is often confused with declarative memory, also called explicit memory.

Understanding the difference matters.

Especially if you use memory techniques, because deliberate mnemonic strategies like the Memory Palace interact with memory differently from skills that gradually become automatic through practice.

In this post, I’ll show you exactly what nondeclarative memory is, how it differs from declarative memory and how you can put both forms of memory to work.

Here’s what this post covers:

• What Is Nondeclarative Memory?
• Examples of Nondeclarative Memory
• Nondeclarative Memory: A Brief History
• Types of Nondeclarative Memory
• What Sleep Research Tells Us About Procedural Learning
• Nondeclarative vs. Declarative Memory
• 3 Practical Ways to Work With Nondeclarative Memory

What Is Nondeclarative Memory?

Declarative memory and nondeclarative memory are two broad ways researchers describe long-term memory.

The distinction is easiest to understand like this:

Declarative memory involves information you can consciously bring to mind and describe.

Nondeclarative memory is expressed through performance, learned responses and changes in behavior.

For example, you can tell someone the steps involved in riding a bicycle.

That’s declarative knowledge.

Actually staying upright, steering and adjusting your balance in real time depends heavily on procedural learning.

That’s nondeclarative memory at work.

Because these learned processes can operate without deliberate retrieval, nondeclarative memory is often grouped under the broader idea of implicit memory.

That doesn’t mean you’re completely unconscious while using it.

It means you don’t necessarily have to consciously retrieve and verbalize the stored knowledge before using it.

Examples of Nondeclarative Memory

Some everyday examples include:

• Performing familiar cooking procedures.
• Riding a bicycle.
• Buttoning and unbuttoning a shirt.
• Typing familiar patterns on a keyboard.
• Executing well-practiced movements on a musical instrument.
• Automatically responding to familiar cues.
• Becoming faster or more accurate at a task through repeated practice.

You can also see an interesting mixture of memory systems when you memorize a song.

At first, you may deliberately recall the lyrics, melody or sequence.

After enough practice, parts of the performance can start flowing with much less conscious effort.

Language learning provides another good example.

When you’re first learning a new language, you may deliberately think about vocabulary and grammatical rules.

With enough exposure and practice, some aspects of speaking become increasingly fluent and automatic.

Contrast that with remembering someone’s phone number, consciously recalling a historical fact or deliberately retrieving a word you studied yesterday.

Those tasks depend much more directly on declarative memory.

Nondeclarative Memory: A Brief History

One useful philosophical precursor to the modern distinction comes from Gilbert Ryle.

In his 1949 book The Concept of Mind, Ryle famously distinguished between:

• Knowing how — knowing how to perform something, and
• Knowing that — knowing that a particular fact is true.

For example:

Knowing how to ride a bicycle is different from knowing that a bicycle has two wheels.

Modern memory science developed much more detailed models than this philosophical distinction.

But the comparison remains useful because nondeclarative memory often shows itself through performance rather than verbal explanation.

Research into patients with selective memory impairments later provided powerful evidence that different kinds of learning and memory can depend on partially different brain systems.

One particularly influential framework appears in Larry Squire and colleagues’ work on declarative and nondeclarative memory systems.

Types of Nondeclarative Memory

Nondeclarative memory is not one single process.

Researchers commonly distinguish several forms, including:

• Procedural learning and skills,
• Priming,
• Classical conditioning, and
• Other forms of non-associative learning.

Source: Structure and Function of Declarative and Nondeclarative Memory Systems, PNAS

Procedural Memory

Procedural memory is one of the most familiar types of memory because you use it constantly.

You acquire many procedural skills through repetition and practice.

Eventually, aspects of the skill can become difficult to describe verbally.

Try explaining precisely how you make all the tiny balance adjustments required to walk across a room.

You probably can’t.

Yet you can perform them easily.

The same principle applies to cycling, handwriting, typing, playing an instrument and many other learned skills.

Improvement in procedural learning is often measured through changes in performance.

You become faster.

More accurate.

More consistent.

Or you can complete a task while devoting less conscious attention to each individual step.

Priming

Priming describes situations in which exposure to something influences how you respond to something later.

The effect may involve the same stimulus or something related to it.

For example, seeing or hearing a word can make it easier to recognize or respond to that word later.

Priming can involve:

• Words,
• Images,
• Sounds,
• Concepts, and
• Other familiar stimuli.

Here’s a simple example:

“Scales is to fish as bark is to…?”

If you immediately answered “tree,” your previous knowledge and associations helped make that response readily available.

Priming is more complicated than a single word-association game, of course.

But the example gives you a feel for how prior exposure and association can influence later processing without requiring deliberate recollection.

Classical Conditioning

Classical conditioning involves learning an association between stimuli.

Ivan Pavlov‘s experiments are the classic example.

A previously neutral cue can acquire the ability to produce a response after being repeatedly paired with another stimulus.

You can see milder versions of this kind of learned association in everyday life.

For example, hearing your own phone’s notification sound can make you automatically reach toward it before you’ve consciously considered what you’re doing.

The key point is that nondeclarative memory extends far beyond physical skills.

It also includes ways that previous experience changes future behavior without requiring you to consciously retrieve a specific memory.

What Sleep Research Tells Us About Procedural Learning

Does sleep matter to memory?

Research strongly suggests that it does.

But the relationship between sleep and different forms of memory is more complicated than saying one stage handles one type of memory while another stage handles something else.

When you learn something, the memory does not simply appear in permanent form.

Processes commonly described as memory consolidation help newly acquired information and skills become more stable over time.

Sleep has been extensively studied as part of this consolidation process.

A major review of sleep and memory research discusses evidence that different stages and features of sleep contribute to memory in different ways.

Procedural learning is particularly interesting.

In experiments involving tasks such as repeated finger-tapping sequences, researchers have found that performance can improve after intervals that include sleep.

These findings helped establish sleep as an important part of the scientific discussion surrounding skill learning and memory consolidation.

However, it’s better not to think of REM as the “procedural memory stage” and non-REM sleep as the “declarative memory stage.”

Modern research describes a more complicated interaction between sleep stages, neural processes, the type of learning involved and when learning takes place.

For our purposes, the useful takeaway is simpler:

What you learn can continue to change and stabilize after the initial practice session.

That’s another reason memory is better understood as a process than as a static storage box.

How Is Nondeclarative Memory Different From Declarative Memory?

Here’s one way to make the distinction instantly clear.

Imagine you’re learning guitar.

Knowing the name of a chord is declarative knowledge.

Remembering which notes appear on the fretboard involves declarative memory.

But executing a familiar chord change smoothly after hundreds of repetitions increasingly involves procedural learning.

One is not better than the other.

You normally use them together.

What Is Declarative Memory?

A friend wants your recommendations for the best Thai food you tried on a trip to Bangkok.

You remember the restaurants, where they were located and which dishes you enjoyed.

Here you’re consciously retrieving information.

That’s declarative memory, also known as explicit memory.

Declarative memory includes information you can deliberately bring to mind and, in many cases, describe verbally.

Examples include:

• Remembering the capital of China.
• Recalling what happened on your 20th birthday.
• Remembering historical facts.
• Consciously recalling the vocabulary of a language you’re learning.
• Using verbal memory to retrieve words and facts.

Declarative memory is commonly divided into two major forms:

Episodic memory involves personally experienced events.

It includes information about what happened, where it happened and other details associated with the experience.

If you want a deeper explanation, I’ve covered episodic memory here.

Semantic memory involves factual and conceptual knowledge that isn’t dependent on mentally reliving a particular personal event.

Knowing what a triangle is, knowing that Paris is in France or understanding the meaning of a word are examples.

You can read my complete guide to semantic memory here.

So What Separates Declarative and Nondeclarative Memory?

Some of the strongest evidence for distinguishing these systems came from research involving people with selective memory impairments.

Studies showed that someone could have serious difficulty forming certain new declarative memories while still demonstrating forms of skill learning.

That finding was enormously important.

It showed researchers that “memory” could not be treated as one single mental faculty.

The influential PNAS review Structure and Function of Declarative and Nondeclarative Memory Systems summarizes much of the evidence behind this distinction.

Different memory tasks rely on distributed neural systems.

For example:

• Structures within the medial temporal lobe, including the hippocampal system, are particularly important for declarative memory.
• The striatum and related basal ganglia systems are strongly involved in many forms of skill and habit learning.
• Priming can involve relevant regions of neocortex.
• The cerebellum and amygdala participate in particular forms of conditioned learning.

That doesn’t mean each kind of memory is sitting inside one isolated brain location.

Memory depends on interacting neural systems, and the exact network involved depends on what you’re learning and how you’re retrieving it.

Source: Memory, Scholarpedia

This distinction is especially important when you start using memory techniques.

A mnemonic strategy such as a Memory Palace is normally used deliberately.

You consciously encode information.

You consciously establish associations.

Then you deliberately retrieve the information.

That’s very different from repeatedly practising a physical skill until portions of its execution become increasingly automatic.

And yet the two can work together beautifully.

3 Practical Ways to Work With Nondeclarative Memory

You don’t need to “hack” nondeclarative memory.

You need to understand what kind of learning you’re dealing with and practise accordingly.

Here are three practical ways to put the distinction to use.

1. Practice Skills Until Individual Steps Require Less Attention

If you want procedural learning, you need actual practice.

Thinking about juggling is not juggling.

Reading about badminton is not playing badminton.

Memorizing the names of ukulele chords is not the same as changing between them smoothly.

This is where repetition matters.

As a skill develops, some of the individual operations can become increasingly fluent and require less conscious control.

Learning to juggle is one I’ve taken up myself.

I’ve found that once a particular movement becomes familiar, I can increase the challenge and work on another layer of the skill.

That’s one of the clearest ways to experience procedural learning directly.

You practise.

Your performance changes.

Then you add another challenge.

2. Give Learning Time to Consolidate

Practice is important.

But what happens between practice sessions matters too.

Memory researchers use the term consolidation to describe processes through which newly acquired memories and skills become more stable.

Sleep has been widely studied as one part of that process.

This doesn’t mean you need a complicated sleep “hack” every time you learn something.

The more useful lesson is that learning does not end the instant you stop practising.

Coming back to a skill over multiple sessions also gives you something else:

A chance to retrieve what you learned, discover what you’ve lost and strengthen the parts that still need work.

That’s closely related to the deliberate recall and retrieval processes I teach for information you want to remember consciously.

3. Combine Procedural Practice With Deliberate Memory Techniques

Here’s where things get especially useful.

The Memory Palace technique is not itself a form of procedural memory.

It is a deliberate mnemonic strategy.

You take information you want to remember and associate it with familiar locations in a controlled sequence.

That gives you a structured way to encode and retrieve information.

But deliberate memory techniques can support activities that also contain a procedural component.

For example, suppose you’re learning a new language.

You might use a Memory Palace to deliberately memorize vocabulary, grammatical information or useful phrases.

Then you practise speaking until many aspects of pronunciation and grammatical processing require less conscious effort.

The declarative and procedural sides of learning support different parts of the same larger skill.

The same applies to music.

You can practise chord changes and picking patterns until they become increasingly automatic.

At the same time, you can use deliberate memory techniques to memorize the notes on the fretboard.

That’s a much more useful way to think about memory than assuming every form of learning requires the same technique.

Put Your Memory Systems to Work Together

Nondeclarative memory helps explain something we experience every day:

With enough practice, learned responses and skills can become available without consciously recalling every individual step.

Declarative memory works differently.

It’s what lets you consciously retrieve facts, experiences, words, concepts and other information.

Neither system operates completely alone.

When you’re learning a language, playing an instrument, developing a physical skill or studying something complex, different forms of memory can work together.

That’s why understanding the distinction is useful.

Use repetition when the goal is fluent performance.

Use deliberate encoding and retrieval practice when the goal is consciously remembering information.

And when you need to remember large amounts of information in a structured way, use a Memory Palace.

That’s exactly what the technique is designed to help you do.

If you want to learn the process step-by-step, sign up for my free memory course and start building your first Memory Palace.