Structural hemispheric asymmetry has long been assumed to guide functional lateralization of the human brain, but empirical evidence for this compelling hypothesis remains scarce. Recently, it has been suggested that microstructural asymmetries may be more relevant to functional lateralization than macrostructural asymmetries. To investigate the link between microstructure and function, we analyzed multimodal MRI data in 907 right-handed participants.
View Article and Find Full Text PDFAthletes in bodybuilding can pose favouring one side or the other of the body while being evaluated in the contests. While previous research assessed lateral bias of posing in a variety of situations, no investigation has been conducted in bodybuilding. We analyzed the lateral posing bias of the Top 15 athletes for the mandatory poses in Classic Physique Mr.
View Article and Find Full Text PDFOnline test protocols are increasingly popular in psychological and neuroscientific research. Despite its relevance to the social functioning, the influence of acute stress on cognitive and affective state empathy is not clearly understood. Recently, a remote online version (TSST-OL) of the Trier Social Stress Test (TSST) was established for use in research with both children and adults.
View Article and Find Full Text PDFEur Arch Psychiatry Clin Neurosci
September 2024
How stress affects functional hemispheric asymmetries is relevant because stress represents a risk factor for the development of mental disorders and various mental disorders are associated with atypical lateralization. Using three lateralization tasks, we investigated whether functional hemispheric asymmetries in the form of hemispheric dominance for language (verbal dichotic listening task), emotion processing (emotional dichotic listening task), and visuo-spatial attention (line bisection task) were affected by acute stress in healthy adults. One hundred twenty right-handed men and women performed these lateralization tasks in randomized order after exposure to a mild online stressor (i.
View Article and Find Full Text PDFSeveral neurodevelopmental disorders are associated with a higher prevalence of atypical laterality (e.g., left-handedness).
View Article and Find Full Text PDFThe traditional classifications of motor skills nature (open vs closed; fine vs gross) have not been considered in handedness investigations. Instead, previous research focused on comparing complex vs less complex motor behaviour, leaving a gap in the literature. We compared manual preference between different motor skill characteristics, namely: fine and closed (FC), gross and closed (GC) and gross and open (GO) tasks.
View Article and Find Full Text PDFAn increased prevalence of mixed-handedness has been reported in several neurodevelopmental and psychiatric disorders. Unfortunately, there is high between-study variability in the definition of mixed-handedness, leading to a major methodological problem in clinical laterality research and endangering replicability and comparability of research findings. Adding to this challenge is the fact that sometimes researchers use the concepts of mixed-handedness and ambidexterity interchangeably.
View Article and Find Full Text PDFEur Arch Psychiatry Clin Neurosci
June 2024
While most people are right-handed, a minority are left-handed or mixed-handed. It has been suggested that mental and developmental disorders are associated with increased prevalence of left-handedness and mixed-handedness. However, substantial heterogeneity exists across disorders, indicating that not all disorders are associated with a considerable shift away from right-handedness.
View Article and Find Full Text PDFThe human brain shows distinct lateralized activation patterns for a range of cognitive processes. One such function, which is thought to be lateralized to the right hemisphere (RH), is human face processing. Its importance for social communication and interaction has led to a plethora of studies investigating face processing in health and disease.
View Article and Find Full Text PDFNo two human brains are alike, and with the rise of precision medicine in neurology, we are seeing an increased emphasis on understanding the individual variability in brain structure and function that renders every brain unique. Functional and structural brain asymmetries are a fundamental principle of brain organization, and recent research suggests substantial individual variability in these asymmetries that needs to be considered in clinical practice. In this Review, we provide an overview of brain asymmetries, variations in such asymmetries and their relevance in the clinical context.
View Article and Find Full Text PDFTwin studies suggest that additive genetic effects account for about a quarter of the variance in handedness. Recently, Schijven et al. used exome-wide sequencing to provide evidence for a role of rare protein-coding variants in handedness.
View Article and Find Full Text PDFStudying behavioural lateralization in animals holds great potential for answering important questions in laterality research and clinical neuroscience. However, comparative research encounters challenges in reliability and validity, requiring new approaches and innovative designs to overcome. Although validated tests exist for some species, there is yet no standard test to compare lateralized manual behaviours between individuals, populations, and animal species.
View Article and Find Full Text PDFOn the surface, the two hemispheres of vertebrate brains look almost perfectly symmetrical, but several motor, sensory, and cognitive systems show a deeply lateralized organization. Importantly, the two hemispheres are connected by various commissures, white matter tracts that cross the brain's midline and enable cross-hemispheric communication. Cross-hemispheric communication has been suggested to play an important role in the emergence of lateralized brain functions.
View Article and Find Full Text PDFData collection in remote and field settings gains importance and popularity in stress research. Accordingly, existing stress induction paradigms have been successfully adapted to remote and field settings. However, guidelines for the comprehensive assessment of biomarkers such as salivary alpha-amylase (sAA) have yet to be sufficiently established for such contexts.
View Article and Find Full Text PDFInt J Bipolar Disord
December 2023
Background: Bipolar disorder (BD) is often seen as a bridge between schizophrenia and depression in terms of symptomatology and etiology. Interestingly, hemispheric asymmetries as well as behavioral lateralization are shifted towards a tendency of left-side or mixed-side bias in schizophrenia whereas no shift is observed in subjects with depression. Given the role of BD with both, (hypo)manic and depressive episodes, investigating hemispheric asymmetries in subjects with BD is an interesting objective.
View Article and Find Full Text PDFTouching a mark on the own body when seeing this mark in a mirror is regarded as a correlate of self-awareness and seems confined to great apes and a few further species. However, this paradigm often produces false-negative results and possibly dichotomizes a gradual evolutionary transition of self-recognition. We hypothesized that this ability is more widespread if ecologically tested and developed such a procedure for a most unlikely candidate: chickens (Gallus gallus domesticus).
View Article and Find Full Text PDFReduced hemispheric asymmetries, as well as their behavioral manifestation in the form of atypical handedness (i.e., non-right, left-, or mixed-handedness), are linked to neurodevelopmental disorders, such as autism spectrum disorder, and several psychiatric disorders, such as schizophrenia.
View Article and Find Full Text PDFSince almost a hundred years, psychologists have investigated the link between hand preference and dyslexia. We present a meta-analysis to determine whether there is indeed an increase in atypical hand preference in dyslexia. We included studies used in two previous meta-analyses (Bishop, 1990; Eglinton & Annett, 1994) as well as studies identified through PubMed MEDLINE, PsycInfo, Google Scholar, and Web of Science up to August 2022.
View Article and Find Full Text PDFThe development of handedness and other form of functional asymmetries is not yet understood in its critical determinants. Early life factors (e.g.
View Article and Find Full Text PDFHandedness is a core phenotype in clinical laterality research and several different disorders such as schizophrenia and autism spectrum disorders have been linked to a higher prevalence of non-right-handedness. Moreover, subclinical personality traits like schizotypy have been linked to a higher prevalence of non-right-handedness. The association with handedness is poorly understood for generalized anxiety disorder and specific phobias, as well as for state and trait anxiety and fear of specific stimuli in nonclinical samples.
View Article and Find Full Text PDFVirtual reality (VR) is increasingly used in neuroscientific research to increase ecological validity without sacrificing experimental control, to provide a richer visual and multisensory experience, and to foster immersion and presence in study participants, which leads to increased motivation and affective experience. But the use of VR, particularly when coupled with neuroimaging or neurostimulation techniques such as electroencephalography (EEG), functional magnetic resonance imaging (fMRI), or transcranial magnetic stimulation (TMS), also yields some challenges. These include intricacies of the technical setup, increased noise in the data due to movement, and a lack of standard protocols for data collection and analysis.
View Article and Find Full Text PDFMost studies on emotion processing induce emotions through images or films. However, this method lacks ecological validity, limiting generalization to real-life emotion processing. More realistic paradigms using virtual reality (VR) may be better suited to investigate authentic emotional states and their neuronal correlates.
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