Search results for "Laterality"
showing 10 items of 307 documents
Melanism is related to behavioural lateralization in nestling barn owls.
2017
5 pages; International audience; Behavioural laterality is a commonly observed phenomenon in many species suggesting there might be an advantage of using dominantly one side over the other for certain tasks. Indeed, lateralized individuals were often shown to be more successful in cognitive tasks compared to non-lateralized conspecifics. However, stressed individuals are also often, but not always, more strongly lateralized. Because barn owl (Tyto alba) females displaying larger black spots on the tip of their ventral feathers produce offspring that are more resistant to a variety of environmental stressful factors, we examined whether laterality is associated with melanin-based coloration.…
Lateralization of complex behaviours in wild greater flamingos.
2018
8 pages; International audience; Lateralization refers to the preferential use of one side of the body to perform certain tasks, often as a consequence of the specialization of cerebral hemispheres. Individuals may benefit from lateralization if it allows them to perform complex tasks simultaneously. Studies on laterality further suggest that sex and age can influence the extent of lateralization. However, most studies on lateralization have been performed on captive individuals, exposed to simplified environments and expressing limited behavioural repertoire. Here, we evaluated behavioural lateralization in the greater flamingo, Phoenicopterus roseus, through observations of wild individua…
Vestibular thalamus: Two distinct graviceptive pathways.
2015
Objective: To determine whether there are distinct thalamic regions statistically associated with either contraversive or ipsiversive disturbance of verticality perception measured by subjective visual vertical (SVV). Methods: We used modern statistical lesion behavior mapping on a sample of 37 stroke patients with isolated thalamic lesions to clarify which thalamic regions are involved in graviceptive otolith processing and whether there are distinct regions associated with contraversive or ipsiversive SVV deviation. Results: We found 2 distinct systems of graviceptive processing within the thalamus. Contraversive tilt of SVV was associated with lesions to the nuclei dorsomedialis, intrala…
High-definition transcranial direct current stimulation to both primary motor cortices improves unimanual and bimanual dexterity.
2017
While most research on brain stimulation with transcranial direct current stimulation (tDCS) targets unimanual motor tasks, little is known about its effects on bimanual motor performance. This study aims to investigate the effects of tDCS on unimanual as well as bimanual motor dexterity. We examined the effects of bihemispheric anodal high-definition tDCS (HD-atDCS) on both primary motor cortices (M1) applied concurrent with unimanual and bimanual motor training. We then measured the effects with the Purdue Pegboard Test (PPT) and compared them to a sham stimulation. Between a pretest and posttest, 31 healthy, right-handed participants practiced the PPT on three consecutive days and receiv…
Exploring the neural correlates of the reversed letter effect: Evidence from left and right parietal patients.
2019
To investigate the hemispheric lateralization of attentional processes during visual search tasks depending on the stimulus material embedding the target, twelve patients with unilateral left (n = 7) or right (n = 5) parietal lesions and 20 age and education matched healthy controls (HC) were recruited. We used a visual search task for a uniquely tilted oblique bar embedded in an object shape 'N' or in its mirror reversal 'И'. The accuracy and the averaged reaction times (RTs) in each stimulus type ('N' or 'И') were analysed.\ud \ud HC presented significantly longer RTs when the target bar was embedded in 'N' among its mirror reversed 'И' (p < .05). This “reversed letter effect” was also…
Is laterality of congenital diaphragmatic hernia a reliable prognostic factor? French national cohort study.
2020
International audience; Objectives: The objective of this study was to assess whether the laterality of congenital diaphragmatic hernia (CDH) was a prognostic factor for neonatal survival.Methods : This was a cohort study using the French national database of the Reference Center for Diaphragmatic Hernias. The principal endpoint was survival after hospitalization in intensive care.We made a comparative study between right CDH and left CDH by univariate and multivariate analysis. Terminations and stillbirths were excluded from analyses of neonatal outcomes.Results: A total of 506 CDH were included with 67 (13%) right CDH and 439 left CDH (87%). Rate of survival was 49% for right CDH and 74% …
Dopamine, Noradrenaline and Serotonin Receptor Densities in the Striatum of Hemiparkinsonian Rats following Botulinum Neurotoxin-A Injection.
2017
Abstract Parkinson’s disease (PD) is characterized by a degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) that causes a dopamine (DA) deficit in the caudate-putamen (CPu) accompanied by compensatory changes in other neurotransmitter systems. These changes result in severe motor and non-motor symptoms. To disclose the role of various receptor binding sites for DA, noradrenaline, and serotonin in the hemiparkinsonian (hemi-PD) rat model induced by unilateral 6-hydroxydopamine (6-OHDA) injection, the densities of D1, D2/D3, α1, α2, and 5HT2A receptors were longitudinally visualized and measured in the CPu of hemi-PD rats by quantitative in vitro receptor autorad…
Interhemispheric inhibition is dynamically regulated during action observation
2016
International audience; It is now well established that the motor system plays a pivotal role in action observation and that the neurophysiological processes underlying perception and action overlaps. However, while various experiments have shown a specific facilitation of the contralateral motor cortex during action observation, no information is available concerning the dynamics of interhemispheric interactions. The aim of the present study was, therefore, to assess interhemispheric inhibition during the observation of others' actions. We designed a transcranial magnetic stimulation (TMS) experiment in which we measured both corticospinal excitability and interhemispheric inhibition, this…
An extensive pattern of atypical neural speech-sound discrimination in newborns at risk of dyslexia.
2019
Objective: Identifying early signs of developmental dyslexia, associated with deficient speech-sound processing, is paramount to establish early interventions. We aimed to find early speech-sound processing deficiencies in dyslexia, expecting diminished and atypically lateralized event-related potentials (ERP) and mismatch responses (MMR) in newborns at dyslexia risk. Methods: ERPs were recorded to a pseudoword and its variants (vowel-duration, vowel-identity, and syllable-frequency changes) from 88 newborns at high or no familial risk. The response significance was tested, and group, laterality, and frontality effects were assessed with repeated-measures ANOVA. Results: An early positive a…
A new 3-d approach to determine functional morphology of cercopithecoid molars.
2005
Summary Functional relationships between diet and tooth morphology form an integral part of primatological and paleontological research. Previously, mostly two-dimensional parameters have been used to compare and interpret the complex crown morphology of cercopithecine and colobine molars. However, as teeth are three-dimensional objects, any dimensional reduction in describing their morphology must result in loss of information. In the current study we use a high resolution optical topometric system to record crown morphology in different wear stages in order to extract three-dimensional (3-d) parameters from virtual 3-d models. Structural parameters such as relief index, occlusal surface a…