Lucy wants to study changes in cognitive skills

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.

well, i can't read it so i'll ask you questions about it : )

if you were a reader and you read the introduction, would you want to read more?

does it start with a question? if so, is it something you would want to read about?

and ask any friends or family for their opinion : )

answer; blank(1); /// the sea; blank (2); / a forest of pines;