FMRI correlates of olfactory processing in typically-developing school-aged children

Psychiatry Res Neuroimaging. 2019 Jan 30;283:67-76. doi: 10.1016/j.pscychresns.2018.11.011. Epub 2018 Dec 2.

Abstract

Human olfactory processing is understudied relative to other sensory modalities, despite its links to neurodevelopmental and neurodegenerative disorders. To address this limitation, we developed a fast, robust fMRI odor paradigm that is appropriate for all ages and levels of cognitive functioning. To test this approach, thirty-four typically developing children aged 7-12 underwent fMRI during brief, repeated exposure to phenylethyl alcohol, a flower-scented odor. Prior to fMRI scanning, olfactory testing (odor detection and identification) was conducted. During fMRI stimulus presentation, odorant release was synchronized to each participant's inspiratory phase to ensure participants were inhaling during the odorant exposure. Between group differences and correlations between activation and odor detection threshold scores were tested using the FMRIB Software Library. Results demonstrated that our 2-min paradigm significantly activated primary and secondary olfactory regions. In addition, a significant relationship between odor detection threshold and higher activation in the right amygdala and lower activation in the left frontal, insular, occipital, and cerebellar regions was observed, suggesting that this approach is sensitive to individual differences in olfactory processing. These findings demonstrate the feasibility of studying olfactory function in children using brain imaging techniques.

Keywords: Odor detection; Olfactory brain circuitry; PEA; Phenyl ethanol; Phenyl ethyl alcohol; Sensory processing; fMRI.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Administration, Inhalation
  • Amygdala / diagnostic imaging
  • Amygdala / drug effects
  • Cerebellum / diagnostic imaging
  • Cerebellum / drug effects
  • Cerebral Cortex / diagnostic imaging
  • Cerebral Cortex / drug effects
  • Child
  • Child Development / drug effects
  • Child Development / physiology*
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Male
  • Neuroimaging / methods
  • Odorants*
  • Olfactory Pathways / diagnostic imaging*
  • Olfactory Pathways / drug effects
  • Olfactory Pathways / physiology*
  • Smell / drug effects
  • Smell / physiology*