Related Experiment Video
Updated: May 18, 2026
10:42
A Free-breathing fMRI Method to Study Human Olfactory Function
Published on: July 30, 2017
A Life Without Olfactory Function Has Limited Effects on Cerebral White Matter Morphology
Anja L Winter1, Moa Peter1, Evelina Thunell1
1Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden, ki.se.
Neural Plasticity
|May 16, 2026
Summary
Individuals born without the sense of smell (isolated congenital anosmia) show reduced white matter volume near the olfactory sulcus. These brain changes are localized and may be due to the absence of olfactory bulbs.
Area of Science:
- Neuroscience
- Neuroanatomy
- Sensory system research
Background:
- Absence of sensory input alters brain morphology, typically in related processing regions.
- Previous studies on white matter (WM) changes in isolated congenital anosmia (ICA) yielded inconsistent findings.
Purpose of the Study:
- To investigate white matter (WM) volume alterations in individuals with isolated congenital anosmia (ICA).
- To determine the localization and extent of WM changes in lifelong olfactory deprivation.
Main Methods:
- Voxel-based morphometry (VBM) and multivoxel pattern analysis (MVPA) were employed.
- Comparison of WM volume between 49 individuals with ICA and age-/sex-matched controls.
Main Results:
- Individuals with ICA exhibited significant reductions in WM volume surrounding the olfactory sulcus.
- No WM alterations were observed near the olfactory (piriform) cortex.
- Morphological changes in ICA were localized and primarily associated with the absence of olfactory bulbs.
Conclusions:
- Lifelong olfactory deprivation in ICA leads to localized white matter alterations around the olfactory sulcus.
- Unlike other sensory losses, olfactory deprivation causes limited morphological changes.
- Non-olfactory functions may recruit olfactory brain regions, potentially explaining the limited structural alterations.
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