Emilia Iannilli | Technische Universität Dresden (original) (raw)

Papers by Emilia Iannilli

Journal of Neuroscience Methods, 2020

Background: Mammalian olfaction begins with transduction in olfactory receptors, continues with e... more Background: Mammalian olfaction begins with transduction in olfactory receptors, continues with extensive processing in the olfactory bulb, and culminates in cortical representation. Most rodent studies on the functional neuroanatomy of olfaction have concentrated on the olfactory bulb, yet whether this structure is tuned only to basic chemical features of odorants or also to higher-order perceptual features is unclear. New method: Whereas studies of the human brain can typically uncover involvement of higher-order feature extraction, this has not been possible in the case of the olfactory bulb, inaccessible to fMRI. The present study examined whether a novel method of acquisition using a facial coil could overcome this limitation. Results: A series of experiments provided preliminary evidence of odor-driven responses in the human olfactory bulb, and found that these responses differed between individuals. Comparison with existing methods and conclusions: The present preliminary technical achievement renders possible to design novel human odor fMRI studies by considering the olfactory system from the olfactory bulb to associative areas.

HAL (Le Centre pour la Communication Scientifique Directe), Nov 28, 2013

Journal of Neuroscience Methods, Apr 1, 2020

PLOS ONE, Jun 12, 2012

How the pleasantness of chemosensory stimuli such as odorants or intranasal trigeminal compounds ... more How the pleasantness of chemosensory stimuli such as odorants or intranasal trigeminal compounds is processed in the human brain has been the focus of considerable recent interest. Yet, so far, only the unimodal form of this hedonic processing has been explored, and not its bimodal form during crossmodal integration of olfactory and trigeminal stimuli. The main purpose of the present study was to investigate this question. To this end, functional magnetic resonance imaging (fMRI) was used in an experiment comparing brain activation related to a pleasant and a relatively unpleasant olfactotrigeminal mixture, and to their individual components (CO 2 alone, Orange alone, Rose alone). Results revealed first common neural activity patterns in response to both mixtures in a number of regions: notably the superior temporal gyrus and the caudate nucleus. Common activations were also observed in the insula, although the pleasant mixture activated the right insula whereas the unpleasant mixture activated the left insula. However, specific activations were observed in anterior cingulate gyrus and the ventral tegmental area only during the perception of the pleasant mixture. These findings emphasized for the firs time the involvement of the latter structures in processing of pleasantness during crossmodal integration of chemosensory stimuli.

Neuroscience, Jun 1, 2016

Given the strong relationship between human olfaction and emotion, it is not surprising that nume... more Given the strong relationship between human olfaction and emotion, it is not surprising that numerous studies have investigated human response to hedonic and arousing qualities of odors. However, neuropsychological research addressed rather the pleasant-unpleasant, and not the arousing-calming dimension of emotional states generated by odorants. The purpose of the presented fMRI study was to evaluate the differences in cerebral processing of olfactory stimuli, focusing on both of these dimensions of emotional experiences, i.e., pleasantness and arousal. We investigated the patterns of activation generated by odors differing in hedonic tone and generated arousal while controlling the stimuli intensity. This design allowed for a new insight to the emotional odor processing with imaging techniques. The pleasantness was related to activation in the cingulate gyrus, the insula, the hippocampal area, the amygdala, and the superior temporal gyrus, whereas arousal affected activation in the thalamic relay. The present study showed also that the emotional states generated by arousing qualities of odorants are an important determinant of magnitude of cerebral activation.

Methods and Protocols in Food Science, 2023

Brain Topography

In migraine, the trigeminal nerve is intimately involved in the pathophysiology of the disease. W... more In migraine, the trigeminal nerve is intimately involved in the pathophysiology of the disease. We hypothesized that alterations in the sensory trigeminal activation in migraine would be reflected by EEG-derived event-related potentials (ERP). We aimed to investigate differences in the temporal and spatial processing of trigeminal stimuli between interictal migraine patients and healthy subjects. ERP to trigeminal stimuli were recorded at 128-channels to allow localization of their cortical sources with high temporal resolution. Seventeen patients with episodic migraine without aura, 17 subjects with episodic migraine with aura, and 17 healthy subjects participated in the study. The first branch of the trigeminal nerve was stimulated using intranasal chemical (CO2), cutaneous electrical, and cutaneous mechanical (air puff) stimuli. Analyses were performed with regard to micro-state segmentation, ERP source localization, and correlation with the patients’ clinical characteristics. To...

The present study compared the temporal and spatial aspects of human olfactory and trigeminal pro... more The present study compared the temporal and spatial aspects of human olfactory and trigeminal processing. A relatively selective trigeminal stimulus, CO 2 , and a relatively selective olfactory stimulus, H 2 S, were delivered with an olfactometer to young, healthy volunteers. The analysis was performed in a classical (5-electrode, main ERPs peaks) and modern approach (high topographical resolution, inverse solution, source localization). Results of microstate segmentation highlighted 5 maps that generally described the two processes at cerebral level. The trigeminal response differed from the olfactory response up to 300 ms after stimulus onset. In this time range, source analysis pointed out that the olfactory stimulation involved olfactory related areas, while trigeminal stimulation involved noxious/somatosensory specific brain areas. Moreover, from 300 ms on our data showed a similarity between the two processes. Statistical parametrical mapping of the differences between conditions suggested greater activation in a specific motor/sniffing network for the CO 2 stimulation (probably related to a regulation of the potential noxious stimulus) and a greater activation of the ipsilateral primary olfactory cortex for H 2 S.

Food Quality and Preference, 2018

Modulation of sensory perception of cheese attributes intensity and texture liking via ortho-and ... more Modulation of sensory perception of cheese attributes intensity and texture liking via ortho-and retro-nasal odors,

Rhinology, 2011

So-called bimodal odorants are able to stimulate the intranasal trigeminal system at relatively l... more So-called bimodal odorants are able to stimulate the intranasal trigeminal system at relatively low concentrations. Using them as stimuli, the current study focused on the interaction between the olfactory and trigeminal systems at a cerebral level. In the experiment, menthol was used at two concentrations, low and high, and these were delivered to two groups of subjects, a healthy control group and an anosmic group who were unable to perceive smells. A computer-controlled olfactometer based on principles of air-dilution was used to deliver the stimuli, while the brain functions were assessed by a functional magnetic resonance imaging (fMRI) technique. SPM5 was used for data analysis. The results showed that normosmic subjects exhibited activation in the anterior cingulate cortex (ACC) and posterior cingulate cortex (PCC), prefrontal cortex (PFC), and cerebellum. Whilst anosmic subjects activated the same area inside the anterior cingulate; moreover a cluster of activation was found...

European Archives of Oto-Rhino-Laryngology, 2014

The currently presented large dataset (n = 1,422) consists of results that have been assembled ov... more The currently presented large dataset (n = 1,422) consists of results that have been assembled over the last 8 years at science fairs using the 16-item odor identification part of the ''Sniffin' Sticks''. In this context, the focus was on olfactory function in children; in addition before testing, we asked participants to rate their olfactory abilities and the patency of the nasal airways. We reinvestigated some simple questions, e.g., differences in olfactory odor identification abilities in relation to age, sex, self-ratings of olfactory function and nasal patency. Three major results evolved: first, consistent with previously published reports, we found that identification scores of the youngest and the oldest participants were lower than the scores obtained by people aged 20-60. Second, we observed an age-related increase in the olfactory abilities of children. Moreover, the self-assessed olfactory abilities were related to actual performance in the smell test, but only in adults, and selfassessed nasal patency was not related to the ''Sniffin' Sticks'' identification score.

Although the brain structures involved in integrating odorant and trigeminal stimuli are well-doc... more Although the brain structures involved in integrating odorant and trigeminal stimuli are well-documented, there is still a need to clarify (1) how emotional response is represented in the human brain during cross-modal interaction between odors and trigeminal stimuli, and (2) whether the degree of congruency between the two types of stimuli influences these emotional responses and their neural processing. These questions were explored combining psychophysics, event-related potentials (ERP) and fMRI in the same group of 17 subjects under a "congruent condition" (intranasal carbon dioxide mixed with the smell of orange, a combination found in soda drinks, for example), and an "incongruent condition" (intranasal carbon dioxide mixed with the smell of rose, a combination not encountered in everyday life). Responses to the 3 constituent stimuli (carbon dioxide, orange, and rose) were also measured. Hedonic and intensity ratings were collected for all stimulations. The congruent bimodal stimulus was rated as more pleasant than the incongruent. This behavioral effect was associated with enhanced neural activity in the hippocampus and anterior cingulate gyrus, indicating that these brain areas mediate reactivation of pleasant and congruent olfactory-trigeminal associations.

NeuroImage, 2014

This study examined whether the memory encoding and short term maintenance of olfactory stimuli i... more This study examined whether the memory encoding and short term maintenance of olfactory stimuli is associated with neurophysiological activation patterns which parallel those described for sensory modalities such as vision and auditory Q7. We examined olfactory event-related potentials in an olfactory change detection task in twentyfour healthy adults and compared the measured activation to that found during passive olfactory stimulation. During the early olfactory post-processing phase, we found a sustained negativity over bilateral frontotemporal areas in the passive perception condition which was enhanced in the active memory task. There was no significant lateralization in either experimental condition. During the maintenance interval at the end of the delay period, we still found sustained activation over bilateral frontotemporal areas which was more negative in trials with correctas compared to incorrectbehavioural responses. This was complemented by a general significantly stronger frontocentral activation. Summarizing, we were able to show that olfactory short term memory involves a parallel sequence of activation as found in other sensory modalities. In addition to olfactory-specific frontotemporal activations in the memory encoding phase, we found slow cortical potentials over frontocentral areas during the memory maintenance phase indicating the activation of a supramodal memory maintenance system. These findings could represent the neurophysiological underpinning of the 'olfactory flacon', the olfactory counterpart to the visual sketchpad and phonological loop embedded in Baddeley's working memory model.

Annals of the New York Academy of Sciences, 2009

Although numerous fMRI studies have been performed on the processing of olfactory information, th... more Although numerous fMRI studies have been performed on the processing of olfactory information, the intranasal trigeminal system so far has not received much attention. In a pilot study stimulants were presented within a constantly flowing airstream birhinally to activate the olfactory (phenylethyl alcohol, H 2 S) or the trigeminal (CO 2) nerves. Both olfactory and trigeminal stimulation activated the ventral insular cortex. Intranasal trigeminal stimulation additionally led to an activation of the midbrain, superior temporal gyrus, anterior caudate nucleus, and the dorsolateral orbitofrontal cortex. Cerebellar activation was reduced relative to odorous stimuli. For all stimuli, right-sided activity was more pronounced. These results suggested that processing of intranasal activation follows a pattern which is, at least to some degree, similar for both trigeminal and olfactory stimulation. This and results from several other studies emphasize the fact that there is a high degree of interaction between the different aspects of the chemical senses, also in the sense that chemosensory-induced activation in the nasal cavity is processed in similar cortical networks. Interactions between the olfactory and trigeminal system can also be seen in patients with acquired olfactory loss, who exhibit reduced trigeminal sensitivity, possibly due to the lack of a central-nervous interaction. Both the orbitofrontal cortex and the rostral insula appear to be of significance in the amplification of trigeminal input, which is missing in patients with olfactory loss.

PloS one, 2016

Long-term exposure to environmental manganese (Mn) affects not only attention and neuromotor func... more Long-term exposure to environmental manganese (Mn) affects not only attention and neuromotor functions but also olfactory functions of a pre-adolescent local population who have spent their whole life span in contaminated areas. In order to investigate the effect of such exposure at the level of the central nervous system we set up a pilot fMRI experiment pointing at differences of brain activities between a non-exposed population (nine subjects) and an exposed one (three subjects). We also measured the volume of the olfactory bulb as well as the identification of standard olfactory stimuli. Our results suggest that young subjects exposed to Mn exhibit a reduction of BOLD signal, subjective odor sensitivity and olfactory bulb volume. Moreover a region of interest SPM analysis showed a specifically reduced response of the limbic system in relation to Mn exposure, suggesting an alteration of the brain network dealing with emotional responses.

Cephalalgia, 2000

Background: Trigeminal/neuronal hyperexcitability and spreading depression activating the trigemi... more Background: Trigeminal/neuronal hyperexcitability and spreading depression activating the trigemino-vascular system are discussed in migraine-pathophysiology. This study investigated trigeminal and olfactory event-related potentials in migraineurs. Methods: Nasal chemosensitivity was assessed in 19 female migraineurs with or without aura > 72 h before or after an attack and in 19 healthy females employing event-related cortical potentials (ERPs) after specific trigeminal stimulation of nasal nociceptors with short pulses of CO2, and specific olfactory stimulation with H2S. Odour thresholds and odour identification performance were also tested. Results: Migraineurs exhibited greater responses to trigeminal stimulation, indicated by significantly larger ERP amplitudes N1. In contrast, olfactory ERP amplitudes P1N1 were significantly smaller in migraineurs. A leave-one-out classification procedure on the basis of these two parameters assigned 76.3% cases correctly. The olfactory ERP amplitude discriminated better between groups than trigeminal ERPs (71.1 vs. 68.4% correct classification). Conclusions: Our data suggest trigeminal hyperexcitability in migraineurs. A general increase of nasal chemosensitivity is not supported because of smaller olfactory ERP amplitudes in migraineurs. Olfactory ERPs discriminate better than trigeminal ERPs between migraineurs and controls, emphasizing the significance of the olfactory system in migraine.

Long-term exposure to environmental manganese (Mn) affects not only attention and neu-romotor fun... more Long-term exposure to environmental manganese (Mn) affects not only attention and neu-romotor functions but also olfactory functions of a pre-adolescent local population who have spent their whole life span in contaminated areas. In order to investigate the effect of such exposure at the level of the central nervous system we set up a pilot fMRI experiment point-ing at differences of brain activities between a non-exposed population (nine subjects) and an exposed one (three subjects). We also measured the volume of the olfactory bulb as well as the identification of standard olfactory stimuli. Our results suggest that young subjects exposed to Mn exhibit a reduction of BOLD signal, subjective odor sensitivity and olfactory bulb volume. Moreover a region of interest SPM analysis showed a specifically reduced response of the limbic system in relation to Mn exposure, suggesting an alteration of the brain network dealing with emotional responses.

Background: The clinical usefulness of olfactory event-related brain potentials (OERPs) to assess... more Background: The clinical usefulness of olfactory event-related brain potentials (OERPs) to assess olfactory function is limited by the relatively low signal-to-noise ratio of the responses identified using conventional time-domain averaging. Recently, it was shown that time-frequency analysis of the obtained EEG signals can markedly improve the signal-to-noise ratio of OERPs in healthy controls, because it enhances both phase-locked and non phase-locked EEG responses. The aim of the present study was to investigate the clinical usefulness of this approach and evaluate its feasibility in a clinical setting. Methodology: We retrospectively analysed EEG recordings obtained from 45 patients (15 anosmic, 15 hyposmic and 15 normosmic). The responses to olfactory stimulation were analysed using conventional time-domain analysis and joint time-frequency analysis. The ability of the two methods to discriminate between anosmic, hyposmic and normosmic patients was assessed using a Receiver Ope...

Food Quality and Preference

Abstract Although scientists have known about the umami taste for decades, it is only recently th... more Abstract Although scientists have known about the umami taste for decades, it is only recently that it has gradually gained wider public recognition as the fifth primary taste. Umami is elicited by l -glutamate, some amino acids and purine nucleotides. Glutamate is found in a wide range of foods but despite that, this taste is not generally included in taste evaluation tests in European countries because it has been found to be hard to conceptualize by the population. To the best of our knowledge, a comprehensive survey on umami familiarity in European countries has not been conducted. Therefore, we chose three countries representative of northern (Finland), central (Germany) and southern Europe (Italy) for our study. Each group contained 300, 271 and 252 participants, respectively. We collected the categorical descriptors spontaneously expressed by volunteers after tasting an umami solution alone, next to the hedonic value perceived in comparison with a watery salt solution and pure water. A significant difference in the hedonic response by country was found. The Finnish sample group used the correct word “umami” at a higher rate (15%) than Italians and Germans (both at 2%). Finland also showed better discrimination between the monosodium glutamate (umami) and sodium chloride (cooking salt) solutions. Overall, the umami taste was rated less pleasant than the salt, females preferring umami more than males, while it was the other way around for salt. Interestingly, a similar percentage of individuals with very low sensitivity for both umami and salt was detected in the countries.