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1.
J Neurosci ; 44(3)2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38050156

RESUMO

Reading acquisition involves the integration of auditory and visual stimuli. Thus, low-level audiovisual multisensory integration might contribute to disrupted reading in developmental dyslexia. Although dyslexia is more frequently diagnosed in males and emerging evidence indicates that the neural basis of dyslexia might differ between sexes, previous studies examining multisensory integration did not evaluate potential sex differences nor tested its neural correlates. In the current study on 88 adolescents and young adults, we found that only males with dyslexia showed a deficit in multisensory integration of simple nonlinguistic stimuli. At the neural level, both females and males with dyslexia presented smaller differences in response to multisensory compared to those in response to unisensory conditions in the N1 and N2 components (early components of event-related potentials associated with sensory processing) than the control group. Additionally, in a subsample of 80 participants matched for nonverbal IQ, only males with dyslexia exhibited smaller differences in the left hemisphere in response to multisensory compared to those in response to unisensory conditions in the N1 component. Our study indicates that deficits of multisensory integration seem to be more severe in males than females with dyslexia. This provides important insights into sex-modulated cognitive processes that might confer vulnerability to reading difficulties.


Assuntos
Percepção Auditiva , Dislexia , Adolescente , Adulto Jovem , Humanos , Masculino , Feminino , Percepção Auditiva/fisiologia , Tempo de Reação/fisiologia , Percepção Visual/fisiologia , Caracteres Sexuais , Estimulação Acústica
2.
Child Dev ; 95(4): e236-e252, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38396333

RESUMO

This study investigated the neural basis of letter and speech sound (LS) integration in 53 typical readers (35 girls, all White) during the first 2 years of reading education (ages 7-9). Changes in both sensory (multisensory vs unisensory) and linguistic (congruent vs incongruent) aspects of LS integration were examined. The left superior temporal cortex and bilateral inferior frontal cortex showed increasing activation for multisensory over unisensory LS over time, driven by reduced activation to speech sounds. No changes were noted in the congruency effect. However, at age nine, heightened activation to incongruent over congruent LS pairs were observed, correlating with individual differences in reading development. This suggests that the incongruency effect evolves at varying rates depending on reading skills.


Assuntos
Leitura , Percepção da Fala , Humanos , Feminino , Masculino , Percepção da Fala/fisiologia , Criança , Desenvolvimento Infantil/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Lobo Temporal/fisiologia , Lobo Frontal/fisiologia , Fonética
3.
Neuroimage ; 278: 120296, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37495199

RESUMO

Learning letter and speech sound (LS) associations is a major step in reading acquisition common for all alphabetic scripts, including Braille used by blind readers. The left superior temporal cortex (STC) plays an important role in audiovisual LS integration in sighted people, but it is still unknown what neural mechanisms are responsible for audiotactile LS integration in blind individuals. Here, we investigated the similarities and differences between LS integration in blind Braille (N = 42, age range: 9-60 y.o.) and sighted print (N = 47, age range: 9-60 y.o.) readers who acquired reading using different sensory modalities. In both groups, the STC responded to both isolated letters and isolated speech sounds, showed enhanced activation when they were presented together, and distinguished between congruent and incongruent letter and speech sound pairs. However, the direction of the congruency effect was different between the groups. Sighted subjects showed higher activity for incongruent LS pairs in the bilateral STC, similarly to previously studied typical readers of transparent orthographies. In the blind, congruent pairs resulted in an increased response in the right STC. These differences may be related to more sequential processing of Braille as compared to print reading. At the same time, behavioral efficiency in LS discrimination decisions and the congruency effect were found to be related to age and reading skill only in sighted participants, suggesting potential differences in the developmental trajectories of LS integration between blind and sighted readers.


Assuntos
Fonética , Percepção Visual , Humanos , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Percepção Visual/fisiologia , Mapeamento Encefálico , Cegueira , Aprendizagem , Leitura
4.
J Neurosci ; 41(33): 7076-7085, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34253624

RESUMO

The white matter (WM) architecture of the human brain changes in response to training, though fine-grained temporal characteristics of training-induced white matter plasticity remain unexplored. We investigated white matter microstructural changes using diffusion tensor imaging at five different time points in 26 sighted female adults during 8 months of training on tactile braille reading. Our results show that training-induced white matter plasticity occurs both within and beyond the trained sensory modality, as reflected by fractional anisotropy (FA) increases in somatosensory and visual cortex, respectively. The observed changes followed distinct time courses, with gradual linear FA increase along the training in the somatosensory cortex and sudden visual cortex cross-modal plasticity occurring after braille input became linguistically meaningful. WM changes observed in these areas returned to baseline after the cessation of learning in line with the supply-demand model of plasticity. These results also indicate that the temporal dynamics of microstructural plasticity in different cortical regions might be modulated by the nature of computational demands. We provide additional evidence that observed FA training-induced changes are behaviorally relevant to tactile reading. Together, these results demonstrate that WM plasticity is a highly dynamic process modulated by the introduction of novel experiences.SIGNIFICANCE STATEMENT Throughout the lifetime the human brain is shaped by various experiences. Training-induced reorganization in white matter (WM) microstructure has been reported, but we know little about its temporal dynamics. To fill this gap, we scanned sighted subjects five times during tactile braille reading training. We observed different dynamics of WM plasticity in the somatosensory and visual cortices implicated in braille reading. The former showed a continuous increase in WM tissue anisotropy along with tactile training, while microstructural changes in the latter were observed only after the participants learned to read braille words. Our results confirm the supply-demand model of brain plasticity and provide evidence that WM reorganization depends on distinct computational demands and functional roles of regions involved in the trained skill.


Assuntos
Aprendizagem por Associação/fisiologia , Imagem de Tensor de Difusão , Plasticidade Neuronal/fisiologia , Leitura , Auxiliares Sensoriais , Tato/fisiologia , Visão Ocular/fisiologia , Substância Branca/fisiologia , Adulto , Feminino , Humanos , Desempenho Psicomotor/fisiologia , Fatores de Tempo , Transtornos da Visão , Adulto Jovem
5.
Neuroimage ; 251: 118889, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35065268

RESUMO

Current models of episodic memory posit that retrieval involves the reenactment of encoding processes. Recent evidence has shown that this reinstatement process - indexed by subsequent encoding-retrieval similarity of brain activity patterns - is related to the activity in the hippocampus during encoding. However, we tend to re-experience emotional events in memory more richly than dull events. The role of amygdala - a critical hub of emotion processing - in reinstatement of emotional events was poorly understood. To investigate it, we leveraged a previously overlooked divergence in the role of amygdala in memory modulation by distinct emotions - disgust and fear. Here we used a novel paradigm in which participants encoded complex events (word pairs) and their memory was tested after 3 weeks, both phases during fMRI scanning. Using representational similarity analysis and univariate analyses, we show that the strength of amygdala activation during encoding was correlated with memory reinstatement of individual event representations in emotion-specific regions. Critically, amygdala modulated reinstatement more for disgust than fear. This was in line with other differences observed at the level of memory performance and neural mechanisms of encoding. Specifically, amygdala and perirhinal cortex were more involved during encoding of disgust-related events, whereas hippocampus and parahippocampal gyrus during encoding of fear-related events. Together, these findings shed a new light on the role of the amygdala and medial temporal lobe regions in encoding and reinstatement of specific emotional memories.


Assuntos
Asco , Tonsila do Cerebelo/diagnóstico por imagem , Mapeamento Encefálico , Medo , Hipocampo/diagnóstico por imagem , Hipocampo/fisiologia , Humanos , Imageamento por Ressonância Magnética , Lobo Temporal/fisiologia
6.
Dev Sci ; 25(2): e13173, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34448328

RESUMO

This study focuses on the role of numerous cognitive skills such as phonological awareness (PA), rapid automatized naming (RAN), visual and selective attention, auditory skills, and implicit learning in developmental dyslexia. We examined the (co)existence of cognitive deficits in dyslexia and assessed cognitive skills' predictive value for reading. First, we compared school-aged children with severe reading impairment (n = 51) to typical readers (n = 71) to explore the individual patterns of deficits in dyslexia. Children with dyslexia, as a group, presented low PA and RAN scores, as well as limited implicit learning skills. However, we found no differences in the other domains. We found a phonological deficit in 51% and a RAN deficit in 26% of children with dyslexia. These deficits coexisted in 14% of the children. Deficits in other cognitive domains were uncommon and most often coexisted with phonological or RAN deficits. Despite having a severe reading impairment, 26% of children with dyslexia did not present any of the tested deficits. Second, in a group of children presenting a wide range of reading abilities (N = 211), we analysed the relationship between cognitive skills and reading level. PA and RAN were independently related to reading abilities. Other skills did not explain any additional variance. The impact of PA and RAN on reading skills differed. While RAN was a consistent predictor of reading, PA predicted reading abilities particularly well in average and good readers with a smaller impact in poorer readers.


Assuntos
Dislexia , Fonética , Aptidão , Conscientização , Criança , Cognição , Dislexia/psicologia , Humanos
7.
Brain Topogr ; 35(2): 219-231, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34775569

RESUMO

Stress may impact the ability to effectively regulate emotions. To study the impact of stressful experiences in early and recent life on emotion regulation, we examined the relationship between early life stress, recent stress, and brain activation during cognitive reappraisal. We investigated two regulation goals: the decrease and increase of emotional response to both negative and positive stimuli. Furthermore, two models of stress consequences were examined: the cumulative and match/mismatch models. A total of 83 participants (Mage = 21.66) took part in the study. There was an interaction between cumulative stress and stimuli valence in the cuneus, superior lateral occipital cortex, superior parietal lobule, supramarginal gyrus extending to superior temporal gyrus, and precentral gyrus extending to supplementary motor area. Interaction between mismatched stress index and stimuli valence was found in the left hippocampus, left insula extending to the orbitofrontal cortex and amygdala, and in a cluster including the anterior cingulate cortex, superior frontal gyrus, and frontal pole. Furthermore, there were differences between the effects of cumulative and mismatched stress indices on brain activation during reappraisal of positive but not negative stimuli. Results indicate that cumulative stress and match/mismatch approaches are both useful for explaining brain activation during reappraisal. This finding is important for our understanding of the multifaceted impact of stress on emotion regulation.


Assuntos
Regulação Emocional , Imageamento por Ressonância Magnética , Adulto , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Emoções/fisiologia , Humanos , Estresse Psicológico/diagnóstico por imagem , Adulto Jovem
8.
Neuroimage ; 231: 117851, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33582273

RESUMO

All writing systems represent units of spoken language. Studies on the neural correlates of reading in different languages show that this skill relies on access to brain areas dedicated to speech processing. Speech-reading convergence onto a common perisylvian network is therefore considered universal among different writing systems. Using fMRI, we test whether this holds true also for tactile Braille reading in the blind. The neural networks for Braille and visual reading overlapped in the left ventral occipitotemporal (vOT) cortex. Even though we showed similar perisylvian specialization for speech in both groups, blind subjects did not engage this speech system for reading. In contrast to the sighted, speech-reading convergence in the blind was absent in the perisylvian network. Instead, the blind engaged vOT not only in reading but also in speech processing. The involvement of the vOT in speech processing and its engagement in reading in the blind suggests that vOT is included in a modality independent language network in the blind, also evidenced by functional connectivity results. The analysis of individual speech-reading convergence suggests that there may be segregated neuronal populations in the vOT for speech processing and reading in the blind.


Assuntos
Cegueira/fisiopatologia , Leitura Labial , Rede Nervosa/fisiologia , Lobo Occipital/fisiologia , Leitura , Lobo Temporal/fisiologia , Tato/fisiologia , Estimulação Acústica/métodos , Adolescente , Adulto , Cegueira/diagnóstico por imagem , Auxiliares de Comunicação para Pessoas com Deficiência , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Plasticidade Neuronal/fisiologia , Lobo Occipital/diagnóstico por imagem , Estimulação Luminosa/métodos , Lobo Temporal/diagnóstico por imagem , Adulto Jovem
9.
Neuroimage ; 226: 117544, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33220408

RESUMO

During foreign language acquisition neural representations of native language and foreign language assimilate. In the reading network, this assimilation leads to a shift from effortful processing to automated reading. Longitudinal studies can track this transition and reveal dynamics that might not become apparent in behavior. Here, we report results from a longitudinal functional magnetic resonance imaging (fMRI) study, which tracked functional changes in the reading network of beginning learners of Greek over one year. We deliberately chose Greek as foreign language that would have similar orthographic transparency but a different alphabet than the native language (Polish). fMRI scans with lexical and semantic decision tasks were performed at five different time points (every ~3 months). Classical language areas (the left inferior frontal gyrus, the left precentral gyrus, and the bilateral supplementary motor cortex), and cognitive control areas (left inferior parietal lobe and bilateral anterior cingulate cortex) showed stronger activation after the first months of instruction as compared to the activation before instruction. This pattern occured in both tasks. Task-related activity in the reading network remained constant throughout the remaining 6 months of learning and was also present in a follow-up scan 3 months after the end of the course. A similar pattern was demonstrated by the analysis of convergence between foreign and native languages occurring within the first months of learning. Additionally, in the lexical task, the extent of spatial overlap, between foreign and native language in Broca's area increased constantly from the beginning till the end of training. Our findings support the notion that reorganization of language networks is achieved after a relatively short time of foreign language instruction. We also demonstrate that cognitive control areas are recruited in foreign language reading at low proficiency levels. No apparent changes in the foreign or native reading network occur after the initial 3 months of learning. This suggests that task demand might be more important than proficiency in regulating the resources needed for efficient foreign language reading.


Assuntos
Encéfalo/diagnóstico por imagem , Idioma , Multilinguismo , Rede Nervosa/diagnóstico por imagem , Plasticidade Neuronal/fisiologia , Leitura , Adulto , Mapeamento Encefálico , Feminino , Lateralidade Funcional/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
10.
Neuroimage ; 227: 117613, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33307223

RESUMO

A growing body of empirical evidence supports the notion of diverse neurobiological processes underlying learning-induced plasticity changes in the human brain. There are still open questions about how brain plasticity depends on cognitive task complexity, how it supports interactions between brain systems and with what temporal and spatial trajectory. We investigated brain and behavioural changes in sighted adults during 8-months training of tactile Braille reading whilst monitoring brain structure and function at 5 different time points. We adopted a novel multivariate approach that includes behavioural data and specific MRI protocols sensitive to tissue properties to assess local functional and structural and myelin changes over time. Our results show that while the reading network, located in the ventral occipitotemporal cortex, rapidly adapts to tactile input, sensory areas show changes in grey matter volume and intra-cortical myelin at different times. This approach has allowed us to examine and describe neuroplastic mechanisms underlying complex cognitive systems and their (sensory) inputs and (motor) outputs differentially, at a mesoscopic level.


Assuntos
Encéfalo/diagnóstico por imagem , Aprendizagem/fisiologia , Plasticidade Neuronal/fisiologia , Leitura , Auxiliares Sensoriais , Percepção do Tato/fisiologia , Adaptação Fisiológica/fisiologia , Adulto , Encéfalo/fisiologia , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética
11.
Neuroimage ; 225: 117503, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33130273

RESUMO

Despite dissimilarities among scripts, a universal hallmark of literacy in skilled readers is the convergent brain activity for print and speech. Little is known, however, whether this differs as a function of grapheme to phoneme transparency in beginning readers. Here we compare speech and orthographic processing circuits in two contrasting languages, Polish and English, in 100 7-year-old children performing fMRI language localizer tasks. Results show limited language variation, with speech-print convergence evident mostly in left frontotemporal perisylvian regions. Correlational and intersect analyses revealed subtle differences in the strength of this coupling in several regions of interest. Specifically, speech-print convergence was higher for transparent Polish than opaque English in the right temporal area, associated with phonological processing. Conversely, speech-print convergence was higher for English than Polish in left fusiform, associated with visual word recognition. We conclude that speech-print convergence is a universal marker of reading even at the beginning of reading acquisition with minor variations that can be explained by the differences in grapheme to phoneme transparency. This finding at the earliest stages of reading acquisition conforms well with claims that reading exhibits a good deal of universality despite writing systems differences.


Assuntos
Encéfalo/diagnóstico por imagem , Idioma , Leitura , Percepção da Fala , Animais , Criança , Feminino , Lobo Frontal/diagnóstico por imagem , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Fonética , Lobo Temporal/diagnóstico por imagem
12.
Hum Brain Mapp ; 42(2): 384-397, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33098616

RESUMO

The neural plasticity underlying language learning is a process rather than a single event. However, the dynamics of training-induced brain reorganization have rarely been examined, especially using a multimodal magnetic resonance imaging approach, which allows us to study the relationship between functional and structural changes. We focus on sign language acquisition in hearing adults who underwent an 8-month long course and five neuroimaging sessions. We assessed what neural changes occurred as participants learned a new language in a different modality-as reflected by task-based activity, connectivity changes, and co-occurring structural alterations. Major changes in the activity pattern appeared after just 3 months of learning, as indicated by increases in activation within the modality-independent perisylvian language network, together with increased activation in modality-dependent parieto-occipital, visuospatial and motion-sensitive regions. Despite further learning, no alterations in activation were detected during the following months. However, enhanced coupling between left-lateralized occipital and inferior frontal regions was observed as the proficiency increased. Furthermore, an increase in gray matter volume was detected in the left inferior frontal gyrus which peaked at the end of learning. Overall, these results showed complexity and temporal distinctiveness of various aspects of brain reorganization associated with learning of new language in different sensory modality.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Audição/fisiologia , Aprendizagem/fisiologia , Imageamento por Ressonância Magnética/métodos , Língua de Sinais , Adulto , Mapeamento Encefálico/métodos , Feminino , Humanos , Imagem Multimodal/métodos , Plasticidade Neuronal/fisiologia , Estimulação Luminosa/métodos , Desempenho Psicomotor/fisiologia , Adulto Jovem
13.
Eur J Neurosci ; 52(6): 3595-3609, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31991019

RESUMO

Despite evidence for a difference in total brain volume between dyslexic and good readers, no previous neuroimaging study examined differences in allometric scaling (i.e. differences in the relationship between regional and total brain volumes) between dyslexic and good readers. The present study aims to fill this gap by testing differences in allometric scaling and regional brain volume differences in dyslexic and good readers. Object-based morphometry analysis was used to determine grey and white matter volumes of the four lobes, the cerebellum and limbic structures in 130 dyslexic and 106 good readers aged 8-14 years. Data were collected across three countries (France, Poland and Germany). Three methodological approaches were used as follows: principal component analysis (PCA), linear regression and multiple-group confirmatory factor analysis (MGCFA). Difference in total brain volume between good and dyslexic readers was Cohen's d = 0.39. We found no difference in allometric scaling, nor in regional brain volume between dyslexic and good readers. Results of our three methodological approaches (PCA, linear regression and MGCFA) were consistent. This study provides evidence for total brain volume differences between dyslexic and control children, but no evidence for differences in the volumes of the four lobes, the cerebellum or limbic structures, once allometry is taken into account. It also finds no evidence for a difference in allometric relationships between the groups. We highlight the methodological interest of the MGCFA approach to investigate such research issues.


Assuntos
Dislexia , Neuroanatomia , Mapeamento Encefálico , Criança , Dislexia/diagnóstico por imagem , Alemanha , Humanos , Imageamento por Ressonância Magnética , Leitura
14.
Cogn Affect Behav Neurosci ; 20(3): 588-603, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32342272

RESUMO

The aim of this study was to characterize neural activation during the processing of negative facial expressions in a non-clinical group of individuals characterized by two factors: the levels of stress experienced in early life and in adulthood. Two models of stress consequences were investigated: the match/mismatch and cumulative stress models. The match/mismatch model assumes that early adversities may promote optimal coping with similar events in the future through fostering the development of coping strategies. The cumulative stress model assumes that effects of stress are additive, regardless of the timing of the stressors. Previous studies suggested that stress can have both cumulative and match/mismatch effects on brain structure and functioning and, consequently, we hypothesized that effects on brain circuitry would be found for both models. We anticipated effects on the neural circuitry of structures engaged in face perception and emotional processing. Hence, the amygdala, fusiform face area, occipital face area, and posterior superior temporal sulcus were selected as seeds for seed-based functional connectivity analyses. The interaction between early and recent stress was related to alterations during the processing of emotional expressions mainly in to the cerebellum, middle temporal gyrus, and supramarginal gyrus. For cumulative stress levels, such alterations were observed in functional connectivity to the middle temporal gyrus, lateral occipital cortex, precuneus, precentral and postcentral gyri, anterior and posterior cingulate gyri, and Heschl's gyrus. This study adds to the growing body of literature suggesting that both the cumulative and the match/mismatch hypotheses are useful in explaining the effects of stress.


Assuntos
Adaptação Psicológica/fisiologia , Experiências Adversas da Infância , Tonsila do Cerebelo/fisiopatologia , Córtex Cerebral/fisiopatologia , Conectoma , Emoções/fisiologia , Reconhecimento Facial/fisiologia , Estresse Psicológico/fisiopatologia , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Expressão Facial , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Fatores de Tempo , Adulto Jovem
15.
Proc Natl Acad Sci U S A ; 114(4): E600-E609, 2017 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-28069964

RESUMO

The principles that guide large-scale cortical reorganization remain unclear. In the blind, several visual regions preserve their task specificity; ventral visual areas, for example, become engaged in auditory and tactile object-recognition tasks. It remains open whether task-specific reorganization is unique to the visual cortex or, alternatively, whether this kind of plasticity is a general principle applying to other cortical areas. Auditory areas can become recruited for visual and tactile input in the deaf. Although nonhuman data suggest that this reorganization might be task specific, human evidence has been lacking. Here we enrolled 15 deaf and 15 hearing adults into an functional MRI experiment during which they discriminated between temporally complex sequences of stimuli (rhythms). Both deaf and hearing subjects performed the task visually, in the central visual field. In addition, hearing subjects performed the same task in the auditory modality. We found that the visual task robustly activated the auditory cortex in deaf subjects, peaking in the posterior-lateral part of high-level auditory areas. This activation pattern was strikingly similar to the pattern found in hearing subjects performing the auditory version of the task. Although performing the visual task in deaf subjects induced an increase in functional connectivity between the auditory cortex and the dorsal visual cortex, no such effect was found in hearing subjects. We conclude that in deaf humans the high-level auditory cortex switches its input modality from sound to vision but preserves its task-specific activation pattern independent of input modality. Task-specific reorganization thus might be a general principle that guides cortical plasticity in the brain.


Assuntos
Córtex Auditivo/fisiologia , Surdez/fisiopatologia , Estimulação Acústica , Adulto , Córtex Auditivo/diagnóstico por imagem , Surdez/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Adulto Jovem
16.
Neuroimage ; 202: 116084, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31400530

RESUMO

Perception via different sensory modalities was traditionally believed to be supported by largely separate brain systems. However, a growing number of studies demonstrate that the visual cortices of typical, sighted adults are involved in tactile and auditory perceptual processing. Here, we investigated the spatiotemporal dynamics of the visual cortex's involvement in a complex tactile task: Braille letter recognition. Sighted subjects underwent Braille training and then participated in a transcranial magnetic stimulation (TMS) study in which they tactually identified single Braille letters. During this task, TMS was applied to their left early visual cortex, visual word form area (VWFA), and left early somatosensory cortex at five time windows from 20 to 520 ms following the Braille letter presentation's onset. The subjects' response accuracy decreased when TMS was applied to the early visual cortex at the 120-220 ms time window and when TMS was applied to the VWFA at the 320-420 ms time window. Stimulation of the early somatosensory cortex did not have a time-specific effect on the accuracy of the subjects' Braille letter recognition, but rather caused a general slowdown during this task. Our results indicate that the involvement of sighted people's visual cortices in tactile perception respects the canonical visual hierarchy-the early tactile processing stages involve the early visual cortex, whereas more advanced tactile computations involve high-level visual areas. Our findings are compatible with the metamodal account of brain organization and suggest that the whole visual cortex may potentially support spatial perception in a task-specific, sensory-independent manner.


Assuntos
Córtex Somatossensorial/fisiologia , Percepção do Tato/fisiologia , Córtex Visual/fisiologia , Feminino , Humanos , Estimulação Magnética Transcraniana , Adulto Jovem
17.
J Child Psychol Psychiatry ; 59(1): 76-87, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28691732

RESUMO

BACKGROUND: Literacy acquisition is a demanding process that induces significant changes in the brain, especially in the spoken and written language networks. Nevertheless, large-scale paediatric fMRI studies are still limited. METHODS: We analyzed fMRI data to show how individual differences in reading performance correlate with brain activation for speech and print in 111 children attending kindergarten or first grade and examined group differences between a matched subset of emergent-readers and prereaders. RESULTS: Across the entire cohort, individual differences analysis revealed that reading skill was positively correlated with the magnitude of activation difference between words and symbol strings in left superior temporal, inferior frontal and fusiform gyri. Group comparisons of the matched subset of pre- and emergent-readers showed higher activity for emergent-readers in left inferior frontal, precentral, and postcentral gyri. Individual differences in activation for natural versus vocoded speech were also positively correlated with reading skill, primarily in the left temporal cortex. However, in contrast to studies on adult illiterates, group comparisons revealed higher activity in prereaders compared to readers in the frontal lobes. Print-speech coactivation was observed only in readers and individual differences analyses revealed a positive correlation between convergence and reading skill in the left superior temporal sulcus. CONCLUSIONS: These results emphasise that a child's brain undergoes several modifications to both visual and oral language systems in the process of learning to read. They also suggest that print-speech convergence is a hallmark of acquiring literacy.


Assuntos
Logro , Encéfalo/fisiologia , Imageamento por Ressonância Magnética/métodos , Leitura , Percepção da Fala/fisiologia , Mapeamento Encefálico/métodos , Criança , Feminino , Humanos , Masculino
18.
Hum Brain Mapp ; 38(2): 900-908, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27712002

RESUMO

Despite decades of research, the anatomical abnormalities associated with developmental dyslexia are still not fully described. Studies have focused on between-group comparisons in which different neuroanatomical measures were generally explored in isolation, disregarding potential interactions between regions and measures. Here, for the first time a multivariate classification approach was used to investigate grey matter disruptions in children with dyslexia in a large (N = 236) multisite sample. A variety of cortical morphological features, including volumetric (volume, thickness and area) and geometric (folding index and mean curvature) measures were taken into account and generalizability of classification was assessed with both 10-fold and leave-one-out cross validation (LOOCV) techniques. Classification into control vs. dyslexic subjects achieved above chance accuracy (AUC = 0.66 and ACC = 0.65 in the case of 10-fold CV, and AUC = 0.65 and ACC = 0.64 using LOOCV) after principled feature selection. Features that discriminated between dyslexic and control children were exclusively situated in the left hemisphere including superior and middle temporal gyri, subparietal sulcus and prefrontal areas. They were related to geometric properties of the cortex, with generally higher mean curvature and a greater folding index characterizing the dyslexic group. Our results support the hypothesis that an atypical curvature pattern with extra folds in left hemispheric perisylvian regions characterizes dyslexia. Hum Brain Mapp 38:900-908, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/patologia , Dislexia/patologia , Aprendizado de Máquina , Adolescente , Algoritmos , Área Sob a Curva , Córtex Cerebral/diagnóstico por imagem , Criança , Bases de Dados Factuais , Dislexia/diagnóstico por imagem , Feminino , França , Lateralidade Funcional , Alemanha , Humanos , Imageamento por Ressonância Magnética , Masculino , Polônia
19.
Behav Res Methods ; 49(4): 1407-1419, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27613018

RESUMO

Emotionally charged pictorial materials are frequently used in phobia research, but no existing standardized picture database is dedicated to the study of different phobias. The present work describes the results of two independent studies through which we sought to develop and validate this type of database-a Set of Fear Inducing Pictures (SFIP). In Study 1, 270 fear-relevant and 130 neutral stimuli were rated for fear, arousal, and valence by four groups of participants; small-animal (N = 34), blood/injection (N = 26), social-fearful (N = 35), and nonfearful participants (N = 22). The results from Study 1 were employed to develop the final version of the SFIP, which includes fear-relevant images of social exposure (N = 40), blood/injection (N = 80), spiders/bugs (N = 80), and angry faces (N = 30), as well as 726 neutral photographs. In Study 2, we aimed to validate the SFIP in a sample of spider, blood/injection, social-fearful, and control individuals (N = 66). The fear-relevant images were rated as being more unpleasant and led to greater fear and arousal in fearful than in nonfearful individuals. The fear images differentiated between the three fear groups in the expected directions. Overall, the present findings provide evidence for the high validity of the SFIP and confirm that the set may be successfully used in phobia research.


Assuntos
Nível de Alerta , Medo/psicologia , Transtornos Fóbicos/psicologia , Estimulação Luminosa , Adulto , Animais , Sangue , Bases de Dados como Assunto , Emoções , Feminino , Humanos , Injeções , Masculino , Fobia Social , Reprodutibilidade dos Testes , Aranhas , Adulto Jovem
20.
Neuroimage ; 132: 406-416, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26931814

RESUMO

Phonological processing ability is a key factor in reading acquisition, predicting its later success or causing reading problems when it is weakened. Our aim here was to establish the neural correlates of auditory word rhyming (a standard phonological measure) in 102 young children with (FHD+) and without familial history of dyslexia (FHD-) in a shallow orthography (i.e. Polish). Secondly, in order to gain a deeper understanding on how schooling shapes brain activity to phonological awareness, a comparison was made of children who had had formal literacy instruction for several months (in first grade) and those who had not yet had any formal instruction in literacy (in kindergarten). FHD+ children compared to FHD- children in the first grade scored lower in an early print task and showed longer reaction times in the in-scanner rhyme task. No behavioral differences between FHD+ and FHD- were found in the kindergarten group. On the neuronal level, overall familial risk was associated with reduced activation in the bilateral temporal, tempo-parietal and inferior temporal-occipital regions, as well as the bilateral inferior and middle frontal gyri. Subcortically, hypoactivation was found in the bilateral thalami, caudate, and right putamen in FHD+. A main effect of the children's grade was present only in the left inferior frontal gyrus, where reduced activation for rhyming was shown in first-graders. Several regions in the ventral occipital cortex, including the fusiform gyrus, and in the right middle frontal and postcentral gyri, displayed an interaction between familial risk and grade. The present results show strong influence of familial risk that may actually increase with formal literacy instruction.


Assuntos
Encéfalo/fisiologia , Dislexia/genética , Predisposição Genética para Doença , Fonética , Leitura , Mapeamento Encefálico , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estudantes
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