CHREST logo Home

CHREST (Chunk Hierarchy and REtrieval STructures) is a cognitive architecture that models human perception, learning, memory, and problem solving. It is distinctive in its emphasis on the importance of perception and attention, and in following human constraints such as limitations on short-term memory and processing speed.

CHREST has been shown to accurately model many different aspects of human cognition across different domains. It is currently the only cognitive architecture being developed in the United Kingdom.


An overview of the architecture of CHREST.
Figure describing the overall architecture of the CHREST system, showing a perception system, a short-term memory store, and a long-term memory store.

CHREST combines low-level aspects of cognition (e.g., mechanisms monitoring information in short-term memory) with high-level aspects of cognition (e.g., use of strategies). It consists of perception facilities for interacting with the external world, short-term memory stores (in particular, visual and verbal memory stores), a long-term memory store, and associated mechanisms for problem solving. Short-term memory in CHREST contains references to chunks held in long-term memory, which are recognised through the discrimination network from information acquired by the perception system.

See Design of CHREST for more details about how the CHREST model works, or History of CHREST for some background about where CHREST came from.


CHREST has been used to closely simulate phenomena in several domains, including chess expertise, memory for computer programs, the use of multiple representations in physics, verbal learning, concept formation, children's acquisition of vocabulary and children's acquisition of syntactic categories in four different languages.

See CHREST projects for more details about these projects.

For More Information

If you find the CHREST model interesting, please consider joining our mailing list. If you have a query or comment about CHREST, please get in touch.