Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Psychiatry Res ; 256: 66-70, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28624674

RESUMO

Many individuals in the general population experience psychotic-like experiences in the absence of a psychotic disorder. The degree of psychological distress associated with these experiences is a key predictor of clinical outcomes. One factor that may influence the degree of distress from psychotic-like experiences is emotion regulation. Although it has been demonstrated that emotion regulation deficits are present in psychotic disorders, the association between emotion regulation and subclinical psychotic-like experiences is not well understood. Here, we examined the associations between frequency of and distress from psychotic-like experiences and several key components of emotion regulation: difficulties with emotion regulation; emotion regulation self-efficacy; and emotion regulation strategy use. Difficulties with emotion regulation and maladaptive patterns of emotion regulation strategy use were associated with the frequency of both positive and negative psychotic-like experiences. In addition, results suggest that habitual acceptance use and reappraisal self-efficacy may serve as protective factors against the distress associated with psychotic-like experiences.


Assuntos
Sintomas Afetivos/psicologia , Emoções , Acontecimentos que Mudam a Vida , Transtornos Psicóticos/psicologia , Estresse Psicológico/psicologia , Adaptação Psicológica , Adulto , Feminino , Humanos , Masculino
2.
Emotion ; 17(4): 572-576, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28206797

RESUMO

Emotion experience and regulation frequently occur in social settings. Social influence is a common source of unconscious change in judgment in many contexts, but it has yet to be investigated as a form of automatic emotion regulation. Here, we demonstrate that nonpredictive social information (i.e., high or low "emotion intensity ratings from other people" that were not related to the actual intensity of the pictures) about the intensity of pleasant and unpleasant picture stimuli can influence self-reported emotional experience and the magnitude of the late positive potential, an event-related potential associated with the detection of emotional salience and sustained attention to motivationally significant stimulus features. These results show that emotional responses to pleasant and unpleasant affective pictures can be altered by nonpredictive social information on both the behavioral and the neurophysiological level. (PsycINFO Database Record


Assuntos
Emoções/fisiologia , Potenciais Evocados/fisiologia , Mudança Social , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
3.
Early Interv Psychiatry ; 11(2): 139-146, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-25702773

RESUMO

AIM: Sub-threshold psychotic experiences (PEs) are common in the general population and may increase risk for psychological distress and psychosis onset, generating a need for effective community screening instruments. This study aimed to explore the utility of a brief, self-report, psychosis risk screening tool in predicting perceived need for psychological treatment among a non-clinical sample, above and beyond that accounted for by accompanying forms of psychopathology or trait neuroticism. METHODS: Construct validity, predictive validity and test-retest reliability of the brief, self-report questionnaire for screening putative prepsychotic states were determined among college students (N = 679). Multiple linear regression analyses were conducted to explore the relationship between PEs and perceived need for psychological services. RESULTS: With the exception of auditory perceptual disturbances, PEs were not significantly associated with one's need for services, or the belief from others that services are needed, after controlling for neuroticism, anxiety and depressive symptoms. Auditory perceptual disturbances were significantly associated with the perceived need for psychological services, even after accounting for these additional symptoms. CONCLUSIONS: These results confirm the usefulness of the psychosis risk screening tool in evaluating the presence of sub-threshold PEs, particularly auditory perceptual disturbances. The relationship between other PEs and a perceived need for psychological services, however, was largely explained by the existence of neurotic traits and anxiety and depressive symptoms. Screening for auditory perceptual disturbances may be useful in identifying unmet clinical need among young adults.


Assuntos
Necessidades e Demandas de Serviços de Saúde , Programas de Rastreamento/psicologia , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/psicologia , Medição de Risco , Inquéritos e Questionários , Adolescente , Estudos Transversais , Feminino , Alucinações/diagnóstico , Alucinações/epidemiologia , Alucinações/psicologia , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Programas de Rastreamento/organização & administração , Psicometria/estatística & dados numéricos , Transtornos Psicóticos/epidemiologia , Reprodutibilidade dos Testes , Medição de Risco/estatística & dados numéricos , Estudantes/psicologia , Virginia , Adulto Jovem
4.
Crisis ; 37(4): 265-270, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27338292

RESUMO

BACKGROUND: Self-esteem is a major contributor to risk for repeated suicide attempts. Prior research has shown that awareness of stigma is associated with reduced self-esteem among people with mental illness. No prior studies have examined the association between self-esteem and stereotype awareness among individuals with past suicide attempts. AIMS: To understand the relationship between stereotype awareness and self-esteem among young adults who have and have not attempted suicide. METHOD: Computerized surveys were administered to college students (N = 637). Linear regression analyses were used to test associations between self-esteem and stereotype awareness, attempt history, and their interaction. RESULTS: There was a significant stereotype awareness by attempt interaction (ß = -.74, p = .006) in the regression analysis. The interaction was explained by a stronger negative association between stereotype awareness and self-esteem among individuals with past suicide attempts (ß = -.50, p = .013) compared with those without attempts (ß = -.09, p = .037). CONCLUSION: Stigma is associated with lower self-esteem within this high-functioning sample of young adults with histories of suicide attempts. Alleviating the impact of stigma at the individual (clinical) or community (public health) levels may improve self-esteem among this high-risk population, which could potentially influence subsequent suicide risk.


Assuntos
Autoimagem , Estigma Social , Tentativa de Suicídio/psicologia , Adolescente , Adulto , Humanos , Masculino , Testes Psicológicos , Estereotipagem , Inquéritos e Questionários , Adulto Jovem
5.
Psychiatry Res ; 238: 68-73, 2016 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-27086213

RESUMO

Schizotypy has been linked to suicide risk, but it is not known whether established suicide-related risk factors mediate this relation. The aim of this study was to assess the mediating effects of depressive symptoms, social anxiety, self-esteem, and intimate disclosure in peer relationships in the relation between interpersonal schizotypy and suicide ideation or lifetime suicide attempts. This aim was tested in 590 young adults using a nonparametric bootstrapping procedure. After inclusion of the mediators, interpersonal schizotypy was no longer directly associated with either suicide ideation or lifetime suicide attempts. Depression and self-esteem mediated the relation between interpersonal schizotypy and suicide ideation. No variables mediated the relation between interpersonal schizotypy and lifetime suicide attempts, and there were no significant direct relations when mediators were included. Schizotypy appears to be a distal risk factor for suicidal behavior; assessing depressive symptoms and self-esteem may provide more proximal information about suicide risk, and may be targets for mitigating suicide risk in individuals with schizotypy.


Assuntos
Depressão/psicologia , Transtorno da Personalidade Esquizotípica/psicologia , Ideação Suicida , Suicídio/psicologia , Adolescente , Feminino , Humanos , Relações Interpessoais , Masculino , Fatores de Risco , Autoimagem , Adulto Jovem
6.
Emotion ; 16(4): 468-474, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26641270

RESUMO

In the present research, we investigated the effects of self- and situation-focused reappraisal, which are 2 distinct types of cognitive reappraisal, on emotion experiences, memory, and electrocortical responses to unpleasant pictures. In Study 1, situation-focused reappraisal was found to improve recall accuracy, whereas self-focused reappraisal had no effect. Both strategy types were associated with reductions in self-reported negative emotion, with larger reductions during situation-focused reappraisal. In Study 2, event-related potentials (ERPs) were measured while participants engaged in the 2 strategy types. Situation-focused, but not self-focused, reappraisal was associated with reductions in the late positive potential, an ERP that reflects facilitated attention to emotional stimuli. Taken together, these findings suggest that reappraisal is not a homogenous regulation strategy; on the contrary, subtypes of reappraisal elicit distinct consequence profiles. (PsycINFO Database Record


Assuntos
Cognição/fisiologia , Emoções/fisiologia , Potenciais Evocados/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
7.
Soc Psychiatry Psychiatr Epidemiol ; 50(12): 1819-30, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26493307

RESUMO

PURPOSE: Psychotic experiences and suicidal behavior commonly co-occur in the general population, which can have implications for suicide prevention approaches. However, little is known about the nature of this relation in non-clinical samples. This cross-sectional study aimed to address a research gap by testing whether the relation between psychotic experiences and suicide-related outcomes (ideation, intent, and attempts) is explained by common social and psychological factors. METHODS: Young adult college students (N = 590) were assessed for psychotic experiences, suicidal behavior, and a comprehensive set of 24 potential shared risk factors selected through review of past epidemiological studies and meta-analyses. Nonparametric bootstrapped regression models were used to examine whether these factors attenuated or eliminated the associations between psychotic experiences and suicide-related outcomes. RESULTS: Psychotic experiences were associated with greater risk for suicidal ideation and behaviors. Adjustment for psychosocial factors, particularly those contributing to cumulative stress, accounted for the associations between psychotic experiences and suicide-related outcomes, except broadly defined suicidal ideation. CONCLUSIONS: These results suggest that the robust associations between psychotic experiences and suicidal behavior demonstrated in past studies may be primarily explained by shared risk factors, rather than by causal relations. In our sample, suicidal behavior and sub-threshold psychosis appear to be trans diagnostic clinical outcomes that share common causes, notably cumulative stress, but do not cause one another.


Assuntos
Transtornos Psicóticos/epidemiologia , Transtornos Psicóticos/psicologia , Ideação Suicida , Adolescente , Adulto , Comorbidade , Estudos Transversais , Feminino , Humanos , Masculino , Fatores de Risco , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Universidades , Adulto Jovem
8.
Health Soc Work ; 40(3): 175-81, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26285356

RESUMO

Individuals with subthreshold psychotic experiences are at increased risk for suicidal thoughts and behavior, similar to those with schizophrenia and other psychotic disorders. This may be explained by shared risk factors such as heightened stress sensitivity or low self-esteem. Understanding the nature of this relationship could inform suicide prevention in social work practice. In this study, authors examined the relationship between self-reported auditory hallucinations and suicidal thoughts, plans, and attempts, in a nonclinical sample of young adults, controlling for scores on the Psychological Stress Index and Rosenberg Self-Esteem Scale. Auditory hallucinations were associated with approximately double the odds of suicidal ideation and plans and four times the odds for suicide attempts. This relationship was not explained by stress sensitivity or self-esteem, which were independently related to hallucinations and suicidality, respectively. Subthreshold auditory hallucinations may be a useful indicator of suicide risk. This association may represent a clinically significant relationship that may be addressed through social work interventions intended to alleviate stress sensitivity or improve self-esteem.


Assuntos
Alucinações/psicologia , Transtornos Psicóticos/psicologia , Autoimagem , Estresse Psicológico/psicologia , Ideação Suicida , Tentativa de Suicídio/psicologia , Adolescente , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Fatores de Risco , Inquéritos e Questionários
9.
Psychiatry Res ; 228(2): 203-8, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-25998000

RESUMO

Animal models and clinical trials in humans suggest that probiotics can have an anxiolytic effect. However, no studies have examined the relationship between probiotics and social anxiety. Here we employ a cross-sectional approach to determine whether consumption of fermented foods likely to contain probiotics interacts with neuroticism to predict social anxiety symptoms. A sample of young adults (N=710, 445 female) completed self-report measures of fermented food consumption, neuroticism, and social anxiety. An interaction model, controlling for demographics, general consumption of healthful foods, and exercise frequency, showed that exercise frequency, neuroticism, and fermented food consumption significantly and independently predicted social anxiety. Moreover, fermented food consumption also interacted with neuroticism in predicting social anxiety. Specifically, for those high in neuroticism, higher frequency of fermented food consumption was associated with fewer symptoms of social anxiety. Taken together with previous studies, the results suggest that fermented foods that contain probiotics may have a protective effect against social anxiety symptoms for those at higher genetic risk, as indexed by trait neuroticism. While additional research is necessary to determine the direction of causality, these results suggest that consumption of fermented foods that contain probiotics may serve as a low-risk intervention for reducing social anxiety.


Assuntos
Transtornos de Ansiedade , Ansiedade/psicologia , Fermentação , Probióticos , Comportamento Social , Adulto , Animais , Ansiedade/etiologia , Estudos Transversais , Feminino , Humanos , Masculino , Neuroticismo , Risco , Autorrelato , Adulto Jovem
10.
Brain Stimul ; 8(2): 185-91, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25499035

RESUMO

BACKGROUND: The cognitive neuropsychological model states that antidepressant treatment alters emotional biases early in treatment, and after this initial change in emotional processing, environmental and social interactions allow for long-term/sustained changes in mood and behavior. OBJECTIVE: Changes in negative self-bias after chronic subcallosal cingulate (SCC) deep brain stimulation (DBS) were investigated with the hypothesis that treatment would lead to changes in emotional biases followed by changes in symptom severity. METHODS: Patients (N = 7) with treatment-resistant depression were assessed at three time points: pre-treatment; after one month stimulation; and after six months stimulation. The P1, P2, P3, and LPP (late positive potential) components of the event-related potential elicited by positive and negative trait adjectives were recorded in both a self-referential task and a general emotion recognition task. RESULTS: Results indicate that DBS reduced automatic attentional bias toward negative words early in treatment, as indexed by the P1 component, and controlled processing of negative words later in treatment, as indexed by the P3 component. Reduction in negative words endorsed as self-descriptive after six months DBS was associated with reduced depression severity after six months DBS. Change in emotional processing may be restricted to the self-referential task. CONCLUSIONS: Together, these results suggest that the cognitive neuropsychological model, developed to explain the time-course of monoamine antidepressant treatment, may also be used as a framework to interpret the antidepressant effects of SCC DBS.


Assuntos
Estimulação Encefálica Profunda , Transtorno Depressivo Resistente a Tratamento/terapia , Emoções/fisiologia , Giro do Cíngulo/fisiologia , Córtex Pré-Frontal/fisiologia , Adulto , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Desempenho Psicomotor/fisiologia
11.
Early Interv Psychiatry ; 9(4): 331-4, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24958508

RESUMO

AIM: Subthreshold psychotic experiences are common in the population and may be clinically significant. Reporting of psychotic experiences through self-report screens may be subject to threats to validity, including social desirability biases. This study examines the influence of social desirability on the reporting of psychotic experiences. METHODS: College students (n = 686) completed a psychosis screen and the Marlowe-Crowne social desirability scale as part of a self-report survey battery. Associations between psychosis and social desirability were tested using logistic regression models. RESULTS: With the exception of auditory hallucinations, all other measures of psychotic experiences were subject to social desirability biases. Respondents who gave more socially desirable answers were less likely to report psychotic experiences. CONCLUSIONS: Respondent's tendency to underreport psychotic experiences should be accounted for when screening for these symptoms clinically. Findings also suggest that population figures based on self-report may underestimate the prevalence of subthreshold delusions but not hallucinations.


Assuntos
Transtornos Psicóticos/psicologia , Desejabilidade Social , Adolescente , Viés , Feminino , Alucinações/psicologia , Humanos , Masculino , Transtornos Psicóticos/diagnóstico , Autorrelato
12.
Soc Cogn Affect Neurosci ; 9(7): 969-76, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23677489

RESUMO

With advancing age, processing resources are shifted away from negative emotional stimuli and toward positive ones. Here, we explored this 'positivity effect' using event-related potentials (ERPs). Participants identified the presence or absence of a visual probe that appeared over photographs of emotional faces. The ERPs elicited by the onsets of angry, sad, happy and neutral faces were recorded. We examined the frontocentral emotional positivity (FcEP), which is defined as a positive deflection in the waveforms elicited by emotional expressions relative to neutral faces early on in the time course of the ERP. The FcEP is thought to reflect enhanced early processing of emotional expressions. The results show that within the first 130 ms young adults show an FcEP to negative emotional expressions, whereas older adults show an FcEP to positive emotional expressions. These findings provide additional evidence that the age-related positivity effect in emotion processing can be traced to automatic processes that are evident very early in the processing of emotional facial expressions.


Assuntos
Envelhecimento/fisiologia , Encéfalo/fisiologia , Emoções , Expressão Facial , Reconhecimento Visual de Modelos/fisiologia , Adolescente , Adulto , Idoso , Potenciais Evocados , Potenciais Evocados Visuais , Face , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Adulto Jovem
13.
Psychophysiology ; 51(1): 22-35, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24147640

RESUMO

Objects compete for representation in our limited capacity visual system. We examined how this competition is influenced by top-down knowledge using event-related potentials. Competition was manipulated by presenting visual search arrays in which the target or distractor was the only color singleton compared to displays in which both singletons were presented. Experiments 1 and 2 manipulated whether the observer knew the color of the target in advance. Experiment 3 ruled out low-level sensory explanations. Results show that, under conditions of competition, the distractor does not elicit an N2pc when the target color is known. However, the N2pc elicited by the target is reduced in the presence of a distractor. These findings suggest that top-down knowledge can prevent the capture of attention by distracting information, but this prior knowledge does not eliminate the competitive influence of the distractor on the target.


Assuntos
Atenção/fisiologia , Potenciais Evocados/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Tempo de Reação , Percepção Visual/fisiologia , Adulto Jovem
14.
Neuropsychopharmacology ; 37(7): 1764-72, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22414813

RESUMO

Deep brain stimulation (DBS) of subcallosal cingulate white matter (SCC) may be an effective approach for treatment-resistant depression (TRD) that otherwise fails to respond to more conventional therapies, but DBS is invasive, costly, and has potential for adverse effects. Therefore, it is important to identify potential biomarkers for predicting antidepressant response before intervention. Resting-state EEG was recorded from 12 TRD patients at pre-treatment baseline, after 4 weeks SCC DBS, and after 24 weeks SCC DBS. Lower frontal theta cordance (FTC) at baseline (and higher FTC after 4 weeks) predicted lower depression severity scores after 24 weeks. Greater FTC increases (baseline-4 weeks) predicted greater decreases in depression severity scores subsequently (4-24 weeks) and over the course of the study (baseline-24 weeks). Predictive relationships were topographically specific to theta cordance for frontal electrodes. Thus, results from this pilot study suggest that baseline FTC and changes early in treatment each have utility as biomarkers for predicting 6-month clinical response to SCC DBS for TRD.


Assuntos
Estimulação Encefálica Profunda , Transtorno Depressivo Resistente a Tratamento/fisiopatologia , Transtorno Depressivo Resistente a Tratamento/terapia , Lobo Frontal/fisiopatologia , Giro do Cíngulo/fisiopatologia , Adulto , Antidepressivos/uso terapêutico , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Valor Preditivo dos Testes , Índice de Gravidade de Doença , Resultado do Tratamento
15.
Psychophysiology ; 49(4): 504-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22176697

RESUMO

Attentional selection requires both the enhancement of target stimuli and the suppression of distractors. Target enhancement and distractor suppression have been associated with separable components of the lateralized event-related potential: the target negativity and distractor positivity (Pd). We examined the distractor suppression mechanisms indexed by the Pd. The Pd may reflect mechanisms that guide attention away from distractors during search or mechanisms involved in the subsequent resolution of target features. To determine which of these alternatives was more likely, we had participants view search arrays that contained only a target, only a distractor, or both. The Pd elicited by distractors was substantially larger when the display also contained a target, consistent with the idea that this component reflects a mechanism of distractor suppression activated during the resolution and disambiguation of target features.


Assuntos
Eletroencefalografia , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Cor , Fenômenos Eletrofisiológicos , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Adulto Jovem
16.
Psychophysiology ; 49(3): 357-68, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22091588

RESUMO

We examined effects of knowing where to attend to-be-remembered information in advance versus after the fact. Participants performed a visuospatial short-term memory task with orienting cues that appeared before or after a memory display and reported whether a probe item had appeared on the cued side. Event-related potentials (ERPs) were recorded for cues, memory displays, and probes. Performance was better in precued versus postcued conditions. ERPs to orienting cues and memory displays were lateralized in relation to the direction of attention in precued but not postcued conditions. ERPs to recognition probes were lateralized, but this was similar between pre- and postcued conditions. Results suggest that we can orient visuospatial attention outwardly to external events and inwardly to remembered events alike, but knowing where to attend information in advance gives a bigger boost to brain and behavior.


Assuntos
Atenção/fisiologia , Potenciais Evocados/fisiologia , Memória de Curto Prazo/fisiologia , Percepção Espacial/fisiologia , Adolescente , Adulto , Sinais (Psicologia) , Eletroencefalografia , Feminino , Humanos , Masculino , Desempenho Psicomotor , Tempo de Reação , Reconhecimento Psicológico
17.
Neurosci Lett ; 495(3): 196-200, 2011 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-21457759

RESUMO

When multiple objects are present in a visual scene, salient and behaviorally relevant objects are attentionally selected and receive enhanced processing at the expense of less salient or less relevant objects. Here we examined three lateralized components of the event-related potential (ERP) - the N2pc, Ptc, and SPCN - as indices of target and distractor processing in a visual search paradigm. Participants responded to the orientation of a target while ignoring an attentionally salient distractor and ERPs elicited by the target and the distractor were obtained. Results indicate that both the target and the distractor elicit an N2pc component which may index the initial attentional selection of both objects. In contrast, only the distractor elicited a significant Ptc, which may reflect the subsequent suppression of distracting or irrelevant information. Thus, the Ptc component appears to be similar to another ERP component - the Pd - which is also thought to reflect distractor suppression. Furthermore, only the target elicited an SPCN component which likely reflects the representation of the target in visual short term memory.


Assuntos
Atenção/fisiologia , Mapeamento Encefálico , Encéfalo/fisiologia , Potenciais Evocados/fisiologia , Movimentos Oculares/fisiologia , Análise de Variância , Eletroencefalografia/métodos , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Próteses Visuais , Adulto Jovem
18.
J Cogn Neurosci ; 23(5): 1113-24, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-20146614

RESUMO

The perceptual load theory of attention posits that attentional selection occurs early in processing when a task is perceptually demanding but occurs late in processing otherwise. We used a frequency-tagged steady-state evoked potential paradigm to investigate the modality specificity of perceptual load-induced distractor filtering and the nature of neural-competitive interactions between task and distractor stimuli. EEG data were recorded while participants monitored a stream of stimuli occurring in rapid serial visual presentation (RSVP) for the appearance of previously assigned targets. Perceptual load was manipulated by assigning targets that were identifiable by color alone (low load) or by the conjunction of color and orientation (high load). The RSVP task was performed alone and in the presence of task-irrelevant visual and auditory distractors. The RSVP stimuli, visual distractors, and auditory distractors were "tagged" by modulating each at a unique frequency (2.5, 8.5, and 40.0 Hz, respectively), which allowed each to be analyzed separately in the frequency domain. We report three important findings regarding the neural mechanisms of perceptual load. First, we replicated previous findings of within-modality distractor filtering and demonstrated a reduction in visual distractor signals with high perceptual load. Second, auditory steady-state distractor signals were unaffected by manipulations of visual perceptual load, consistent with the idea that perceptual load-induced distractor filtering is modality specific. Third, analysis of task-related signals revealed that visual distractors competed with task stimuli for representation and that increased perceptual load appeared to resolve this competition in favor of the task stimulus.


Assuntos
Atenção/fisiologia , Discriminação Psicológica/fisiologia , Potenciais Evocados/fisiologia , Área de Dependência-Independência , Mascaramento Perceptivo/fisiologia , Estimulação Acústica , Análise de Variância , Eletroencefalografia , Feminino , Humanos , Masculino , Processos Mentais/fisiologia , Inibição Neural/fisiologia , Estimulação Luminosa , Valores de Referência , Adulto Jovem
19.
Psychol Aging ; 26(1): 224-31, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21058866

RESUMO

Although positive and negative images enhance the visual processing of young adults, recent work suggests that a life-span shift in emotion processing goals may lead older adults to avoid negative images. To examine this tendency for older adults to regulate their intake of negative emotional information, the current study investigated age-related differences in the perceptual boost received by probes appearing over facial expressions of emotion. Visually-evoked event-related potentials were recorded from the scalp over cortical regions associated with visual processing as a probe appeared over facial expressions depicting anger, sadness, happiness, or no emotion. The activity of the visual system in response to each probe was operationalized in terms of the P1 component of the event-related potentials evoked by the probe. For young adults, the visual system was more active (i.e., greater P1 amplitude) when the probes appeared over any of the emotional facial expressions. However, for older adults, the visual system displayed reduced activity when the probe appeared over angry facial expressions.


Assuntos
Ira , Inteligência Emocional , Percepção Visual , Adolescente , Adulto , Fatores Etários , Idoso , Ira/fisiologia , Atenção/fisiologia , Eletroencefalografia , Inteligência Emocional/fisiologia , Emoções/fisiologia , Potenciais Evocados Visuais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Percepção Visual/fisiologia , Adulto Jovem
20.
PLoS One ; 5(9)2010 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-20862327

RESUMO

BACKGROUND: Selective visual attention is the process by which the visual system enhances behaviorally relevant stimuli and filters out others. Visual attention is thought to operate through a cortical mechanism known as biased competition. Representations of stimuli within cortical visual areas compete such that they mutually suppress each others' neural response. Competition increases with stimulus proximity and can be biased in favor of one stimulus (over another) as a function of stimulus significance, salience, or expectancy. Though there is considerable evidence of biased competition within the human visual system, the dynamics of the process remain unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here, we used scalp-recorded electroencephalography (EEG) to examine neural correlates of biased competition in the human visual system. In two experiments, subjects performed a task requiring them to either simultaneously identify two targets (Experiment 1) or discriminate one target while ignoring a decoy (Experiment 2). Competition was manipulated by altering the spatial separation between target(s) and/or decoy. Both experimental tasks should induce competition between stimuli. However, only the task of Experiment 2 should invoke a strong bias in favor of the target (over the decoy). The amplitude of two lateralized components of the event-related potential, the N2pc and Ptc, mirrored these predictions. N2pc amplitude increased with increasing stimulus separation in Experiments 1 and 2. However, Ptc amplitude varied only in Experiment 2, becoming more positive with decreased spatial separation. CONCLUSIONS/SIGNIFICANCE: These results suggest that N2pc and Ptc components may index distinct processes of biased competition--N2pc reflecting visual competitive interactions and Ptc reflecting a bias in processing necessary to individuate task-relevant stimuli.


Assuntos
Potenciais Evocados , Percepção Visual , Adolescente , Atenção , Eletroencefalografia , Feminino , Humanos , Masculino , Córtex Visual/fisiologia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...