Alan Baddeley is a psychologist of work. In 1974 it develops a theory explaining why the Working memory (MdT) would be made up:

• of a Central Administrator (executive system) who allows:

• the division of the attention and the cognitive resources,
• decision makings relating to the transfer in the long-term Memory of the processed data storage;
• and of two systems " esclaves" with the first:
• the Phonological Loop which allow a mental autorépétition,
• the Visuo-Space Note-book which allows the coordination of the mental imagery and to carry out the visuo-space tasks.