6. Design an experimental study to evaluate the different roles of the striatum and the hippocampus in how humans navigate spatial environments. In your answer, briefly review what you know about the roles of the striatum and the hippocampus in spatial navigation based on past Iiterature (provide as accurate references as you can). Then reason out your hypothesis about what cognitive processes distinguishes the roles of these two brain regions and how you might test your hypothesis. Describe your proposed experimental design, the instruments you would use, the measures you would acquire and the analyses you would do to answer your hypothesis, as well as your predicted results (20 pts).