In reply to Nancy White.

The sub-title explains it fairly well, but here's more from the book:

"When we say that the Brain Science Program sits at the intersection of mathematics and medicine, of computer science and neurophysiology, what we are really saying is that the people in the program have managed to connect these fields, and through these connections they have come up with new creative insights. Individuals, teams or organizations step into the Intersection by associating concepts from one field with concepts in another."

"The key difference between a field and an intersection of fields lies in how concepts within them are combined. If you operate within a field, you primarily are able to combine concepts within that particular field, generating ideas that evolve along a particular direction - what I call directional ideas. When you step into the Intersection, you can combine concepts between multiple fields, generating ideas that leap in new directions - what I call intersectional ideas. The difference between these two types of ideas is significant"