Brain Lateralization Research Articles

Simplified Attachable EEG Revealed Child Development Dependent Neurofeedback Brain Acute Activities in Comparison with Visual Numerical Discrimination Task and Resting.

The development of an easy-to-attach electroencephalograph (EEG) would enable its frequent use for the assessment of neurodevelopment and clinical monitoring. In this study, we designed a two-channel EEG headband measurement device that could be used safely and was easily attachable and removable without the need for restraint or electrode paste or gel. Next, we explored the use of this device for neurofeedback applications relevant to education or neurocognitive development. We developed a prototype visual neurofeedback game in which the size of a familiar local mascot changes in the PC display depending on the user’s brain wave activity. We tested this application at a local children’s play event. Children at the event were invited to experience the game and, upon agreement, were provided with an explanation of the game and support in attaching the EEG device. The game began with a consecutive number visual discrimination task which was followed by an open-eye resting condition and then a neurofeedback task. Preliminary linear regression analyses by the least-squares method of the acquired EEG and age data in 30 participants from 5 to 20 years old suggested an age-dependent left brain lateralization of beta waves at the neurofeedback stage (p = 0.052) and of alpha waves at the open-eye resting stage (p = 0.044) with potential involvement of other wave bands. These results require further validation.

Sunlight and lifestyle: linking prenatal light conditions and personality development in a wild bird

Even though personality is a major determinant of individual survival, the development of animal personality traits is still poorly understood. Beyond an individual's genetic background, personality may be shaped by the conditions experienced during embryonic development. Light is a salient and variable ecological factor that can affect organismal physiology, establish brain asymmetries and ultimately modulate postnatal phenotypes across multiple taxa. Exposure to light is known to vary among avian embryos due to changes in parental incubatory constancy, but whether differences in the prenatal light environment can influence offspring personality development has rarely been explored. Here, we investigated whether the prenatal light environment shapes a key dimension of animal personality, the shy–bold axis, in hatchlings of a semiprecocial seabird, the yellow-legged gull, Larus michahellis . In gulls, the prenatal light environment may be especially important for last-laid eggs, as parental attendance during late incubation is more variable for last-laid than for senior eggs. We manipulated the levels of embryonic exposure to light (within the natural range previously documented in the wild) during the last stages of egg incubation and assessed differences in boldness in newly hatched junior chicks. We then used structural equation modelling to explore whether the effect of prenatal light exposure on the shy–bold axis is linked to the establishment of brain asymmetries (lateralization) and/or changes in plasma corticosterone levels. Prenatal light exposure promoted bolder phenotypes in gull chicks, which may improve their individual performance when competing for parental resources. Prenatal light also promoted the lateralization of the begging behaviour in newly hatched chicks, which was negatively associated with boldness. Finally, light induced changes in glucocorticoid levels, but these changes did not impact chicks' personality. Our findings unambiguously confirm that the prenatal light environment strongly affects the development of shy–bold phenotypes in gull hatchlings through a complex multipath mechanism. • Can the prenatal environment shape animal personality? • Last-hatched gull eggs are highly exposed to sunlight during late incubation. • We explored whether prenatal exposure to light shapes boldness in hatchlings. • Prenatal light promoted bold phenotypes and brain lateralization in gull chicks. • These adjustments might improve chick performance under competitive disadvantage.

The Study of Cortical Lateralization and Motor Performance Evoked by External Visual Stimulus During Continuous Training

Motor imagery (MI) as an important way of motor learning has been studied widely. The visual task stimulus is an efficient way to improve MI abilities; however, its impact mechanism on motor training is still obscure. This study aimed to explore the influence of visual task stimulus on MI during continuous training. Three types of kinesthetic motor imageries, including a visual task stimulus, a visual stimulus, or no stimulus, were assessed. Brain lateralization and the variations of the event-related desynchronization were investigated. The results demonstrated a greater improvement motor performance after a visual task stimulus. The MI evoked by the visual task shows the most complex event-related lateralization (ERL) among the three contexts, with the presence of many ERL components. These results reveal a complex process of planning, attention focusing, and information processing on the brain, and the complexity of the information process increases with the one of external visual stimulus. This work provides a promising foundation for the incorporation of visual-task stimuli as a strategy to improve motor ability during motor training and motor rehabilitation.

Performance on inhibitory tasks does not relate to handedness in several small groups of Callitrichids.

Brain lateralization, a trait ubiquitous in vertebrates and invertebrates, refers to structural differences between the left and right sides of the brain or to the left and right sides controlling different functions or processing information in different ways. Many studies have looked into the advantages of lateralized brains and discovered that cerebral lateralization confers a fitness advantage. Enhancing cognitive ability has been proposed as one of the potential benefits of the lateralized brain, however, this has not been widely validated. In this study, we investigated the handedness of 34 subjects from four groups of Callitrichids, as well as their performance in two inhibitory control tasks (the revised A-not-B task and the cylinder task). The subjects had strong individual hand preferences, and only a few zoo-born individuals were ambidextrous. Sex and generation influence the strength of hand preference. In the cylinder task, the subjects showed differences between groups, and the performance of the second-generation was better than that of the first-generation. We found that neither the strength of hand preferences (ABS-HI) or direction of hand preferences (HI) was linked with success on the two inhibitory tasks. That is, we were unable to support the enhanced cognitive function hypothesis. We believe that individual ontogeny and the type of cognitive task have an impact on the support of this hypothesis. The advantages of lateralized brain may be reflected in tests that require multiple cognitive abilities.

Reduced Neural Specialization for Word-level Linguistic Prosody in Children with Autism.

Children with autism often show atypical brain lateralization for speech and language processing, however, it is unclear what linguistic component contributes to this phenomenon. Here we measured event-related potential (ERP) responses in 21 school-age autistic children and 25 age-matched neurotypical (NT) peers during listening to word-level prosodic stimuli. We found that both groups displayed larger late negative response (LNR) amplitude to native prosody than to nonnative prosody; however, unlike the NT group exhibiting left-lateralized LNR distinction of prosodic phonology, the autism group showed no evidence of LNR lateralization. Moreover, in both groups, the LNR effects were only present for prosodic phonology but not for phoneme-free prosodic acoustics. These results extended the findings of inadequate neural specialization for language in autism to sub-lexical prosodic structures.

Brain laterality evaluated by F-18 fluorodeoxyglucose positron emission computed tomography in autism spectrum disorders

Background and rationaleAutism spectrum disorder (ASD) is a neuropsychiatric disorder that has no curative treatment. Little is known about the brain laterality in patients with ASD. F-18 fluorodeoxyglucose positron emission computed tomography (F-18 FDG PET/CT) is a neuroimaging technique that is suitable for ASD owing to its ability to detect whole brain functional abnormalities in a short time and is feasible in ASD patients. The purpose of this study was to evaluate brain laterality using F-18 FDG PET/CT in patients with high-functioning ASD.Materials and methodsThis case-control study recruited eight ASD patients who met the DSM-5 criteria, the recorded data of eight controls matched for age, sex, and handedness were also enrolled. The resting state of brain glucose metabolism in the regions of interest (ROIs) was analyzed using the Q.Brain software. Brain glucose metabolism and laterality index in each ROI of ASD patients were compared with those of the controls. The pattern of brain metabolism was analyzed using visual analysis and is reported in the data description.ResultsThe ASD group’s overall brain glucose metabolism was lower than that of the control group in both the left and right hemispheres, with mean differences of 1.54 and 1.21, respectively. We found statistically lower mean glucose metabolism for ASD patients than controls in the left prefrontal lateral (Z = 1.96, p = 0.049). The left laterality index was found in nine ROIs for ASD and 11 ROIs for the control. The left laterality index in the ASD group was significantly lower than that in the control group in the prefrontal lateral (Z = 2.52, p = 0.012), precuneus (Z = 2.10, p = 0.036), and parietal inferior (Z = 1.96, p = 0.049) regions.ConclusionIndividuals with ASD have lower brain glucose metabolism than control. In addition, the number of ROIs for left laterality index in the ASD group was lower than control. Left laterality defects may be one of the causes of ASD. This knowledge can be useful in the treatment of ASD by increasing the left-brain metabolism. This trial was registered in the Thai Clinical Trials Registry (TCTR20210705005).

The effects of alphabetic literacy, linguistic-processing demand and tone type on the dichotic listening of lexical tones.

Brain lateralization of lexical tone processing remains a matter of debate. In this study we used a dichotic listening paradigm to examine the influences of the knowledge of Jyutping (a romanization writing system which provides explicit Cantonese tone markers), linguistic-processing demand and tone type on the ear preference pattern of native tone processing in Hong Kong Cantonese speakers. While participants with little knowledge of Jyutping showed a previously reported left-ear advantage (LEA), those with a good level of Jyutping expertise exhibited either a right-ear advantage or bilateral processing during lexical tone identification and contour tone discrimination, respectively. As for the effect of linguistic-processing demand, while an LEA was found in acoustic/phonetic perception situations, this advantage disappeared and was replaced by a bilateral pattern in conditions that involved a greater extent of linguistic processing, suggesting an increased involvement of the left hemisphere. Regarding the effect of tone type, both groups showed an LEA in level tone discrimination, but only the Jyutping group demonstrated a bilateral pattern in contour tone discrimination. Overall, knowledge of written codes of tones, greater degree of linguistic processing and contour tone processing seem to influence the brain lateralization of lexical tone processing in native listeners of Cantonese by increasing the recruitment of the left-hemisphere language network.

Is Reduced Visual Processing the Price of Language?

We suggest a later timeline for full language capabilities in Homo sapiens, placing the emergence of language over 200,000 years after the emergence of our species. The late Paleolithic period saw several significant changes. Homo sapiens became more gracile and gradually lost significant brain volumes. Detailed realistic cave paintings disappeared completely, and iconic/symbolic ones appeared at other sites. This may indicate a shift in perceptual abilities, away from an accurate perception of the present. Language in modern humans interact with vision. One example is the McGurk effect. Studies show that artistic abilities may improve when language-related brain areas are damaged or temporarily knocked out. Language relies on many pre-existing non-linguistic functions. We suggest that an overwhelming flow of perceptual information, vision, in particular, was an obstacle to language, as is sometimes implied in autism with relative language impairment. We systematically review the recent research literature investigating the relationship between language and perception. We see homologues of language-relevant brain functions predating language. Recent findings show brain lateralization for communicative gestures in other primates without language, supporting the idea that a language-ready brain may be overwhelmed by raw perception, thus blocking overt language from evolving. We find support in converging evidence for a change in neural organization away from raw perception, thus pushing the emergence of language closer in time. A recent origin of language makes it possible to investigate the genetic origins of language.

Foot Dominance as a Biological Marker of Schizophrenia- Analysis of the Items from the Chapman & Chapman Foot Dominance Scale

Objective: The aim was to investigate left foot dominance as a biological marker of neurodevelopmental disorder in schizophrenia. Material and methods: The Chapman & Chapman Foot Dominance Scale, administered as performance assessments, not as preference questionnaire, was assessed in a sample of 180 subjects (98 schizophrenic patients and 82 controls). Multivariate Analysis of Variance (MANOVA), non-parametric and cluster analyses were used to analyze the data. Results: Left foot dominance was significantly higher in schizophrenic patients in comparison to control subjects. Conclusion: As hand dominance is influenced by cultural factors, footedness might be a better-suited candidate biomarker for motor brain lateralization. We propose foot dominance as a useful, reliable, and more culturally independent indicator of brain lateralization.

Crossed functional specialization between the basal ganglia and cerebellum during vocal emotion decoding: Insights from stroke and Parkinson’s disease

There is growing evidence that both the basal ganglia and the cerebellum play functional roles in emotion processing, either directly or indirectly, through their connections with cortical and subcortical structures. However, the lateralization of this complex processing in emotion recognition remains unclear. To address this issue, we investigated emotional prosody recognition in individuals with Parkinson’s disease (model of basal ganglia dysfunction) or cerebellar stroke patients, as well as in matched healthy controls (n = 24 in each group). We analysed performances according to the lateralization of the predominant brain degeneration/lesion. Results showed that a right (basal ganglia and cerebellar) hemispheric dysfunction was likely to induce greater deficits than a left one. Moreover, deficits following left hemispheric dysfunction were only observed in cerebellar stroke patients, and these deficits resembled those observed after degeneration of the right basal ganglia. Additional analyses taking disease duration / time since stroke into consideration revealed a worsening of performances in patients with predominantly right-sided lesions over time. These results point to the differential, but complementary, involvement of the cerebellum and basal ganglia in emotional prosody decoding, with a probable hemispheric specialization according to the level of cognitive integration.

Review of the Factors Affecting Dichotic Listening

Background and Aim: Dichotic listening (DL) test is a non-invasive method used to study hemispheric asymmetry, hemispheric dominance for language processing, or brain lateralization. In addition to the type, concurrence, and the intensity of stimuli presented to the ears, other factors exist that may have less effect on the DL test results. This review study aims to find these factors. Recent Findings: The factors that affects the DL included ear advantage, attention, working memory, gender, and top-down and bottom-up factors. These factors were reviewed and discussed in detail so that more precise test results can be obtained. Moreover, due to the significant effects of each factor on the test results, manipulation of these factors was also reviewed. Conclusion: According to the results of previous studies, ear advantage, attention, working memory, gender, and top-down and bottom-up factors play an important role in the interpretation of DL results; their negligence during the test can affect the outcomes and provide incorrect brain lateralization results. Keywords: Dichotic listening; ear advantage; top-down; bottom-up; working memory; attention

The Grammatical Effects of Nyanja on Pupils Learning English in Selected Junior Secondary Schools of Chongwe District, Zambia

The purpose of the study was to investigate grammatical effects of Nyanja as first language (L1) on pupils learning English as a second language in Chongwe district. Chongwe district is home for people of different tribes (Soli, Chewa, Bemba, Tonga, Lozi, Lenje, Shona and Ndebele). As a result, the community is multilingual. This multilingual environment has sometimes negatively impacted on some children in the learning of English in areas such as syntax, semantics, grammar and vocabulary in English. The consequence of these negative effects has led to lack of full communication and understanding of topics taught in class and in school. The study is important in informing policy makers of the challenges that the first language (L1) creates in the learning of English. It may also act as a bridging document for existing gaps in line with the effects of Nyanja on pupils learning English language. The researcher interviewed 79 respondents that were systematically selected from each of the six different sites of Chongwe district namely kampekete, Mwalumina, Chilyabale, Lwimba, Lukoshi and Nchute primary schools. The current study employed triangulated method based on the grounded theory. It used the qualitative method for both collecting and analyzing data. The data was collected from teachers of English, other subject teachers and from basic school pupils of the six selected schools. The instruments used were questionnaires. The methods used to collect data were face to face interviews, group discussion and recordings. Thereafter data was analysed manually using descriptive explanation and narration. Among many things, the study found that learners with Nyanja background had problems in areas of spelling, pronunciation, translation, grammar, choice of register to use in correct contexts because English was introduced late to learners finding their brain optimal time to acquire language in good accent, pronunciation, fluency in English grammatical system already passed and learners brain were already anchored in Nyanja, a language with totally different stress, intonation and grammar. This assertion matches with Lundeberg (1967) when he established that brain lateralization finishes at puberty and that it leads to the end of brain’s ability to acquire language with fluency and accuracy. Therefore, the study recommended i) the alignment of English language from pupil’s first contact with the teacher in school and ii) English should be embraced as language of medium instruction in all the grades in schools.

Extra food provisioning does not affect behavioral lateralization in nestling lesser kestrels.

Costs and benefits of brain lateralization may depend on environmental conditions. Growing evidence indicates that the development of brain functional asymmetries is adaptively shaped by the environmental conditions experienced during early life. Food availability early in life could act as a proxy of the environmental conditions encountered during adulthood, but its potential modulatory effect on lateralization has received little attention. We increased food supply from egg laying to early nestling rearing in a wild population of lesser kestrels Falco naumanni, a sexually dimorphic raptor, and quantified the lateralization of preening behavior (head turning direction). As more lateralized individuals may perform better in highly competitive contexts, we expected that extra food provisioning, by reducing the level of intra-brood competition for food, would reduce the strength of lateralization. We found that extra food provisioning improved nestling growth, but it did not significantly affect the strength or direction of nestling lateralization. In addition, maternal body condition did not explain variation in nestling lateralization. Independently of extra food provisioning, the direction of lateralization differed between the sexes, with female nestlings turning more often toward their right. Our findings indicate that early food availability does not modulate behavioral lateralization in a motor task, suggesting limited phenotypic plasticity in this trait.

Dynamic changes in brain lateralization correlate with human cognitive performance.

Hemispheric lateralization constitutes a core architectural principle of human brain organization underlying cognition, often argued to represent a stable, trait-like feature. However, emerging evidence underlines the inherently dynamic nature of brain networks, in which time-resolved alterations in functional lateralization remain uncharted. Integrating dynamic network approaches with the concept of hemispheric laterality, we map the spatiotemporal architecture of whole-brain lateralization in a large sample of high-quality resting-state fMRI data (N = 991, Human Connectome Project). We reveal distinct laterality dynamics across lower-order sensorimotor systems and higher-order associative networks. Specifically, we expose 2 aspects of the laterality dynamics: laterality fluctuations (LF), defined as the standard deviation of laterality time series, and laterality reversal (LR), referring to the number of zero crossings in laterality time series. These 2 measures are associated with moderate and extreme changes in laterality over time, respectively. While LF depict positive association with language function and cognitive flexibility, LR shows a negative association with the same cognitive abilities. These opposing interactions indicate a dynamic balance between intra and interhemispheric communication, i.e., segregation and integration of information across hemispheres. Furthermore, in their time-resolved laterality index, the default mode and language networks correlate negatively with visual/sensorimotor and attention networks, which are linked to better cognitive abilities. Finally, the laterality dynamics are associated with functional connectivity changes of higher-order brain networks and correlate with regional metabolism and structural connectivity. Our results provide insights into the adaptive nature of the lateralized brain and new perspectives for future studies of human cognition, genetics, and brain disorders.

Designing Personalised Blended Learning Courses for Engineering Students

Blended Learning is a well balanced fusion of face-to-face learning and online experiences. In this paper we discuss some design aspects concerning the optimal proportion between the two means of education applied to Engineering students. Our approach is taking into account the creative potential of engineering students and their type of thinking that have been previously investigated through the Brain Lateralization Information System (BLIS) [1]. In this paper we aim at identifying ways in which creative thinking and problem solving techniques can be implemented as personalized Blended Education Programs for students attending courses in the fields of Engineering. A blended course has an integrated online component and a concomitant face-to-face seat time, in order to reach student populations that cannot attend a fully face-to-face program. The advantages of face to face and the advantages of online activities have been put into balance and discussed. The purposes behind learning activities should be expressed by: community building, trust building, spontaneous reaction, clarification on one hand and reflection, analysis, exploration, creation on the other hand. In our efforts of designing a blended course we have considered the best suited modality for each specialty.

Electrocorticography to Investigate Age-Related Brain Lateralization on Pediatric Motor Inhibition.

Response inhibition refers to the ability to suppress inappropriate actions that interfere with goal-driven behavior. The inferior frontal gyrus (IFG) is known to be associated with inhibition of a motor response by assuming executive control over motor cortex outputs. This study aimed to evaluate the pediatric development of response inhibition through subdural electrocorticography (ECoG) recording. Subdural ECoG recorded neural activities simultaneously during a Go/No-Go task, which was optimized for children. Different frequency power [theta: 4–8 Hz; beta: 12–40 Hz; high-gamma (HG): 70–200 Hz] was estimated within the IFG and motor cortex. Age-related analysis was computed by each bandpass power ratio between Go and No-Go conditions, and phase-amplitude coupling (PAC) over IFG by using the modulating index metric in two conditions. For all the eight pediatric patients, HG power was more activated in No-Go trials than in Go trials, in either right- or left-side IFG when available. In the IFG region, the power over theta and HG in No-Go conditions was higher than those in Go conditions, with significance over the right side (p < 0.05). The age-related lateralization from both sides to the right side was observed from the ratio of HG power and PAC value between the No-Go and Go trials. In the pediatric population, the role of motor inhibition was observed in both IFG, with age-related lateralization to the right side, which was proved in the previous functional magnetic resonance imaging studies. In this study, the evidence correlation of age and response inhibition was observed directly by the evidence of cortical recordings.

ヒト脳の側性化と臨床

ヒト脳の側性化と臨床

Image-Based Learning Using Gradient Class Activation Maps for Enhanced Physiological Interpretability of Motor Imagery Skills

Brain activity stimulated by the motor imagery paradigm (MI) is measured by Electroencephalography (EEG), which has several advantages to be implemented with the widely used Brain–Computer Interfaces (BCIs) technology. However, the substantial inter/intra variability of recorded data significantly influences individual skills on the achieved performance. This study explores the ability to distinguish between MI tasks and the interpretability of the brain’s ability to produce elicited mental responses with improved accuracy. We develop a Deep and Wide Convolutional Neuronal Network fed by a set of topoplots extracted from the multichannel EEG data. Further, we perform a visualization technique based on gradient-based class activation maps (namely, GradCam++) at different intervals along the MI paradigm timeline to account for intra-subject variability in neural responses over time. We also cluster the dynamic spatial representation of the extracted maps across the subject set to come to a deeper understanding of MI-BCI coordination skills. According to the results obtained from the evaluated GigaScience Database of motor-evoked potentials, the developed approach enhances the physiological explanation of motor imagery in aspects such as neural synchronization between rhythms, brain lateralization, and the ability to predict the MI onset responses and their evolution during training sessions.

In vivo brain iron concentration in healthy individuals at 3.0 T magnetic resonance imaging: a prospective cross-sectional study.

To quantify iron deposits in the basal ganglia and to evaluate its relation to age, sex, body mass index and brain laterality. Prospective observational study. Data were collected from the patients' electronic medical records. The concentration of iron deposits in the brain was assessed using whole-brain MRI at 3.0 Tesla. 138 participants were selected, 69.6% were female and the mean age was 47 ± 19 years. The κ coefficient was very strong (k = 0.92, p < 0.001). Age showed a moderate correlation between iron deposits in the caudate and putamen nuclei, on both right and left sides. In overall and right-handed individuals, a significantly higher iron concentration was observed on the left side for the caudate nucleus, putamen, thalamus, globus pallidus, and centrum semiovale, and for left-handed individuals, it was also observed in the left side-for the putamen and centrum semiovale. A weak correlation was shown between body mass index and left and right substantia nigra, left caudate nuclei, left putamen and right globus pallidus. Our results showed a significantly higher iron deposit on the left side in most brain regions. In addition, the body mass index may also be related to iron overload, especially in the caudate nucleus. Brain iron deposits may be normal, owing to aging, or be pathological, such as neurodegeneration. Thus, it is important to know how much is expected of iron deposition in the brain of healthy populations.

Lateralization in feeding is food type specific and impacts feeding success in wild birds.

Current research suggests that hemispheric lateralization has significant fitness consequences. Foraging, as a basic survival function, is a perfect research model to test the fitness impact of lateralization. However, our understanding of lateralized feeding behavior is based predominantly on laboratory studies, while the evidence from wild animals in natural settings is limited. Here we studied visual lateralization in yellow‐footed green pigeons (Treron phoenicoptera) feeding in the wild. We aimed to test whether different types of food objects requiring different searching strategies elicit different eye/hemisphere biases. When feeding on relatively large, uniformly colored food objects (mahua flowers) which can be present or absent in the viewed patch, the majority of pigeons relied mostly on the left eye–right hemisphere. In contrast, when feeding on smaller and more abundant food objects, with color cues signaling its ripeness (sacred figs), right‐eye (left‐hemisphere) preference prevailed. Our results demonstrate that oppositely directed visual biases previously found in different experimental tasks occur in natural feeding situations in the form of lateralized viewing strategies specific for different types of food. The results suggest that pigeons rely on the hemisphere providing more advantages for the consumption of the particular type of food objects, implying the relevance of brain lateralization as a plastic adaptation to ecological demands. We assessed the success of food discrimination and consumption to examine the link between lateralization and cognitive performance. The use of the preferred eye resulted in better discrimination of food items. Discrimination accuracy and feeding efficiency were significantly higher in lateralized individuals. The results showed that visual lateralization impacted pigeons’ feeding success, implicating important fitness benefits associated with lateralization.