Hormonelle Veränderungen und deren Einfluss auf die Geruchswahrnehmung

Die vorliegende Arbeit beschäftigt sich mit dem Einfluss von hormonellen Schwankungen im Verlauf des Menstruationszyklus sowie der Beeinflussung durch die Einnahme oraler Kontrazeptiva auf die Geruchswahrnehmung. Da-zu wurden die Teilbereiche Wahrnehmungsschwelle, Diskriminations- und Identifikationsfähigkeit untersucht. Diese Fragestellung ist von Interesse, da die Datenlage zum Einfluss hormoneller Veränderungen auf die Geruchs-wahrnehmung bisher in weiten Bereichen inkonsistent ist. Außerdem wurden bisher ausschließlich Untersuchungen zur Wahrnehmungsschwelle durchge-führt. Untersucht wurden 80 Kaukasier, davon 60 Frauen und 20 Männer im Alter von 18 bis 44 Jahren. Die 60 Frauen unterteilten sich in 20 Pilleverwenderin-nen und 40 Frauen, die keine hormonellen Verhütungsmittel einsetzen. Von diesen 40 Frauen befanden sich 20 zum Zeitpunkt der Ersttestung in der Fol-luikulärphase, die anderen 20 in der Lutealphase. Alle 80 Personen wurden im Abstand von zwei bis sieben nach der ersten Testung erneut untersucht. Dabei wurde bei den Frauen, die keine Hormone einnahmen, darauf geach-tet, dass jene, die zum ersten Untersuchungstermin in der Follikullärphase getestet wurden, die zweite Untersuchung in der Lutealphase stattfand und umgekehrt. Alle Testpersonen hatten zumindest Maturaabschluss und waren Nichtrau-cher. Es zeigten sich keine Unterschiede in Bezug auf die eigene Bildung und den familiären Bildungshintergrund. Um mögliche Einflüsse der kognitiven Leistungsfähigkeit kontrollieren zu können, wurden die kristalline Intelligenz, die Verarbeitungsgeschwindigkeit und die kognitive Flexibilität gemessen. Auch die aktuelle Stimmung wurde erhoben, um mögliche Beeinflussungen feststellen zu können. Die Erhebung der Riechleistung erfolgte mit Sniffin’ Sticks der Firma Burghart Medizintechnik. Es handelt sich dabei um Filzstifte, die mit Duftstoffen gefüllt sind. Im Schwellentest wurde die Wahrnehmungsschwelle für n-Butanol in einem single-staircase Verfahren mit drei Antwortalternativen durchgeführt. 112 Für die Ermittlung der Wahrnehmungsschwelle stehen 16 verschiedene Kon-zentrationen von n-Butanol zur Verfügung. Im Diskriminationstest werden 16 Tripletts an Stiften nacheinander präsentiert. Jedes Triplett besteht aus einem Duftstoffpaar und einem Einzelgeruch. Ziel der Untersuchung ist es, den Stift herauszufinden, der den Einzelgeruch enthält. Im Identifikationstest werden 16 verschiedene Duftstoffe vorgegeben. Die Testperson hat die Aufgabe, an-hand einer Antwortkarte mit vier Antwortmöglichkeiten den Geruch zu benen-nen. Es werden Ergebnisse pro Teiltest und für den Gesamtscore (SDI) aus-gewertet. Die Untersuchung hat gezeigt, dass es zu einer Veränderung der Riechfähig-keit zwischen den beiden Zyklusphasen kommt. Frauen in der Lutealphase erreichten in allen Teilbereichen höhere Werte als in der Follikulärphase, al-lerdings zeigten nur der SDI-Wert und die Wahrnehmungsschwelle signifikan-te Unterschiede auf. Frauen, die hormonelle Verhütungsmittel einnehmen, zeigten im SDI-Wert ähnliche Ergebnisse, wie Frauen in der Lutealphase. Dieses Ergebnis lässt darauf schließen, dass die Veränderung des Hormon-spiegels Einfluss auf die Leistung im Geruchstest hat. Der Geruch von n-Butanol in der stärksten Konzentration wurde von Frauen in der Lutealphase als unangenehmer bewertet. Die Konzentration, die drei Stufen über der Schwelle liegt, wurde von Frauen in der Follikulärphase als intensiver bewertet. Diese Ergebnisse kann dadurch begründet werden, dass die Wahrnehmungsschwelle weniger sensitiv war, und die Stifte daher auch tatsächlich intensiver waren. Diese Begründung wird durch den fehlenden Unterschied in der Intensitätsbewertung der stärksten Konzentration gestützt. Als weitere Forschungsansätze sind Untersuchungen mit Frauen mit bzw. ohne Hormonersatztherapie nach der Menopause von Interesse. Außerdem sollte genauer darauf eingegangen werden, ob die Testpersonen das Gefühl haben zu raten, oder ob sie sicher sind richtig zu liegen.Hormones influence a wide range of human behaviour including the sense of smell. Previous studies demonstrated a significant impact of sex hormone concentration on olfactory thresholds in females. However, regarding dis-crimination and identification of odours only limited data exist and show in-consistent results. Therefore, this study seeks to answer the question if a broader range of olfactory performance, i.e. identification, discrimination and olfactory threshold as well as hedonic valence of n-butanol, is determined by cyclical hormonal variations. As oral contraceptives cause an artificial rise in the hormone level, we further tested whether hormone-intake can lead to changes in odour perception. In the present study we examined 80 healthy non-smoking Caucasians (60 females, 20 males) ranging from 18 to 44 years. The female group consisted of 20 pill users and 40 females without hormone-intake. The latter were di-vided into two cycle phases: follicular (day 1 to 14) and luteal phase (day 15 to 28/30). Between two and seven weeks after the first testing all participants were tested twice. Females who had their first test during follicular phase were retested in their luteal phase and vice versa. Olfactory performance was examined by Sniffin’ Sticks, which provide the testing of olfactory threshold, odour discrimination and odour identification. Moreover, all participants rated the intensity and pleasantness of n-butanol. Data analysis revealed significant gender differences in odour discrimination and odour identification. Females showed a better performance in both tasks. Moreover, a significant impact of menstrual cycle phase occurred, indicating that women have a more sensitive odour threshold in the luteal phase. For the other tests no significant difference emerged. Pill users did not differ from other groups. Regarding the valence rating of n-butanol, females in the luteal phase rated the dilution as less pleasant. During the follicular phase the dilu-tion of n-butanol three steps above the threshold was rated as most intense. As females had a less sensitive odour threshold during the follicular phase, the dilution three steps above the threshold was indeed more intensive. This presumption is supported by the result that there was no difference in the most intensive dilution. Moreover, a significant correlation between duration of pill-intake and olfactory performance emerged pointing to better performance with longer intake. In addition, a better overall olfactory performance was found at the second testing. Comparing the groups, only females who were testes first in the fol-licular phase showed a significant improvement. For pill users and men a trend to a better performance was observed. Females who were tested first in the luteal phase tended towards a deterioration of olfactory performance. This result supports the assumption of a modulating influence of the cycle phase on olfactory performance. Hence, our data show that odour performance is influenced by menstrual cy-cle phase and pill-intake and thus indicate that this ability is modulated by hormonal changes. Future research should clarify whether menstrual cycle phases and hormone-intake lead to changes in valence and intensity ratings of different odours

Entwicklung der Modalität im Erstspracherwerb des Deutschen

Im Rahmen einer Einzelfallstudie wird der Erwerb vom Modus Modalität eines österreichischen Kindes im Alter von 1;7 bis 4;3 untersucht. Dabei hat sich gezeigt, dass erst ab dem Übergang in die protomorphologische Phase mehrere Formen der Modalität verwendet. Morphologische Marker treten erst nach Modalverben und Modalpartikeln auf. Bis zum Alter von 4;3 sind nur Beispiele deontischer Modalität zu finden. Auch die Mutter verwendet im Umgang mit dem Kind keine Formen epistemischer Modalität

Cortical thickness in the right medial frontal gyrus predicts planning performance in healthy children and adolescents

The ability to plan is an important part of the set of the cognitive skills called “executive functions.” To be able to plan actions in advance is of great importance in everyday life and constitutes one of the major key features for academic as well as economic success. The present study aimed to investigate the neuroanatomical correlates of planning in normally developing children, as measured by the cortical thickness of the prefrontal cortex. Eighteen healthy children and adolescents underwent structural MRI examinations and the Tower of London (ToL) task. A multiple regression analysis revealed that the cortical thickness of the right caudal middle frontal gyrus (cMFG) was a significant predictor of planning performance. Neither the cortical thickness of any other prefrontal area nor gender were significantly associated with performance in the ToL task. The results of the present exploratory study suggest that the cortical thickness of the right, but not the left cMFG, is positively correlated with performance in the ToL task. We, therefore, conclude that increased cortical thickness may be more beneficial for higher-order processes, such as information integration, than for lower-order processes, such as the analysis of external information

Cluster analysis.

<p>Agglomerative hierarchical cluster analysis for the whole data set to define the natural division of groups: Pairs of object were defined in the data set (for every subject: duration of intake and TDI score), then a similarity matrix representing every pair of objects of the data set was obtained and a hierarchical cluster tree was built by using the distance information. Clustering then was subsequently conducted by pruning the branches of the hierarchical tree based on the consistency criterion and two subclusters were obtained (cluster 1: marked with dots, cluster 2: marked with crosses).</p

Detailed results of olfactory performance measures in the two groups of low (0.020mg EE) and high-dose (0.030mg EE) OCs and the control condition of women who do not take any OCs.

<p>Detailed results of olfactory performance measures in the two groups of low (0.020mg EE) and high-dose (0.030mg EE) OCs and the control condition of women who do not take any OCs.</p

Contraceptive Use Affects Overall Olfactory Performance: Investigation of Estradiol Dosage and Duration of Intake

<div><p>The influence of female sex steroids on cognitive performance and sensory perception has been investigated for decades. However, previous research that studied olfaction revealed inconsistent results. The main aim of this study was to investigate the effects of different ethinyl estradiol (EE) concentrations of oral contraceptives and duration of intake on olfactory function. Forty-two healthy women, with regular intake of either high or low EE dosage over at least one year and up to 15 years participated in this study. Results revealed a significant concordance between <i>a priori</i> categorization in the two groups with high and low EE dosage and data-driven hierarchical clustering (p = 0.008). Furthermore, significantly higher olfactory performance was observed in women using low-dose products compared to women using high-dosed products (p = 0.019). These findings indicate different effects of pill use with regard to EE concentration. We therefore strongly recommend the acquisition of information about EE dosage of oral contraceptives to reduce potential confounding factors when investigating sensory systems.</p></div

Graphic representation of the correlation between overall olfactory performance (TDI score) and the duration of OC intake.

<p>High (circles) and low (triangles) estradiol dosage in OC products are presented separately. Lines mark the corresponding linear trend. This graph shows the interaction between EE dose and duration of intake. Each point in the plot represents the individual response of a participant in the olfactory performance assessment.</p

The impact of olfactory dysfunction on interoceptive awareness

This study aimed to investigate how the impairment of the olfactory system influences interoception. Interoception is known as the awareness of one's body or the sense of the condition of the body; more precisely, this construct is defined as the processing, representation, and perception of the internal physical state. Interoceptive sensitivity and chemosensory performance were assessed in 77 subjects, including 43 functional anosmics, 18 hyposmics, and 16 healthy controls. Interoceptive awareness was predicted by odor detection threshold, as well as the duration of olfactory loss in patients who suffered from reduced olfactory functionthe longer the olfactory impairment, the worse the perception of bodily signals. The results of this study will significantly contribute to the basic understanding of the multifaceted effects of olfactory alterations.(VLID)484744

Recovery of olfactory function induces neuroplasticity effects in patients with smell loss

The plasticity of brain function, especially reorganization after stroke or sensory loss, has been investigated extensively. Based upon its special characteristics, the olfactory system allows the investigation of functional networks in patients with smell loss, as it holds the unique ability to be activated by the sensorimotor act of sniffing, without the presentation of an odor. In the present study, subjects with chronic peripheral smell loss and healthy controls were investigated using functional magnetic resonance imaging (fMRI) to compare functional networks in one of the major olfactory areas before and after an olfactory training program. Data analysis revealed that olfactory training induced alterations in functional connectivity networks. Thus, olfactory training is capable of inducing neural reorganization processes. Furthermore, these findings provide evidence for the underlying neural mechanisms of olfactory training