Craik and Lockhart’s theory (1972) is the theory that repetition of information improves memorization only when the repetition is done in depth and for the purpose of semantically processing the material.
This theory is called ‘processing depth theory’.
This duo of scientists (Fergus Craik and Robert Lockhart presented this model as an alternative to previous theories of memory (included that proposed by Atkinson and Shiffrin) which had divided memory into sensory, functional and long-term stages.
Thus, deeply processed memories in the brain are more durable, whereas superficial processing of memories leads to memories that are easily erased.
In other words, it is the method and depth of processing that affects how well an experience is stored in memory, rather than repetition.
Semantic (deep) processing occurs in three ways:
- Connecting an object / situation, etc. to something else;
- The act of thinking about the meaning of something;
- Dealing with the importance of something.
In other words, how we process information affects how that information will be remembered. Semantic processing involves us thinking deeply about an event (for example), so that the memory of that event is easily accessible.
Conversely, superficial treatment of something causes it to quickly disintegrate and be forgotten.
To determine the level of processing between semantic and phonemic encoding, 26 word pairs were shown to 837 undergraduate students and each participant had 30 seconds to determine whether it was an association of categories or a rhyming relationship. Participants were then asked to recall and associate the given word pairs.
As scientists had anticipated, associating the word with a category presented deeper processing and produced greater retention.
The decline of memory with age according to Craik
According to the scientist, the normal decline of memory appears around the 30s and can pose certain problems from the 60s onward, with a decline in working memory, episodic memory and the ability to retrieve precise information.