( ( Although ( ( ( functional mapping ) ( of ( the ( human brain ) ) ) ) ( has ( ( yielded ( much information ) ) ( about ( cortex ( and ( other ( gray-matter structures ) ) ) ) ) ) ) ) ) ( , ( ( relatively little ) ( ( has ( been ( learned ( about ( ( the ( white-matter tracts ) ) ( that ( connect ( these ( gray-matter structures ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Although) (S (NP (NP (JJ functional) (NN mapping)) (PP (IN of) (NP (DT the) (JJ human) (NN brain)))) (VP (VBZ has) (VP (VBN yielded) (NP (JJ much) (NN information)) (PP (IN about) (NP (NN cortex) (CC and) (JJ other) (NN gray-matter) (NNS structures))))))) (, ,) (NP (RB relatively) (JJ little)) (VP (VBZ has) (VP (VBN been) (VP (VBN learned) (PP (IN about) (NP (NP (DT the) (JJ white-matter) (NNS tracts)) (SBAR (WHNP (WDT that)) (S (VP (VBP connect) (NP (DT these) (JJ gray-matter) (NNS structures)))))))))) (. .)))
Although functional mapping of the human brain has yielded much information about cortex and other gray-matter structures, relatively little has been learned about the white-matter tracts that connect these gray-matter structures.
(ROOT (S (NP (NP (JJS Most)) (PP (IN of) (NP (DT the) (JJ gray) (NN matter)))) (VP (VBZ is) (PP (IN on) (NP (NP (DT the) (NN surface)) (PP (IN of) (NP (DT the) (NN brain))))) (, ,) (S (VP (VBG surrounding) (NP (JJ white) (NN matter))))) (. .)))