scholarly journals Bilingual experiences induce dynamic structural changes to basal ganglia and the thalamus

2021 ◽  
Author(s):  
Michal Korenar ◽  
Jeanine Treffers-Daller ◽  
Christos Pliatsikas
Keyword(s):  
Basal Ganglia ◽  
Structural Changes ◽  
Brain Regions ◽  
Caudate Nuclei ◽  
Linear Pattern ◽  
Wide Range ◽  
Non Linear ◽  
Additive Mixed Models ◽  
Linear Effects ◽  
Structural Adaptations

Abstract Bilingualism has been linked to structural adaptations of subcortical brain regions that are important nodes in controlling of multiple languages. However, research on the location and extent of these adaptations has yielded variable patterns. Existing literature on bilingualism-induced brain adaptations has so far largely overseen evidence from other domains that experience-based structural neuroplasticity often triggers non-linear adaptations which follow expansion-renormalisation trajectories. Here we use generalised additive mixed models (GAMMs) to investigate the non-linear effects of quantified bilingual experiences on the basal ganglia and thalamus in a sample of bilinguals with wide range of bilingual experiences. Our results revealed that volumes of bilateral caudate nuclei and accumbens were positively related to bilingual experiences in a non-linear pattern, with increases followed by decreases, in the most experienced bilinguals, suggesting a return to baseline volume at higher levels of bilingual experience. Moreover, volumes of putamen and thalamus were positively linearly predicted by bilingual experiences. The results offer the first direct evidence that bilingualism, similarly to other cognitively demanding skills, leads to dynamic subcortical structural adaptations which can be nonlinear, in line with expansion-renormalisation models of experience-dependent neuroplasticity.

scholarly journals NeAT: a Nonlinear Analysis Toolbox for Neuroimaging

2020 ◽  
Vol 18 (4) ◽  
pp. 517-530
Author(s):  
Adrià Casamitjana ◽  
◽  
Verónica Vilaplana ◽  
Santi Puch ◽  
Asier Aduriz ◽  
...  
Keyword(s):  
Linear Models ◽  
Brain Aging ◽  
Nonlinear Effects ◽  
Brain Morphology ◽  
Model Estimation ◽  
Wide Range ◽  
Non Linear ◽  
Linear Effects ◽  
Interaction With Age ◽  
User Friendly

Abstract NeAT is a modular, flexible and user-friendly neuroimaging analysis toolbox for modeling linear and nonlinear effects overcoming the limitations of the standard neuroimaging methods which are solely based on linear models. NeAT provides a wide range of statistical and machine learning non-linear methods for model estimation, several metrics based on curve fitting and complexity for model inference and a graphical user interface (GUI) for visualization of results. We illustrate its usefulness on two study cases where non-linear effects have been previously established. Firstly, we study the nonlinear effects of Alzheimer’s disease on brain morphology (volume and cortical thickness). Secondly, we analyze the effect of the apolipoprotein APOE-ε4 genotype on brain aging and its interaction with age. NeAT is fully documented and publicly distributed at https://imatge-upc.github.io/neat-tool/.

Emphasis Terms for Warning Directives on Compliance Intent

2007 ◽  
Vol 51 (9) ◽  
pp. 569-573 ◽  
Author(s):  
Soyun Kim ◽  
Jennifer Cowley ◽  
Michael S. Wogalter
Keyword(s):  
Federal Law ◽  
Wide Range ◽  
Non Linear ◽  
Linear Effects ◽  
Hazard Levels

Instructions on how to avoid hazards are an important aspect of warnings. Because message brevity is beneficial for effectiveness, the wording ought to be useful in motivating compliance. Participants ( N=132) evaluated 37 single and two-word emphasis phrases (e.g., “critical” or “absolutely crucial”) that could be added to a directive (or instructions) statement to indicate the degree of compliance necessity. Manipulated were one or two-word (phrase) emphasis terms (e.g., “critical,” “must,” and “absolutely critical”). Participants rated the compliance intent for each of these. Results showed a wide range of ratings across word/phrase conditions (from “extremely critical” and “urgent” as the highest to “optional” as the lowest). Linear (additive) and non linear effects were yielded by the pattern of means for word/phrase combinations. “Federal Law” was one of the highest rated items confirming similar previous findings. Implications are discussed including the potential for matching terms with hazard levels.

scholarly journals White matter degeneration in remote brain areas of stroke patients with motor impairment due to basal ganglia lesions

2021 ◽  
Author(s):  
Xuejin Cao ◽  
Zan Wang ◽  
Xiaohui Chen ◽  
Yanli Liu ◽  
Wei Wang ◽  
...  
Keyword(s):  
White Matter ◽  
Basal Ganglia ◽  
Structural Changes ◽  
Diffusion Tensor ◽  
Motor Impairment ◽  
Brain Regions ◽  
Stroke Patients ◽  
Brain Areas ◽  
Structural Network ◽  
Multivariate Pattern

Abstract Diffusion tensor imaging (DTI) studies have revealed distinct white matter characteristics of the brain following diseases. Beyond the lesion-symptom maps, stroke is characterized by extensive structural and functional alterations of brain areas remote to local lesions. Here, we further investigated the structural changes over a global level by using DTI data of ten ischemic stroke patients showing motor impairment due to basal ganglia lesions and 11 healthy controls. DTI data were processed to obtain fractional anisotropy (FA) maps, and multivariate pattern analysis (MVPA) was used to explore brain regions that play an important role in classification based on FA maps. The white matter (WM) structural network was constructed by the deterministic fiber-tracking approach. In comparison with the controls, the stroke patients showed FA reductions in the perilesional basal ganglia, brainstem, and bilateral frontal lobes. Using network-based statistics (NBS), we found a significant reduction in the WM subnetwork in stroke patients. We identified the patterns of WM degeneration affecting brain areas remote to the lesions, revealing the abnormal organization of the structural network in stroke patients, which may be helpful in understanding of the neural mechanisms underlying hemiplegia.

Some Complexities of Multiple Inhibitor Interactions in Fibrinolytic Systems

1968 ◽  
Vol 19 (01/02) ◽  
pp. 117-128 ◽  
Author(s):  
R. E Maxwell ◽  
J. W Nawrocki ◽  
Violet S. Nickel
Keyword(s):  
Structural Changes ◽  
Non Linear ◽  
Substrate Conversion ◽  
Variable Extent ◽  
Combined Action ◽  
Linear Effects

SummaryHuman or canine fibrin polymers which are structurally altered by the combined action of plasmin and EACA show an increased resistance to digestion by trypsin, but not to digestion by chymotrypsin. These observations support the concept that EACA inhibition of fibrinolysis is to a variable extent a function of structural changes in the substrate, and that the changes may be related to the susceptibility of lysyl- and arginyl-sites attacked by plasmin and trypsin, but not by chymotrypsin.In plasma, the fibrin modification reactions mediated by plasmin + EACA are analogous to those in purified systems, with quantitative differences resulting from the presence of other inhibitors, and perhaps from earlier gelation of the developing polymers.This complexity of the action of EACA must be taken into account in comparing its effects with those of other inhibitors, which also have variable and non-linear effects related to prevention of autodigestion of plasmin, antagonistic or potentiative combinations of inhibitors, and interference with substrate conversion.

scholarly journals Mathematical modeling of temporal changes in snow-firn properties in the cold season

1997 ◽  
Vol 24 ◽  
pp. 309-313 ◽  
Author(s):  
Elena Guseva-Lozinski
Keyword(s):  
Mathematical Model ◽  
Structural Changes ◽  
Structural Parameters ◽  
Meteorological Data ◽  
Cold Season ◽  
Structural Equations ◽  
High Mountain ◽  
Thermomechanical Model ◽  
Wide Range ◽  
Non Linear

The paper describes a non-linear dynamic thermomechanical model of the snow–firn development in the high mountain environment during the cold season. The model allows the estimation of the thermal and mechanical development of snow in an inhomogeneous stratified snowpack and in the upper part of the firn layer, the development of the snow–firn structure and transformation of snow into firn. The non-linear mathematical model consists of a heat problem, water-vapor diffusion problem, densification of the snow–firn layer, structural equations and strength conditions of the metamorphosed snow–firn depending on its temperature, structural parameters, density and rate of sublimation. The model includes conditions of snow transformation into firn and its structural changes. These equations are non-linear and coupled. The iterative finite-difference numerical method was used for the calculations and involved a full mathematical model. Numerical experiments were implemented using the complete model as well as real. The numerical computations were made for various meteorological data, temperature gradients and in the wide range of structural parameters. The calculation results were found to be in good agreement with the results of observations.

scholarly journals Mathematical modeling of temporal changes in snow-firn properties in the cold season

1997 ◽  
Vol 24 ◽  
pp. 309-313
Author(s):  
Elena Guseva-Lozinski
Keyword(s):  
Mathematical Model ◽  
Structural Changes ◽  
Structural Parameters ◽  
Meteorological Data ◽  
Cold Season ◽  
Structural Equations ◽  
High Mountain ◽  
Thermomechanical Model ◽  
Wide Range ◽  
Non Linear

The paper describes a non-linear dynamic thermomechanical model of the snow–firn development in the high mountain environment during the cold season. The model allows the estimation of the thermal and mechanical development of snow in an inhomogeneous stratified snowpack and in the upper part of the firn layer, the development of the snow–firn structure and transformation of snow into firn. The non-linear mathematical model consists of a heat problem, water-vapor diffusion problem, densification of the snow–firn layer, structural equations and strength conditions of the metamorphosed snow–firn depending on its temperature, structural parameters, density and rate of sublimation. The model includes conditions of snow transformation into firn and its structural changes. These equations are non-linear and coupled. The iterative finite-difference numerical method was used for the calculations and involved a full mathematical model. Numerical experiments were implemented using the complete model as well as real. The numerical computations were made for various meteorological data, temperature gradients and in the wide range of structural parameters. The calculation results were found to be in good agreement with the results of observations.

Reduced Thalamus Volume and Enhanced Thalamus and Fronto-Parietal Network Integration in the Chess Experts

2020 ◽  
Vol 30 (10) ◽  
pp. 5560-5569
Author(s):  
Yanpei Wang ◽  
Chenyi Zuo ◽  
Daoyang Wang ◽  
Sha Tao ◽  
Lei Hao
Keyword(s):  
Working Memory ◽  
Visual Processing ◽  
Structural Changes ◽  
Gray Matter Volume ◽  
Functional Integration ◽  
Brain Regions ◽  
Resting State Functional Connectivity ◽  
External Stimulation ◽  
Wide Range ◽  
Chess Players

Abstract The ability of chess experts depends to a large extent on spatial visual processing, attention, and working memory, all of which are thought to be mediated by the thalamus. This study explored whether continued practice and rehearsal over a long period of time results in structural changes in the thalamic region. We found smaller gray matter volume regions in the thalami of expert Chinese chess players in comparison with novice players. We then used these regions as seeds for resting-state functional connectivity analysis and observed significantly strengthened integration between the thalamus and fronto-parietal network in expert Chinese chess players. This strengthened integration that includes a group of brain regions showing an increase in activation to external stimulation, particularly during tasks relying on working memory and attention. Our findings demonstrate structural changes in the thalamus caused by a wide range of engagement in chess problem solving, and that this strengthened functional integration with widely distributed circuitry better supports high-level cognitive control of behavior.

scholarly journals Structural Correlates of Neurological Signs in Huntington’s Disease: A Quantitative Approach

1994 ◽  
Vol 7 (3-4) ◽  
pp. 127-134 ◽  
Author(s):  
E. A. Loh ◽  
J. K. A. Roberts ◽  
E. Mohr
Keyword(s):  
Basal Ganglia ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Structural Changes ◽  
Third Ventricle ◽  
Strongly Correlated ◽  
Caudate Nuclei ◽  
Computed Tomographic ◽  
The Third ◽  
Motor Abnormality

Huntington's disease (HD) is a genetically transmitted disorder associated with atrophy of the basal ganglia. Studies of the neuroanatomical correlates of HD have focused primarily on the anterior areas of the basal ganglia and on establishing an association between structural changes resulting from the presence and course of the illness. The objective of the present study was to assess the value of measurements of the third ventrical and lentiform regions. Computed tomographic (CT) brain scan measures of the basal ganglia of patients in the “early” and “late” stages of the disease were correlated with scores on a quantified neurological examination (QNE) and compared with scans of age-matched control groups. Basal ganglia atrophy was assessed by two conventional “anterior” measures: the maximal distance between the frontal horns of the lateral ventricles (FH) and the minimum distance between the caudate nuclei (CC), and two measures of more “posterior” regions: the width of the third ventricle (3V), and a measure of the lentiform regions (LENTI). In the group of patients with HD, CT scan measures were strongly correlated with disease duration. Further, in the “late” group, all CT measures were significantly correlated with QNE scores, with the two “posterior” measures being equally, if not more strongly correlated with QNE scores than the conventional “anterior” measures. Separate correlations of the CT indices of atrophy and QNE scores in the “early” and “late” HD groups revealed relationships between basal ganglia atrophy and motor abnormality consistent with earlier reports.

Some insights into the dynamics of defective structures

1998 ◽  
Vol 212 (6) ◽  
pp. 441-454 ◽  
Author(s):  
J A Brandon
Keyword(s):  
Damage Assessment ◽  
Nonlinear Response ◽  
Structural Integrity ◽  
Integrity Assessment ◽  
Response Behaviour ◽  
Chaotic Vibrations ◽  
Primary Activity ◽  
Wide Range ◽  
Non Linear ◽  
Linear Effects

As a general principle, it should be assumed that defective structures will exhibit nonlinear response behaviour. The primary activity of the Cardiff research group over the last ten years has been the identification of the types of non-linear phenomena encountered in the dynamics of defective structures together with an estimation of their observability, albeit in a qualitative sense. A wide range of classical non-linear effects from subharmonic oscillations to chaotic vibrations has been observed. It is argued that structural integrity assessment can be enhanced by incorporating these non-linear effects into damage assessment criteria.

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