Answer:
automatic processing.
Step-by-step explanation:
Automatic processing -
It is a type of muscle memory , where the people repeats the task again , as he has already done it several times and is very sure about the particular task , is referred to as automatic processing .
In this method, the person need not give a second thought while making any decision , it is all just in his mind.
Hence, from the question,
Justin was engaging in automatic processing.