Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 124
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cogn Affect Behav Neurosci ; 24(3): 599-614, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38316707

RESUMO

Understanding facial emotions is fundamental to interact in social environments and modify behavior accordingly. Neurodegenerative processes can progressively transform affective responses and affect social competence. This exploratory study examined the neurocognitive correlates of face recognition, in individuals with two mild cognitive impairment (MCI) etiologies (prodromal to dementia - MCI, or consequent to Parkinson's disease - PD-MCI). Performance on the identification and memorization of neutral and emotional facial expressions was assessed in 31 individuals with MCI, 26 with PD-MCI, and 30 healthy controls (HC). Individuals with MCI exhibited selective impairment in recognizing faces expressing fear, along with difficulties in remembering both neutral and emotional faces. Conversely, individuals with PD-MCI showed no differences compared with the HC in either emotion recognition or memory. In MCI, no significant association emerged between the memory for facial expressions and cognitive difficulties. In PD-MCI, regression analyses showed significant associations with higher-level cognitive functions in the emotional memory task, suggesting the presence of compensatory mechanisms. In a subset of participants, voxel-based morphometry revealed that the performance on emotional tasks correlated with regional changes in gray matter volume. The performance in the matching of negative expressions was predicted by volumetric changes in brain areas engaged in face and emotional processing, in particular increased volume in thalamic nuclei and atrophy in the right parietal cortex. Future studies should leverage on neuroimaging data to determine whether differences in emotional recognition are mediated by pathology-specific atrophic patterns.


Assuntos
Disfunção Cognitiva , Emoções , Expressão Facial , Reconhecimento Facial , Imageamento por Ressonância Magnética , Humanos , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/diagnóstico por imagem , Masculino , Feminino , Idoso , Reconhecimento Facial/fisiologia , Emoções/fisiologia , Pessoa de Meia-Idade , Doença de Parkinson/fisiopatologia , Doença de Parkinson/diagnóstico por imagem , Reconhecimento Psicológico/fisiologia , Testes Neuropsicológicos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia
2.
Behav Res Methods ; 56(2): 934-951, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36894759

RESUMO

The spatial Stroop task measures the ability to resolve interference between relevant and irrelevant spatial information. We recently proposed a four-choice spatial Stroop task that ensures methodological advantages over the original color-word verbal Stroop task, requiring participants to indicate the direction of an arrow while ignoring its position in one of the screen corners. However, its peripheral spatial arrangement might represent a methodological weakness and could introduce experimental confounds. Thus, aiming at improving our "Peripheral" spatial Stroop, we designed and made available five novel spatial Stroop tasks (Perifoveal, Navon, Figure-Ground, Flanker, and Saliency), wherein the stimuli appeared at the center of the screen. In a within-subjects online study, we compared the six versions to identify which task produced the largest but also the most reliable and robust Stroop effect. Indeed, although internal reliability is frequently overlooked, its estimate is fundamental, also in light of the recently proposed reliability paradox. Data analyses were performed using both the classical general linear model analytical approach and two multilevel modelling approaches (linear mixed models and random coefficient analysis), which specifically served for more accurately estimating the Stroop effect by explaining intra-subject, trial-by-trial variability. We then assessed our results based on their robustness to such analytic flexibility. Overall, our results indicate that the Perifoveal spatial Stroop is the best alternative task for its statistical properties and methodological advantages. Interestingly, our results also indicate that the Peripheral and Perifoveal Stroop effects were not only the largest, but also those with highest and most robust internal reliability.


Assuntos
Atenção , Humanos , Teste de Stroop , Tempo de Reação , Reprodutibilidade dos Testes
3.
Exp Brain Res ; 241(7): 1919-1930, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37354350

RESUMO

Many cognitive processes, ranging from perception to action, depend on the ability to predict the timing of forthcoming events. Yet, how the brain uses predictive models in the temporal domain is still an unsolved question. In previous work, we began to explore the neural correlates of temporal predictions by using a computational approach in which an ideal Bayesian observer learned the temporal probabilities of target onsets in a simple reaction time task. Because the task was specifically designed to disambiguate updating of predictive models and surprise, changes in temporal probabilities were explicitly cued. However, in the real world, we are usually incidentally exposed to changes in the statistics of the environment. Here, we thus aimed to further investigate the electroencephalographic (EEG) correlates of Bayesian belief updating and surprise associated with incidental learning of temporal probabilities. In line with our previous EEG study, results showed distinct P3-like modulations for updating and surprise. While surprise was indexed by an early fronto-central P3-like modulation, updating was associated with a later and more posterior P3 modulation. Moreover, updating was associated with a P2-like potential at centro-parietal electrodes, likely capturing integration processes between prior beliefs and likelihood of the observed event. These findings support previous evidence of trial-by-trial variability of P3 amplitudes as an index of dissociable inferential processes. Coupled with our previous findings, the present study strongly bolsters the view of the P3 as a key brain signature of temporal Bayesian inference. Data and scripts are shared on OSF: osf.io/sdy8j/.


Assuntos
Encéfalo , Eletroencefalografia , Humanos , Teorema de Bayes , Mapeamento Encefálico , Tempo de Reação
4.
Behav Res Methods ; 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37620747

RESUMO

The Stroop task is a seminal paradigm in experimental psychology, so much that various variants of the classical color-word version have been proposed. Here we offer a methodological review of them to emphasize the importance of designing methodologically rigorous Stroop tasks. This is not an end by itself, but it is fundamental to achieve adequate measurement validity, which is currently hindered by methodological heterogeneity and limitations. Among the several Stroop task variants in the literature, our methodological overview shows that the spatial Stroop task is not only a potentially methodologically adequate variant, which can thus assure measuring the Stroop effect with the required validity, but it might even allow researchers to overcome some of the methodological limitations of the classical paradigm due to its use of verbal stimuli. We thus focused on the spatial Stroop tasks in the literature to verify whether they really exploit such inherent potentiality. However, we show that this was generally not the case because only a few of them (1) are purely spatial, (2) ensure both all the three types of conflicts/facilitations (at the stimulus, response, and task levels) and the dimensional overlaps considered fundamental for yielding a complete Stroop effect according to the multiple loci account and Kornblum's theory, respectively, and (3) controlled for low-level binding and priming effects that could bias the estimated Stroop effect. Based on these methodological considerations, we present some examples of spatial Stroop tasks that, in our view, satisfy such requirements and, thus, ensure producing complete Stroop effects.

5.
Curr Psychol ; 42(6): 4653-4662, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-33994757

RESUMO

Dementia with Lewy bodies (DLB) is a neurodegenerative disease characterized by cognitive, behavioral and motor symptoms and has a more challenging clinical management and poorer prognosis compared to other forms of dementia. The experience of lockdown leads to negative psychological outcomes for fragile people such as elderly with dementia, particularly for DLB, causing a worsening of cognitive and neuropsychiatric symptoms. Since an individual's feeling of time passage is strongly related to their cognitive and emotional state, it is conceivable to expect alterations of this construct in people with DLB during such a difficult period. We therefore assessed the subjective experience of the passage of time for present and past time intervals (Subjective Time Questionnaire, STQ) during the lockdown due to coronavirus disease (COVID-19) in 22 patients with DLB (17 of which were re-tested in a post-lockdown period) and compared their experience with that of 14 caregivers with similar age. Patients showed a significantly slower perception of present and past time spent under lockdown restrictions. We argue that these alterations might be related to the distinctive features of DLB and their exacerbation recorded by the patients' caregivers during the period of lockdown, though our results show that the patients' experience of time passage in a post-lockdown period remained similarly slow. Overall, we show an impairment of the subjective perception of time passage in DLB tested during the COVID-19 lockdown. Supplementary Information: The online version contains supplementary material available at 10.1007/s12144-021-01811-7.

6.
Neuroimage ; 264: 119714, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36309331

RESUMO

BACKGROUND: Transcranial magnetic stimulation (TMS) is a widely used technique for the noninvasive assessment and manipulation of brain activity and behavior. Although extensively used for research and clinical purposes, recent studies have questioned the reliability of TMS findings because of the high inter-individual variability that has been observed. OBJECTIVE: In this study, we compared the efficacy and reliability of different targeting scenarios on the TMS-evoked response. METHODS: 24 subjects underwent a single pulse stimulation protocol over two parietal nodes belonging to the Dorsal Attention (DAN) and Default Mode (DMN) Networks respectively. Across visits, the stimulated target for both networks was chosen either based on group-derived networks' maps or personalized network topography based on individual anatomy and functional profile. All stimulation visits were conducted twice, one month apart, during concomitant electroencephalography recording. RESULTS: At the network level, we did not observe significant differences in the TMS-evoked response between targeting conditions. However, reliable patterns of activity were observed- for both networks tested- following the individualized targeting approach. When the same analyses were carried out at the electrode space level, evidence of reliable patterns was observed following the individualized stimulation of the DAN, but not of the DMN. CONCLUSIONS: Our findings suggest that individualization of stimulation sites might ensure reliability of the evoked TMS-response across visits. Furthermore, individualized stimulation sites appear to be of foremost importance in highly variable, high order task-positive networks, such as the DAN.


Assuntos
Eletroencefalografia , Estimulação Magnética Transcraniana , Humanos , Estimulação Magnética Transcraniana/métodos , Reprodutibilidade dos Testes , Atenção/fisiologia
7.
Cogn Emot ; 36(7): 1389-1403, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36154616

RESUMO

Depressive symptoms are characterised by reduced cognitive control. However, whether depressive symptoms are linked to difficulty in exerting cognitive control in general or over emotional content specifically remains unclear. To better differentiate between affective interference or general cognitive control difficulties in people with depressive symptoms, we employed a non emotional (cold) and an emotional (hot) version of a task-switching paradigm in a nonclinical sample of young adults (N = 82) with varying levels of depressive symptoms. Depressive symptoms were linked to greater difficulties in exerting cognitive control in complex situations (mixed-task blocks) compared to simple and semiautomatic situations (single-task blocks) in both task versions. Moreover, greater depressive symptoms were associated with longer latencies in the emotional version of the task across all trial types. Thus, the emotion-specific effect was not modulated by the degree of cognitive control required to perform the task. In sum, depressive symptoms were characterised by a general difficulty to exert cognitive control in both emotional and non emotional contexts and by greater difficulty in even simple attentional processing of emotional material. This study granted novel insights on the extent of cognitive control difficulties in emotional and non emotional contexts for people with depressive symptoms.


Assuntos
Depressão , Emoções , Adulto Jovem , Humanos , Depressão/psicologia , Resolução de Problemas , Atenção , Cognição
8.
J Cogn Neurosci ; 33(9): 1679-1697, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33135967

RESUMO

This narrative review addresses the neural bases of two executive functions: criterion setting, that is, the capacity to flexibly set up and select task rules and associations between stimuli, responses, and nonresponses, and monitoring, that is, the process of continuously evaluating whether task rules are being applied optimally. There is a documented tendency for criterion setting and monitoring to differentially recruit left and right lateral prefrontal regions and connected networks, respectively, above and beyond the specific task context. This model, known as the ROtman-Baycrest Battery to Investigate Attention (ROBBIA) model, initially sprung from extensive neuropsychological work led by Don Stuss. In subsequent years, multimodal lines of empirical investigation on both healthy individuals and patients with brain damage, coming from functional neuroimaging, EEG, neurostimulation, individual difference approaches, and, again, neuropsychology, so to "complete the circle," corroborated the functional mapping across the two hemispheres as predicted by the model. More recent electrophysiological evidence has further shown that hemispheric differences in intrinsic prefrontal dynamics are able to predict cognitive performance in tasks tapping these domain-general functions. These empirical contributions will be presented together with contrasting evidence, limits, and possible future directions to better fine-tune this model and extend its scope to new fields.


Assuntos
Função Executiva , Neuroimagem Funcional , Mapeamento Encefálico , Lateralidade Funcional , Humanos , Individualidade , Imageamento por Ressonância Magnética
9.
J Cogn Neurosci ; 33(9): 1766-1783, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34375415

RESUMO

It has been proposed that at least two distinct processes are engaged during task-switching: reconfiguration of the currently relevant task-set and interference resolution arising from the competing task-set. Whereas in healthy individuals the two are difficult to disentangle, their disruption is thought to cause different impairments in brain-damaged patients. Yet, the observed deficits are inconsistent across studies and do not allow drawing conclusions regarding their independence. Forty-one brain tumor patients were tested on a task-switching paradigm. We compared their performance between switch and repeat trials (switch cost) to assess rule reconfiguration, and between trials requiring the same response (congruent) and a different response for the two tasks (incongruent) to assess interference control. In line with previous studies, we found the greatest proportion of errors on incongruent trials, suggesting an interference control impairment. However, a closer look at the distribution of errors between two task rules revealed a rule perseveration impairment: Patients with high error rate on incongruent trials often applied only one task rule throughout the task and less frequently switched to the alternative one. Multivariate lesion-symptom mapping analysis unveiled the relationship between lesions localized in left orbitofrontal and posterior subcortical regions and perseveration scores, measured as absolute difference in accuracy between two task rules. This finding points to a more severe task-setting impairment, not reflected as a mere switching deficit, but instead as a difficulty in creating multiple stable task representations, in line with recent accounts of OFC functions suggesting its critical role in representing task states.


Assuntos
Lesões Encefálicas , Neoplasias Encefálicas , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/diagnóstico por imagem , Humanos , Desempenho Psicomotor , Tempo de Reação
10.
Neuroimage ; 231: 117867, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592246

RESUMO

The brain predicts the timing of forthcoming events to optimize responses to them. Temporal predictions have been formalized in terms of the hazard function, which integrates prior beliefs on the likely timing of stimulus occurrence with information conveyed by the passage of time. However, how the human brain updates prior temporal beliefs is still elusive. Here we investigated electroencephalographic (EEG) signatures associated with Bayes-optimal updating of temporal beliefs. Given that updating usually occurs in response to surprising events, we sought to disentangle EEG correlates of updating from those associated with surprise. Twenty-six participants performed a temporal foreperiod task, which comprised a subset of surprising events not eliciting updating. EEG data were analyzed through a regression-based massive approach in the electrode and source space. Distinct late positive, centro-parietally distributed, event-related potentials (ERPs) were associated with surprise and belief updating in the electrode space. While surprise modulated the commonly observed P3b, updating was associated with a later and more sustained P3b-like waveform deflection. Results from source analyses revealed that neural encoding of surprise comprises neural activity in the cingulo-opercular network (CON) and parietal regions. These data provide evidence that temporal predictions are computed in a Bayesian manner, and that this is reflected in P3 modulations, akin to other cognitive domains. Overall, our study revealed that analyzing P3 modulations provides an important window into the Bayesian brain. Data and scripts are shared on OSF: https://osf.io/ckqa5/.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Eletroencefalografia/métodos , Imageamento por Ressonância Magnética/métodos , Estimulação Luminosa/métodos , Desempenho Psicomotor/fisiologia , Adulto , Teorema de Bayes , Potenciais Evocados P300/fisiologia , Feminino , Humanos , Masculino , Adulto Jovem
11.
Neuroimage ; 227: 117655, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33333318

RESUMO

Different cortical regions respond with distinct rhythmic patterns of neural oscillations to Transcranial Magnetic Stimulation (TMS). We investigated natural frequencies induced by TMS in left and right homologous dorsolateral prefrontal cortices (DLPFC) and related hemispheric differences. In 12 healthy young adults, single-pulse TMS was delivered in different blocks close to F3 and F4 channels to target left and right DLPFC. An occipital site near PO3 was stimulated as control. TMS-related spectral perturbation analyses were performed on recorded EEG data. A widespread unspecific increase in theta power was observed for all stimulation sites. However, occipital TMS induced greater alpha activity and a 10.58 Hz natural frequency, while TMS over the left and right DLPFC resulted in similar beta band modulations and a natural frequency of 18.77 and 18.5 Hz, respectively. In particular, TMS-related specific increase in beta activity was stronger for the right than the left DLPFC. The right DLPFC is more specifically tuned to its natural beta frequency when it is directly stimulated by TMS than with TMS over the left counterpart (or a posterior region), while the left DLPFC increases its beta activity more similarly irrespective of whether it is directly stimulated or through right homologous stimulation. These results yield important implications for both basic neuroscience research on inter-hemispheric prefrontal interactions and clinical applications.


Assuntos
Córtex Pré-Frontal/fisiologia , Estimulação Magnética Transcraniana/métodos , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
12.
Neuroimage ; 235: 118013, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-33794357

RESUMO

Resilience is the capacity of complex systems to persist in the face of external perturbations and retain their functional properties and performance. In the present study, we investigated how individual variations in brain resilience, which might influence response to stress, aging and disease, are influenced by genetics and/or the environment, with potential implications for the implementation of resilience-boosting interventions. Resilience estimates were derived from in silico lesioning of either brain regions or functional connections constituting the connectome of healthy individuals belonging to two different large and unique datasets of twins, specifically: 463 individual twins from the Human Connectome Project and 453 individual twins from the Colorado Longitudinal Twin Study. As has been reported previously, moderate heritability was found for several topological indexes of brain efficiency and modularity. Importantly, evidence of heritability was found for resilience measures based on removal of brain connections rather than specific single regions, suggesting that genetic influences on resilience are preferentially directed toward region-to-region communication rather than local brain activity. Specifically, the strongest genetic influence was observed for moderately weak, long-range connections between a specific subset of functional brain networks: the Default Mode, Visual and Sensorimotor networks. These findings may help identify a link between brain resilience and network-level alterations observed in neurological and psychiatric diseases, as well as inform future studies investigating brain shielding interventions against physiological and pathological perturbations.


Assuntos
Encéfalo/fisiologia , Rede Nervosa/fisiologia , Adulto , Mapeamento Encefálico/métodos , Conectoma , Meio Ambiente , Feminino , Variação Genética , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Resiliência Psicológica , Gêmeos , Adulto Jovem
13.
Hum Brain Mapp ; 41(1): 256-269, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31532053

RESUMO

Resting-state functional magnetic resonance imaging (rs-fMRI) has the potential to shed light on the pathophysiological mechanisms of Huntington's disease (HD), paving the way to new therapeutic interventions. A systematic literature review was conducted in three online databases according to PRISMA guidelines, using keywords for HD, functional connectivity, and rs-fMRI. We included studies investigating connectivity in presymptomatic (pre-HD) and manifest HD gene carriers compared to healthy controls, implementing seed-based connectivity, independent component analysis, regional property, and graph analysis approaches. Visual network showed reduced connectivity in manifest HD, while network/areas underpinning motor functions were consistently altered in both manifest HD and pre-HD, showing disease stage-dependent changes. Cognitive networks underlying executive and attentional functions showed divergent anterior-posterior alterations, possibly reflecting compensatory mechanisms. The involvement of these networks in pre-HD is still unclear. In conclusion, aberrant connectivity of the sensory-motor network is observed in the early stage of HD while, as pathology spreads, other networks might be affected, such as the visual and executive/attentional networks. Moreover, sensory-motor and executive networks exhibit hyper- and hypo-connectivity patterns following different spatiotemporal trajectories. These findings could potentially help to implement future huntingtin-lowering interventions.


Assuntos
Córtex Cerebral/fisiopatologia , Conectoma , Doença de Huntington/fisiopatologia , Rede Nervosa/fisiopatologia , Sintomas Prodrômicos , Córtex Cerebral/diagnóstico por imagem , Humanos , Doença de Huntington/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem
14.
Cogn Affect Behav Neurosci ; 20(2): 294-308, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31989458

RESUMO

Intrinsic brain dynamics may play an important role in explaining interindividual variability in executive functions. In the present electroencephalography (EEG) study, we focused on the brain lateralization patterns predicting performance on three different monitoring tasks of temporal, verbal, and spatial nature. These tasks were administered to healthy young participants after their EEG was recorded during a resting state session. Behavioral indices of monitoring efficiency were computed for each task and a source-based spectral analysis was performed on participants' resting-state EEG activity. A lateralization index was then computed for each of 75 homologous cortical regions as the right-left difference score for the log-transformed power ratio between beta and alpha frequencies. Finally, skipped Pearson correlations between the lateralization index in each cortical region and behavioral performance of the three monitoring tasks were computed. An intersection among the three tasks showed that right-lateralization in different prefrontal regions, including the middle frontal gyrus, was positively correlated with monitoring abilities across the three tasks. In conclusion, right-lateralized brain mechanisms set the stage for the ability to monitor for targets in the environment, independently of the specific task characteristics. These mechanisms are grounded in hemispheric asymmetry dynamics already observable at rest.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiologia , Função Executiva/fisiologia , Lateralidade Funcional/fisiologia , Adulto , Eletroencefalografia/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Adulto Jovem
15.
J Headache Pain ; 21(1): 63, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-32493204

RESUMO

This meta-analytical review assesses the utility of the Trail Making Test (TMT), versions A and B, in detecting migraine-related cognitive deficits. A comprehensive literature search was performed in two electronic databases and other sources to obtain relevant studies administering TMT to migraine patients. Search terms included "migraine" and "Trail Making". Only studies in which the TMT-A, TMT-B or both were administered to adult patients suffering from migraine with and without aura were included. All pooled meta-analyses were based on random effects models. A total of 14 studies for TMT-A and 15 for TMT-B met inclusion criteria and were subjected to meta-analyses. Results showed that performance is worse in migraine patients than in controls for both the TMT-A (Hedges' g = -.28) and TMT-B (g = -.37), with no difference between migraine with and without aura. This study demonstrates the sensitivity of the TMT in detecting cognitive alterations in migraine. This test should be considered for inclusion in cognitive batteries assessing patients with migraine.


Assuntos
Enxaqueca com Aura/diagnóstico , Enxaqueca com Aura/psicologia , Enxaqueca sem Aura/diagnóstico , Enxaqueca sem Aura/psicologia , Teste de Sequência Alfanumérica , Adulto , Idoso , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia , Feminino , Humanos , Masculino , Enxaqueca com Aura/epidemiologia , Enxaqueca sem Aura/epidemiologia
16.
Neuroimage ; 202: 116097, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31415885

RESUMO

The brain predicts the timing of forthcoming events to optimize processes in response to them. Temporal predictions are driven by both our prior expectations on the likely timing of stimulus occurrence and the information conveyed by the passage of time. Specifically, such predictions can be described in terms of the hazard function, that is, the conditional probability that an event will occur, given it has not yet occurred. Events violating expectations cause surprise and often induce updating of prior expectations. While it is well-known that the brain is able to track the temporal hazard of event occurrence, the question of how prior temporal expectations are updated is still unsettled. Here we combined a Bayesian computational approach with brain imaging to map updating of temporal expectations in the human brain. Moreover, since updating is usually highly correlated with surprise, participants performed a task that allowed partially differentiating between the two processes. Results showed that updating and surprise differently modulated activity in areas belonging to two critical networks for cognitive control, the fronto-parietal (FPN) and the cingulo-opercular network (CON). Overall, these data provide a first computational characterization of the neural correlates associated with updating and surprise related to temporal expectation.


Assuntos
Antecipação Psicológica/fisiologia , Encéfalo/fisiologia , Modelos Neurológicos , Motivação/fisiologia , Adulto , Teorema de Bayes , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Fatores de Tempo , Adulto Jovem
17.
Neuroimage ; 202: 116062, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31369810

RESUMO

Several studies have evaluated the effect of anodal transcranial direct current stimulation (tDCS) over the prefrontal cortex (PFC) for the enhancement of working memory (WM) performance in healthy older adults. However, the mixed results obtained so far suggest the need for concurrent brain imaging, in order to more directly examine tDCS effects. The present study adopted a continuous multimodal approach utilizing functional near-infrared spectroscopy (fNIRS) to examine the interactive effects of tDCS combined with manipulations of reward motivation. Twenty-one older adults (mean age = 69.7 years; SD = 5.05) performed an experimental visuo-spatial WM task before, during and after the delivery of 1.5 mA anodal tDCS/sham over the left prefrontal cortex (PFC). During stimulation, participants received performance-contingent reward for every fast and correct response during the WM task. In both sessions, hemodynamic activity of the bilateral frontal, motor and parietal areas was recorded across the entire duration of the WM task. Cognitive functions and reward sensitivity were also assessed with standard measures. Results demonstrated a significant impact of tDCS on both WM performance and hemodynamic activity. Specifically, faster responses in the WM task were observed both during and after anodal tDCS, while no differences were found under sham control conditions. However, these effects emerged only when taking into account individual visuo-spatial WM capacity. Additionally, during and after the anodal tDCS, increased hemodynamic activity relative to sham was observed in the bilateral PFC, while no effects of tDCS were detected in the motor and parietal areas. These results provide the first evidence of tDCS-dependent functional changes in PFC activity in healthy older adults during the execution of a WM task. Moreover, they highlight the utility of combining reward motivation with prefrontal anodal tDCS, as a potential strategy to improve WM efficiency in low performing healthy older adults.


Assuntos
Envelhecimento Cognitivo/fisiologia , Memória de Curto Prazo/fisiologia , Motivação/fisiologia , Córtex Pré-Frontal/fisiologia , Recompensa , Espectroscopia de Luz Próxima ao Infravermelho , Estimulação Transcraniana por Corrente Contínua , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
J Cogn Neurosci ; 29(5): 769-779, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27897669

RESUMO

The ability to suppress irrelevant information while executing a task, also known as interference resistance ability, is a function of pFC that is critical for successful goal-directed human behavior. In the study of interference resistance and, more generally, executive functions, two key questions are still open: Does pFC contribute to cognitive control abilities through lateralized but domain-general mechanisms or through hemispheric specialization of domain-specific processes? And what are the underlying causes of interindividual differences in executive control performance? To shed light on these issues, here we employed an interindividual difference approach to investigate whether participants' hemispheric asymmetry in resting-state electrophysiological brain dynamics may reflect their variability in domain-general interference resistance. We recorded participants' resting-state electroencephalographic activity and performed spectral power analyses on the estimated cortical source activity. To measure participants' lateralized brain dynamics at rest, we computed the right-left hemispheric asymmetry score for the ß/α power ratio. To measure their domain-general interference resistance ability, verbal and spatial Stroop tasks were used. Robust correlations followed by intersection analyses showed that participants with stronger resting-state-related left-lateralized activity in different pFC regions, namely the mid-posterior superior frontal gyrus, middle and posterior middle frontal gyrus, and inferior frontal junction, were more able to inhibit irrelevant information in both domains. The present results confirm and extend previous findings showing that neurophysiological difference factors may explain interindividual differences in executive functioning. They also provide support for the hypothesis of a left pFC hemispheric specialization for domain-independent phasic cognitive control processes mediating Stroop performance.


Assuntos
Eletroencefalografia/métodos , Função Executiva/fisiologia , Lateralidade Funcional/fisiologia , Córtex Pré-Frontal/fisiologia , Processamento de Sinais Assistido por Computador , Adulto , Humanos , Teste de Stroop , Adulto Jovem
19.
Neuroimage ; 124(Pt A): 843-857, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26416650

RESUMO

In our daily life, we constantly exert sustained and phasic cognitive control processes to manage multiple competing task sets and rapidly switch between them. Increasing research efforts are attempting to unveil how the brain mediates these processes, highlighting the importance of the prefrontal cortex. An intriguing question concerns the influence of hemispheric asymmetries and whether it may be generalized to different cognitive domains depending on lateralized processing. Another currently open question concerns the underlying causes of the observed huge inter-individual variability in cognitive control abilities. Here we tackle these issues by investigating whether participants' hemispheric asymmetry in intrinsic (i.e., resting-state-related) brain dynamics can reflect differences in their phasic and/or sustained cognitive control abilities regardless of the cognitive domain. To this aim, we recorded human participants' resting-state electroencephalographic activity and performed a source-based spectral analysis to assess their lateralized brain dynamics at rest. Moreover, we used three task-switching paradigms involving different cognitive domains to assess participants' domain-general phasic and sustained cognitive control abilities. By performing a series of correlations and an intersection analysis, we showed that participants with stronger left- and right-lateralized intrinsic brain activity in the middle frontal gyrus were more able, respectively, to exert phasic and sustained cognitive control. We propose that the variability in participants' prefrontal hemispheric asymmetry in the intrinsic electrophysiological spectral profile reflects individual differences in preferentially engaging either the left-lateralized, phasic or the right-lateralized, sustained cognitive control processes to regulate their behavior in response to changing task demands, regardless of the specific cognitive domain involved.


Assuntos
Cognição/fisiologia , Eletroencefalografia/métodos , Eletroencefalografia/estatística & dados numéricos , Córtex Pré-Frontal/fisiologia , Percepção de Cores/fisiologia , Feminino , Percepção de Forma/fisiologia , Lateralidade Funcional/fisiologia , Humanos , Individualidade , Masculino , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Adulto Jovem
20.
Audiol Neurootol ; 21 Suppl 1: 21-28, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27806352

RESUMO

A growing interest in cognitive effects associated with speech and hearing processes is spreading throughout the scientific community essentially guided by evidence that central and peripheral hearing loss is associated with cognitive decline. For the present research, 125 participants older than 65 years of age (105 with hearing impairment and 20 with normal hearing) were enrolled, divided into 6 groups according to their degree of hearing loss and assessed to determine the effects of the treatment applied. Patients in our research program routinely undergo an extensive audiological and cognitive evaluation protocol providing results from the Digit Span test, Stroop color-word test, Montreal Cognitive Assessment and Geriatric Depression Scale, before and after rehabilitation. Data analysis was performed for a cross-sectional and longitudinal study of the outcomes for the different treatment groups. Each group demonstrated improvement after auditory rehabilitation or training on short- and long-term memory tasks, level of depression and cognitive status scores. Auditory rehabilitation by cochlear implants or hearing aids is effective also among older adults (median age of 74 years) with different degrees of hearing loss, and enables positive improvements in terms of social isolation, depression and cognitive performance.


Assuntos
Envelhecimento , Implante Coclear/métodos , Disfunção Cognitiva/psicologia , Correção de Deficiência Auditiva/métodos , Depressão/psicologia , Auxiliares de Audição , Perda Auditiva/reabilitação , Idoso , Idoso de 80 Anos ou mais , Implantes Cocleares , Cognição , Estudos Transversais , Surdez/psicologia , Surdez/reabilitação , Feminino , Audição , Perda Auditiva/psicologia , Humanos , Estudos Longitudinais , Masculino , Índice de Gravidade de Doença , Fala , Percepção da Fala
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA