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1.
Neuroimage ; 294: 120649, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38759354

RESUMO

Neurobehavioral studies have provided evidence for the effectiveness of anodal tDCS on language production, by stimulation of the left Inferior Frontal Gyrus (IFG) or of left Temporo-Parietal Junction (TPJ). However, tDCS is currently not used in clinical practice outside of trials, because behavioral effects have been inconsistent and underlying neural effects unclear. Here, we propose to elucidate the neural correlates of verb and noun learning and to determine if they can be modulated with anodal high-definition (HD) tDCS stimulation. Thirty-six neurotypical participants were randomly allocated to anodal HD-tDCS over either the left IFG, the left TPJ, or sham stimulation. On day one, participants performed a naming task (pre-test). On day two, participants underwent a new-word learning task with rare nouns and verbs concurrently to HD-tDCS for 20 min. The third day consisted of a post-test of naming performance. EEG was recorded at rest and during naming on each day. Verb learning was significantly facilitated by left IFG stimulation. HD-tDCS over the left IFG enhanced functional connectivity between the left IFG and TPJ and this correlated with improved learning. HD-tDCS over the left TPJ enabled stronger local activation of the stimulated area (as indexed by greater alpha and beta-band power decrease) during naming, but this did not translate into better learning. Thus, tDCS can induce local activation or modulation of network interactions. Only the enhancement of network interactions, but not the increase in local activation, leads to robust improvement of word learning. This emphasizes the need to develop new neuromodulation methods influencing network interactions. Our study suggests that this may be achieved through behavioral activation of one area and concomitant activation of another area with HD-tDCS.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Humanos , Estimulação Transcraniana por Corrente Contínua/métodos , Feminino , Masculino , Adulto , Adulto Jovem , Eletroencefalografia/métodos , Córtex Pré-Frontal/fisiologia , Lobo Parietal/fisiologia , Aprendizagem Verbal/fisiologia , Lobo Temporal/fisiologia , Aprendizagem/fisiologia
2.
Neurobiol Learn Mem ; 192: 107622, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35462028

RESUMO

Broca's area in the left hemisphere of the human neocortex has been suggested as a major hub for acquisition, storage, and access of linguistic information, abstract words in particular. Direct causal evidence for the latter, however, is still scarce; filling this gap was the goal of the present study. Using transcranial direct current stimulation (tDCS) of Broca's region, we aimed to delineate the involvement of this area in abstract and concrete word acquisition. The experiment used a between-subject design and involved 15 min of anodal or cathodal tDCS over Broca's area, or a sham/placebo control condition. The stimulation procedure was followed by a contextual learning session, in which participants were exposed to new concrete and abstract words embedded into short five-sentence texts. Finally, a set of behavioural assessment tasks was run to assess the learning outcomes immediately after the training (Day 1) and with a 24-hour delay (Day 2). The results showed that participants recognised novel abstract words more accurately after both anodal and cathodal tDCS in comparison with the sham condition on Day 1, which was also accompanied by longer recognition times (presumably due to deeper lexico-semantic processing), supporting the role of Broca's region in acquisition of abstract semantics. They were also more successful when recalling concrete words after cathodal tDCS, which indicates a degree of Broca's area involvement in forming memory circuits for concrete words as well. A decrease in the accuracy of recall of word forms and their meanings, as well as in recognition, was observed for all stimulation groups and both types of semantics on Day 2. The results suggest that both anodal and cathodal tDCS of Broca's area improves immediate contextual learning of novel vocabulary, predominantly affecting abstract semantics.


Assuntos
Área de Broca , Estimulação Transcraniana por Corrente Contínua , Área de Broca/fisiologia , Humanos , Idioma , Semântica , Estimulação Transcraniana por Corrente Contínua/métodos , Vocabulário
3.
Neuroimage ; 224: 117405, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32992002

RESUMO

Semantic retrieval is flexible, allowing us to focus on subsets of features and associations that are relevant to the current task or context: for example, we use taxonomic relations to locate items in the supermarket (carrots are a vegetable), but thematic associations to decide which tools we need when cooking (carrot goes with peeler). We used fMRI to investigate the neural basis of this form of semantic flexibility; in particular, we asked how retrieval unfolds differently when participants have advanced knowledge of the type of link to retrieve between concepts (taxonomic or thematic). Participants performed a semantic relatedness judgement task: on half the trials, they were cued to search for a taxonomic or thematic link, while on the remaining trials, they judged relatedness without knowing which type of semantic relationship would be relevant. Left inferior frontal gyrus showed greater activation when participants knew the trial type in advance. An overlapping region showed a stronger response when the semantic relationship between the items was weaker, suggesting this structure supports both top-down and bottom-up forms of semantic control. Multivariate pattern analysis further revealed that the neural response in left inferior frontal gyrus reflects goal information related to different conceptual relationships. Top-down control specifically modulated the response in visual cortex: when the goal was unknown, there was greater deactivation to the first word, and greater activation to the second word. We conclude that top-down control of semantic retrieval is primarily achieved through the gating of task-relevant 'spoke' regions.


Assuntos
Associação , Cognição/fisiologia , Objetivos , Julgamento , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Visual/diagnóstico por imagem , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Classificação , Feminino , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Córtex Pré-Frontal/fisiologia , Semântica , Córtex Visual/fisiologia , Adulto Jovem
4.
Neuroimage ; 222: 117268, 2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-32818615

RESUMO

The left inferior frontal gyrus (IFG) including Broca's area is involved in the processing of many language subdomains, and thus, research on the evolutional and human developmental characteristics of the left IFG will shed light on how language emerges and maturates. In this study, we used diffusion magnetic resonance imaging (dMRI) and resting-state functional MRI (fMRI) to investigate the evolutional and developmental patterns of the left IFG in humans (age 6-8, age 11-13, and age 16-18 years) and macaques. Tractography-based parcellation was used to define the subcomponents of left IFG and consistently identified four subregions in both humans and macaques. This parcellation scheme for left IFG in human was supported by specific coactivation patterns and functional characterization for each subregion. During evolution and development, we found increased functional balance, amplitude of low frequency fluctuations, functional integration, and functional couplings. We also observed higher fractional anisotropy values, i.e. better myelination of dorsal and ventral white matter language pathways during evolution and development. We assume that the resting-state functional connectivity and task-related coactivation mapping are associated with hierarchical language processing. Our findings have shown the evolutional and human developmental patterns of left IFG, and will contribute to the understanding of how the human language evolves and how atypical language developmental disorders may occur.


Assuntos
Idioma , Rede Nervosa/fisiologia , Vias Neurais/fisiologia , Córtex Pré-Frontal/fisiologia , Mapeamento Encefálico/métodos , Criança , Compreensão/fisiologia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Córtex Pré-Frontal/crescimento & desenvolvimento
5.
Hum Brain Mapp ; 41(16): 4562-4573, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32701218

RESUMO

In contrast to a substantial body of research on the neural basis of cognitive performance in several academic domains, less is known about how the brain generates metacognitive (MC) awareness of such performance. The existing work on the neurobiological underpinnings of metacognition has almost exclusively been done in adults and has largely focused on lower level cognitive processing domains, such as perceptual decision-making. Extending this body of evidence, we investigated MC monitoring by asking children to solve arithmetic problems, an educationally relevant higher-order process, while providing concurrent MC reports during fMRI acquisition. Results are reported on 50 primary school children aged 9-10 years old. The current study is the first to demonstrate that brain activity during MC monitoring, relative to the control task, increased in the left inferior frontal gyrus in children. This brain activity further correlated with children's arithmetic development over a 3-year time period. These data are in line with the frequently suggested, yet never empirically tested, hypothesis that activity in the prefrontal cortex during arithmetic is related to the higher-order process of MC monitoring.


Assuntos
Mapeamento Encefálico , Desenvolvimento Infantil/fisiologia , Função Executiva/fisiologia , Imageamento por Ressonância Magnética , Conceitos Matemáticos , Metacognição/fisiologia , Córtex Pré-Frontal/fisiologia , Criança , Feminino , Humanos , Estudos Longitudinais , Masculino , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/crescimento & desenvolvimento
6.
BMC Geriatr ; 20(1): 486, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-33218309

RESUMO

BACKGROUND: The present study aimed to provide a basis for future research examining the neural mechanisms that underlie the beneficial effect of an intervention program, Photo-Integrated Conversation Moderated by Robots (PICMOR), on verbal fluency in older adults as identified in our previous randomized controlled trial. In this preliminary report, we conducted an additional experiment using resting-state functional magnetic resonance imaging (rsfMRI) after the intervention period. Specifically, we investigated the resting-state functional connectivity (rsFC) characteristics of the intervention group (INT) compared to the control group (CONT). METHODS: rsfMRI data were acquired from 31 and 30 participants in INT and CONT, respectively, after the intervention. In the analyses, two of the most important regions in verbal fluency, the left inferior and middle frontal gyri, were selected as seed regions, and the rsFCs were compared between groups. We also conducted regression analyses for rsFCs using the difference in individual phonemic verbal fluency task (PVFT) scores between the pre- and post-intervention periods (i.e., post- minus pre-intervention) as an independent variable. RESULTS: We found higher rsFC in INT than in CONT between the left inferior frontal gyrus as a seed region and the temporal pole and middle frontal gyrus. The rsFC strength between the left inferior frontal gyrus and temporal pole positively correlated with an increased PVFT score between the pre- and post-intervention periods. In contrast, we found lower rsFC in INT than in CONT between the left middle frontal gyrus as a seed region and the posterior cingulate cortex, precuneus, and postcentral gyrus. CONCLUSIONS: Our findings suggest that the beneficial intervention effect of PICMOR on verbal fluency is characterized by enhanced rsFC of the left inferior frontal gyrus with semantic and executive control-related regions and suppressed rsFC between the left middle frontal gyrus and posterior cortical midline structures. No definitive conclusions can be made because of a lack of rsfMRI data before the intervention. However, this pilot study provides the candidates for rsFCs, reflecting the beneficial effects of PICMOR on the brain network involved in verbal fluency. TRIAL REGISTRATION: The trial was retrospectively registered at the UMIN Clinical Trials Registry ( UMIN000036667 ) (May 7th, 2019).


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Idoso , Encéfalo/diagnóstico por imagem , Função Executiva , Humanos , Projetos Piloto
7.
J Neurosci Res ; 97(11): 1430-1454, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31254311

RESUMO

Transcranial direct current stimulation (tDCS) effects in cognition are inconsistent across studies. This study aimed to discuss why typical models might be insufficient to explain these effects, and to investigate a brain state factor, task load, with behavioral experiments on phonological processing. The motor theory of speech perception states that motor codes for articulation take part in speech perception, a view sharpened by neuroimaging findings, which show that the motor role in phonological processing is weighted by the nature of the tasks. Three groups of 20 participants, each under a different tDCS condition (anodal, cathodal, or sham), performed a categorical perception (CP), a lexical decision (LD), and a word naming (WN) task while stimulated on the pars opercularis of the left inferior frontal gyrus, a language area typically involved with the motor role. These tasks were assumed to be subserved by a network of nodes which included the target, believed to be increasingly relevant for performance from speech perception to speech production. A-tDCS facilitation and C-tDCS downregulation should directly increase with the relevance of the target for the task. Downregulation of a low relevance node could result in facilitation by compensation from other nodes. Overall, our brain stimulation findings support the neuroimaging literature in that motor participation in phonological processing depends on task nature and show that tDCS effects are modulated by task load relative to the target. Outcomes such as the improved performance following cathodal tDCS in CP and WN suggest that compensatory mechanisms may take place when the tasks involve more complex neuronal networks.


Assuntos
Área de Broca/fisiologia , Percepção da Fala/fisiologia , Fala/fisiologia , Estimulação Transcraniana por Corrente Contínua , Adulto , Feminino , Humanos , Masculino , Desempenho Psicomotor , Adulto Jovem
8.
Cogn Neuropsychol ; 36(3-4): 167-177, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29865937

RESUMO

Neuropsychological, neuroimaging and electrophysiological studies demonstrate that abstract and concrete word processing relies not only on the activity of a common bilateral network but also on dedicated networks. The neuropsychological literature has shown that a selective sparing of abstract relative to concrete words can be documented in lesions of the left anterior temporal regions. We investigated concrete and abstract word processing in 10 patients undergoing direct electrical stimulation (DES) for brain mapping during awake surgery in the left hemisphere. A lexical decision and a concreteness judgment task were added to the neuropsychological assessment during intra-operative monitoring. On the concreteness judgment, DES delivered over the inferior frontal gyrus significantly decreased abstract word accuracy while accuracy for concrete words decreased when the anterior temporal cortex was stimulated. These results are consistent with a lexical-semantic model that distinguishes between concrete and abstract words related to different neural substrates in the left hemisphere.


Assuntos
Mapeamento Encefálico/métodos , Neuroanatomia/métodos , Testes Neuropsicológicos/normas , Processamento de Texto/métodos , Adulto , Feminino , Humanos , Masculino , Vigília
9.
J Int Neuropsychol Soc ; 25(3): 331-335, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30691540

RESUMO

OBJECTIVES: This study examined the effects of anodal transcranial direct current stimulation (a-tDCS) on sentence and word comprehension in healthy adults. METHODS: Healthy adult participants, aged between 19 and 30 years, received either a-tDCS over the left inferior frontal gyrus (n=18) or sham stimulation (n=18). Participants completed sentence comprehension and word comprehension tasks before and during stimulation. Accuracy and reaction times (RTs) were recorded as participants completed both tasks. RESULTS: a-tDCS was found to significantly decrease RT on the sentence comprehension task compared to baseline. There was no change in RT following sham stimulation. a-tDCS was not found to have a significant effect on accuracy. Also, a-tDCS did not affect accuracy or RTs on the word comprehension task. CONCLUSIONS: The study provides evidence that non-invasive anodal electrical stimulation can modulate sentence comprehension in healthy adults, at least compared to their baseline performance. (JINS, 2019, 25, 331-335).


Assuntos
Compreensão/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Córtex Pré-Frontal/fisiologia , Desempenho Psicomotor/fisiologia , Percepção da Fala/fisiologia , Estimulação Transcraniana por Corrente Contínua , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Reconhecimento Visual de Modelos/efeitos da radiação , Placebos , Tempo de Reação/fisiologia , Adulto Jovem
10.
Cogn Neuropsychol ; 34(1-2): 21-25, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28691606

RESUMO

Through computational modelling of language behaviour in both healthy and brain-damaged individuals, Anders, Riès, van Maanen and Alario ( in press ) propose that to facilitate word selection when alternatives compete for production, the left lateral prefrontal cortex (PFC) changes the threshold for word selection. Because selecting a word during multiword speech involves resolving competition from target-related competitors as well as words produced in the past and future, a word-selection deficit caused by damage to the left PFC may result in difficulties in producing multiword speech. I review evidence in support of this hypothesis and discuss alternative explanations. Future work should extend Anders and colleagues' conclusions to understand whether a deficit in word selection when producing single words accounts for failures to communicate via multiword speech.


Assuntos
Afasia/patologia , Idioma , Córtex Pré-Frontal/patologia , Fala/fisiologia , Feminino , Humanos , Masculino
11.
Cereb Cortex ; 26(7): 3169-82, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26209843

RESUMO

Semantic priming is a crucial phenomenon to study the organization of semantic memory. A novel type of priming effect, integrative priming, has been identified behaviorally, whereby a prime word facilitates recognition of a target word when the 2 concepts can be combined to form a unitary representation. We used both functional and anatomical imaging approaches to investigate the neural substrates supporting such integrative priming, and compare them with those in semantic priming. Similar behavioral priming effects for both semantic (Bread-Cake) and integrative conditions (Cherry-Cake) were observed when compared with an unrelated condition. However, a clearly dissociated brain response was observed between these 2 types of priming. The semantic-priming effect was localized to the posterior superior temporal and middle temporal gyrus. In contrast, the integrative-priming effect localized to the left anterior inferior frontal gyrus and left anterior temporal cortices. Furthermore, fiber tractography showed that the integrative-priming regions were connected via uncinate fasciculus fiber bundle forming an integrative circuit, whereas the semantic-priming regions connected to the posterior frontal cortex via separated pathways. The results point to dissociable neural pathways underlying the 2 distinct types of priming, illuminating the neural circuitry organization of semantic representation and integration.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Reconhecimento Psicológico/fisiologia , Priming de Repetição/fisiologia , Semântica , Adolescente , Adulto , Análise de Variância , Associação , Mapeamento Encefálico , Imagem de Tensor de Difusão , Feminino , Humanos , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiologia , Testes Neuropsicológicos , Tempo de Reação , Adulto Jovem
12.
Neuroimage ; 136: 26-36, 2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27188219

RESUMO

In everyday life we need to continuously regulate our emotional responses according to their social context. Strategies of emotion regulation allow individuals to control time, intensity, nature and expression of emotional responses to environmental stimuli. The left inferior frontal gyrus (LIFG) is involved in the cognitive control of the selection of semantic content. We hypothesized that it might also be involved in the regulation of emotional feelings and expressions. We applied continuous theta burst stimulation (cTBS) over LIFG or a control site before a newly-developed ecological regulation task that required participants to produce storytelling of pictures with negative or neutral valence to either a peer (unregulated condition) or a child (regulated condition). Linguistic, expressive, and physiological responses were analyzed in order to assess the effects of LIFG-cTBS on emotion regulation. Results showed that the emotion regulation context modulated the emotional content of narrative productions, but not the physiologic orienting response or the early expressive behavior to negative stimuli. Furthermore, LIFG-cTBS disrupted the text-level structuring of negative picture storytelling and the early cardiac and muscular response to negative pictures; however, it did not affect the contextual emotional regulation of storytelling. These results may suggest that LIFG is involved in the initial detection of the affective arousal of emotional stimuli.


Assuntos
Nível de Alerta/fisiologia , Estimulação Elétrica/métodos , Emoções/fisiologia , Narração , Córtex Pré-Frontal/fisiologia , Percepção Visual/fisiologia , Mapeamento Encefálico , Feminino , Humanos , Masculino , Rede Nervosa/fisiologia
13.
Psychol Med ; 46(3): 505-18, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26647849

RESUMO

BACKGROUND: A hallmark symptom after psychological trauma is the presence of intrusive memories. It is unclear why only some moments of trauma become intrusive, and how these memories involuntarily return to mind. Understanding the neural mechanisms involved in the encoding and involuntary recall of intrusive memories may elucidate these questions. METHOD: Participants (n = 35) underwent functional magnetic resonance imaging (fMRI) while being exposed to traumatic film footage. After film viewing, participants indicated within the scanner, while undergoing fMRI, if they experienced an intrusive memory of the film. Further intrusive memories in daily life were recorded for 7 days. After 7 days, participants completed a recognition memory test. Intrusive memory encoding was captured by comparing activity at the time of viewing 'Intrusive scenes' (scenes recalled involuntarily), 'Control scenes' (scenes never recalled involuntarily) and 'Potential scenes' (scenes recalled involuntarily by others but not that individual). Signal change associated with intrusive memory involuntary recall was modelled using finite impulse response basis functions. RESULTS: We found a widespread pattern of increased activation for Intrusive v. both Potential and Control scenes at encoding. The left inferior frontal gyrus and middle temporal gyrus showed increased activity in Intrusive scenes compared with Potential scenes, but not in Intrusive scenes compared with Control scenes. This pattern of activation persisted when taking recognition memory performance into account. Intrusive memory involuntary recall was characterized by activity in frontal regions, notably the left inferior frontal gyrus. CONCLUSIONS: The left inferior frontal gyrus may be implicated in both the encoding and involuntary recall of intrusive memories.


Assuntos
Memória Episódica , Rememoração Mental , Córtex Pré-Frontal/fisiopatologia , Trauma Psicológico/fisiopatologia , Lobo Temporal/fisiopatologia , Adolescente , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Transtornos de Estresse Pós-Traumáticos/psicologia , Reino Unido , Adulto Jovem
14.
Cogn Neuropsychol ; 32(5): 243-65, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26216232

RESUMO

Prior research has shown that patients with damage to the left inferior frontal gyrus (LIFG) can have difficulties in executive control as well as understanding syntactic garden-paths, that is, sentences with a temporary syntactic ambiguity that resolve towards a less preferred interpretation. The present study tested two LIFG patients on object/subject garden path and matched syntactically unambiguous sentences. Besides syntactic ambiguity, support for the preferred but ultimately inappropriate interpretation was manipulated via verb bias, using verbs that were neutral between alternative analyses and verbs that were biased towards the context-inappropriate option. The LIFG patients, a non-LIFG patient, and healthy controls were tested on a sentence interpretation task (Experiment 1) and grammaticality judgement (Experiment 2). In contrast to the non-LIFG patient and controls, the LIFG patients showed impaired thematic role assignment across garden-path as well as unambiguous sentences, which tended to be worse with biased verbs. The results argue for a role of executive control in overcoming verb bias across diverse sentence processing situations, including, but not limited to, garden-path revision.


Assuntos
Compreensão/fisiologia , Função Executiva/fisiologia , Lobo Frontal/fisiologia , Idioma , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Testes de Linguagem , Masculino , Pessoa de Meia-Idade , Semântica
15.
Brain Lang ; 256: 105458, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39197357

RESUMO

This study investigated the causal enhancing effect of transcranial photobiomodulation (tPBM) over the left inferior frontal gyrus (LIFG) on syntactically complex Mandarin Chinese first language (L1) and second language (L2) sentence processing performances. Two (L1 and L2) groups of participants (thirty per group) were recruited to receive the double-blind, sham-controlled tPBM intervention via LIFG, followed by the sentence processing, the verbal working memory (WM), and the visual WM tasks. Results revealed a consistent pattern for both groups: (a) tPBM enhanced sentence processing performance but not verbal WM for linear processing of unstructured sequences and visual WM performances; (b) Participants with lower sentence processing performances under sham tPBM benefited more from active tPBM. Taken together, the current study substantiated that tPBM enhanced L1 and L2 sentence processing, and would serve as a promising and cost-effective noninvasive brain stimulation (NIBS) tool for future applications on upregulating the human language faculty.


Assuntos
Memória de Curto Prazo , Humanos , Masculino , Feminino , Adulto Jovem , Memória de Curto Prazo/fisiologia , Idioma , Adulto , Método Duplo-Cego , Terapia com Luz de Baixa Intensidade/métodos , Córtex Pré-Frontal/fisiologia , Lobo Frontal/fisiologia , Multilinguismo
16.
Brain Sci ; 14(1)2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38275521

RESUMO

The dual-process theory of thought rests on the co-existence of two different thinking modalities: a quick, automatic, and associative process opposed to a slow, thoughtful, and deliberative process. The increasing interest in determining the neural foundation of the dual-process distinction has yielded mixed results, also given the difficulty of applying the fMRI standard approach to tasks usually employed in the cognitive literature. We report an activation likelihood estimation (ALE) meta-analysis to investigate the neural foundation of the dual-process theory of thought. Eligible studies allowed for the identification of cerebral areas associated with dual-process theory-based tasks without differentiating between fast and slow thinking. The ALE algorithm converged on the medial frontal cortex, superior frontal cortex, anterior cingulate cortex, insula, and left inferior frontal gyrus. These structures partially overlap with the cerebral areas recurrently reported in the literature about the neural basis of the dual-process distinction, where the PARCS theory-based interpretation emphasizes the role of the right inferior gyrus. The results confirm the potential (but still almost unexplored) common ground between the dual-process literature and the cognitive control literature.

17.
Brain Behav ; 14(5): e3490, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38680077

RESUMO

Word finding difficulty is a frequent complaint in older age and disease states, but treatment options are lacking for such verbal retrieval deficits. Better understanding of the neurophysiological and neuroanatomical basis of verbal retrieval function may inform effective interventions. In this article, we review the current evidence of a neural retrieval circuit central to verbal production, including words and semantic memory, that involves the pre-supplementary motor area (pre-SMA), striatum (particularly caudate nucleus), and thalamus. We aim to offer a modified neural circuit framework expanded upon a memory retrieval model proposed in 2013 by Hart et al., as evidence from electrophysiological, functional brain imaging, and noninvasive electrical brain stimulation studies have provided additional pieces of information that converge on a shared neural circuit for retrieval of memory and words. We propose that both the left inferior frontal gyrus and fronto-polar regions should be included in the expanded circuit. All these regions have their respective functional roles during verbal retrieval, such as selection and inhibition during search, initiation and termination of search, maintenance of co-activation across cortical regions, as well as final activation of the retrieved information. We will also highlight the structural connectivity from and to the pre-SMA (e.g., frontal aslant tract and fronto-striatal tract) that facilitates communication between the regions within this circuit. Finally, we will discuss how this circuit and its correlated activity may be affected by disease states and how this circuit may serve as a novel target engagement for neuromodulatory treatment of verbal retrieval deficits.


Assuntos
Transtornos da Memória , Rememoração Mental , Semântica , Humanos , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Encéfalo/diagnóstico por imagem , Transtornos da Memória/fisiopatologia , Transtornos da Memória/terapia , Rememoração Mental/fisiologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiologia , Rede Nervosa/fisiopatologia , Vias Neurais/fisiologia , Vias Neurais/fisiopatologia , Tálamo/fisiologia , Tálamo/diagnóstico por imagem , Tálamo/fisiopatologia
18.
Brain Cogn ; 83(2): 218-26, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24056237

RESUMO

OBJECTIVE: Contrasts of verbal fluency and automatic speech provide an opportunity to evaluate the neural underpinnings of generativity and flexibility in autism spectrum disorders (ASD). METHOD: We used functional magnetic resonance imaging (fMRI) to contrast brain activity in high functioning ASD (n=17, mean verbal IQ=117) and neurotypical (NT; n=20, mean verbal IQ=112) adolescent and young adult males (12-23years). Participants responded to three word generation conditions: automatic speech (reciting months), category fluency, and letter fluency. RESULTS: Our paradigm closely mirrored behavioral fluency tasks by requiring overt, free recall word generation while controlling for differences in verbal output between the groups and systematically increasing the task demand. The ASD group showed reduced neural response compared to the NT participants during fluency tasks in multiple regions of left anterior and posterior cortices, and sub-cortical structures. Six of these regions fell in cortico-striatal circuits previously linked to repetitive behaviors (Langen, Durston, Kas, van Engeland, & Staal, 2011), and activity in two of them (putamen and thalamus) was negatively correlated with autism repetitive behavior symptoms in the ASD group. In addition, response in left inferior frontal gyrus was differentially modulated in the ASD, relative to the NT, group as a function of task demand. CONCLUSIONS: These data indicate a specific, atypical brain response in ASD to demanding generativity tasks that may have relevance to repetitive behavior symptoms in ASD as well as to difficulties generating original verbal responses.


Assuntos
Encéfalo/fisiopatologia , Transtornos Globais do Desenvolvimento Infantil/fisiopatologia , Função Executiva/fisiologia , Comportamento Verbal/fisiologia , Adolescente , Mapeamento Encefálico , Criança , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
19.
Cortex ; 168: 27-48, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37639907

RESUMO

The study of an Ischemic stroke infarction allows verifying how the lesion produces alterations in the neuronal networks resulting in cognitive deficits. It also allows the verification of adaptive and maladaptive cerebral reorganization related to the injury. In our previous fMRI study, we found that patients without ischemic vascular lesions in left inferior frontal gyrus showed an efficient compensation mechanism during the associative encoding of face name pairs, by the increased activation of ventrolateral and dorsolateral areas of contralesional hemisphere associated with better memory performance. While patients with ischemic vascular lesions on left inferior frontal gyrus (IFG) demonstrated worse memory performance and no signs of compensation mechanism. The present study explores more of these findings by analyzing perilesional and contralesional activations related to unfamiliar face name associative encoding in adults with chronic ischemic stroke, with or without left IFG lesion, compared to healthy controls. The main results showed that stroke survivors without lesions in IFG demonstrated increased activation in perilesional and contralesional prefrontal regions associated with better associative memory recognition, which are indicative of adaptive compensatory mechanisms. However, they also showed a negative correlation between the activation of right anterior prefrontal and inferior parietal regions and the associative memory performance, which may indicate the presence of maladaptive interhemispheric disinhibition. On the other hand, stroke survivors with IFG lesions demonstrated negative correlations in activations of the ipsilesional inferior parietal cortex and positive correlations in activations of the left middle frontal gyrus and left precentral cortex, which demonstrate the simultaneous occurrence of adaptive and maladaptive brain reorganization mechanisms in this group. However, the increase in perilesional prefrontal regions, associated with bilateral activation of the hippocampus and amygdala, was not enough to compensate for the inefficiency of associative memory performance. Finally, the differences in activation observed in stroke survivors reflect their clinical heterogeneity and demonstrate that adaptive or maladaptive compensatory mechanisms can coexist in the same group of patients. Furthermore, they reinforce the importance of the left IFG in the associative encoding of unfamiliar face name pairs and may suggest a deficit in associative memory related to injury in this region.

20.
Transl Pediatr ; 11(9): 1552-1561, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36247884

RESUMO

Background: Benign epilepsy with centrotemporal spikes (BECTS) is one of the most common pediatric epileptic syndromes. Recent studies have shown that BECTS can lead to significant language dysfunction. Although research supports the role of the left inferior frontal gyrus (LIFG) in BECTS, it is unclear whether the subregions of the LIFG show different change patterns in patients with this syndrome. Methods: Using resting-state functional magnetic resonance imaging (fMRI) data in a group of 49 BECTS patients and 49 healthy controls, we investigated whether the BECTS patients show abnormal connectivity patterns of the LIFG subregions. Results: Compared with healthy controls, the BECTS patients exhibited higher connectivity between the following: the inferior frontal sulcus (IFS) and the right anterior cingulate cortex (ACC), and the ventral area 44 (A44v) region and the left hippocampus/parahippocampus. Also, a decreased connectivity was found between the IFS and the left inferior temporal gyrus (ITG). No other significant differences in functional connectivity were found in the other 4 functional subregions of the LIFG in the BECTS. Conclusions: These findings provide evidence for BECTS-related functional connectivity patterns of the LIFG subregions and suggest that different subregions may be involved in different neural circuits associated with language function in the BECTS.

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