( ( An experiment ) ( ( ( used ( four groups ) ) ( to ( test ( ( long ( term ( habituation training ) ) ) ( in ( the Aplysia ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT An) (NN experiment)) (VP (VBD used) (NP (CD four) (NNS groups)) (S (VP (TO to) (VP (VB test) (NP (NP (JJ long) (NN term) (NN habituation) (NN training)) (PP (IN in) (NP (DT the) (NNP Aplysia)))))))) (. .)))
An experiment used four groups to test long term habituation training in the Aplysia.
(ROOT (S (NP (NNP Habituation)) (VP (VBZ is) (NP (NP (DT the) (NN term)) (PP (IN for) (S (VP (VBG getting) (VP (VBN used) (PP (TO to) (NP (NN something))) (PP (IN after) (S (VP (VBG being) (VP (ADVP (RB consistently)) (VBN exposed) (PP (TO to) (NP (PRP it))))))))))))) (. .)))