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This study aimed to investigate the perception of loudness in response to changes in fundamental frequency (F0) in spoken sounds, as well as the influence of linguistic background on this perceptual process. The results revealed that participants perceived changes in F0 to have accompanying changes in loudness, with a trend of lower F0 sounds being perceived as louder than higher F0 sounds. This finding contrasts with previous studies on pure tones, where increases in frequency typically led to increases in loudness. Furthermore, the study examined differences between two distinct groups of participants: Chinese-speaking and English-speaking individuals. It was observed that English-speaking participants exhibited a greater sensitivity to minor intensity changes compared to Chinese-speaking participants. This discrepancy in sensitivity suggests that linguistic background may play a significant role in shaping the perception of loudness in spoken sound. The study's findings contribute to our understanding of how F0 variations are perceived in terms of loudness, and highlight the potential impact of language experience on this perceptual process.
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Percepção Sonora , Percepção da Fala , Humanos , Masculino , Feminino , Percepção Sonora/fisiologia , Adulto , Adulto Jovem , Percepção da Fala/fisiologia , Acústica da Fala , IdiomaRESUMO
In this study, using the self/other adjective judgment task, we aimed to explore how people perceive themselves in comparison to various other people, including friends, strangers, and those they dislike. Next, using representational similarity analysis, we sought to elucidate how these perceptual similarities and differences are represented in brain activity and how aggressiveness is related to these representations. Behavioral ratings show that, on average, people tend to consider themselves more like their friends than neutral strangers, and least like people they dislike. This pattern of similarity is positively correlated with neural representation in social and cognitive circuits of the brain and negatively correlated with neural representation in emotional centers that may represent emotional arousal associated with various social objects. Aggressiveness seems to predispose a person to a pattern of behavior that is the opposite of the average pattern, that is, a tendency to think of oneself as less like one's friends and more like one's enemies. This corresponds to an increase in the similarity of the behavioral representation with the representation in the emotional centers and a decrease in its similarity with the representation in the social and cognitive centers. This can be seen as evidence that in individuals prone to aggression, behavior in the social environment may depend to a greater extent on the representation of social objects in the emotional rather than social and cognitive brain circuits.
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Agressão , Encéfalo , Humanos , Nível de Alerta , Emoções , AmigosRESUMO
Intraindividual response time variability (RTV) is considered as a general marker of neurological health. In adults, the central executive and salience networks (task-positive networks, TPN) and the default mode network (DMN) are critical for RTV. Given that RTV decreases with growing up, and that boys are likely somewhat behind girls with respect to the network development, we aimed to clarify age and sex effects. Electroencephalogram was recorded during Stroop-like test performance in 124 typically developing children aged 5-12 years. Network fluctuations were calculated as changes of current source density (CSD) in regions of interest (ROIs) from pretest to 1-s test interval. In boys, TPN activation (CSD increase in ROIs included in the TPN) was associated with lower RTV, suggesting a greater engagement of attentional control. In children younger than 9.5 years, higher response stability was associated with the predominance of TPN activation over DMN activation (CSD increase in ROIs included in the TPN > that in the DMN); this predominance increased with age, suggesting that variability among younger children may be due to network immaturity. These findings suggest that the TPN and DMN may play different roles within the network mechanisms of RTV in boys and girls and at different developmental stages.
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Atenção , Imageamento por Ressonância Magnética , Adulto , Masculino , Feminino , Criança , Humanos , Tempo de Reação , Atenção/fisiologia , Imageamento por Ressonância Magnética/métodos , Encéfalo , Rede Nervosa , Mapeamento EncefálicoRESUMO
This paper extends frequency domain quantitative electroencephalography (qEEG) methods pursuing higher sensitivity to detect Brain Developmental Disorders. Prior qEEG work lacked integration of cross-spectral information omitting important functional connectivity descriptors. Lack of geographical diversity precluded accounting for site-specific variance, increasing qEEG nuisance variance. We ameliorate these weaknesses. (i) Create lifespan Riemannian multinational qEEG norms for cross-spectral tensors. These norms result from the HarMNqEEG project fostered by the Global Brain Consortium. We calculate the norms with data from 9 countries, 12 devices, and 14 studies, including 1564 subjects. Instead of raw data, only anonymized metadata and EEG cross-spectral tensors were shared. After visual and automatic quality control, developmental equations for the mean and standard deviation of qEEG traditional and Riemannian DPs were calculated using additive mixed-effects models. We demonstrate qEEG "batch effects" and provide methods to calculate harmonized z-scores. (ii) We also show that harmonized Riemannian norms produce z-scores with increased diagnostic accuracy predicting brain dysfunction produced by malnutrition in the first year of life and detecting COVID induced brain dysfunction. (iii) We offer open code and data to calculate different individual z-scores from the HarMNqEEG dataset. These results contribute to developing bias-free, low-cost neuroimaging technologies applicable in various health settings.
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Encefalopatias , COVID-19 , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Eletroencefalografia/métodos , HumanosRESUMO
A number of studies have shown that the presence of short (S), as opposed to long (L), allele of the serotonin transporter-linked polymorphic region (5-HTTLPR) is associated with a higher risk for depression following exposure to stressful life events. However, many other studies failed to confirm this association. One reason for this inconsistency might be the fact that the interaction of the 5-HTTLPR polymorphism with stress may relate not to depression per se, but rather to adaptive or maladaptive emotion regulation strategies. Here we show that individuals homozygous for the long allele respond to stressful events by reappraising their emotional meaning, which may hamper the harmful effect of stress on mental health. In S genotype carriers, on the other hand, stress triggers the appearance of intrusive thoughts and vain attempts to suppress them, which in this group acts as a mediator between stress and depressive symptoms. These findings are in line with neuroimaging studies showing that 5-HTTLPR polymorphism has an effect on the connectivity among key areas involved in emotion regulation.
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Depressão/genética , Emoções , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Estresse Psicológico/genética , Adulto , Alelos , Depressão/complicações , Feminino , Genótipo , Homozigoto , Humanos , Masculino , Polimorfismo Genético , Estresse Psicológico/complicaçõesRESUMO
Brain responses to stimulus presentations may vary widely across subjects in both time course and spatial origins. Multi-subject EEG source imaging studies that apply Independent Component Analysis (ICA) to data concatenated across subjects have overlooked the fact that projections to the scalp sensors from functionally equivalent cortical sources vary from subject to subject. This study demonstrates an approach to spatiotemporal independent component decomposition and alignment that spatially co-registers the MR-derived cortical topographies of individual subjects to a well-defined, shared spherical topology (Fischl et al., 1999). Its efficacy for identifying functionally equivalent EEG sources in multi-subject analysis is demonstrated by analyzing EEG and behavioral data from a stop-signal paradigm using two source-imaging approaches, both based on individual subject independent source decompositions. The first, two-stage approach uses temporal infomax ICA to separate each subject's data into temporally independent components (ICs), then estimates the source density distribution of each IC process from its scalp map and clusters similar sources across subjects (Makeig et al., 2002). The second approach, Electromagnetic Spatiotemporal Independent Component Analysis (EMSICA), combines ICA decomposition and source current density estimation of the artifact-rejected data into a single spatiotemporal ICA decomposition for each subject (Tsai et al., 2006), concurrently identifying both the spatial source distribution of each cortical source and its event-related dynamics. Applied to the stop-signal task data, both approaches gave IC clusters that separately accounted for EEG processes expected in stop-signal tasks, including pre/postcentral mu rhythms, anterior-cingulate theta rhythm, and right-inferior frontal responses, the EMSICA clusters exhibiting more tightly correlated source areas and time-frequency features.
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Algoritmos , Encéfalo/fisiologia , Modelos Neurológicos , Processamento de Sinais Assistido por Computador , Adulto , Eletroencefalografia , Humanos , MasculinoRESUMO
It is assumed that cognitive processes are provided by the regulatory interactions of different brain networks. The three most stable resting state networks, among which the default mode network (DMN), the central executive network (CEN) and the salience network (SN) are considered to be the key neurocognitive networks for understanding higher cognitive functions. Peculiarities of changes in the connectivity of resting state networks of an individual entering a new environment and after a year of adaptation in this environment remain poorly studied. The aim of this study was to investigate the peculiarities of the connectivity of resting state networks calculated in EEG data in students right after moving to an unfamiliar environment and one year after moving. 128-channel EEGs were recorded in the resting state in 45 students (all men) aged from 18 to 29 years, who moved to the North region of Russia (Yakutsk, Republic of Sakha (Yakutia)). Resting state networks were calculated by the seed-based method. The subjects had increased SN connectivity with the sensorimotor cortex and the posterior node of DMN (posterior cingulate cortex and precuneus) in the condition when they were exposed to a new unfamiliar environment, compared to the condition after a year in the same environment. In general, the obtained data are consistent with the notion of increased SN functioning when encountering new significant stimuli and tasks, i.e. new environmental conditions, and the representation of SN as closely related to the function of homeostasis regulation according to organism's internal goals and environmental requirements.
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Mapeamento Encefálico , Córtex Sensório-Motor , Masculino , Humanos , Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética/métodos , Encéfalo/fisiologia , Cognição , Giro do Cíngulo/fisiologia , Rede Nervosa/fisiologiaRESUMO
Self-appraisal is a process that leads to the formation of self-esteem, which contributes to subjective well-being and mental health. Neuroimaging studies link self-esteem with the activity of the medial prefrontal cortex (MPFC), right temporoparietal junction (rTPJ), posterior cingulate cortex (PCC), anterior insula (AIns), and dorsolateral prefrontal cortex. It is not known, however, how the process of self-appraisal itself is mediated by the brain and how different nodes of the self-appraisal network interact with each other. In this study, we used multilevel mediation analysis of functional MRI data recorded during the trait adjective judgment task, treating the emotional valence of adjectives as the predictor, behavioral response as the dependent variable, and brain activity as the mediator. The mediation effect was revealed in the rTPJ. Dynamic causal modeling showed that positive self-descriptions trigger communication within the network, with the rTPJ exerting the strongest excitatory output and MPFC receiving the strongest excitatory input. rAIns receives the strongest inhibitory input and sends exclusively inhibitory connections to other regions pointing out to its role in the processing of negative self-descriptions. Analysis of individual differences showed that in some individuals, self-appraisal is mostly driven by the endorsement of positive self-descriptions and is accompanied by increased activation and communication between rTPJ, MPFC, and PCC. In others, self-appraisal is driven by the rejection of negative self-descriptions and is accompanied by increased activation of rAIns and inhibition of PCC and MPFC. Membership of these groups was predicted by different personality variables. This evidence uncovers different mechanisms of positive self-bias, which may contribute to different facets of self-esteem and are associated with different personality profiles.
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In the current study, we aimed to investigate the associations between the natural variability in hyperactivity and inattention scores, as well as their combination with EEG oscillatory responses in the Stop-Signal task in a sample of healthy children. During performance, the Stop-Signal task EEGs were recorded in 94 Caucasian children (40 girls) from 7 to 10 years. Hyperactivity/inattention and inattention scores positively correlated with RT variability. Hyperactivity/inattention and inattention scores negatively correlated with an increase in beta spectral power in the first 200 ms after presentation of the Go stimulus. Such results are in line with the lack of arousal model in ADHD children and can be associated with less sensory arousal in the early stages of perception in children with symptoms of inattention. The subsequent greater increase in theta rhythm at about 300 ms after presentation of the Go stimulus in children with higher inattention scores may be associated with increased attention processes and compensation for insufficient vigilance in the early stages of perception.
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Neuroimaging studies have revealed a multitude of brain regions associated with self- and other-referential processing, but the question how the distinction between self, close other, and distant other is processed in the brain still remains unanswered. The default mode network (DMN) is the primary network associated with the processing of self, whereas task-positive networks (TPN) are indispensable for the processing of external objects. We hypothesize that self- and close-other-processing would engage DMN more than TPN, whereas distant-other-processing would engage TPN to a greater extent. To test this hypothesis, we used functional magnetic resonance imaging (fMRI) functional connectivity data obtained in the course of a trait adjective judgment task while subjects evaluated themselves, the best friend, a neutral stranger, and an unpleasant person. A positive association between the degree of self-relatedness and the degree of DMN dominance was revealed in cortical midline structures (CMS) and the left lateral prefrontal cortex. Relative to TPN, DMN showed greater connectivity in me than in friend, in friend than in stranger, and in stranger than in unpleasant conditions. These results show that the less the evaluated person is perceived as self-related, the more the balance of activity in the brain shifts from the DMN to the TPN.
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The aim of the study was to investigate the characteristics of the oscillatory dynamics of brain activity during the perception of negative, positive, and neutral sentences in healthy individuals with differing severity of depressive symptoms at the preclinical stage. The study involved 34 healthy people (22 women). The severity of the symptoms of depression was assessed using Beck's Depression Inventory (BDI II). Using independent component analysis and the function of dipfit in the EEGlab software, the EEG was divided into components and their localizations were calculated. To assess the induced responses, event-related spectral perturbations were calculated. The perception of emotional sentences was accompanied by a more pronounced increase in theta rhythm in the group with lower severity of depressive symptoms. The perception of all types of sentences was accompanied by a decrease in beta rhythm in the group with lower severity of depressive symptoms. The effects were localized to the precuneus. The decrease of oscillatory responses in the theta and beta ranges in individuals with a high severity of depressive symptoms suggests a reduction of attention to the emotional content and meaning of the sentences.
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Depressão/fisiopatologia , Emoções/fisiologia , Percepção/fisiologia , Ritmo Teta/fisiologia , Adulto , Ritmo beta/fisiologia , Depressão/psicologia , Feminino , Voluntários Saudáveis/psicologia , Humanos , Idioma , Masculino , Adulto JovemRESUMO
This study examined children's performance on the Stroop-like animal size test and its relations to parent-reported temperamental effortful control, personality, and common emotional and behavioral problems in a Russian sample of 5-12-year-olds (N = 202). The animal size test demonstrated a Stroop-like effect for accuracy and response time (RT) in both genders and across all ages. Children's performance on the animal size test considerably improved with age such that older children performed more accurately, were faster and their responses were less variable than younger children's responses. The findings indicated that RT was negatively related to temperamental trait of effortful control and its key components, attention focusing and inhibitory control, whereas RT variability was negatively related to both regulatory traits, effortful control and conscientiousness, and their components. Children's performance on the AST was meaningfully related to hyperactivity-inattention, externalizing behavior and overall level of childhood psychopathology. These findings provide support for the usefulness of the animal size test in the neuropsychological assessment of preschool and school-age children.
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Transtornos do Comportamento Infantil/psicologia , Comportamento Infantil/psicologia , Personalidade/fisiologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Comportamento Problema/psicologiaRESUMO
The relationship between trait anxiety and event-related EEG oscillatory reactions in the stop-signal paradigm was studied in 15 non-clinical subjects with average age of 26 years (13 men). In the paradigm, subjects responded to target stimuli by pressing one of the two choice buttons. In 30 out of 130 trials, target presentation was followed by a stop-signal, indicating that subjects had to refrain from a prepared motor response. The subject's level of anxiety was assessed using the State Trait Anxiety Inventory. Wide-band desynchronization (8-25 Hz) was found before button-press. It was sustained after the subjects pressed the button at 7-14 Hz frequency range. Also, synchronization at 15-25 Hz band occurred in 400-1400 ms after the button-press. Synchronization at lower frequencies (1-7 Hz) was also found during 0-700 ms after the stop-signal onset. Also, desynchronization at 8-20 Hz was found in 300-800 ms after stop-signal onset. The group with higher anxiety showed desynchronization at 10-13 Hz in 0-800 ms after the button-press, whereas the group with lower anxiety showed synchronization at the same frequency range. In 0-600 ms after stop-signal onset, desynchronization at 8-13 Hz was observed in the group with higher anxiety, whereas the group with lower anxiety demonstrated synchronization or weak desynchronization. Our findings support the Eysenck et al. [M.W. Eysenck, N. Derakshan, R. Santos, M.G. Calvo, Anxiety and cognitive performance: attentional control theory, Emotion 7(2) (2007) 336-356] theory that subjects with higher anxiety have more attentional control over reaction and increased use of processing resources as compared with lower anxiety subjects.
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Transtornos de Ansiedade/fisiopatologia , Atenção/fisiologia , Córtex Cerebral/fisiopatologia , Cognição/fisiologia , Eletroencefalografia/métodos , Potenciais Evocados/fisiologia , Adulto , Transtornos de Ansiedade/diagnóstico , Mapeamento Encefálico , Sincronização Cortical , Tomada de Decisões/fisiologia , Emoções/fisiologia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Tempo de Reação/fisiologiaRESUMO
EEG cross-frequency amplitude-amplitude correlation (CF-AAC) has been considered as a potential marker of social anxiety and other affective disturbances. Functional significance of this phenomenon remains unclear, partly because the majority of studies used channel-level analysis, which precluded the spatial localization of observed effects. It is not also clear whether CF-AAC may serve as a marker of specific pathological conditions and specific states, or a more general predisposition to affective disturbances. We used source-level analysis of EEG data obtained in resting conditions in a nonclinical sample and patients with major depressive disorder (MDD) and investigated associations of CF-AAC measures with a broad range of known risk factors for affective disorders, including age, gender, genotype, stress exposure, personality, and self-reported 'neurotic' symptomatology. A consistent pattern of associations showed that all investigated risk factors were associated with an enhancement of CF-AAC in cortical regions associated with emotional and self-referential processing. It could be concluded that CF-AAC is a promising candidate marker of a general predisposition to affective disorders at preclinical stages.
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In this study, we aimed to compare the oscillatory dynamics accompanying self-referential and non-self-referential stimulus-independent thoughts. Electroencephalograms were recorded in 30 healthy participants who were asked to press buttons classifying their spontaneous thoughts as self-referential or non-self-referential. EEG data were analyzed using independent component analysis in conjunction with dipole localization. Self-referential thoughts, as compared to non-self-referential thoughts, were accompanied by more pronounced decreases of theta, alpha, and beta spectral power in the anterior hub of the default-mode network, in the left lateral prefrontal, motor/somatosensory, and temporal cortices. These oscillatory dynamics are interpreted as a reflection of autobiographical memory retrieval intrinsic to self-referential thoughts. Abbreviations: BA: Brodmann area; BOLD: blood oxygenation level-dependent; DMN: default mode network; EEG: electroencephalogram; ERSP: event-related spectral perturbations; fMRI: functional magnetic resonance imaging; PCC: posterior cingulate cortex; PET: positron emission tomography; PFC: prefrontal cortex; SIT: stimulus-independent thought; WM: working memory.
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Ondas Encefálicas/fisiologia , Córtex Cerebral/fisiologia , Ego , Potenciais Evocados/fisiologia , Memória Episódica , Rememoração Mental/fisiologia , Rede Nervosa/fisiologia , Pensamento/fisiologia , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
It is generally assumed that different electroencephalogram (EEG) frequency bands are somehow related to different computational modes in the brain. Integration of these computational modes is reflected in the phenomenon of cross-frequency coupling (CFC). On slow temporal scales, CFC may reflect trait-like properties, which posits a question of its developmental trends. This is the first study that explored source-level CFC measures in a developmental perspective using both cross-sectional and longitudinal designs. CFC measures demonstrated good test-retest stability and proved to be higher in adults in cortical areas participating in sensory-motor integration, response inhibition, and attentional control. In children, greater CFC was observed in parietal regions involved in self-centered cognition. Over the period from 7 to 10 years, CFC demonstrated nonlinear growth trajectories. Introversion was associated with higher CFC in cortical areas related to emotion, attention, and social cognition, implying that the association between introversion and CFC appears early in the development.
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The serotonin transporter plays an important role in serotonergic neuromodulation. It is known that polymorphisms in the serotonin transporter gene are linked to the dysregulation of emotions. In the current study, we aimed to investigate the impact of variation in the gene encoding serotonin transporter polymorphism on oscillatory dynamics during inhibition of planned movement in the stop signal paradigm. During performance the stop signal paradigm, electroencephalograms (EEGs) were recorded in 90 healthy Caucasian children (39 girls) from 7 to 12 years. Buccal epithelium probes were taken from all participants. The La, Lg, and S alleles of serotonin transporter-linked polymorphic region (5-HTTLPR) polymorphism were detected in the DNA samples using PCR. LaLa genotype carriers did not differ from LaS\LgS and LgS\LgLg\SS carriers in a number of successful inhibitions of a prepotent response. Carriers of LaLa exhibit higher alpha and beta event-related spectral perturbations (ERSP) in parietal and occipital cortices after the presentation of signal of inhibition of movement than LaS\LgS and LgS\LgLg\SS carriers. Results are consistent with current literature and confirm that S allele carriers are more predisposed to disturbances in cognitive control.
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In the last decade, event-related potential and functional magnetic resonance imaging studies were very useful in temporal and spatial localization of brain processes involved in the recognition of emotional facial expressions. However, frequency characteristics of the underlying processes have been less studied. Besides, most of the studies did not take into account personality-related individual differences. In this study, effects of explicit and implicit anxiety on the oscillatory dynamics of cortical responses elicited by presentation of angry, neutral, and happy faces were investigated using time-frequency decomposition by means of wavelet transform. Both explicit and implicit anxiety were associated with higher alpha band desynchronization, which was most pronounced during presentation of angry faces. Within theta and delta bands, effects appeared to be opposite for explicit and implicit anxiety measures. In implicitly anxious subjects, frontal delta and theta synchronization upon the presentation of angry and happy (but not neutral) faces was found to be higher than in low anxiety ones, whereas explicit anxiety was associated with a lower theta band synchronization. The results are discussed in terms of conscious and controlled vs. unconscious and intuitive information processing associated with explicit and implicit personality measures.
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Encéfalo/fisiologia , Emoções/fisiologia , Potenciais Evocados/fisiologia , Expressão Facial , Adolescente , Adulto , Ritmo alfa , Análise de Variância , Ira/fisiologia , Ansiedade/fisiopatologia , Ansiedade/psicologia , Mapeamento Encefálico/métodos , Ritmo Delta , Eletroencefalografia , Feminino , Felicidade , Humanos , Masculino , Reconhecimento Visual de Modelos/fisiologia , Estimulação Luminosa/métodos , Psicometria/métodos , Psicometria/estatística & dados numéricos , Tempo de Reação/fisiologia , Reconhecimento Psicológico/fisiologia , Ritmo Teta , Percepção Visual/fisiologia , Adulto JovemRESUMO
OBJECTIVE: It is not always clear whether inhibition or attention deficit underlies a failure to stop a prepared motor response. One possible way to approach this question is to resort to measures of evoked oscillations since functional correlates of different frequency oscillations are relatively well understood. METHODS: The present study examined event-related oscillations during a stop-signal task in non-clinical adults. In 25% of trials of an auditory discrimination tasks subjects had to refrain from a prepared motor response. RESULTS: In successful stop trials, the Go N2 peaked later and the Stop N2 peaked earlier than in failed stop trials. Relative to successful, failed stop trials were associated with a larger N1-N2 and Go P3, and a smaller Stop P3 in the central and posterior cortical regions. The latter effect was exclusively determined by evoked delta oscillations, whereas all other frequency bands contributed to enhanced responses in failed comparative to successful stop trials. CONCLUSIONS: The sum of presented evidence seems to show that success or failure to stop mostly depends on how the subject prepares for the Go and Stop stimuli in advance. If attention is more directed towards the Stop signal, the stopping succeeds, otherwise it fails. SIGNIFICANCE: These data may contribute to understanding the cognitive basis of successful and unsuccessful stopping performance.
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Atenção/fisiologia , Discriminação Psicológica/fisiologia , Potenciais Evocados P300/fisiologia , Inibição Psicológica , Estimulação Acústica/métodos , Adolescente , Adulto , Análise de Variância , Mapeamento Encefálico , Relação Dose-Resposta à Radiação , Eletroencefalografia , Feminino , Humanos , Masculino , Psicofísica , Tempo de Reação/fisiologiaRESUMO
There is much evidence to confirm the view that slow waves of delta and theta ranges are linked to activation whereas alpha oscillations are somehow related to inhibition processes. In the domain of individual differences, impulsive behavior is frequently associated with increased spectral power of slow oscillations whereas Behavioral Inhibition (BI) may be associated with higher reactivity within alpha band. Here it is hypothesized that Impulsivity would predispose to higher responding in low frequencies whereas BI would predispose to higher responding within alpha band. In a sample of 51 subjects, evoked and induced responses to auditory stimuli were studied in two experimental sessions: 1) in a simple discrimination task and 2) in a stop-signal task in which subjects had to be ready to withdraw the prepared motor response. Impulsive subjects showed higher baseline delta, theta and alpha power and higher magnitude of induced responses in low frequencies. They also showed lower phase-locking in low frequencies to auditory stimuli and higher phase-locking to the overt behavioral response onset. High BI scorers showed higher baseline alpha power and higher desynchronization in this frequency band in response to stimuli. The reported findings appear to support the idea that low frequency oscillations are associated with behavioral approach and alpha with behavioral inhibition tendencies but these associations are only valid for induced responses to stimuli.