Procedural Memory

Understanding Procedural Memory

As the name implies, procedural memory is memory for procedures. The memory expert Gilbert Ryle (1949) called such “knowledge” knowing how.

You know how to cut your food with knife and fork, how to walk, how to read and write, how to do long division, how to peel a banana, how to operate a microscope, how to walk around the block, how to chat with friends, how to browse the Web.

The defining characteristic of procedural knowledge is that you can perform some procedure. It isn’t your knowledge about the procedure; it is your ability to perform the procedure. Such knowledge cannot be expressed.

Procedural knowledge, therefore, does not depend on conscious recollection; instead, the knowledge can be demonstrated without the need to be aware of where and how the original knowledge initially took place.

For this reason, most people with memory impairment show normal or relatively normal procedural memory. H.M. Opens in new window, the most famous amnesic patient of all time (Scoville & Milner, 1957), was able to perform motor tasks despite a very severe episodic memory Opens in new window impairment.

Cohen and Corkin (1981) showed that H.M. was also able to perform the complex Tower of Hanoi puzzle even though he had no recollection of ever having done the task before.

Numerous other studies have demonstrated that amnesic patients Opens in new window can learn certain tasks.

Once again, you must avoid confusing declarative with nondeclarative knowledge.

In addition to knowing how to walk, read, write, do long division, and peel a banana (all of which are examples of procedural knowledge), you probably know that you can do these things, which is declarative knowledge. But knowing that you can do them is different from being able to do them.

The distinction is best conveyed through examples. The most common example may be touch typing. If you can touch type, then you have procedural knowledge of this skill, but your declarative knowledge of it may be limited. Take a moment to type, or pretend to type, the sentence, Procedural knowledge is implicit.

Now, tell me what finger you used to hit the ‘k’ key. Chances are you cannot say. Yet, if you are a competent touch typist, you just typed the word knowledge without hesitation. It is as if your fingers know which keys to hit, but you do not!

Indeed, if you try to type while thinking about which keys to hit with each finger, your typing will slow dramatically, and you will likely make more mistakes than usual.

Your declarative knowledge will interfere with your skilled procedural knowledge. The educational researcher Benjamin Bloom (1986) once noted that “the capable touch-typist doing 50 to 60 words per minute hasn’t the faintest notion of what each finger is doing at any time” (p.73).

Bela Kuroli provides a different sort of example of the nondeclarative nature of procedural knowledge.

As the example of Mr. Kuroli illustrates, the distinction between declarative and procedural knowledge leads to conclusions that run counter to common sense.

Procedural memory accrues through experience and is evidenced by changes in behavior. Conscious awareness of procedural memory is not necessary for accurate performance of a skill.

For instance, the automated and reflexive actions involved in driving an automobile depend on procedural memory.

Procedural memory accumulates slowly through practice and repetition. Once a procedural memory is established, it usually lasts a lifetime. For example, people never forget how to ride a bicycle, and even individuals with advanced Alzheimer’s disease Opens in new window retain their procedural knowledge.