( ( When ( this happens ) ) ( , ( you ( ( may ( lose ( ( a function ) ( that ( is ( controlled ( by ( ( that part ) ( of ( your brain ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (DT this)) (VP (VBZ happens)))) (, ,) (NP (PRP you)) (VP (MD may) (VP (VB lose) (NP (NP (DT a) (NN function)) (SBAR (WHNP (WDT that)) (S (VP (VBZ is) (VP (VBN controlled) (PP (IN by) (NP (NP (DT that) (NN part)) (PP (IN of) (NP (PRP$ your) (NN brain)))))))))))) (. .)))
When this happens, you may lose a function that is controlled by that part of your brain.
(ROOT (S (ADVP (RB Not) (RB surprisingly)) (, ,) (NP (JJ controlling) (NN flight)) (VP (VBZ is) (NP (NP (DT the) (NN function)) (PP (IN of) (NP (NP (DT the) (ADJP (RBS most) (JJ developed)) (NN part)) (PP (IN of) (NP (NP (DT a) (NN bird) (POS 's)) (NN brain))))))) (. .)))