RESUMEN
Background: Asthma and allergic diseases are common chronic non-communicable conditions that can negatively impact the quality of life of patients. Psychological factors play a role in both the onset and progression of these conditions. The purpose of this study was to examine the relationship between handedness and emotion regulation and cognitive emotion regulation strategies in patients with asthma and allergies in Isfahan, central Iran. Methods: We employed a causal-comparative research design. The study population consisted of all patients visiting Asthma and Allergy Clinic in Isfahan. One hundred participants were selected through probability sampling. Data were collected using the Emotion Regulation Questionnaire and the Cognitive Emotion Regulation Strategies Questionnaire, and were analyzed using univariate analysis of variance (ANOVA). Results: Cognitive emotion regulation was significantly different between right-handed and left-handed patients with asthma and allergies (P=0.0001). A significant difference was also observed between the two groups in their emotion regulation strategies (P=0.031). The rate of positive and negative cognitive regulation strategies was higher in left-handed individuals with asthma and allergies, compared to right-handed individuals. Conclusion: Overall, handedness has a significant impact on the behavior and mental health of patients suffering from asthma and allergies. Therefore, handedness should be taken into consideration in interventions for emotion regulation.
RESUMEN
In a study of patterns of language laterality in left- and right-handers, Woodhead et al. (Woodhead ZVJ, Thompson PA, Karlsson EM, Bishop DVM. 2021 R. Soc. Open Sci. 8, 200696. (doi:10.1098/rsos.200696)) noted that several tasks showed no bias to the left hemisphere in left-handed individuals. This might appear to suggest that these functions were mediated by the two hemispheres working together equally-what can be termed 'hemispheric equipoise'. Here, I consider an alternative possibility that individuals show lateral bias on these tasks, but the bias can occur to either the left or right-a form of fluctuating asymmetry. Further analysis of the distributions of data from individuals in Woodhead et al. is compared with simulated data. The pattern of results suggests that the impression of hemispheric equipoise may be an artefact of reliance on group data: even though the group mean does not differ from zero, a high proportion of individuals are biased to the left or right.
RESUMEN
Our objective in this study was to investigate the effect of moderate-intensity aerobic exercise on visuospatial attention bias. We examined line bisection performance at rest before exercise and then immediately after exercise in 20 young adults. Pre-exercise, there was a larger leftward bias in subjective midpoint judgment of all participants than post-exercise (p < .001). Thus, leftward error magnitude decreased according to aerobic exercise, as there were rightward shifts after the exercise. The participants' performancse were modulated by the hand used to perform manual bisection tasks (p < .02). Participants erred to the left of the true midpoint with the non-dominant hand and to the right of the true midpoint with the dominant hand. The use of the non-dominant hand led to greater leftward error than the errors obtained using the dominant hand, though there was no interaction effect between hand use and effort. These findings suggest that moderate aerobic exercise can benefit visuospatial attention in adults.
RESUMEN
This study investigated the stroke and slope characteristics in left-handed and right-handed handwriting. Stroke (letters t, f, d, and H) and slope (letters t, f, l, d, and g) directions were analyzed on in-house samples (n = 64), revealing statistically significant differences (p ≤ 0.05) between the groups. Right-handers predominantly exhibited left-to-right strokes (98%-100%), while left-handers showed greater variability. Although statistically significant for most letters analyzed, slope direction did not demonstrate consistent patterns. A logistic regression model was developed and validated on the same sample to classify handedness based on the averaged strokes of the letter "t." The model was further tested on samples (n = 252) from a publicly available handwriting database. If the model classified the sample as produced by left hand, it was correct in 100% of cases. In contrast, when the model classified writing as right-handed, it was correct in 73%-97% of cases, depending on the validation sample. The model classified writing as of left-handed origin if more than 36% of the letters "t" had a stroke from right to left, while otherwise, writing was classified as of right-handed origin. The developed method showed great potential for classifying the handedness of the author of disputed handwriting, thus eliminating individuals as text authors or narrowing down the pool of potential authors.
RESUMEN
An 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. Therefore, having a consensus on how to determine mixed-handedness and how to distinguish it from ambidexterity is crucial for clinical laterality research. To this end, hand preference and hand performance data from more than 600 participants from the Dortmund Vital Study (Trial registration: ClinicalTrials.gov NCT05155397), a population-based study in Germany, was analyzed to ascertain an optimal classification to determine mixed-handedness and ambidexterity. Using a combination of latent class analyses, effect size determination, and comparisons with the existing literature, we establish that an LQ cut-off criterion of +/-60 for mixed-handedness is optimal for future clinical laterality studies. Moreover, we show that mixed-handedness and ambidexterity are not identical and that the terms should not be used interchangeably. We further highlight the need for a consensus on how to mathematically determine ambidexterity as results of existing categorization schemes largely differ.Trial registration: ClinicalTrials.gov NCT05155397; https://clinicaltrials.gov/ct2/show/NCT05155397.
Asunto(s)
Lateralidad Funcional , Humanos , Lateralidad Funcional/fisiología , Femenino , Masculino , Adulto , Fenotipo , Persona de Mediana Edad , Adulto Joven , Adolescente , AncianoRESUMEN
Research has established the influence of short-term physical practice for enhancing action prediction in right-handed (RH) individuals. In addition to benefits of physical practice for these later assessed perceptual-cognitive skills, effector-specific interference has been shown through action-incongruent secondary tasks (motor interference tasks). Here we investigated this experience-driven facilitation of action predictions and effector-specific interference in left-handed (LH) novices, before and after practicing a dart throwing task. Participants watched either RH (n = 19) or LH (n = 24) videos of temporally occluded dart throws, across a control condition and three secondary-task conditions: tone-monitoring, RH or LH force monitoring. These conditions were completed before and after physical practice throwing with the LH. Significantly greater improvement in prediction accuracy was shown post-practice for the LH- versus RH-video group. Consistent with previous work, effector-specific interference was shown, exclusive to the LH-video group. Only when doing the LH force monitoring task did the LH-video group show secondary task interference in prediction accuracy. These data support the idea that short-term physical practice resulted in the development of an effector-specific motor representation. The results are also consistent with other work in RH individuals (showing RH motor interference) and hence rule out the interpretation that these effector specific effects are due to the disruption of more generalized motor processes, thought to be lateralized to the left-hemisphere of the brain.
RESUMEN
Background: Hand laterality has an impact on surgical gestures. In this study, we sought to measure the multi-parameter variability of the microsurgical gesture depending on the hand used and the differences between expert microsurgeons and novices. Methods: Ten experienced microsurgeons and twenty medical students with no prior microsurgical experience performed arterial anastomosis on a chicken wing artery using dominant and non-dominant hands. We measured time and force using a homemade force-sensing microsurgical needle holder, heart rate variability with a Polar H10 chest strap, anxiety with the STAI-Y questionnaire and anastomosis quality using the MARS 10 scale. Results: In the microsurgeons' group, duration of anastomosis (p = 0.037), force applied to the needle holder (p = 0.047), anxiety (p = 0.05) and MARS10 (p = 0.291) were better with the dominant hand. For novices, there was no difference between the dominant and non-dominant hand pertaining to force, time and stress level. There were no differences between microsurgeons and novices pertaining to force and anxiety using the non-dominant hand. Conclusions: The study highlighted a marked laterality among microsurgical experts, a finding that may be explained by current learning methods. Surprisingly, no laterality is observed in students, suggesting that for a specific gesture completely different from everyday tasks, laterality is not predefined. Ambidexterity training in the residency curriculum seems relevant and may help microsurgeons improve performance and postoperative outcomes.
RESUMEN
Objectives: The effects of sex and handedness on financial capacity performance remain unexplored both in healthy older adults and in patients with amnestic mild cognitive impairment (aMCI). Methods: The aim of this study was to study the effect of the above factors (sex, handedness, and health condition), following a factorial experimental design; hence, eight groups (each with ten individuals) with similar demographic characteristics (age and education level) were formed consisting of right/left-handed, women/men and healthy/not healthy (with a diagnosis of aMCI) older adults. Mini-Mental State Examination (MMSE) was administered as a measure of general cognitive ability, and Legal Capacity for Property Law Transactions Assessment Scale (LCPLTAS) was used as an indicator of financial capacity; moreover, GDS-15 was used to assess depressive symptomatology. Self-reports of hand preference were also included. Results: Although as expected healthy men and women regardless of their handedness outperformed aMCI patients on MMSE and LCPLTAS, performance on cash transactions, bank statement management, bill payment, financial decision making, and knowledge of personal assets from LCPLTAS is significantly higher for right-handed aMCI women compared with left-handed aMCI women. Conclusions: Future research should further elucidate the reasons for this left-handed female patient with aMCI profile in larger groups of patients. This is an exploratory study, and the small sample size limits the strength of conclusions; further studies on this topic are needed.
RESUMEN
Structural and functional asymmetries are traceable in every form of life, and some lateralities are homologous. Functionally speaking, the division of labour between the two halves of the brain is a basic characteristic of the nervous system that arose even before the appearance of vertebrates. The most well-known expression of this specialisation in humans is hand dominance, also known as handedness. Even if hand/limb/paw dominance is far more commonly associated with the presence of a nervous system, it is also observed in its own form in aneural organisms, such as plants. To date, little is known regarding the possible functional significance of this dominance in plants, and many questions remain open (among them, whether it reflects a generalised behavioural asymmetry). Here, we propose a comparative approach to the study of handedness, including plants, by taking advantage of the experimental models and paradigms already used to study laterality in humans and various animal species. By taking this approach, we aim to enrich our knowledge of the concept of handedness across natural kingdoms.
RESUMEN
Handedness has traditionally been employed as a proxy of brain lateralization in research. Alzheimer's disease (AD) manifests as a neurodegenerative disorder characterized by impairments across various neuropsychological functions, including visuospatial and language, many of which exhibit lateralization in the human brain. While previous studies have investigated the relationship between AD and handedness, findings have been inconsistent. This article aims to provide an up-to-date overview of studies investigating hand preference in AD and the subtypes, specifically early- and late-onset AD. Through a synthesis of these studies, we conclude that handedness currently lacks utility as a diagnostic biomarker for AD and its subtypes, and this is further supported by the meta-analytic results based on data from over 10,000 AD patients. We emphasize the necessity for future research endeavors, particularly those leveraging advanced neuroimaging techniques to explore the role of brain asymmetry in AD.
Asunto(s)
Enfermedad de Alzheimer , Encéfalo , Lateralidad Funcional , Enfermedad de Alzheimer/fisiopatología , Humanos , Lateralidad Funcional/fisiología , Encéfalo/fisiopatologíaRESUMEN
Different forearm postures can modulate corticospinal excitability. However, there is no consensus on whether handedness plays a role in such a mechanism. This study investigated the effects of 3 forearm postures (pronation, neutral, and supination) on the corticospinal excitability of muscles from the dominant and nondominant upper limbs. Surface electromyography was recorded from the abductor digiti minimi, flexor pollicis brevis, and flexor carpi radialis from both sides of 12 right-handed volunteers. Transcranial magnetic stimulation pulses were applied to each muscle's hotspot in both cerebral hemispheres. Motor-evoked potential peak-to-peak amplitude and latency and resting motor threshold were measured. The data were evaluated by analysis of variance. The level of significance was set at 5%. The resting motor threshold was similar for the 3 muscles and both sides. Motor-evoked potential peak-to-peak amplitude from flexor pollicis brevis was lower during supination, and the dominant upper limb latency was longer. The flexor carpi radialis presented lower motor-evoked potential peak-to-peak amplitudes for neutral and shorter latencies during supination. Abductor digiti minimi seemed not to be affected by posture or side. Different muscles from dominant and nondominant sides may undergo corticospinal modulation, even distally localized from a particular joint and under rest.
Asunto(s)
Electromiografía , Potenciales Evocados Motores , Antebrazo , Mano , Músculo Esquelético , Postura , Tractos Piramidales , Estimulación Magnética Transcraneal , Humanos , Músculo Esquelético/fisiología , Masculino , Antebrazo/fisiología , Postura/fisiología , Potenciales Evocados Motores/fisiología , Mano/fisiología , Femenino , Tractos Piramidales/fisiología , Adulto , Lateralidad Funcional/fisiología , Adulto JovenRESUMEN
Reaction time (RT) is a widely used measure for testing physical performance in motor tasks. This study focused on assessing the processing speed in athletes. Twenty-five healthy volunteers were assigned to the control (n = 16) or athletes groups (n = 9). They were evaluated during motor reaction tasks based on visual stimuli and three difficulty conditions. Physiological measures were obtained from motion capture and electromyography recordings of several muscles. Two RT phases, decision-making (DMK) and electromechanical delay (EMD), were used to analyze the processing speed. The results show significant RT differences between groups. The athletes were ~30% faster compared to the control group. Despite the fact that all participants were right-handed, RT did not show any differences between hands performances in any group. However, DMK time revealed significant differences between the hands. Controls showed a longer DMK time for the right-hand election, ~20% more than the left, while athletes showed no such disparity. These findings reveal that quantifying the decision-making component of reaction time is crucial to assessing processing speed in sport. This approach could facilitate the monitoring of adaptations in both motor-cognitive and neuromuscular processes. The theoretical implications presented in this study offer perspectives on handedness research.
RESUMEN
BACKGROUND: Left-handedness is a condition that reverses the typical left cerebral dominance of motor control to an atypical right dominance. The impact of this distinct control - and its associated neuroanatomical peculiarities - on other cognitive functions such as music processing or playing a musical instrument remains unexplored. Previous studies in right-handed population have linked musicianship to a larger volume in the (right) auditory cortex and a larger volume in the (right) arcuate fasciculus. RESULTS: In our study, we reveal that left-handed musicians (n = 55), in comparison to left-handed non-musicians (n = 75), exhibit a larger gray matter volume in both the left and right Heschl's gyrus, critical for auditory processing. They also present a higher number of streamlines across the anterior segment of the right arcuate fasciculus. Importantly, atypical hemispheric lateralization of speech (notably prevalent among left-handers) was associated to a rightward asymmetry of the AF, in contrast to the leftward asymmetry exhibited by the typically lateralized. CONCLUSIONS: These findings suggest that left-handed musicians share similar neuroanatomical characteristics with their right-handed counterparts. However, atypical lateralization of speech might potentiate the right audiomotor pathway, which has been associated with musicianship and better musical skills. This may help explain why musicians are more prevalent among left-handers and shed light on their cognitive advantages.
Asunto(s)
Lateralidad Funcional , Música , Humanos , Masculino , Lateralidad Funcional/fisiología , Femenino , Adulto , Adulto Joven , Corteza Auditiva/anatomía & histología , Corteza Auditiva/fisiología , Imagen por Resonancia Magnética , Sustancia Gris/anatomía & histología , Sustancia Gris/diagnóstico por imagen , Percepción Auditiva/fisiología , Encéfalo/anatomía & histología , Encéfalo/fisiologíaRESUMEN
Hand preference is the preferential use of one hand for a single task. Its study provides insight into the neural mechanisms underlying motor skills, perception, and cognitive functions. From a comparative perspective, it also offers a window into evolutionary history, shedding light on whether manual preferences stem from genetics, environmental influences, or a combination of both. However, there is a paucity of information on preferential hand use for several primate taxa. Here we examine hand preference for the first time in mantled howler monkeys (Alouatta palliata) to determine if there is preferential hand use at the individual and population level as well as sex differences in hand use. We followed 17 wild adult individuals for 10 months and used focal animal sampling (506 focal samples) to record hand use in two types of self-directed behaviors, touching (1246 events) and scratching (1115 events). According to the binomial tests, four individuals were right-hand-preferent, two were left-hand-preferent, and 11 were ambilateral during touching, whereas for scratching seven individuals were right-hand-preferent, two were left-hand-preferent, and eight were ambilateral. At the population level, there was ambilaterality in both behaviors. At the individual level, according to the HI index, hand preference in touching and scratching were not associated and did not vary between sexes. These findings concur with previous studies with howler monkeys and other taxa suggesting that population-level hand preference is not a universal trait across primates.
Asunto(s)
Alouatta , Animales , Alouatta/fisiología , Masculino , Femenino , Lateralidad Funcional , Mano/fisiología , Conducta AnimalRESUMEN
Twin 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. These included the gene encoding beta-tubulin, TUBB4B, suggesting that microtubules are relevant for handedness ontogenesis.
Asunto(s)
Lateralidad Funcional , Tubulina (Proteína) , Tubulina (Proteína)/genética , Humanos , Lateralidad Funcional/genética , Variación Genética , Microtúbulos/genéticaRESUMEN
Objective.This study explores the changes in the organization of functional brain networks induced by performing a visuomotor integration task, as revealed by noninvasive spontaneous electroencephalographic traces (EEG).Approach.EEG data were acquired during the execution of the Nine Hole Peg Test (NHPT) with the dominant and non-dominant hands in a group of 44 right-handed volunteers. Both spectral analysis and phase-based connectivity analysis were performed in the theta (Ï), mu (µ) and beta (ß) bands. Graph Theoretical Analysis (GTA) was also performed to investigate the topological reorganization induced by motor task execution.Main results.Spectral analysis revealed an increase of frontoparietal Ï power and a spatially diffused reduction ofµand ß contribution, regardless of the hand used. GTA showed a significant increase in network integration induced by movement performed with the dominant limb compared to baseline in the Ï band. Theµand ß bands were associated with a reduction in network integration during the NHPT. In theµrhythm, this result was more evident for the right-hand movement, while in the ß band, results did not show dependence on the laterality. Finally, correlation analysis highlighted an association between frequency-specific topology measures and task performance for both hands.Significance.Our results show that functional brain networks reorganize during visually guided movements in a frequency-dependent manner, differently depending on the hand used (dominant/non dominant).
Asunto(s)
Encéfalo , Electroencefalografía , Lateralidad Funcional , Mano , Movimiento , Red Nerviosa , Desempeño Psicomotor , Humanos , Masculino , Electroencefalografía/métodos , Femenino , Mano/fisiología , Adulto , Desempeño Psicomotor/fisiología , Movimiento/fisiología , Adulto Joven , Red Nerviosa/fisiología , Lateralidad Funcional/fisiología , Encéfalo/fisiología , Percepción Visual/fisiologíaRESUMEN
Handedness, a complex human aspect that reflects the functional lateralization of the hemispheres, also interacts with the immune system. This study aimed to expand the knowledge of the lateralization of hand, foot, and eye activities in patients with immune-mediated (IM) or other (noIM) neurological diseases and to clarify the properties of the Edinburgh Handedness Inventory (EHI) in an Italian population. Three hundred thirty-four patients with IM or noIM diseases affecting the brain or spine and peripheral nervous system were interviewed about stressful events preceding the disease, subjective handedness, and familiarity for left-handedness or ambidexterity. The patients and 40 healthy subjects underwent EHI examination. In the whole group of participants, 24 items of the EHI were classified into five factors (Hand Transitive, Hand Refined, Hand Median, Foot, Eye), demonstrating good reliability and validity. Chronological age had a significant influence on hand and foot EHI factors and the laterality quotient (LQ), particularly on writing and painting. In the patient groups, EHI factors and the LQ were also predicted by age of disease onset, duration of disease, and family history of left-handedness or ambidexterity. No differences were found between patients and healthy subjects, but pencil use scored significantly lower in patients with IM diseases than in those with noIM brain diseases. These results demonstrate that the lateralization of hand and foot activities is not a fixed human aspect, but that it can change throughout life, especially for abstract and symbolic activities. Chronic neurological diseases can cause changes in handedness. This may explain why, unlike systemic immunological diseases, IM neurological diseases are not closely associated with left-handedness. In these patients, the long version of the EHI is appropriate for determining the lateralization of body activities to contextualize the neurological picture; therefore, these findings extend the Italian normative data sets.
RESUMEN
Left and right-hand exhibit differences in the execution of movements. Particularly, it has been shown that manual goal-directed aiming is more accurate with the right hand than with the left, which has been explained through the shorter time spent by the right hand in the feedback phase (FB). This explanation makes sense for the temporal aspects of the task; however, there is a lack of explanations for the spatial aspects. The present study hypothesizes that the right hand is more associated with the FB, while the left hand is more strongly associated with the pre-programming phase (PP). In addition, the present study aims to investigate differences between hands in functional brain connectivity (FBC). We hypothesize an increase in FBC of the right hand compared to the left hand. Twenty-two participants performed 20 trials of the goal-directed aiming task with both hands. Overall, the results confirm the study's hypotheses. Although the right hand stopped far from the target at the PP, it exhibited a lower final position error than the left hand. These findings imply that during the FB, the right hand compensates for the higher error observed in the PP, using the visual feedback to approach the target more closely than the left hand. Conversely, the left hand displayed a lower error at the PP than the right. Also, the right hand displayed greater FBC within and between brain hemispheres. This heightened connectivity in the right hand might be associated with inhibitory mechanisms between hemispheres.
Asunto(s)
Encéfalo , Electroencefalografía , Lateralidad Funcional , Mano , Desempeño Psicomotor , Humanos , Masculino , Electroencefalografía/métodos , Femenino , Desempeño Psicomotor/fisiología , Mano/fisiología , Adulto Joven , Adulto , Lateralidad Funcional/fisiología , Encéfalo/fisiología , Retroalimentación Sensorial/fisiologíaRESUMEN
Regions in the brain that are selective for images of hands and tools have been suggested to be lateralised to the left hemisphere of right-handed individuals. In left-handers, many functions related to tool use or tool pantomime may also depend more on the left hemisphere. This result seems surprising, given that the dominant hand of these individuals is controlled by the right hemisphere. One explanation is that the left hemisphere is dominant for speech and language in the majority of left-handers, suggesting a supraordinate control system for complex motor sequencing that is required for skilled tool use, as well as for speech. In the present study, we examine if this left-hemispheric specialisation extends to perception of hands and tools in left- and right-handed individuals. We, crucially, also include a group of left-handers with right-hemispheric language dominance to examine their asymmetry biases. The results suggest that tools lateralise to the left hemisphere in most right-handed individuals with left-hemispheric language dominance. Tools also lateralise to the language dominant hemisphere in right-hemispheric language dominant left-handers, but the result for left-hemispheric language dominant left-handers are more varied, and no clear bias towards one hemisphere is found. Hands did not show a group-level asymmetry pattern in any of the groups. These results suggest a more complex picture regarding hemispheric overlap of hand and tool representations, and that visual appearance of tools may be driven in part by both language dominance and the hemisphere which controls the motor-dominant hand.
Asunto(s)
Dominancia Cerebral , Lateralidad Funcional , Humanos , Lenguaje , Encéfalo , Habla , PercepciónRESUMEN
Lateralization is a key aspect of brain architecture and handedness is its primary manifestation. The Edinburgh Handedness Inventory (EHI) and the laterality quotient (LQ) assess the direction and consistency of handedness and require translation and cross-cultural adaptation to guarantee construct validity. We developed a standardized Italian EHI version. The developed Italian version was tested on 202 Italian subjects, classified into three hand types based on their LQs: right, mixed, and left. The frequency of left-handedness in Italians and other populations was compared to previous data. LQs from the twenty- and the ten-item original inventories were also compared. We conducted a factorial analysis. Mcdonald's Omega tested internal consistency. The prevalence of left-handedness was 6.4%, consistent with prior findings in Italian samples and other EHI translations. Age was the only socio-demographic variable that significantly affected the LQ. The internal consistency of the Italian EHI was excellent. Handedness is a feature of several cognitive functions and some neuropsychological diseases; it is influenced by socio-demographic and cultural factors and the instrument used to assess it. To provide a consistent and comparable evaluation of the construct, we recommend using this validated Italian translation of the EHI.