While declarative memory Opens in new window stores consciously accessible memories of fact-based information (i.e., knowing “what”), the knowledge of “how” something is done is stored in nondeclarative memory.
Nondeclarative memory (sometimes called implicit memory) is a component of long-term memoryOpens in new window devoted to knowing how to do something and is referred as a “heterogeneous” collection of unconscious learning capacities that are expressed through performance and do not afford access to any conscious memory content.
Most nondeclarative memories are knowledge of how to do muscular acts, which have no language component. Such memories are essentially the same as motor skills that have been practiced severally to the point that they can be performed automatically without conscious thought.
Playing the piano, knowing how to produce a clear tone on a wind instrument, knowing how to ride a bicycle, knowing how to jump rope, and the likes are examples of nondeclarative memory.
These memories are acquired through experience and learning just like declarative memories. However, unlike declarative memory’s conscious recollection of learning events and awareness of what is known, nondeclarative memory is inaccessible to conscious awareness.
Thus one may know how to produce a clear tone on an instrument, but not be able to tell anyone else how to do it. For example, bicycle riders remember how to balance a bicycle even though they cannot declaratively retrieve that information.
Because nondeclarative memory operates subconsciously, its functions do not demand attentional resources and working memory capacity.
The groups of neurons that process these memories are probably not connected to the groups of neurons that process language; nondeclarative and declarative memory are thought to reside in different parts of the brain.
Although nondeclarative memory cannot be tested by asking examiners to recall information, the existence of nondeclarative memories can be documented by observing performance or a change in behavior.
Types of Nondeclarative Memory
At least three types of memory are typically ascribed to nondeclarative memory:
- classical conditioning, and
- procedural or motor skill learning.
Priming refers to an unconscious process whereby identification or performance is enhanced by recent, prior exposure to related information.
During priming, cues prompt accurate recall or performance without the individual’s recollection of the acquired information or that it was previously learned.
Priming is essentially the capability of previous experience to affect recall without any conscious awareness that this is taking place. It is an activation of unconscious context.
This is a different kind of memory use than conscious recollection, and it takes place all of the time in the everyday phenomenon called recognition.
We recognize objects, people, and their names automatically, without ever realizing that this use of knowledge is an act of memory. A musical example of priming would be feeling that there is something familiar about a musical phrase that is like one we have heard earlier in the same piece.
2. Classical Conditioning
In classical conditioning, the individual learns the predictive relationship of one environmental stimulus with another.
The conditioning begins when an initially neutral stimulus is paired with an unconditioned stimulus that elicits the response in the absence of the unconditioned stimulus.
The classic example is Pavlov’s dog Opens in new window learning that a sound reliably predicted the delivery of food. Retrieval and resulting behavior are elicited by cues similar to those encoded during learning.
The retrieval of the associative relationship is quick and usually unconscious, with the expected behavior indicating that there is memory of the connection.
3. Procedural Memory
Procedural memory (also known as motor skill learning) is knowing how to do something; it includes skills and habits.
Although conscious processes are involved in the early stages of most procedural learning, and the training can generally be recalled, procedural learning can happen without the ability to recall the training.
Even when individuals can consciously access the steps involved in a learned procedure or skill, conscious retrieval is not necessary for performance of the skill. Hence, it is considered a type of nondeclarative memory.
Procedural memory Opens in new window accumulates slowly through experience, usually through laborious, repetitive practice and is evidenced by changes in behavior. Once 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 retain their procedural knowledge.
Certain kinds of emotional memories also appear to be nondeclarative. An emotional response to an immediate experience, while seeming to originate in the present moment, may actually be an unconscious reactivation of a previous emotional response to a similar situation.
It follows from all the above that nondeclarative memories may be the only types of memories we can have before we acquire language. Very young children would thus have almost exclusively nondeclarative memories.
It is also the primary type of memory used by most other organisms with nervous systems, which use memory all the time without being aware they are using it. What remains unclear, however, is how the transition is made from the prelinguistic to the linguistic stage of development.