TY - JOUR

T1 - Neural correlates of olfactory processing in congenital blindness

AU - Kupers, R

AU - Beaulieu-Lefebvre, M

AU - Schneider, F C

AU - Kassuba, T

AU - Paulson, O B

AU - Siebner, H R

AU - Ptito, M

N1 - Copyright © 2011 Elsevier Ltd. All rights reserved.

PY - 2011/6

Y1 - 2011/6

N2 - Adaptive neuroplastic changes have been well documented in congenitally blind individuals for the processing of tactile and auditory information. By contrast, very few studies have investigated olfactory processing in the absence of vision. There is ample evidence that the olfactory system is highly plastic and that blind individuals rely more on their sense of smell than the sighted do. The olfactory system in the blind is therefore likely to be susceptible to cross-modal changes similar to those observed for the tactile and auditory modalities. To test this hypothesis, we used functional magnetic resonance imaging to measure changes in the blood-oxygenation level-dependent signal in congenitally blind and blindfolded sighted control subjects during a simple odor detection task. We found several group differences in task-related activations. Compared to sighted controls, congenitally blind subjects more strongly activated primary (right amygdala) and secondary (right orbitofrontal cortex and bilateral hippocampus) olfactory areas. In addition, widespread task-related activations were found throughout the whole extent of the occipital cortex in blind but not in sighted participants. The stronger recruitment of the occipital cortex during odor detection demonstrates a preferential access of olfactory stimuli to this area when vision is lacking from birth. This finding expands current knowledge about the supramodal function of the visually deprived occipital cortex in congenital blindness, linking it also to olfactory processing in addition to tactile and auditory processing.

AB - Adaptive neuroplastic changes have been well documented in congenitally blind individuals for the processing of tactile and auditory information. By contrast, very few studies have investigated olfactory processing in the absence of vision. There is ample evidence that the olfactory system is highly plastic and that blind individuals rely more on their sense of smell than the sighted do. The olfactory system in the blind is therefore likely to be susceptible to cross-modal changes similar to those observed for the tactile and auditory modalities. To test this hypothesis, we used functional magnetic resonance imaging to measure changes in the blood-oxygenation level-dependent signal in congenitally blind and blindfolded sighted control subjects during a simple odor detection task. We found several group differences in task-related activations. Compared to sighted controls, congenitally blind subjects more strongly activated primary (right amygdala) and secondary (right orbitofrontal cortex and bilateral hippocampus) olfactory areas. In addition, widespread task-related activations were found throughout the whole extent of the occipital cortex in blind but not in sighted participants. The stronger recruitment of the occipital cortex during odor detection demonstrates a preferential access of olfactory stimuli to this area when vision is lacking from birth. This finding expands current knowledge about the supramodal function of the visually deprived occipital cortex in congenital blindness, linking it also to olfactory processing in addition to tactile and auditory processing.

KW - Adult

KW - Amygdala/physiology

KW - Blindness/congenital

KW - Female

KW - Frontal Lobe/physiology

KW - Heart/physiology

KW - Hippocampus/physiology

KW - Humans

KW - Image Processing, Computer-Assisted

KW - Magnetic Resonance Imaging

KW - Male

KW - Mediodorsal Thalamic Nucleus/physiology

KW - Neuronal Plasticity/physiology

KW - Occipital Lobe/physiology

KW - Odorants

KW - Oximetry

KW - Oxygen/blood

KW - Psychomotor Performance/physiology

KW - Respiratory Mechanics/physiology

KW - Smell/physiology

KW - Somatosensory Cortex/physiology

KW - Stimulation, Chemical

KW - Visual Cortex/physiology

U2 - 10.1016/j.neuropsychologia.2011.03.033

DO - 10.1016/j.neuropsychologia.2011.03.033

M3 - Journal article

C2 - 21458471

VL - 49

SP - 2037

EP - 2044

JO - Neuropsychologia

JF - Neuropsychologia

SN - 0028-3932

IS - 7

ER -