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Declarative Learning

Declarative learning is acquiring information that one can speak about. Declarative knowledge is also use-independent. This is in contrast with procedural or motor learning. The capital of a state is a declarative piece of information, while knowing how to ride a bike is not. Episodic memory and semantic memory are a further division of declarative information.

There are two ways to learn a telephone number, memorize it using your Declarative Memory or punch it into your brain 1,000 times to create a habit. Habit learning is called striatal memory or striatum memory. Declarative memory uses your Medial Temporal Lobe and you can recall the telephone number at will. Habit (Striatum) memory activates the telephone number only when you are at the phone and uses your right-hemisphere's skill Pattern Recognition.

Understanding of the portions of the brain involved in forming different types of memories can be gleaned from studies of patients or animals with damage to specific portions of the brain. Stark, Gordon and Stark describe how damage to the Medial Temporal Lobe (MTL) results in problems with both episodic and declarative memory. In such patients, non-declarative memory is intact. This provides evidence for fundamentally different patterns for forming these distinct types of memories. For example, amnesia patients are found to have trouble remembering information outside the conditions in which it was learned. This was attributed to an impairment of declarative memory due to damage in the MTL. They used this knowledge to develop learning strategies for people suffering from amnesia. Lee, Barense and Kim suggest that rather than the MTL compromising a single memory system, different parts of the MTL may be involved in forming different types of memories. The hippocampus may be primarily involved in forming episodic and contextual memories while the perirhinal cortex may be involved in remembering objects and memories based on familiarity.

Bayley, Frascino and Squiree, on the other hand, tested patients with large MTL lesions and no capacity for declarative learning for their ability to learn by habit. They tested the patients with a concurrent discrimination learning task in which involves which in a pair of two objects is correct. People with intact ability for declarative learning can learn the task in several days. They found that patients with MTL lesions gradually acquired knowledge over an eight week period. The patients were not, however. able to describe the task or the objects. Yin and Knowlton discuss evidence the basal ganglia (dorsal striatum) is involved in the formation of habit memory. For example, amnesia patients are able to complete a probabilistic classification task normally. This task is a test of habit memory. Patients with Parkinson's disease, which affects striatal functioning can also complete the task, but show a very different pattern of brain activation using fMRI. Parkinson's patients show activation in the hippocaampus and MTL, indicating they are using declarative learning to complete the task. Control subjects show activation in the striatum.

Research indicates Declarative and Habit memory compete with each other during distraction. When in doubt the brain chooses Habit memory because it is automatic. Poldrack and coworkers tested the hypothesis that distraction can change the way a task is learned. In their experiment, they played a series of high and low tones while asking subjects to do a simple probabilistic classification task. In the single task (ST) case, subjects only learned to predict the weather. In the dual task (DT) case, subjects were also asked to count the number of high pitched tones. The ability to use the learned knowledge was found to be about the same in either case. However, subjects were significantly better at identifying cue-associations (a test of declarative knowledge) when trained under ST rather than DT conditions. Furthermore, fMRI showed activity in the hippocampus was associated with performance under ST, but not DT conditions, whereas activity in the putamen showed the opposite correlation. The authors conclude that while distraction may not decrease the level of learning, it can result in a reduced ability to flexibly use that knowledge

Chi and Ohlsson make a distinction between simple declarative knowledge and complex declarative knowledge. Complex learning takes more time and involves more complex processes than memorizing basic facts. There are several dimensions that define declarative knowledge. The first is the amount of declarative knowledge a person can remember. They provide an estimate that a person can remember about one million pieces of information. The second is the organization of the knowledge. Several different models for the organization of knowledge exist: semantic networks, theories and schema. All attempt to capture the fact that declarative knowledge is complex, interrelated and organized into groups of patterns or domains. As one learns new declarative knowledge, the size of the knowledge base will increase. As one gains more knowledge of a subject, the effectiveness of learning new material increases. If the new knowledge is added without a major change in its structure, the knowledge is said to be assimilated. As one learns more about a subject, the information becomes more densely connected, more consistent and more fine-grained. If information cannot be assimilated into a person's current schema, a more complex representation may need to b formed by combining schema, moving to a higher level of abstraction or by changing perspective. Acquisition of complex declarative knowledge involves moving along a number of these dimensions.

In education, one factor that must be dealt with is that people often have well developed prior conceptions from their everyday experience. When the conceptions are incorrect (for example, force must be applied to keep an object moving), these misconceptions are very resistant to change. Another problem that can result is that if new knowledge contradicts misconceptions, the new knowledge can be distorted in the process of assimilation. Rather than assimilate the new knowledge, it might be held in abeyance (postpone dealing with the conflict), the person might attempt to bolster support for their current thinking or recalibrate (lower the importance of the new information).

Tileston discusses learning strategies for declarative knowledge. She describes semantic memory as involving knowledge learned from words, symbols and abstractions. Storing knowledge requires making a connection to stored facts and experience. The brain can understand material sooner if their is a prior connection to the new knowledge. The more the teacher helps the student make connections to new information, the better the learning experience. To retrieve semantic memories requires either rehearsal or a hook by which to retrieve the memory. Rehearsal can be rote or elaborative. Storing semantic memory requires good use of language, making it difficult for English language learners. She also says that semantic memory is most difficult to recall and is more likely to be recalled if embedded within episodic or procedural memory- which is more brain friendly. The brain does not like isolated facts- it prefers patterns. To recall declarative information requires making hooks by providing relevance or fitting the information into a pattern. Relevance is considered to be the most important hook.

See also

• Descriptive knowledge
• Procedural knowledge

Further reading

• K. J. Holyoak & R. G. Morrison (Eds.) 2005. Cambridge Handbook of Thinking and Reasoning. New York: Cambridge University Press.
• Larry R. Squire & Eric R. Kandel 1999. MEMORY From Mind to Molecules. New York: W. H. Freeman and Company.