title: Aroma helps to preserve information processing resources of the brain in healthy subjects but not in temporal lobe epilepsy.
abstract: OBJECTIVE
  Inhalation of ylang-ylang aroma has been shown to reduce the auditory P300, an event-related potential thought to reflect higher-order processing. Because olfactory function is sometimes disturbed in temporal lobe epilepsy (TLE), the objective of the present study was to determine whether the effect of ylang-ylang aroma on the auditory P300 was impaired in patients with TLE.
  
  
  METHODS
  Fourteen subjects with TLE and 14 healthy controls participated in this study. Electroencephalograms were recorded during an auditory oddball task, and ylang-ylang aroma or odorless air was delivered through a mask.
  
  
  RESULTS
  We found that the ylang-ylang aroma prolonged the latencies of P300 in both groups. The ylang-ylang aroma significantly reduced the P300 amplitudes of healthy subjects as described previously. However, in TLE patients, the P300 was unaffected by the aroma.
  
  
  CONCLUSIONS
  The current results show that exposure to the ylang-ylang aroma reduced information processing resources in healthy subjects but had limited effects in patients with TLE. We suggest that impaired higher-order olfactory processing in TLE patients may inhibit the effects of the ylang-ylang aroma on the P300.
authors.affiliation: Section of Liaison Psychiatry and Palliative Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan. satslppm@tmd.ac.jp
authors.forename: Satsuki
authors.initials: S
authors.lastname: Watanabe
authors.forename: Keiko
authors.initials: K
authors.lastname: Hara
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ohta
authors.forename: Hiroko
authors.initials: H
authors.lastname: Iino
authors.forename: Miho
authors.initials: M
authors.lastname: Miyajima
authors.forename: Ayasa
authors.initials: A
authors.lastname: Matsuda
authors.forename: Minoru
authors.initials: M
authors.lastname: Hara
authors.forename: Taketoshi
authors.initials: T
authors.lastname: Maehara
authors.forename: Masato
authors.initials: M
authors.lastname: Matsuura
authors.forename: Eisuke
authors.initials: E
authors.lastname: Matsushima
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D019341:Aromatherapy / Q000379:methods*; D001921:Brain / Q000503:physiopathology*; D054362:Cananga / Q000737:chemistry*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D018913:Event-Related Potentials, P300 / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000187:drug effects*; D008875:Middle Aged; D011930:Reaction Time / Q000187:drug effects; D055815:Young Adult