Smoking modulates language lateralization in a sex-specific way

WOS: 000285668200003PubMed ID: 20951712Smoking affects a widespread network of neuronal functions by altering the properties of acetylcholinergic transmission. Recent studies show that nicotine consumption affects ascending auditory pathways and alters auditory attention, particularly in men. Here we show that smoking affects language lateralization in a sex-specific way. We assessed brain asymmetries of 90 healthy, right-handed participants using a classic consonant-vowel syllable dichotic listening paradigm in a 2 x 3 experimental design with sex (male, female) and smoking status (non-smoker, light smoker, heavy smoker) as between-subject factors. Our results revealed that male smokers had a significantly less lateralized response pattern compared to the other groups due to a decreased response rate of their right ear. This finding suggests a group-specific impairment of the speech dominant left hemisphere. In addition, decreased overall response accuracy was observed in male smokers compared to the other experimental groups. Similar adverse effects of smoking were not detected in women. Further, a significant negative correlation was detected between the severity of nicotine dependency and response accuracy in male bur not in female smokers. Taken together, these results show that smoking modulates functional brain lateralization significantly and in a sexually dimorphic manner. Given that some psychiatric disorders have been associated with altered brain asymmetries and increased smoking prevalence, nicotinergic effects need to be specifically investigated in this context in future studies. (C) 2010 Elsevier Ltd. All rights reserved.DFGGerman Research Foundation (DFG) [Gu227/11]; DAADDeutscher Akademischer Austausch Dienst (DAAD)This research was supported by the DFG research grant (Gu227/11) and by the DAAD PhD-Net grant. We would also like to thank the participants for contributing their time

Lateralization of the avian magnetic compass : analysis of its early plasticity

CITATION: Gehring, D., et al. 2017. Lateralization of the avian magnetic compass : analysis of its early plasticity. Symmetry, 9(5):77, doi:10.3390/sym9050077.The original publication is available at https://www.mdpi.comIn European Robins, Erithacus rubecula, the magnetic compass is lateralized in favor of the right eye/left hemisphere of the brain. This lateralization develops during the first winter and initially shows a great plasticity. During the first spring migration, it can be temporarily removed by covering the right eye. In the present paper, we used the migratory orientation of robins to analyze the circumstances under which the lateralization can be undone. Already a period of 11/2 h being monocularly left-eyed before tests began proved sufficient to restore the ability to use the left eye for orientation, but this effect was rather short-lived, as lateralization recurred again within the next 11/2 h. Interpretable magnetic information mediated by the left eye was necessary for removing the lateralization. In addition, monocularly, the left eye seeing robins could adjust to magnetic intensities outside the normal functional window, but this ability was not transferred to the “right-eye system”. Our results make it clear that asymmetry of magnetic compass perception is amenable to short-term changes, depending on lateralized stimulation. This could mean that the left hemispheric dominance for the analysis of magnetic compass information depends on lateralized interhemispheric interactions that in young birds can swiftly be altered by environmental effects.https://www.mdpi.com/2073-8994/9/5/77Publisher's versio

Extinction Learning from a Mechanistic and Systems Perspective

Throughout their lifetime, animals learn to associate stimuli with their consequences. Following memory acquisition and consolidation, circumstances may arise that necessitate that initially learned behaviour is no longer relevant. The ensuing process is called extinction learning and involves a novel and complex learning procedure that involves a large number of neural entities. While the neural fundaments of the initial acquisition are well studied, our understanding of the behavioural and neural basis of extinction is still limited and derives mostly from rodent data acquired through fear conditioning paradigms. Fear conditioning and extinction in rodents is a spectacularly successful paradigm within behavioral neuroscience. However, in recent years, new approaches have been emerging that examine the mechanisms of extinction learning in different setting that also involve appetitive models, a broader comparative perspective, a focus on other brain systems, an examination of hormonal factors, and conditioning of immune responses. Only a broader analysis of the neural fundaments of extinction learning will finally uncover shared and distinct mechanisms that underlie extinction learning in different functional systems. The papers compiled in this Research Topic offer new and valuable insights into the mechanisms and functional implementation of extinction learning at its different levels of complexity, and form the basis for new concepts and research ideas in this field

Lateralization of the avian magnetic compass : analysis of its early plasticity

CITATION: Gehring, D., et al. 2017. Lateralization of the avian magnetic compass : analysis of its early plasticity. Symmetry, 9(5):77, doi:10.3390/sym9050077.The original publication is available at https://www.mdpi.comIn European Robins, Erithacus rubecula, the magnetic compass is lateralized in favor of the right eye/left hemisphere of the brain. This lateralization develops during the first winter and initially shows a great plasticity. During the first spring migration, it can be temporarily removed by covering the right eye. In the present paper, we used the migratory orientation of robins to analyze the circumstances under which the lateralization can be undone. Already a period of 11/2 h being monocularly left-eyed before tests began proved sufficient to restore the ability to use the left eye for orientation, but this effect was rather short-lived, as lateralization recurred again within the next 11/2 h. Interpretable magnetic information mediated by the left eye was necessary for removing the lateralization. In addition, monocularly, the left eye seeing robins could adjust to magnetic intensities outside the normal functional window, but this ability was not transferred to the “right-eye system”. Our results make it clear that asymmetry of magnetic compass perception is amenable to short-term changes, depending on lateralized stimulation. This could mean that the left hemispheric dominance for the analysis of magnetic compass information depends on lateralized interhemispheric interactions that in young birds can swiftly be altered by environmental effects.https://www.mdpi.com/2073-8994/9/5/77Publisher's versio

Visual Asymmetries in Japanese Quail (Coturnix japonica) Retain a Lifelong Potential for Plasticity

WOS: 000268530000013PubMed ID: 19634940Adult Japanese quail display left-eye/right-hemisphere dominance in visually guided sexual tracking. In 2 experiments, the authors set out to answer if this functional cerebral asymmetry is modifiable by posthatch monocular deprivation, In Experiment 1, the left or the right eye of 2-day old quail were closed for 70 days. Quail were run in a left- or a right-turning runway to obtain access to a conspecific of the opposite sex. The performance of both left and right eye systems was equal. In Experiment 2, the deprived eyes of the quail were opened and the previously open eyes were closed. They were tested with the same runways. Overall, running speed was very low, but the quail showed a left-eye/right-hemisphere superiority. Altogether, these experiments evince 3 insights into cerebral asymmetries in quail. First, posthatch asymmetries of visual input can alter lateralized behavior to an important extent. Second, cerebral asymmetries could involve an interhemispheric inhibition that can be modified by epigenetic factors. Third, even long-term visual deprivation does not abolish a previously established cerebral asymmetry

Lateralization and cognitive systems

Left-right asymmetries of structure and function are a common organization principle in the brains of humans and non-human vertebrates alike. While there are inherently asymmetric systems such as the human language system or the song system of songbirds, the impact of structural or functional asymmetries on perception, cognition and behavior is not necessarily limited to these systems. For example, performance in experimental paradigms that assess executive functions such as inhibition, planning or action monitoring is influenced by information processing in the bottom-up channel. Depending on the type of stimuli used, one hemisphere can be more efficient in processing than the other and these functional cerebral asymmetries have been shown to modulate the efficacy of executive functions via the bottom-up channel. We only begin to understand the complex neuronal mechanisms underlying this interaction between hemispheric asymmetries and cognitive systems. Therefore, it is the aim of this Research Topics to further elucidate how structural or functional hemispheric asymmetries modulate perception, cognition and behavior in the broadest sense

Lateralization of magnetic compass orientation in pigeons

The aim of our study was to test for lateralization of magnetic compass orientation in pigeons. Having shown that pigeons are capable of learning magnetic compass directions in an operant task, we wanted to know whether the brain hemispheres contribute differently and how the lateralization pattern relates to findings in other avian species. Birds that had learnt to locate food in an operant chamber by means of magnetic directions were tested for lateralization of magnetic compass orientation by temporarily covering one eye. Successful orientation occurred under all conditions of viewing. Thus, pigeons can perceive and process magnetic compass directions with the right eye and left brain hemisphere as well as the left eye and right brain hemisphere. However, while the right brain hemisphere tended to confuse the learned direction with its opposite (axial response), the left brain hemisphere specifically preferred the correct direction. Our findings demonstrate bilateral processing of magnetic information, but also suggest qualitative differences in how the left and the right brain deal with magnetic cues

Magnetoreception of Directional Information in Birds Requires Nondegraded Vision

The magnetic compass orientation of birds is light dependent. The respective directional information, originating in radical pair processes, is mediated by the right eye. These findings suggest possible interactions between magnetoreception and vision, in particular with the perception of contours, because the right eye has been found to be dominant in discrimination tasks requiring object vision. Here we report tests in the local geomagnetic field with European robins wearing goggles equipped with a clear and a frosted foil of equal translucence of 70%. Robins with a clear foil on the right eye and a frosted foil on the left eye oriented in the migratory direction as well as birds using both eyes. Birds with a frosted foil that blurred vision on the right eye and a clear foil on the left eye, in contrast, were disoriented. These findings are the first to show that avian magnetoreception requires, in addition to light, a nondegraded image formation along the projectional streams of the right retina. This suggests crucial interactions between the processing of visual pattern information and the conversion of magnetic input into directional information