Понимание синтаксически сложных предложений: связь правильности и скорости с характеристиками проводящих путей головного мозга
Age-related changes in language processing have not yet been as well-studied as those in perception, memory, attention or cognition. Specifically with regard to syntactic processing, it is still debatable whether only the processing speed or also accuracy decreases with age. The present study investigated the effect of age and individual differences on syntactic processing in healthy adults. Specifically, we tested the effect of age on the speed of reading syntactically complex sentences and the accuracy of their comprehension, and explored the neural correlates of individual differences in speed and accuracy when taking age into account. The analysis was limited to white matter and used diffusion tensor imaging and tract-based spatial statistics to analyze fractional anisotropy of white-matter tracts. The reading speed was found to become slower with age; however, sentence comprehension accuracy was unaffected by age. Thus, similar to the processing speed decrease in many other cognitive domains, a decrease in sentence processing speed seems to be a compensatory mechanisms that ensures that processing accuracy is maintained. The study did not find any significant correlates of individual differences in syntactic processing accuracy, which is likely due to small sample size.
In vivo evaluation of the brain white matter maturation is still a challenging task with no existing gold standards. In this article we propose an original approach to evaluate the early maturation of the white matter bundles, which is based on comparison of infant and adult groups using the Mahalanobis distance computed from four complementary MRI parameters: quantitative qT1 and qT2 relaxation times, longitudinal λ║ and transverse λ⊥ diffusivities from diffusion tensor imaging. Such multi-parametric approach is expected to better describe maturational asynchrony than conventional univariate approaches because it takes into account complementary dependencies of the parameters on different maturational processes, notably the decrease in water content and the myelination. Our approach was tested on 17 healthy infants (aged 3- to 21-week old) for 18 different bundles. It finely confirmed maturational asynchrony across the bundles: the spino-thalamic tract, the optic radiations, the cortico-spinal tract and the fornix have the most advanced maturation, while the superior longitudinal and arcuate fasciculi, the anterior limb of the internal capsule and the external capsule have the most delayed maturation. Furthermore, this approach was more reliable than univariate approaches as it revealed more maturational relationships between the bundles and did not violate a priori assumptions on the temporal order of the bundle maturation. Mahalanobis distances decreased exponentially with age in all bundles, with the only difference between them explained by different onsets of maturation. Estimation of these relative delays confirmed that the most dramatic changes occur during the first post-natal year.
The study is based on the analysis of event-related potentials (ERPs) accompanying processing referentially ambiguous pronouns under condition when disambiguation is necessary for effective task performance. Participants were asked to match the pronoun in the second sentence with its antecedent (the noun phrase it is related to) in the first sentence in two conditions: experimental (two possible antecedents) and control (only one possible antecedent). Processing referentially ambiguous pronouns as compared to the control condition elicited an Nref effect – a diffuse ERP deflection 300–400 ms poststimulus that was earlier observed in Dutch and Chinese. Moreover, in contrast to previous results, no P600 effect – late positivity associated with acceptability judgment under condition of referential ambiguity – was found. Our data in comparison with results of previous studies indicate that strategies in processing referentially ambiguous pronouns (acceptability judgment) are determined not only by experimental task but also by absence/presence of anomalous trials in the experimental materials.
Studying how the healthy human brain develops is important to understand early pathological mechanisms and to assess the influence of fetal or perinatal events on later life. Brain development relies on complex and intermingled mechanisms especially during gestation and first post-natal months, with intense interactions between genetic, epigenetic and environmental factors. Although the baby's brain is organized early on, it is not a miniature adult brain: regional brain changes are asynchronous and protracted, i.e. sensory-motor regions develop early and quickly, whereas associative regions develop later and slowly over decades. Concurrently, the infant/child gradually achieves new performances, but how brain maturation relates to changes in behavior is poorly understood, requiring non-invasive in vivo imaging studies such as magnetic resonance imaging (MRI). Two main processes of early white matter development are reviewed: (1) establishment of connections between brain regions within functional networks, leading to adult-like organization during the last trimester of gestation, (2) maturation (myelination) of these connections during infancy to provide efficient transfers of information. Current knowledge from post-mortem descriptions and in vivo MRI studies is summed up, focusing on T1- and T2-weighted imaging, diffusion tensor imaging, and quantitative mapping of T1/T2 relaxation times, myelin water fraction and magnetization transfer ratio.
The mechanisms of lateralization of language processing are still not fully understood by neurolinguistics today. The current study aims to study the relation between language lateralization and such factors as individual handedness, familial sinistrality and tractography metrics of the corpus callosum (CC). We collected fMRI and DTI data, as well as information about individual handedness and familial sinistrality in 50 neurologically healthy Russian speakers. According to the results, language lateralization is related to the volume and fractional anisotropy of CC, as well as individual handedness. Specifically, people with greater right-hand preference and people with a larger volume and higher fractional anisotropy of CC have greater lateralization of language-related activation to the left hemisphere of a brain.
The book describes theinterdependent relations between the multilingualism and literary creativity.
This book presents an interdisciplinary approach to the problem of mental lexicon organization. Several models of visual word recognition as well as brain mechanisms of reading are discussed. Also, such basic neurolinguistic topics are reviewed here as brain structure and functioning, memory organization, models of the mental lexicon and lexical access, electrophysiological approach to speech and language research, aphasia’s types and developmental language disorders (SLI, developmental dyslexia), genetics of language impairments, and so on. Finally, this monograph gives the results of four eye tracking experiments on visual word recognition during reading.
The present book is address to a wide range of researchers (linguists, neurophysiologists, psychologists, artificial intelligence specialists, philosophers) who works are associated with cognitive brain research.