I would rate this SAQ response in the high band (7-8). It effectively meets the demands of the command term "explain" by providing a focused answer that discusses one relevant study (Broca's research) in detail. It summarizes the key aspects of Broca's study and methodology, and draws an appropriate conclusion about how this research contributed to understanding of localization of function in the brain. The response demonstrates accurate knowledge and understanding of Broca's research and its significance.