Jonathon recites four numbers to Stephan and asks him to repeat the numbers back to him, only backward. Stephan uses his memory to retain the numbers and transform them prior to repeating them back to Jonathon.

Working memory                  

Explanation:

Jonathon recites four numbers to Stephan and asks him to repeat the numbers back to him, only backward. Stephan uses his working memory to retain the numbers and transform them prior to repeating them back to Jonathon.

Working memory can also be referred to as operational memory, it is the active short-term memory that has the capacity to store limited amount of items for a limited period of time.