( ( According ( to ( Frontier Herbs ) ) ) ( , ( ( ( the use ) ( of ( ( essential oils ) ( in aromatherapy ) ) ) ) ( ( ( is effective ) ( because ( ( the ( human brain ) ) ( responds ( to ( ( past memories ) ( associated ( with ( a scent ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (VBG According) (PP (TO to) (NP (NNP Frontier) (NNPS Herbs)))) (, ,) (NP (NP (DT the) (NN use)) (PP (IN of) (NP (NP (JJ essential) (NNS oils)) (PP (IN in) (NP (NN aromatherapy)))))) (VP (VBZ is) (ADJP (JJ effective)) (SBAR (IN because) (S (NP (DT the) (JJ human) (NN brain)) (VP (VBZ responds) (PP (TO to) (NP (NP (JJ past) (NNS memories)) (VP (VBN associated) (PP (IN with) (NP (DT a) (NN scent)))))))))) (. .)))
According to Frontier Herbs, the use of essential oils in aromatherapy is effective because the human brain responds to past memories associated with a scent.
(ROOT (S (NP (JJ Specific) (NNS scents)) (VP (VBP are) (ADVP (RB often)) (VP (VBN associated) (PP (IN with) (NP (NNS memories))))) (. .)))