Mapping Brain Activity Induced by Olfaction of Virgin Olive Oil Aroma

Abstract

The difficulty of explaining sensory descriptors of virgin olive oil aroma by the analysis of volatile compounds is partially due to the subjective opinions of panelists and the lack of information of the neural mechanisms that ultimately produce a sensory perception. In this study the technique of functional magnetic resonance imaging (fMRI) has been applied to study brain activity during the smelling of virgin olive oil of different qualities. The volatile compounds of the samples were analyzed by solid-phase microextraction gas chromatography to explain the differences in the aromas presented to the subjects during the fMRI experiments. Comparing the pleasant and unpleasant aromas, the most evident differences in brain activity were found at the anterior cingulate gyrus (Brodmann area 32) and at the temporal lobe (Brodmann area 38). The activations were also observed when subjects smelled dilutions of heptanal and hexanoic acid, both compounds being responsible for off-flavors. Other areas were inherent to the olfaction task (e.g., Brodmann area 10) and to the intensity of the aroma (Brodmann area 6).

A neuroimaging study of pleasant and unpleasant olfactory perceptions of virgin olive oil

“…However, a further step in this study is necessary to examine the different activities by means of a 2 nd level analysis (two samples t-test) that consider the variability among different groups of subjects. This study would allow confirming previous results centered on fMRI studies of virgin olive oil aroma (García-González et al, 2011) and would allow obtaining more detailed information between the activations caused by pleasant and unpleasant aromas. Thus, the aim of this paper is to study the brain activity in response of smelling the aroma of virgin olive oils from different sensory qualities and considering different individuals.…”

“…The results of the two-sample t test study allow comparing human brain areas that are activated in an inter-subject study (Figure 2), unlike a 1 st level study, which is more appropriate for intra-subject studies (García-González et al, 2011). Table 2 shows several brain regions that were activated in the course of the experiments and they are split into left and right hemispheres because of their different locations (x y z MNI coordinates: mean±standard error of the mean) and the lateralization of the olfactory system.…”

“…Furthermore, the samples may be presented to induce an orthonasal and/or retronasal stimulation (Cerf-Ducastel and Murphy, 2001), which introduces an additional variability source. Therefore, the studies of the neural activities induced by olfaction require the use of an optimized system of odorant delivery to be reproducible throughout all the experiments (Tabert et al, 2007;García-González et al, 2011). In general terms, the functional studies of olfaction have described activations in the primary olfactory cortex (POC), which receives direct input from the olfactory bulb and it comprises piriform cortex, entorhinal cortex and periamygdaloid cortex.…”

“…In a previous study we also addressed a study on brain activities when individuals smelled virgin olive oil from different qualities (García-González et al, 2011). However, a further step in this study is necessary to examine the different activities by means of a 2 nd level analysis (two samples t-test) that consider the variability among different groups of subjects.…”

Chinese Massage Combined with Herbal Ointment for Athletes with Nonspecific Low Back Pain: A Randomized Controlled Trial

“…Second, some studies supported that aromatherapy helps the body to improve immune response [21, 22]. In addition, some researchers maintains the aroma smell of most aromatic oils affects the nervous system through the olfactory system in aromatherapy massage [23, 24]. So the smell of the herbal ointment may have related therapeutic effects, although there are not related researches.…”