At Hopkins, Lashley minored in psychology under John B. Watson, whom he continued to work closely with him after receiving his PhD. It was during this time that Lashley worked with Franz and was introduced to his training/ablation method. Watson had a great deal of influence on Lashley. Together the two conducted field experiments and studied the effects of different drugs on maze learning of rats. Watson helped Lashley to focus on specific problems in learning and experimental investigation, followed by locating the area of the cerebrum involved in learning and discrimination.