Let's start with breaking this down for a clear meaning:
Measuring the brain waves of human beings while they are engaged in different types of thought hopefully will enable neuropsychologists better to understand the relationship between the structures of the brain and thinking.
So a couple of things are happening-
1. by measuring the brain waves of humans engaged in different types of thinking
2. neuropsychologists hope to better understand something
3. what is that? the relationship between the structure of the brain and thinking.
So we have an ongoing act of measuring brain waves with the hope that is will result in n increased understanding. The sentence is in the progressive tense and using the conditional “would” here to convey expectations and assumptions about the future is appropriate and maintains the intended meaning.
Does that help?