Much of geographic education is a process of training students to think geographically when they look at a photo, map, or other spatial representation. Research on human cognition, however, has undergone a revolution in the past 20 years. Before the 1990s, human brain research consisted mainly of finding people whose brains had been damaged by strokes or in wars or industrial accidents, and measuring what kinds of "thinking” they could no longer do. Then, several new brain-scanning technologies made it possible to observe brain activity as people did various activities. That kind of research clearly shows that spatial thinking is a complex process. A skilled map reader appears to engage different brain structures in order to compare places, delimit regions, describe spatial patterns or transitions, recognize spatial associations, identify spatial hierarchies, and so forth. That fact has implications for curriculum development, educational materials design, and student assessment.