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1.
Psychol Aging ; 35(5): 720-728, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32744853

RESUMO

Inhibitory control is thought to be critical for appropriate response selection in an ever-changing environment and to decline with age. However, experimental paradigms (e.g., go/no-go) confound stimulus frequency with demands to respond or inhibit responding. The present study eliminated that confound by using a modified go/no-go task controlling for stimulus frequency differences (using frequent-go, infrequent-go, and infrequent no-go types of stimuli) in healthy older and young adults. Event-related potential (ERP) components related to detection of response conflict (N2) and response evaluation (P3) were also examined. Behaviorally, older and young adults were sensitive to stimulus frequencies indicated by significant slowing for the infrequent-go compared with the frequent-go stimuli observed in both groups. Furthermore, older adults were characterized by reduced commission errors and overall slowing, suggesting that they could take advantage of their slower performance. Increase of N2 amplitude was evident for correctly inhibited no-go stimuli in both groups. In contrast, no-go stimulus-related increase in P3 amplitude could be observed only in the young. Stimulus frequency-related ERP amplitude differences were not significant either in the young or in the older adults. These results suggest preserved behavioral control over inappropriate responses in older adults and indicate that efficient response inhibition is related to compensatory mechanisms. The age-related decrease in the P3 amplitude suggests that the evaluation of response inhibition (a) could be independent of the detection of response conflict and (b) supports the notion of strategic differences in performance with age. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Assuntos
Potenciais Evocados/fisiologia , Envelhecimento Saudável/genética , Desempenho Psicomotor/fisiologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
2.
PLoS One ; 15(6): e0234397, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32584827

RESUMO

When we perform an action, the outcome that follows it can change the value we place on that behaviour, making it more or less likely to be repeated in the future. However, the values that we learn are not objective: we interpret the outcomes that we receive for ourselves relative to those that share our environment, i.e. we engage in social comparison. The temporal dynamics of physiological responses to stimulus valuation in social learning tasks are poorly understood, particularly in human participants. Therefore, we recorded stimulus-locked event-related potentials with 64-channel EEG to examine stimulus valuation, following the design of a study previously used in macaques. Pairs of participants performed a social learning task in which they received outcomes sequentially for a presented stimulus (partner first) by pressing a button in response to a cue. There were two conditions: one in which stimulus values varied for the participant but output a constant rate of reward for the partner (self-variable blocks), and another condition in which this payout was reversed (other-variable blocks). We then measured participants' self-reported competitiveness. Approximately 200 ms post-stimulus, an ERP related to stimulus evaluation and attentional processing appeared to encode own stimulus value in self-variable blocks. In other-variable blocks the same pattern of activity was reversed, even though the value of the stimulus for the participant did not depend on the stimulus presented. Outcome-locked analyses further showed that attention dedicated to the partner's outcome was greater in more competitive participants. We conclude that subjective stimulus value can be reflected in early stimulus-locked ERP responses and that competitive participants may be more invested in their own performance relative to the other player, hence their increased interest in the outcome of their partner.


Assuntos
Aprendizado Social/fisiologia , Adulto , Atenção/fisiologia , Comportamento Competitivo/fisiologia , Sinais (Psicologia) , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Resposta Galvânica da Pele/fisiologia , Humanos , Masculino , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Recompensa
3.
Proc Natl Acad Sci U S A ; 117(27): 16055-16064, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571942

RESUMO

Visual awareness is thought to result from integration of low- and high-level processing; instances of integration failure provide a crucial window into the cognitive and neural bases of awareness. We present neurophysiological evidence of complex cognitive processing in the absence of awareness, raising questions about the conditions necessary for visual awareness. We describe an individual with a neurodegenerative disease who exhibits impaired visual awareness for the digits 2 to 9, and stimuli presented in close proximity to these digits, due to perceptual distortion. We identified robust event-related potential responses indicating 1) face detection with the N170 component and 2) task-dependent target-word detection with the P3b component, despite no awareness of the presence of faces or target words. These data force us to reconsider the relationship between neural processing and visual awareness; even stimuli processed by a workspace-like cognitive system can remain inaccessible to awareness. We discuss how this finding challenges and constrains theories of visual awareness.


Assuntos
Cognição/fisiologia , Potenciais Evocados/fisiologia , Transtornos da Visão/metabolismo , Percepção Visual/fisiologia , Conscientização/fisiologia , Encéfalo/fisiologia , Eletroencefalografia , Potenciais Evocados Visuais/fisiologia , Face , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Neurodegenerativas , Estimulação Luminosa , Córtex Visual/fisiologia
4.
Acta Psychol (Amst) ; 208: 103102, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32512322

RESUMO

Using event-related potentials we examined the mechanisms that underlie the influence of affective context information on evaluative judgments in affective priming (AP). Participants (N = 44) evaluated a priori neutral target ideographs that were preceded by 800-ms negative, neutral or positive prime pictures. We observed a significant AP effect (APE), with more positive target ratings for targets following positive versus negative primes, with neutral primes lying in between. A greater individual APE was associated with increased attention for the primes, indicated by larger amplitudes of parietal positive slow wave (PSW) and more pronounced prime affect discrimination mirrored in affect-specific variations of parieto-occipital prime P1 and parietal prime P2, P300, and PSW amplitudes. This confirms previous theoretical and empirical work suggesting that the size of the APE critically depends on the extent of prime-elicited affective activation. Furthermore, a greater individual APE was related to generally reduced depth of target processing as mirrored in smaller overall amplitudes of attention-sensitive target-related P1, P2, P300, and PSW. In addition, in the total sample P2, P300, and PSW were smaller for targets following AP eliciting, attention-capturing emotional, as compared to neutral primes. Based on the observed coincidence of increased processing of affective versus neutral primes, and specifically reduced processing of those targets that followed affective primes, we propose prime-target resource competition as an additional, not yet described process contributing to AP in the neutral-target paradigm.


Assuntos
Afeto , Atenção/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Emoções , Humanos , Tempo de Reação
5.
PLoS One ; 15(5): e0232928, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32433672

RESUMO

The information available through our senses is noisy, incomplete, and ambiguous. Our perceptual systems have to resolve this ambiguity to construct stable and reliable percepts. Previous EEG studies found large amplitude differences in two event-related potential (ERP) components 200 and 400 ms after stimulus onset when comparing ambiguous with disambiguated visual information ("ERP Ambiguity Effects"). These effects so far generalized across classical ambiguous figures from different visual categories at lower (geometry, motion) and intermediate (Gestalt perception) levels. The present study aimed to examine whether these ERP Effects are restricted to ambiguous figures or whether they also occur for different degrees of visibility. Smiley faces with low and high visibility of emotional expressions, as well as abstract figures with low and high visibility of a target curvature were presented. We thus compared ambiguity effects in geometric cube stimuli with visibility in emotional faces, and with visibility in abstract figures. ERP Effects were replicated for the geometric stimuli and very similar ERP Effects were found for stimuli with emotional face expressions but also for abstract figures. Conclusively, the ERP amplitude effects generalize across fundamentally different stimulus categories and show highly similar effects for different degrees of stimulus ambiguity and stimulus visibility. We postulate the existence of a high-level/meta-perceptual evaluation instance, beyond sensory details, that estimates the certainty of a perceptual decision. The ERP Effects may reflect differences in evaluation results.


Assuntos
Potenciais Evocados Visuais/fisiologia , Percepção/fisiologia , Percepção Visual/fisiologia , Adulto , Eletroencefalografia , Emoções , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Ilusões Ópticas , Estimulação Luminosa/métodos , Sorriso
6.
J Vis Exp ; (157)2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32225146

RESUMO

Neuropsychiatric diagnoses like ADHD are based on subjective methods like interviews, rating scales and observations. There is a need for more brain-based supplements. Stimulant medication is the most common treatment for ADHD. Clinically useful predictors of response have so far not been reported. The aim of this paper is to describe the EEG based methods we apply to extract potential biomarkers for brain dysfunction. Examples relate to biomarkers for pediatric ADHD, and prediction of medication response. The main emphasis is on Event Related Potentials (ERPs). A nineteen channel EEG is recorded during a 3 min eyes-opened task, a 3 min eyes-closed task, and a 20 min cued visual GO/NOGO task (VCPT). ERPs are recorded during this task. The goal of the ERP protocol is to extract biomarkers of assumed brain dysfunctions that significantly differentiate between a patient group and healthy controls. The protocol includes recording during standard conditions and artifact correction. ERP waves can be used or transformed into latent components. The components of the patient group are compared with controls, empathizing components that, when compared, show relatively high effect sizes. Sub-groups of the patients are selected on the basis of the cluster analysis in the space of the components. Treatment procedure (such as medication, tDCS or neurofeedback protocol) can be applied and the changes in components related to treatment in the subgroups are observed, forming the basis for clinical recommendations. The methods described were applied in a study of 87 pediatric ADHD patients. The index of medication response discriminated significantly between responders and non-responders with a large, and clinically meaningful effect size (d = 1.84). In an ongoing study comparing ADHD children with matched controls, several variables discriminate significantly between patients and controls. The global index will exceed d = .8. The EEG based methods described here could be clinically meaningful.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Biomarcadores/química , Encéfalo/fisiopatologia , Eletroencefalografia/métodos , Potenciais Evocados/fisiologia , Adolescente , Criança , Feminino , Humanos , Masculino
7.
Proc Natl Acad Sci U S A ; 117(19): 10575-10584, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32341167

RESUMO

Even though humans are mostly not aware of their heartbeats, several heartbeat-related effects have been reported to influence conscious perception. It is not clear whether these effects are distinct or related phenomena, or whether they are early sensory effects or late decisional processes. Combining electroencephalography and electrocardiography, along with signal detection theory analyses, we identify two distinct heartbeat-related influences on conscious perception differentially related to early vs. late somatosensory processing. First, an effect on early sensory processing was found for the heartbeat-evoked potential (HEP), a marker of cardiac interoception. The amplitude of the prestimulus HEP negatively correlated with localization and detection of somatosensory stimuli, reflecting a more conservative detection bias (criterion). Importantly, higher HEP amplitudes were followed by decreases in early (P50) as well as late (N140, P300) somatosensory-evoked potential (SEP) amplitudes. Second, stimulus timing along the cardiac cycle also affected perception. During systole, stimuli were detected and correctly localized less frequently, relating to a shift in perceptual sensitivity. This perceptual attenuation was accompanied by the suppression of only late SEP components (P300) and was stronger for individuals with a more stable heart rate. Both heart-related effects were independent of alpha oscillations' influence on somatosensory processing. We explain cardiac cycle timing effects in a predictive coding account and suggest that HEP-related effects might reflect spontaneous shifts between interoception and exteroception or modulations of general attentional resources. Thus, our results provide a general conceptual framework to explain how internal signals can be integrated into our conscious perception of the world.


Assuntos
Frequência Cardíaca/fisiologia , Interocepção/fisiologia , Percepção/fisiologia , Adulto , Atenção/fisiologia , Conscientização/fisiologia , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Estado de Consciência/fisiologia , Eletrocardiografia/métodos , Eletroencefalografia/métodos , Potenciais Evocados/fisiologia , Potenciais Somatossensoriais Evocados/fisiologia , Feminino , Coração/fisiologia , Humanos , Masculino , Córtex Somatossensorial/fisiologia
8.
Proc Natl Acad Sci U S A ; 117(18): 9800-9807, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32312813

RESUMO

Does infant temperament predict adult personality and life-course patterns? To date, there is scant evidence examining relations between child temperament and adult outcomes, and extant research has relied on limited methods for measuring temperament such as maternal report. This prospective longitudinal study followed a cohort of infants (n = 165) for three decades to examine whether infant behavioral inhibition, a temperament characterized by cautious and fearful behaviors to unfamiliar situations, shapes long-term personality, social relationships, vocational/education, and mental health outcomes in adulthood. At age 14 mo, behavioral inhibition was assessed using an observation paradigm. In adolescence (15 y; n = 115), error monitoring event-related potentials were measured in a flanker task. In adulthood (26 y; n = 109), personality, psychopathology, and sociodemographics were self-reported using questionnaires. We found that infants with higher levels of behavioral inhibition at 14 mo grew up to become more reserved and introverted adults (ß = 0.34) with lower social functioning with friends and family (ß = -0.23) at age 26. Infant behavioral inhibition was also a specific risk factor for adult internalizing (i.e., anxiety and depression, ß = 0.20) psychopathology, rather than a transdiagnostic risk for general and externalizing psychopathology. We identified a neurophysiologic mechanism underlying risk and resilience for later psychopathology. Heightened error monitoring in adolescence moderated higher levels of adult internalizing psychopathology among behaviorally inhibited individuals. These findings suggest meaningful continuity between infant temperament and the development of adult personality. They provide the earliest evidence suggesting that the foundation of long-term well-being is rooted in individual differences in temperament observed in infancy.


Assuntos
Medo/psicologia , Inibição Psicológica , Personalidade/fisiologia , Temperamento/fisiologia , Adolescente , Adulto , Ansiedade/fisiopatologia , Ansiedade/psicologia , Criança , Pré-Escolar , Potenciais Evocados/fisiologia , Medo/fisiologia , Feminino , Humanos , Individualidade , Lactente , Estudos Longitudinais , Masculino , Estudos Prospectivos , Fatores de Risco
9.
J Med Life ; 13(1): 102-106, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32341710

RESUMO

Children suffering from conductive or mixed hearing loss may benefit from a bone-anchored hearing aid system (BAHA Attract implantable prosthesis). After audiological rehabilitation, different aspects of development are improving. The objective of this case report is to propose a comprehensive framework for monitoring cortical auditory function after implantation of a bone-anchored hearing aid system by using electrophysiological and neuropsychological measurements. We present the case of a seven-year-old boy with a congenital hearing loss due to a plurimalformative syndrome, including outer and middle ear malformation. After the diagnosis of hearing loss and the audiological rehabilitation with a BAHA Attract implantable prosthesis, the cortical auditory evoked potentials were recorded. We performed a neuropsychological evaluation using the Wechsler Intelligence Scale for Children - Fourth Edition, which was applied according to a standard procedure. The P1 latency was delayed according to the age (an objective biomarker for quantifying cortical auditory function). The neuropsychological evaluation revealed that the child's working memory and verbal reasoning abilities were in the borderline range comparing with his nonverbal reasoning abilities and processing abilities, which were in the average and below-average range, respectively. Cortical auditory evoked potentials, along with neuropsychological evaluation, could be an essential tool for monitoring cortical auditory function in children with hearing loss after a bone-anchored hearing aid implantation.


Assuntos
Córtex Auditivo/fisiologia , Fenômenos Eletrofisiológicos , Auxiliares de Audição , Criança , Orelha Externa/anormalidades , Orelha Externa/fisiopatologia , Potenciais Evocados/fisiologia , Humanos , Anormalidades Maxilomandibulares/fisiopatologia , Masculino , Microstomia/fisiopatologia
10.
Nat Commun ; 11(1): 1948, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32327660

RESUMO

Neural responses in the cerebral cortex change dramatically between the 'synchronized' state during sleep and 'desynchronized' state during wakefulness. Our understanding of cortical state emerges largely from experiments performed in sensory areas of head-fixed or tethered rodents due to technical limitations of recording from larger freely-moving animals for several hours. Here, we report a system integrating wireless electrophysiology, wireless eye tracking, and real-time video analysis to examine the dynamics of population activity in a high-level, executive area - dorsolateral prefrontal cortex (dlPFC) of unrestrained monkey. This technology allows us to identify cortical substates during quiet and active wakefulness, and transitions in population activity during rest. We further show that narrow-spiking neurons exhibit stronger synchronized fluctuations in population activity than broad-spiking neurons regardless of state. Our results show that cortical state is controlled by behavioral demands and arousal by asymmetrically modulating the slow response fluctuations of local excitatory and inhibitory cell populations.


Assuntos
Sincronização Cortical/fisiologia , Rede Nervosa/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Comportamento Animal/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Locomoção/fisiologia , Macaca mulatta , Masculino , Monitorização Ambulatorial , Rede Nervosa/citologia , Neurônios/fisiologia , Córtex Pré-Frontal/citologia , Sono/fisiologia , Vigília/fisiologia , Tecnologia sem Fio
11.
Psychopharmacology (Berl) ; 237(7): 2019-2030, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32313980

RESUMO

Predicting what will happen in the future in terms of potential reward is essential in daily life. The aim of the current study was to investigate the neurotransmitter systems involved in the anticipation of reward value and probability. We hypothesized that dopaminergic and noradrenergic antagonism would affect anticipation of reward value and probability, respectively. Twenty-three healthy participants were included in a haloperidol (2 mg) × clonidine (0.150 mg) × placebo cross-over design and subjected to a Go/NoGo experimental task during which cues signaled the probability of subsequent target appearance. Reward value (amount of money that could be won for correct and fast responding to the target) as well as probability of target appearance was orthogonally manipulated across four task blocks. Cue-elicited EEG event-related potentials were recorded to assess anticipation of value and probability, respectively. The processing of reward value was affected by dopaminergic antagonism (haloperidol), as evidenced by reduction of the reward-related positivity and P300 to reward cues. This reduction was specifically significant for subjects with high baseline dopamine levels for the P300 and most pronounced for these subjects for the reward-related positivity. In contrast, the processing of reward probability was affected by noradrenergic antagonism (clonidine). In addition, both drugs reduced overall performance (omission rate, response speed variability). We conclude that at least anticipation of reward value and probability, respectively, is specifically affected by dopaminergic versus noradrenergic antagonism.


Assuntos
Antecipação Psicológica/fisiologia , Dopamina/metabolismo , Potenciais Evocados/fisiologia , Norepinefrina/metabolismo , Recompensa , Agonistas de Receptores Adrenérgicos alfa 2/farmacologia , Adulto , Antecipação Psicológica/efeitos dos fármacos , Sinais (Psicologia) , Antagonistas de Dopamina/farmacologia , Potenciais Evocados/efeitos dos fármacos , Humanos , Masculino , Norepinefrina/agonistas , Probabilidade , Tempo de Reação/fisiologia , Adulto Jovem
12.
PLoS One ; 15(4): e0231021, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32282823

RESUMO

While prediction errors have been established to instigate learning through model adaptation, recent studies have stressed the role of model-compliant events in predictive processing. Specifically, probabilistic information at critical points in time (so-called checkpoints) has been suggested to be sampled in order to evaluate the internal model, particularly in uncertain contexts. This way, initial model-based expectations are iteratively reaffirmed under uncertainty, even in the absence of prediction errors. Using electroencephalography (EEG), the present study aimed to investigate the interplay of such global uncertainty information and local adjustment cues prompting on-line adjustments of expectations. Within a stream of single digits, participants were to detect ordered sequences (i.e., 3-4-5-6-7) that had a regular length of five digits and were occasionally extended to seven digits. Over time, these extensions were either rare (low irreducible uncertainty) or frequent (high uncertainty) and could be unexpected or indicated by incidental colour cues. Accounting for cue information, an N400 component was revealed as the correlate of locally unexpected (vs expected) outcomes, reflecting effortful integration of incongruous information. As for model-compliant information, multivariate pattern decoding within the P3b time frame demonstrated effective exploitation of local (adjustment cues vs non-informative analogues) and global information (high vs low uncertainty regular endings) sampled from probabilistic events. Finally, superior fit of a global model (disregarding local adjustments) compared to a local model (including local adjustments) in a representational similarity analysis underscored the precedence of global reference frames in hierarchical predictive processing. Overall, results suggest that just like error-induced model adaptation, model evaluation is not limited to either local or global information. Following the hierarchical organisation of predictive processing, model evaluation too can occur at several levels of the processing hierarchy.


Assuntos
Pensamento , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Modelos Neurológicos , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa , Probabilidade , Pensamento/fisiologia , Incerteza , Adulto Jovem
13.
J Vis ; 20(3): 5, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32196068

RESUMO

Previous electroencephalographic research on attentional salience did not fully capture the complexities of low-level vision, which relies on both cone-opponent chromatic and cone-additive luminance mechanisms. We systematically varied color and luminance contrast using a visual search task for a higher contrast target to assess the degree to which the salience-computing attentional mechanisms are constrained by low-level visual inputs. In our first experiment, stimuli were defined by contrast that isolated chromatic or luminance mechanisms. In our second experiment, targets were defined by contrasts that isolated or combined achromatic and chromatic mechanisms. In both experiments, event-related potential waveforms contralateral and ipsilateral to the target were qualitatively different for chromatic- compared to luminance-defined stimuli. The same was true of the difference waves computed from these waveforms, with isoluminant stimuli eliciting a mid-latency posterior contralateral negativity (PCN) component and achromatic stimuli eliciting a complex of multiple components, including an early posterior contralateral positivity followed by a late-latency PCN. Combining color with luminance resulted in waveform and difference wave patterns equivalent to those of achromatic stimuli. When large levels of chromaticity contrast were added to targets with small levels of luminance contrast, PCN latency was speeded. In conclusion, the mechanisms underlying attentional salience are constrained by the low-level inputs they receive. Furthermore, speeded PCN latencies for stimuli that combine color and luminance signals compared to stimuli that contain luminance alone demonstrate that color and luminance channels are integrated during pre-attentive visual processing, before top-down allocation of attention is triggered.


Assuntos
Adaptação Ocular/fisiologia , Percepção de Cores/fisiologia , Neurônios Retinianos/fisiologia , Percepção Visual/fisiologia , Adulto , Sensibilidades de Contraste/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , Adulto Jovem
14.
PLoS One ; 15(3): e0229515, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130232

RESUMO

Category-based induction involves the generalization of a novel property (conclusion property) to a new category (conclusion category), based on the knowledge that a category exemplar (premise category) has the respective novel property. Previous studies have shown that conclusion specificity (i.e., specific [S] or generic categories [G]) influences category-based induction. However, the timing of brain activity underlying this effect is not well known, especially with controlling the similarities of premise and conclusion categories between S and G arguments. In this study, the event-related potential (ERP) responses to category-based induction between S and G arguments were compared under both congruent (+, premise and conclusion categories are related) and incongruent (-, premise and conclusion categories are unrelated) arguments; additionally, the similarities of premise and conclusion categories between S and G arguments were controlled. The results showed that replicating this effect, S+ arguments have increased "strong" response rates compared to G+ arguments, suggesting that category-based induction is contingent on factors beyond matched similarities. Moreover, S arguments have more liberal inductive decision thresholds than G arguments, which suggest that conclusion specificity affects the inductive decision reflected by inductive decision thresholds. Furthermore, G+ arguments elicit greater P3a amplitudes than S+ arguments, which suggest greater attention resources allocation to the review of decisions for G+ arguments than that for S+ arguments. Taken together, the conclusion specificity effect during semantic category-based induction can be revealed by "strong" response rates, inductive decision thresholds, and P3a component after controlling the premise-conclusion similarity, providing evidence that category-based induction rely on more than simple similarity judgment and conclusion specificity would affect category-based induction.


Assuntos
Tomada de Decisões/fisiologia , Potenciais Evocados/fisiologia , Aprendizagem/fisiologia , Adolescente , Adulto , Encéfalo/fisiologia , Eletroencefalografia , Feminino , Generalização Psicológica/fisiologia , Humanos , Julgamento/fisiologia , Conhecimento , Masculino , Semântica , Adulto Jovem
15.
PLoS One ; 15(3): e0229169, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32168357

RESUMO

In this event-related potential (ERP) study we reevaluate syntax-first approaches to sentence processing by implementing a novel paradigm in French that includes correct sentences, pure syntactic category violations, lexical-semantic anomalies, and combined anomalies. Our balanced design systematically controlled for target word (noun vs. verb) and the context immediately preceding it. Group results from 36 native speakers of Quebec French revealed that, up to 300 ms, ERPs elicited by syntactic category violations were comparable with ERP responses to correct sentences, showing that there is no early activation reflecting syntactic category identification. Instead, in response to all anomalous conditions, we observed an N400 followed by a P600. Combined anomalies yielded additive effects of syntactic category and lexical-semantic anomalies on the N400, and a large P600 effect similar to the one observed in the pure syntactic condition. These results provide strong evidence against the hypothesis that (i) syntactic categories are processed first, and (ii) that syntactic category errors "block" lexical-semantic processing. Further, the N400 effect in response to pure syntactic category violations reflects a mismatch detection between a predicted word-stem and the actual target. This mechanism takes place simultaneously (and potentially in parallel) with lexical-semantic processing. In contrast, an interaction of syntax and semantics for the P600 reveals that the same neurocognitive resources are recruited for syntactic and semantic integration, both promoted by the implementation of an acceptability judgement task in our design. Additional analyses of individual data complemented these observations: during sentence processing, participants did not rely on one single cognitive mechanism reflected by either the N400 or the P600 effect but on both, suggesting that the biphasic N400-P600 ERP wave can indeed be considered to be an index of phrase-structure violations in most individuals, at least if they are realized on content words.


Assuntos
Potenciais Evocados/fisiologia , Idioma , Semântica , Percepção da Fala/fisiologia , Fala/fisiologia , Adulto , Eletroencefalografia , Feminino , França , Humanos , Individualidade , Masculino , Quebeque , Priming de Repetição/fisiologia , Adulto Jovem
16.
PLoS Biol ; 18(3): e3000625, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32119658

RESUMO

Working memory (WM) is important to maintain information over short time periods to provide some stability in a constantly changing environment. However, brain activity is inherently dynamic, raising a challenge for maintaining stable mental states. To investigate the relationship between WM stability and neural dynamics, we used electroencephalography to measure the neural response to impulse stimuli during a WM delay. Multivariate pattern analysis revealed representations were both stable and dynamic: there was a clear difference in neural states between time-specific impulse responses, reflecting dynamic changes, yet the coding scheme for memorised orientations was stable. This suggests that a stable subcomponent in WM enables stable maintenance within a dynamic system. A stable coding scheme simplifies readout for WM-guided behaviour, whereas the low-dimensional dynamic component could provide additional temporal information. Despite having a stable subspace, WM is clearly not perfect-memory performance still degrades over time. Indeed, we find that even within the stable coding scheme, memories drift during maintenance. When averaged across trials, such drift contributes to the width of the error distribution.


Assuntos
Memória de Curto Prazo/fisiologia , Processamento de Sinais Assistido por Computador , Adulto , Encéfalo/fisiologia , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Análise Multivariada , Experimentação Humana não Terapêutica , Estimulação Luminosa
17.
Nat Commun ; 11(1): 1298, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32157080

RESUMO

Any experienced event may be encoded and retained in detail as part of our episodic memory, and may also refer and contribute to our generalized knowledge stored in semantic memory. The beginnings of this declarative memory formation are only poorly understood. Even less is known about the interrelation between episodic and semantic memory during the earliest developmental stages. Here, we show that the formation of episodic memories in 14- to 17-month-old infants depends on sleep, subsequent to exposure to novel events. Infant brain responses reveal that, after sleep-dependent consolidation, the newly stored events are not processed semantically, although appropriate lexical-semantic memories are present and accessible by similar events that were not experienced before the nap. We propose that temporarily disabled semantic processing protects precise episodic memories from interference with generalized semantic memories. Selectively restricted semantic access could also trigger semantic refinement, and thus, might even improve semantic memory.


Assuntos
Consolidação da Memória/fisiologia , Memória Episódica , Semântica , Sono/fisiologia , Potenciais Evocados/fisiologia , Feminino , Humanos , Lactente , Masculino , Sono REM/fisiologia
18.
J Neurosci ; 40(14): 2906-2913, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32122954

RESUMO

To date it is poorly understood how and when deviance processing interacts with awareness and task relevance. Furthermore, an important issue in the study of consciousness is the prevalent confound of conscious perception with the requirement of reporting it. This study addresses these topics using a no-report inattentional blindness paradigm with a visual oddball sequence of geometrical shapes presented to male and female human participants. Electrophysiological responses were obtained in three physically identical Phases A-C that differed only with respect to the instructions: (A) participants were uninformed about the shapes and attended an unrelated foreground task (inattentional blind), (B) were informed about the shapes but still attended the foreground task, and (C) attended the shapes. Conscious processing of shapes was indexed by the visual awareness negativity but not a P3. Deviance processing was associated with the visual mismatch negativity independently of consciousness and task relevance. The oddball P3, however, only emerged when the stimuli were task relevant, and was absent for consciously perceived but task irrelevant stimuli. The P3 thus does not represent a reliable marker of stimulus awareness. This result pattern supports the view of hierarchical predictive processing, where lower levels display automatic deviance processing, whereas higher levels require attention and task relevance.SIGNIFICANCE STATEMENT To react to potentially important changes in our environment it is fundamental to detect deviations from regularities of sensory input. It has yet to be understood how awareness and task relevance of this input interact with deviance processing. We investigated the role of awareness in deviance detection while at the same time circumventing the confound of awareness and report by means of a no-report paradigm. Our results suggest that early processes are elicited automatically, whereas, contrary to prominent theories, late processes do not depend on awareness but on task-based attention.


Assuntos
Atenção/fisiologia , Conscientização/fisiologia , Encéfalo/fisiologia , Potenciais Evocados/fisiologia , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Percepção Visual/fisiologia , Adulto Jovem
19.
J Neurosci ; 40(16): 3304-3317, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32205341

RESUMO

Although the etiology of schizophrenia is still unknown, it is accepted to be a neurodevelopmental disorder that results from the interaction of genetic vulnerabilities and environmental insults. Although schizophrenia's pathophysiology is still unclear, postmortem studies point toward a dysfunction of cortical interneurons as a central element. It has been suggested that alterations in parvalbumin-positive interneurons in schizophrenia are the consequence of a deficient signaling through NMDARs. Animal studies demonstrated that early postnatal ablation of the NMDAR in corticolimbic interneurons induces neurobiochemical, physiological, behavioral, and epidemiological phenotypes related to schizophrenia. Notably, the behavioral abnormalities emerge only after animals complete their maturation during adolescence and are absent if the NMDAR is deleted during adulthood. This suggests that interneuron dysfunction must interact with development to impact on behavior. Here, we assess in vivo how an early NMDAR ablation in corticolimbic interneurons impacts on mPFC and ventral hippocampus functional connectivity before and after adolescence. In juvenile male mice, NMDAR ablation results in several pathophysiological traits, including increased cortical activity and decreased entrainment to local gamma and distal hippocampal theta rhythms. In addition, adult male KO mice showed reduced ventral hippocampus-mPFC-evoked potentials and an augmented low-frequency stimulation LTD of the pathway, suggesting that there is a functional disconnection between both structures in adult KO mice. Our results demonstrate that early genetic abnormalities in interneurons can interact with postnatal development during adolescence, triggering pathophysiological mechanisms related to schizophrenia that exceed those caused by NMDAR interneuron hypofunction alone.SIGNIFICANCE STATEMENT NMDAR hypofunction in cortical interneurons has been linked to schizophrenia pathophysiology. How a dysfunction of GABAergic cortical interneurons interacts with maturation during adolescence has not been clarified yet. Here, we demonstrate in vivo that early postnatal ablation of the NMDAR in corticolimbic interneurons results in an overactive but desynchronized PFC before adolescence. Final postnatal maturation during this stage outspreads the impact of the genetic manipulation toward a functional disconnection of the ventral hippocampal-prefrontal pathway, probably as a consequence of an exacerbated propensity toward hippocampal-evoked depotentiation plasticity. Our results demonstrate a complex interaction between genetic and developmental factors affecting cortical interneurons and PFC function.


Assuntos
Hipocampo/metabolismo , Interneurônios/metabolismo , Córtex Pré-Frontal/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Esquizofrenia/metabolismo , Animais , Modelos Animais de Doenças , Potenciais Evocados/fisiologia , Masculino , Camundongos , Camundongos Knockout , Vias Neurais/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Esquizofrenia/genética , Transdução de Sinais/fisiologia , Ritmo Teta/fisiologia
20.
Neuron ; 106(2): 256-264.e3, 2020 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-32084331

RESUMO

Maintaining multiple items in working memory (WM) is central to human behavior. Persistently active neurons are thought to be a mechanism to maintain WMs, but it remains unclear how such activity is coordinated when multiple items are kept in memory. We show that memoranda-selective persistently active neurons in the human medial temporal lobe phase lock to ongoing slow-frequency (1-7 Hz) oscillations during WM maintenance. The properties of phase locking are dependent on memory content and load. During high memory loads, the phase of the oscillatory activity to which neurons phase lock provides information about memory content not available in the firing rate of the neurons. We provide a computational model that reveals that inhibitory-feedback-mediated competition between multiple persistently active neurons reproduces this phenomenon. This work reveals a mechanism for the active maintenance of multiple items in WM that relies on persistently active neurons whose activation is orchestrated by oscillatory activity.


Assuntos
Memória de Curto Prazo/fisiologia , Neurônios/fisiologia , Eletroencefalografia , Fenômenos Eletrofisiológicos , Potenciais Evocados/fisiologia , Retroalimentação Psicológica , Humanos , Estimulação Luminosa , Lobo Temporal/fisiologia , Ritmo Teta
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