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1.
J Nepal Health Res Counc ; 21(4): 599-602, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38616589

RESUMO

BACKGROUND: Bruch's membrane opening area is the circular area around the disc of Bruch's membrane, which is devoid of Bruch's membrane and can be assessed by capturing the retinal imaging system by Spectral-domain optical coherence tomography. BMOA can be a new landmark in analyzing the glaucomatous optic nerve head, myopic optic disc, optic neuropathy and uveitic disc edema. This is the first study from South Asia to evaluate the normal Bruch's membrane opening area among Nepalese eyes. METHODS: This hospital-based, cross-sectional, quantitative, observational study cross-sectional study was conducted in a tertiary eye care hospital in Nepal. Healthy immunocompetent Nepalese participants of both genders and different age groups were enrolled. The mean average Bruch's membrane opening area of each eyes, the difference in Bruch's membrane opening area between the two eyes and the gender of varying age groups were analyzed. RESULTS: Around 162 eyes (81 participants) were analyzed. The mean age was 56.69±17.5years. The mean average Bruch's membrane opening area of the right and left eye was 2.53±0.58 mm2 and 2.50 ±0.58 mm2. There was no significant difference in the Bruch's membrane opening area in either eye in both genders of any age group. CONCLUSION: The Bruch's membrane opening area does not differ significantly according to the laterality, gender and age group in Nepalese eyes.


Assuntos
Lâmina Basilar da Corioide , População do Sul da Ásia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Lâmina Basilar da Corioide/diagnóstico por imagem , Estudos Transversais , Lateralidade Funcional , Nepal
3.
Nat Commun ; 15(1): 2632, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38565598

RESUMO

Handedness is a manifestation of brain hemispheric specialization. Left-handedness occurs at increased rates in neurodevelopmental disorders. Genome-wide association studies have identified common genetic effects on handedness or brain asymmetry, which mostly involve variants outside protein-coding regions and may affect gene expression. Implicated genes include several that encode tubulins (microtubule components) or microtubule-associated proteins. Here we examine whether left-handedness is also influenced by rare coding variants (frequencies ≤ 1%), using exome data from 38,043 left-handed and 313,271 right-handed individuals from the UK Biobank. The beta-tubulin gene TUBB4B shows exome-wide significant association, with a rate of rare coding variants 2.7 times higher in left-handers than right-handers. The TUBB4B variants are mostly heterozygous missense changes, but include two frameshifts found only in left-handers. Other TUBB4B variants have been linked to sensorineural and/or ciliopathic disorders, but not the variants found here. Among genes previously implicated in autism or schizophrenia by exome screening, DSCAM and FOXP1 show evidence for rare coding variant association with left-handedness. The exome-wide heritability of left-handedness due to rare coding variants was 0.91%. This study reveals a role for rare, protein-altering variants in left-handedness, providing further evidence for the involvement of microtubules and disorder-relevant genes.


Assuntos
Lateralidade Funcional , Estudo de Associação Genômica Ampla , Humanos , Exoma/genética , Encéfalo , Proteínas Repressoras/genética , Fatores de Transcrição Forkhead/genética
4.
Nat Commun ; 15(1): 2355, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491089

RESUMO

Handedness develops early in life, but the structural and functional brain connectivity patterns associated with it remains unknown. Here we investigate associations between handedness and the asymmetry of brain connectivity in 9- to 10-years old children from the Adolescent Brain Cognitive Development (ABCD) study. Compared to right-handers, left-handers had increased global functional connectivity density in the left-hand motor area and decreased it in the right-hand motor area. A connectivity-based index of handedness provided a sharper differentiation between right- and left-handers. The laterality of hand-motor connectivity varied as a function of handedness in unimodal sensorimotor cortices, heteromodal areas, and cerebellum (P < 0.001) and reproduced across all regions of interest in Discovery and Replication subsamples. Here we show a strong association between handedness and the laterality of the functional connectivity patterns in the absence of differences in structural connectivity, brain morphometrics, and cortical myelin between left, right, and mixed handed children.


Assuntos
Lateralidade Funcional , Córtex Sensório-Motor , Adolescente , Criança , Humanos , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Cerebelo
5.
Headache ; 64(3): 259-265, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38433351

RESUMO

OBJECTIVE: The goal of this study was to clarify whether clinical differences exist between patients with migraine who experience headache that is typically left-sided ("left-migraine") versus right-sided ("right-migraine") during attacks. BACKGROUND: Migraine has been associated with unilateral headache for millennia and remains a supportive trait for the clinical diagnosis of migraine of the International Classification of Headache Disorders. It is currently unknown why headache in migraine is commonly unilateral, and whether headache-sidedness is associated with other clinical features. METHODS: This is a cross-sectional study comparing left- versus right-migraine using all available intake questionnaires of new patients evaluated at an academic tertiary headache center over a 20-year period. Eligibility was based on patient written responses indicating the typical location of headache during attacks. In our analyses, the side of headache (left or right) was the predictor variable. The outcomes included various migraine characteristics and psychiatric comorbidities. RESULTS: We identified 6527 patients with migraine, of which 340 met study eligibility criteria. Of these, 48.8% (166/340) had left migraine, and 51.2% (174/340) had right migraine. When comparing patients with left- versus right-migraine, patients with left migraine experienced 3.6 fewer headache-free days (95% confidence interval [CI] 1.3-5.9; p = 0.002) and 2.4 more severe headache days (95% CI 0.8-4.1; p = 0.004) in the previous 4 weeks. No significant differences in age, sex, handedness, migraine characteristics, or psychiatric comorbidities were identified between the two groups. CONCLUSIONS: Patients with migraine with typically left-sided headache during attacks reported a higher burden of headache frequency and severity than those with typically right-sided headache during attacks. These findings may have implications for our understanding of migraine pathophysiology, treatment, and clinical trial design.


Assuntos
Transtornos de Enxaqueca , Humanos , Estudos Transversais , Transtornos de Enxaqueca/tratamento farmacológico , Cefaleia , Lateralidade Funcional/fisiologia , Inquéritos e Questionários
6.
PeerJ ; 12: e17036, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38436021

RESUMO

Accelerometers are sensors proven to be useful to analyze the lying behavior of cows. For reasons of algorithm transparency and control, researchers often prefer to use their own data analysis scripts rather than proprietary software. We developed the triact R package that assists animal scientists in analyzing the lying behavior of cows from raw data recorded with a triaxial accelerometer (manufacturer agnostic) attached to a hind leg. In a user-friendly workflow, triact allows the determination of common measures for lying behavior including total lying duration, the number of lying bouts, and the mean duration of lying bouts. Further capabilities are the description of lying laterality and the calculation of proxies for the level of physical activity of the cow. In this publication we describe the functionality of triact and the rationales behind the implemented algorithms. The triact R package is developed as an open-source project and freely available via the CRAN repository.


Assuntos
Algoritmos , Análise de Dados , Feminino , Animais , Bovinos , Lateralidade Funcional , Registros , Acelerometria
7.
Sci Rep ; 14(1): 6456, 2024 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-38499660

RESUMO

The aim was to investigate the effect of breathing conditions and swimming pace on the relationships between the impairment, the breathing laterality and motor coordination symmetry in elite front crawl Para swimmers. Fifteen elite Para swimmers with unilateral physical impairment or with visual impairment and unilateral breathing preference performed eight 25 m using four breathing conditions (every three strokes, every two strokes on preferred and non-preferred breathing side and apnea) at slow and fast paces in a randomized order. Multicamera video system and five sensors have been used to assess arm and leg stroke phases and to compute symmetry of arm coordination (SIIdC) and of leg kick rate (SIKR). Our findings emphasized motor coordination asymmetry whatever the breathing conditions and swimming paces, highlighting the influence of impairment. Multinomial logistic regression exhibited a high probability for motor coordination asymmetry (SIIdC and SIKR) to be present in categories of Para swimmers with impairment and breathing laterality on the same side, suggesting the joined effect of unilateral impairment and unilateral breathing. Moreover, unilateral physical impairment and breathing laterality could also occur on different sides and generate motor coordination asymmetry on different sides and different levels (arms vs. legs). Finally, visual impairment seems amplify the effect of unilateral breathing on motor coordination asymmetry.


Assuntos
Lateralidade Funcional , Fenômenos Fisiológicos Musculoesqueléticos , Humanos , Fenômenos Biomecânicos , Respiração , Natação , Braço , Transtornos da Visão
8.
Neuropsychologia ; 196: 108837, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38428518

RESUMO

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.


Assuntos
Dominância Cerebral , Lateralidade Funcional , Humanos , Idioma , Encéfalo , Fala , Percepção
9.
Neuropsychologia ; 196: 108848, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38432323

RESUMO

This study aimed to investigate whether neurological patients presenting with a bias in line bisection show specific problems in bisecting a line into two equal parts or their line bisection bias rather reflects a special case of a deficit in proportional reasoning more generally. In the latter case, the bias should also be observed for segmentations into thirds or quarters. To address this question, six neglect patients with a line bisection bias were administered additional tasks involving horizontal lines (e.g., segmentation into thirds and quarters, number line estimation, etc.). Their performance was compared to five neglect patients without a line bisection bias, 10 patients with right hemispheric lesions without neglect, and 32 healthy controls. Most interestingly, results indicated that neglect patients with a line bisection bias also overestimated segments on the left of the line (e.g., one third, one quarter) when dissecting lines into parts smaller than halves. In contrast, such segmentation biases were more nuanced when the required line segmentation was framed as a number line estimation task with either fractions or whole numbers. Taken together, this suggests a generalization of line bisection bias towards a segmentation or proportional processing bias, which is congruent with attentional weighting accounts of line bisection/neglect. As such, patients with a line bisection bias do not seem to have specific problems bisecting a line, but seem to suffer from a more general deficit processing proportions.


Assuntos
Lateralidade Funcional , Transtornos da Percepção , Humanos , Transtornos da Percepção/etiologia , Atenção , Viés , Generalização Psicológica , Percepção Espacial
10.
Nat Commun ; 15(1): 2639, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38531844

RESUMO

Asymmetry between the left and right hemisphere is a key feature of brain organization. Hemispheric functional specialization underlies some of the most advanced human-defining cognitive operations, such as articulated language, perspective taking, or rapid detection of facial cues. Yet, genetic investigations into brain asymmetry have mostly relied on common variants, which typically exert small effects on brain-related phenotypes. Here, we leverage rare genomic deletions and duplications to study how genetic alterations reverberate in human brain and behavior. We designed a pattern-learning approach to dissect the impact of eight high-effect-size copy number variations (CNVs) on brain asymmetry in a multi-site cohort of 552 CNV carriers and 290 non-carriers. Isolated multivariate brain asymmetry patterns spotlighted regions typically thought to subserve lateralized functions, including language, hearing, as well as visual, face and word recognition. Planum temporale asymmetry emerged as especially susceptible to deletions and duplications of specific gene sets. Targeted analysis of common variants through genome-wide association study (GWAS) consolidated partly diverging genetic influences on the right versus left planum temporale structure. In conclusion, our gene-brain-behavior data fusion highlights the consequences of genetically controlled brain lateralization on uniquely human cognitive capacities.


Assuntos
Variações do Número de Cópias de DNA , Estudo de Associação Genômica Ampla , Humanos , Lateralidade Funcional , Mapeamento Encefálico , Encéfalo , Imageamento por Ressonância Magnética
11.
Neurosci Biobehav Rev ; 160: 105622, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38490498

RESUMO

The present review examined the consequences of focal brain injury on spatial attention studied with cueing paradigms, with a particular focus on the disengagement deficit, which refers to the abnormal slowing of reactions following an ipsilesional cue. Our review supports the established notion that the disengagement deficit is a functional marker of spatial neglect and is particularly pronounced when elicited by peripheral cues. Recent research has revealed that this deficit critically depends on cues that have task-relevant characteristics or are associated with negative reinforcement. Attentional capture by task-relevant cues is contingent on damage to the right temporo-parietal junction (TPJ) and is modulated by functional connections between the TPJ and the right insular cortex. Furthermore, damage to the dorsal premotor or prefrontal cortex (dPMC/dPFC) reduces the effect of task-relevant cues. These findings support an interactive model of the disengagement deficit, involving the right TPJ, the insula, and the dPMC/dPFC. These interconnected regions play a crucial role in regulating and adapting spatial attention to changing intrinsic values of stimuli in the environment.


Assuntos
Lesões Encefálicas , Transtornos da Percepção , Humanos , Córtex Pré-Frontal , Transtornos da Percepção/etiologia , Sinais (Psicologia) , Percepção Espacial/fisiologia , Lobo Parietal/fisiologia , Lateralidade Funcional/fisiologia , Tempo de Reação/fisiologia
12.
Sci Rep ; 14(1): 2776, 2024 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-38307983

RESUMO

Autistic children often exhibit atypical brain lateralization of language processing, but it is unclear what aspects of language contribute to this phenomenon. This study employed functional near-infrared spectroscopy to measure hemispheric lateralization by estimating hemodynamic responses associated with processing linguistic and non-linguistic auditory stimuli. The study involved a group of autistic children (N = 20, mean age = 5.8 years) and a comparison group of nonautistic peers (N = 20, mean age = 6.5 years). The children were presented with stimuli with systematically decreasing linguistic relevance: naturalistic native speech, meaningless native speech with scrambled word order, nonnative speech, and music. The results revealed that both groups showed left lateralization in the temporal lobe when listening to naturalistic native speech. However, the distinction emerged between autism and nonautistic in terms of processing the linguistic hierarchy. Specifically, the nonautistic comparison group demonstrated a systematic reduction in left lateralization as linguistic relevance decreased. In contrast, the autism group displayed no such pattern and showed no lateralization when listening to scrambled native speech accompanied by enhanced response in the right hemisphere. These results provide evidence of atypical neural specialization for spoken language in preschool- and school-age autistic children and shed new light on the underlying linguistic correlates contributing to such atypicality at the sublexical level.


Assuntos
Transtorno Autístico , Percepção da Fala , Criança , Humanos , Pré-Escolar , Fala/fisiologia , Lateralidade Funcional/fisiologia , Percepção da Fala/fisiologia , Encéfalo/fisiologia
13.
Curr Med Imaging ; 20: 1-9, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38389361

RESUMO

OBJECTIVE: Cytoarchitectonic mapping has revealed distinct subregions within Broadmann area 4 (BA 4) - BA 4a and BA 4p - with varying functional roles across tasks. We investigate their functional connectivity using resting-state functional magnetic resonance imaging (rsfMRI) to explore bilateral differences and the impact of handedness on connectivity within major brain networks. METHODS: This retrospective study involved 54 left- and right-handed subjects. We employed regions-to-regions-network rsfMRI analysis to examine the Cytoarchitectonic mapping of BA 4a and BA 4p functional connectivity with eight major brain networks. RESULTS: Our findings reveal differential connectivity patterns in both right-handed and left-handed subjects: Both right-handed subjects' BA 4a and BA 4p subregions exhibit connections to sensorimotor, dorsal attention, frontoparietal, and anterior cerebellar networks. Notably, BA 4a shows unique connectivity to the posterior cerebellum, lateral visual networks, and select salience regions. Similar connectivity patterns are observed in left-handed subjects, with BA 4a linked to sensorimotor, dorsal attention, frontoparietal, and anterior cerebellar networks. However, BA 4a in left-handed subjects shows distinct connectivity only to the posterior cerebellum. In both groups, the right portion of BA 4 demonstrates heightened connectivity compared to the left portion within each subregion. CONCLUSION: Our study uncovers complex patterns of functional connectivity within BA 4a and BA 4p, influenced by handedness. These findings emphasize the importance of considering hemisphere-specific and handedness-related factors in functional connectivity analyses, with potential implications for understanding brain organization in health and neurodegenerative diseases.


Assuntos
Mapeamento Encefálico , Córtex Motor , Humanos , Mapeamento Encefálico/métodos , Córtex Motor/diagnóstico por imagem , Lateralidade Funcional , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos
14.
Nat Commun ; 15(1): 956, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38302499

RESUMO

The human brain demonstrates structural and functional asymmetries which have implications for ageing and mental and neurological disease development. We used a set of magnetic resonance imaging (MRI) metrics derived from structural and diffusion MRI data in N=48,040 UK Biobank participants to evaluate age-related differences in brain asymmetry. Most regional grey and white matter metrics presented asymmetry, which were higher later in life. Informed by these results, we conducted hemispheric brain age (HBA) predictions from left/right multimodal MRI metrics. HBA was concordant to conventional brain age predictions, using metrics from both hemispheres, but offers a supplemental general marker of brain asymmetry when setting left/right HBA into relationship with each other. In contrast to WM brain asymmetries, left/right discrepancies in HBA are lower at higher ages. Our findings outline various sex-specific differences, particularly important for brain age estimates, and the value of further investigating the role of brain asymmetries in brain ageing and disease development.


Assuntos
Lateralidade Funcional , Substância Branca , Masculino , Feminino , Humanos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Imageamento por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
15.
Am J Occup Ther ; 78(2)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38305818

RESUMO

IMPORTANCE: Handedness and motor asymmetry are important features of occupational performance. With an increased understanding of the basic neural mechanisms surrounding handedness, clinicians will be better able to implement targeted, evidence-based neurorehabilitation interventions to promote functional independence. OBJECTIVE: To review the basic neural mechanisms behind handedness and their implications for central and peripheral nervous system injury. DATA SOURCES: Relevant published literature obtained via MEDLINE. FINDINGS: Handedness, along with performance asymmetries observed between the dominant and nondominant hands, may be due to hemispheric specializations for motor control. These specializations contribute to predictable motor control deficits that are dependent on which hemisphere or limb has been affected. Clinical practice recommendations for occupational therapists and other rehabilitation specialists are presented. CONCLUSIONS AND RELEVANCE: It is vital that occupational therapists and other rehabilitation specialists consider handedness and hemispheric lateralization during evaluation and treatment. With an increased understanding of the basic neural mechanisms surrounding handedness, clinicians will be better able to implement targeted, evidence-based neurorehabilitation interventions to promote functional independence. Plain-Language Summary: The goal of this narrative review is to increase clinicians' understanding of the basic neural mechanisms related to handedness (the tendency to select one hand over the other for specific tasks) and their implications for central and peripheral nervous system injury and rehabilitation. An enhanced understanding of these mechanisms may allow clinicians to better tailor neurorehabilitation interventions to address motor deficits and promote functional independence.


Assuntos
Lateralidade Funcional , Mãos , Humanos , Lateralidade Funcional/fisiologia , Mãos/fisiologia , Sistema Nervoso Periférico , Idioma
16.
Hum Mov Sci ; 94: 103196, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38402657

RESUMO

Perception of task goal influences motor performance and coordination. In bimanual actions, it is unclear how one's perception of task goals influences bimanual coordination and performance in individuals with unilateral stroke. We characterized inter-limb coordination differences in individuals with chronic right- and left-hemisphere damaged (RCVA: n = 24, LCVA: n = 24) stroke and age-matched neurotypical controls (n = 24) as they completed bimanual reaching tasks under distinct goal conditions. In the dual-goal condition, participants reached to move two virtual bricks (cursors) assigned to each hand toward independent targets. In the common-goal condition, they moved a central common virtual brick representing both hands to a single, central target. Spatial and temporal coordination (cross-correlation coefficients of hand velocity and their time-lag), the redundant axis deviations (the hand deviations in the axis orthogonal to the axis along the cursor-target direction), and the contribution ratio of the paretic hand were measured. Compared to the dual-goal condition, reaching actions to the common-goal demonstrated better spatial bimanual coordination in all three participant groups. Temporal coordination was better during common-goal than dual-goal actions only for the LCVA group. Additionally, and novel to this field, sex, as a biological variable, differently influenced movement time and redundant axis deviation in participants with stroke under the common-goal condition. Specifically, female stroke survivors showed larger movements in the redundant axes and, consequently, longer movement times, which was more prominent in the LCVA group. Our results indicate that perception of task goals influences bimanual coordination, with common goal improving spatial coordination in neurotypical individuals and individuals with unilateral stroke and providing additional advantage for temporal coordination in those with LCVA. Sex influences bimanual performance in stroke survivors and needs to be considered in future investigations.


Assuntos
Objetivos , Acidente Vascular Cerebral , Humanos , Feminino , Formação de Conceito , Mãos , Extremidade Superior , Movimento , Lateralidade Funcional , Desempenho Psicomotor
17.
Science ; 383(6686): 937-938, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38422133

RESUMO

Experiments suggest chemical reaction rates explain how proteins came to be built from left-handed building blocks.


Assuntos
Aminoácidos , Dipeptídeos , Lateralidade Funcional , Origem da Vida , Aminoácidos/química , Dipeptídeos/química
18.
Cereb Cortex ; 34(2)2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-38300180

RESUMO

Psychophysical observations indicate that the spatial profile of visuospatial attention includes a central enhancement around the attentional focus, encircled by a narrow zone of reduced excitability in the immediate surround. This inhibitory ring optimally amplifies relevant target information, likely stemming from top-down frontoparietal recurrent activity modulating early visual cortex activations. However, the mechanisms through which neural suppression gives rise to the surrounding attenuation and any potential hemispheric specialization remain unclear. We used transcranial magnetic stimulation to evaluate the role of two regions of the dorsal attention network in the center-surround profile: the frontal eye field and the intraparietal sulcus. Participants performed a psychophysical task that mapped the entire spatial attentional profile, while transcranial magnetic stimulation was delivered either to intraparietal sulcus or frontal eye field on the right (Experiment 1) and left (Experiment 2) hemisphere. Results showed that stimulation of right frontal eye field and right intraparietal sulcus significantly changed the center-surround profile, by widening the inhibitory ring around the attentional focus. The stimulation on the left frontal eye field, but not left intraparietal sulcus, induced a general decrease in performance but did not alter the center-surround profile. Results point to a pivotal role of the right dorsal attention network in orchestrating inhibitory spatial mechanisms required to limit interference by surrounding distractors.


Assuntos
Lateralidade Funcional , Estimulação Magnética Transcraniana , Humanos , Lateralidade Funcional/fisiologia , Lobo Parietal/fisiologia , Lobo Frontal/fisiologia , Estimulação Luminosa/métodos , Imageamento por Ressonância Magnética , Mapeamento Encefálico
19.
Brain Res ; 1830: 148831, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38412885

RESUMO

The human brain is localized and distributed. On the one hand, each cognitive function tends to involve one hemisphere more than the other, also known as the principle of lateralization. On the other hand, interactions among brain regions in the form of functional connectivity (FC) are indispensable for intact function. Recent years have seen growing interest in the association between lateralization and FC. However, FC metrics vary from spurious correlation to causal associations. If lateralization manifests local processing and causal network interactions, more causally valid FC metrics should predict lateralization index (LI) better than FC based on simple correlations. The present study directly investigates this hypothesis within the activity flow framework to compare the association between lateralization and four brain connectivity metrics: correlation-based FC, multiple-regression FC, partial-correlation FC, and combinedFC. We propose two modeling approaches: the one-step approach, which models the relationship between LI and FC directly, and the two-step approach, which predicts the brain activation and calculates the LI. Our results indicated that multiple-regression FC, partial-correlation FC, and combinedFC could significantly improve the model prediction compared to correlation-based FC, which was consistent in a spatial working memory task (typically right-lateralized) and a language task (typically left-lateralized). The one-step and two-step approach yielded similar conclusions. In addition, the finding was replicated in a clinical sample of schizophrenia (SZ), bipolar disorder (BP), and attention deficit hyperactivity disorder (ADHD). The present study suggests that the causal interactions among brain regions help shape the lateralization pattern.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Encéfalo/fisiologia , Mapeamento Encefálico , Memória de Curto Prazo , Idioma , Lateralidade Funcional/fisiologia
20.
Laterality ; 29(2): 169-183, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38408188

RESUMO

McGilchrist [McGilchrist, I. (2009). The master and His emissary: The divided brain and the making of the modern world. Yale University Press] argued that Western society has undergone a population-level shift from greater right hemisphere influence on cognition to increasingly greater left hemisphere influence over the past few centuries. Four historical lifestyle changes that replaced behaviours associated with right hemisphere activation with behaviours associated with left hemisphere activation may be responsible: (i) shifts from standing to sitting, (ii) from being outdoors to indoors, (iii) from communal to solitary activities, and (iv) from analogue/concrete to holistic/abstract representations.


Assuntos
Encéfalo , Lateralidade Funcional , Humanos , Lateralidade Funcional/fisiologia , Encéfalo/fisiologia , Estilo de Vida
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