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2.
Dev Psychopathol ; 27(4 Pt 1): 1285-94, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26439074

RESUMO

Feedback negativity (FN) is an event-related potential elicited by monetary reward and loss; it is thought to relate to reward-related neural activity and has been linked to depression in children and adults. In the current study, we examined the stability of FN, and its relationship with depression in adolescents, over 2 years in 45 8- to 13-year-old children. From Time 1 to Time 2, FN in response to monetary loss and in response to monetary gain showed moderate to strong reliability (rs = .64 and .67, respectively); these relationships remained significant even when accounting for related variables. FN also demonstrated high within-session reliability. Moreover, the relationship between a blunted FN and greater depression observed at Time 1 was reproduced at Time 2, and the magnitude of FN at Time 1 predicted depressive symptomatology at Time 2. These findings are consistent with the hypothesis that FN and its relationship with depression remain consistent over the course of development, and that FN may prospectively predict later depressive symptomatology. The current results suggest that FN may be suitable as a biomarker of depressive symptoms during adolescence.


Assuntos
Variação Contingente Negativa/fisiologia , Transtorno Depressivo/fisiopatologia , Transtorno Depressivo/psicologia , Eletroencefalografia , Retroalimentação , Adolescente , Adulto , Criança , Transtorno Depressivo/diagnóstico , Retroalimentação Psicológica/fisiologia , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Recompensa
4.
J Abnorm Psychol ; 124(2): 233-45, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25643205

RESUMO

Despite the alarming increase in the prevalence of depression during adolescence, particularly among female adolescents, the pathophysiology of depression in adolescents remains largely unknown. Event-related potentials (ERPs) provide an ideal approach to investigate cognitive-affective processes associated with depression in adolescents, especially in the context of negative self-referential processing biases. In this study, healthy (n = 30) and depressed (n = 22) female adolescents completed a self-referential encoding task while ERP data were recorded. To examine cognitive-affective processes associated with self-referential processing, P1, P2, and late positive potential (LPP) responses to negative and positive words were investigated, and intracortical sources of scalp effects were probed using low-resolution electromagnetic tomography (LORETA). Additionally, we tested whether key cognitive processes (e.g., maladaptive self-view, self-criticism) previously implicated in depression related to ERP components. Relative to healthy female subjects, depressed females endorsed more negative and fewer positive words, and free recalled and recognized fewer positive words. With respect to ERPs, compared with healthy female adolescents, depressed adolescents exhibited greater P1 amplitudes following negative words, which was associated with a more maladaptive self-view and self-criticism. In both early and late LPP responses, depressed females showed greater activity following negative versus positive words, whereas healthy females demonstrated the opposite pattern. For both P1 and LPP, LORETA revealed reduced inferior frontal gyrus activity in response to negative words in depressed versus healthy female adolescents. Collectively, these findings suggest that the P1 and LPP reflect biased self-referential processing in female adolescents with depression. Potential treatment implications are discussed. (PsycINFO Database Record


Assuntos
Afeto/fisiologia , Transtorno Depressivo Maior/fisiopatologia , Potenciais Evocados/fisiologia , Córtex Pré-Frontal/fisiopatologia , Autoimagem , Adolescente , Feminino , Humanos
5.
Cogn Emot ; 29(8): 1505-16, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25559501

RESUMO

A person's ability to control their own sexual arousal is important both to reduce the risks associated with some sexual behaviours and to respond sexually with intimate partners. A lack of control over sexual urges is a proposed feature of "hypersexual disorder", though some evidence suggests that sexual desire predicts the self-regulation of sexual arousal better than hypersexuality. In the current study, a sample (N = 116) of men and women recruited from community ads viewed a series of 20-second neutral and sexual films. Before each sexual film, participants were instructed to increase their sexual arousal, decrease their sexual arousal or respond as usual. Higher levels of desire for sex with a partner consistently predicted failures to downregulate sexual arousal. Hypersexuality was unrelated. These findings replicate Winters et al.'s study and extend their findings by including upregulation, women, a new measure of hypersexuality and a higher-trial design.


Assuntos
Nível de Alerta , Libido , Autocontrole , Comportamento Sexual , Feminino , Humanos , Masculino , Adulto Jovem
6.
J Abnorm Child Psychol ; 43(5): 821-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25092483

RESUMO

The error-related negativity (ERN) is a negative deflection in the event-related potential (ERP) occurring approximately 50 ms after error commission at fronto-central electrode sites and is thought to reflect the activation of a generic error monitoring system. Several studies have reported an increased ERN in clinically anxious children, and suggest that anxious children are more sensitive to error commission--although the mechanisms underlying this association are not clear. We have previously found that punishing errors results in a larger ERN, an effect that persists after punishment ends. It is possible that learning-related experiences that impact sensitivity to errors may lead to an increased ERN. In particular, punitive parenting might sensitize children to errors and increase their ERN. We tested this possibility in the current study by prospectively examining the relationship between parenting style during early childhood and children's ERN approximately 3 years later. Initially, 295 parents and children (approximately 3 years old) participated in a structured observational measure of parenting behavior, and parents completed a self-report measure of parenting style. At a follow-up assessment approximately 3 years later, the ERN was elicited during a Go/No-Go task, and diagnostic interviews were completed with parents to assess child psychopathology. Results suggested that both observational measures of hostile parenting and self-report measures of authoritarian parenting style uniquely predicted a larger ERN in children 3 years later. We previously reported that children in this sample with anxiety disorders were characterized by an increased ERN. A mediation analysis indicated that ERN magnitude mediated the relationship between harsh parenting and child anxiety disorder. Results suggest that parenting may shape children's error processing through environmental conditioning and thereby risk for anxiety, although future work is needed to confirm this hypothesis.


Assuntos
Encéfalo/fisiopatologia , Potenciais Evocados/fisiologia , Relações Pais-Filho , Poder Familiar/psicologia , Punição/psicologia , Ansiedade/fisiopatologia , Criança , Eletroencefalografia , Feminino , Seguimentos , Humanos , Masculino , Testes Neuropsicológicos , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Autorrelato , Meio Social
7.
Soc Cogn Affect Neurosci ; 10(4): 577-83, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25062842

RESUMO

Threatening stimuli have been shown to preferentially capture attention using a range of tasks and measures. However, attentional bias to threat has not typically been found in unselected individuals using behavioral measures in the dot-probe task, one of the most common ways of examining attention to threat. The present study leveraged event-related potentials (ERPs) in conjunction with behavioral measures in the dot-probe task to examine whether more direct measures of attention might reveal an attentional bias to threat in unselected individuals. As in previous dot-probe studies, we found no evidence of an attentional bias to threat using reaction time; additionally, this measure exhibited poor internal reliability. In contrast, ERPs revealed an initial shift of attention to threat-related stimuli, reflected by the N2pc, which showed moderate internal reliability. However, there was no evidence of sustained engagement with the threat-related stimuli, as measured by the late positive potential (LPP). Together, these results demonstrate that unselected individuals do initially allocate attention to threat in the dot-probe task, and further, that this bias is better characterized by neural measures of attention than traditional behavioral measures. These results have implications for the study of attention to threat in both unselected and anxious populations.


Assuntos
Atenção/fisiologia , Eletroencefalografia , Medo/fisiologia , Desempenho Psicomotor/fisiologia , Adolescente , Adulto , Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
8.
Emotion ; 15(1): 12-16, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25151513

RESUMO

Unpredictability increases amygdala activity and vigilance toward threat. The error-related negativity (ERN) is an electrophysiological response to errors and is posited to reflect sensitivity to potential threat. The present study examined whether the ERN was modulated by predictable or unpredictable task-irrelevant auditory stimuli. Twenty-three participants completed a speeded response task designed to elicit the ERN, and were simultaneously exposed to predictable and unpredictable tone sequences. Participants retrospectively rated their anxiety to the predictable and unpredictable tone sequences and indicated which tone sequence they disliked the most. Unpredictable tones were rated as slightly more anxiety-provoking compared to predictable tones, but participants were evenly split regarding which sequence they disliked the most. Fewer errors were committed during unpredictable relative to predictable tones. Finally, the ERN--but not the correct response negativity (CRN)--was increased during unpredictable relative to predictable tones. The present study demonstrated that an unpredictable context can increase vigilance and potentiate neural processing of errors. These data suggest that an unpredictable environmental context may increase error value. Implications for understanding anxiety disorders are discussed.


Assuntos
Ansiedade/psicologia , Incerteza , Estimulação Acústica , Adolescente , Transtornos de Ansiedade/psicologia , Atenção/fisiologia , Eletrofisiologia , Feminino , Humanos , Masculino , Modelos Psicológicos , Tempo de Reação , Autorrelato
9.
Cogn Affect Behav Neurosci ; 15(1): 45-54, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25139377

RESUMO

The present experiments were designed to examine the influences of picture duration, task relevance, and affective content on neural measures of sustained engagement, as indexed by the late positive potential (LPP). Much prior work has shown that the event-related potential in and around the P3-here referred to as the early LPP-is modulated by affective content, nonaffective task relevance, and stimulus duration. However, later portions of the LPP (>1,000 ms) may represent either a return to baseline or a continued physiological process related to motivational engagement. In the present experiments, we tested whether modulation of the later LPP depends on varying motivational engagement using stimulus duration, affective content, and task relevance. The results of Experiment 1 revealed that stimulus duration modulates the sustained LPP (i.e., 1,000-2,000 ms) in response to affective, but not task-relevant, stimuli from a modified counting oddball task. The results of Experiment 2 revealed that the sustained increase in the LPP is sensitive to both emotional content and task relevance when the task requires sustained engagement with target stimuli (e.g., determining the duration of stimulus presentation). The impacts of emotional content and task relevance had additive effects on the later portion of the LPP. In sum, both emotional content and task relevance can result in a protracted increase in the later LPP. These data suggest that affective content automatically sustains engagement, whereas task relevance only prolongs engagement when it is necessary for task completion.


Assuntos
Córtex Cerebral/fisiologia , Emoções/fisiologia , Potenciais Evocados/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Análise e Desempenho de Tarefas , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
10.
Biol Psychol ; 104: 41-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25433097

RESUMO

Reward reactivity and positive emotion are key components of a theoretical, early-emerging approach motivational system, yet few studies have examined associations between positive emotion and neural reactivity to reward across development. In this multi-method prospective study, we examined the association of laboratory observations of positive emotionality (PE) at age 3 and self-reported positive affect (PA) at age 9 with an event-related potential component sensitive to the relative response to winning vs. losing money, the feedback negativity (ΔFN), at age 9 (N=381). Males had a larger ΔFN than females, and both greater observed PE at age 3 and self-reported PA at age 9 significantly, but modestly, predicted an enhanced ΔFN at age 9. Negative emotionality and behavioral inhibition did not predict ΔFN. Results contribute to understanding the neural correlates of PE and suggest that the FN and PE may be related to the same biobehavioral approach system.


Assuntos
Afeto/fisiologia , Encéfalo/fisiologia , Potenciais Evocados/fisiologia , Motivação/fisiologia , Recompensa , Criança , Pré-Escolar , Eletroencefalografia , Emoções/fisiologia , Feminino , Humanos , Masculino , Estudos Prospectivos , Autorrelato , Fatores Sexuais
11.
Psychophysiology ; 52(4): 449-59, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25327938

RESUMO

Feedback indicating monetary loss elicits an apparent negative deflection in the event-related potential (ERP) that has been referred to as the feedback error-related negativity, medial frontal negativity, feedback-related negativity, and feedback negativity-all conceptualizations that suggest a negative ERP component that is greater for loss than gain. In the current paper, I review a programmatic line of research indicating that this apparent negativity actually reflects a reward-related positivity (RewP) that is absent or suppressed following nonreward. I situate the RewP within a broader nomological network of reward processing and individual differences in sensitivity to rewards. Further, I review work linking reductions in the RewP to increased depressive symptoms and risk for depression. Finally, I discuss future directions for research on the RewP.


Assuntos
Encéfalo/fisiopatologia , Depressão/diagnóstico , Transtorno Depressivo/diagnóstico , Potenciais Evocados/fisiologia , Recompensa , Biomarcadores , Mapeamento Encefálico , Depressão/fisiopatologia , Transtorno Depressivo/fisiopatologia , Eletroencefalografia , Humanos
12.
Soc Cogn Affect Neurosci ; 10(3): 424-34, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24795435

RESUMO

Affect-modulated event-related potentials (ERPs) are increasingly used to study psychopathology and individual differences in emotion processing. Many have suggested that variation in these neural responses reflects genetically mediated risk. However, to date, no studies have demonstrated genetic contributions to affect-modulated ERPs. The present study therefore sought to examine the heritability of a range of ERPs elicited during affective picture viewing. One hundred and thirty monozygotic and 124 dizygotic twin pairs passively viewed 30 pleasant, 30 neutral and 30 unpleasant images for 6 s each. The early posterior negativity was scored for each subject; in addition, the P300/late positive potential (LPP) was scored in multiple time windows and sites. Results indicate that the centro-parietal P300 (occurring between 300 and 600 ms) is subject to substantial genetic contributions. Furthermore, variance in the P300 elicited by affective stimuli was moderately heritable even after controlling for the P300 elicited by neutral stimuli. Later and more frontal activation (i.e. between 1000 and 3000 ms) also showed evidence of heritablity. Early parietal, and perhaps later frontal portions of the P300/LPP complex, may therefore represent promising neurobehavioral markers of genetically influenced processing of emotional information.


Assuntos
Emoções/fisiologia , Potenciais Evocados/fisiologia , Percepção Social , Adulto , Mapeamento Encefálico , Eletroencefalografia , Potenciais Evocados P300/fisiologia , Feminino , Lobo Frontal/crescimento & desenvolvimento , Lobo Frontal/fisiologia , Genética Comportamental , Humanos , Individualidade , Masculino , Lobo Parietal/crescimento & desenvolvimento , Lobo Parietal/fisiologia , Estimulação Luminosa , Gêmeos Dizigóticos , Gêmeos Monozigóticos
13.
Front Psychol ; 5: 1368, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25538644

RESUMO

The dot-probe task is often considered a gold standard in the field for investigating attentional bias to threat. However, serious issues with the task have been raised. Specifically, a number of studies have demonstrated that the traditional reaction time (RT) measure of attentional bias to threat in the dot-probe task has poor internal reliability and poor test-retest reliability. In addition, although threatening stimuli capture attention in other paradigms, attentional bias to threat has not usually been found in typical research participants in the dot-probe task. However, when attention is measured in the dot-probe task with the N2pc component of the event-related potential waveform, substantial attentional orienting to threat is observed, and the internal reliability is moderate. To provide a rigorous comparison of the reliability of this N2pc measure and the conventional behavioral measure, as well as to examine the relationship of these measures to anxiety, the present study examined the N2pc in conjunction with RT in the dot-probe task in a large sample of participants (N = 96). As in previous studies, RT showed no bias to threatening images across the sample and exhibited poor internal reliability. Moreover, this measure did not relate to trait anxiety. By contrast, the N2pc revealed a significant initial shift of attention to threat, and this measure was internally reliable. However, the N2pc was not correlated with trait anxiety, indicating that it does not provide a meaningful index of individual differences in anxiety in the dot-probe task. Together, these results indicate a serious need to develop new tasks and methods to more reliably investigate attentional bias to threat and its relationship to anxiety in both clinical and non-clinical populations.

14.
Schizophr Res ; 160(1-3): 208-15, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25449716

RESUMO

BACKGROUND: Cognitive impairments and delusions are hallmarks of schizophrenia, and are thought to be due in part to abnormalities in semantic priming. The N400, a neural measure of semantic processing, is found to be reduced in schizophrenia. However, it is unclear if individuals with other psychoses (e.g., mood disorders or substance abuse with psychotic features) also show this impairment, and whether N400 reduction relates to real-world functioning and recovery. METHODS: Eighty-nine individuals from the Suffolk County Mental Health Project, a longitudinal study of first-admission psychosis, and 35 healthy adults were assessed using matched, related, and unrelated picture-word pairs to elicit the N400. Patients' real-world functioning, symptomatology, and recovery were tracked since first hospitalization; EEG assessment was completed during year 15 of the study. RESULTS: Participants with schizophrenia had slower reaction times and reduced N400 to semantically incongruent stimuli relative to healthy participants. Schizophrenia and other psychoses did not differ on N400, suggesting that N400 abnormalities characterize psychosis broadly. When grouped by recovery status, patients who remained ill had a significantly blunted N400, while those who recovered did not differ from healthy adults. Few patients with schizophrenia achieved recovery; therefore recovery results are limited to the other psychosis group. Furthermore, reduced N400 and increased reaction times correlated with greater psychotic symptoms, worse global assessment of functioning scores, unemployment, and impaired social functioning. CONCLUSIONS: Abnormalities in the N400 are not specific to schizophrenia; in addition, the N400 may be a useful neural correlate of recovery and real-world functioning across psychotic disorders.


Assuntos
Encéfalo/fisiopatologia , Potenciais Evocados/fisiologia , Transtornos Psicóticos/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Esquizofrenia/fisiopatologia , Adulto , Eletroencefalografia , Feminino , Hospitalização , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Estimulação Luminosa , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/terapia , Tempo de Reação , Leitura , Esquizofrenia/diagnóstico , Esquizofrenia/terapia , Semântica , Percepção Visual/fisiologia
15.
Dev Cogn Neurosci ; 10: 140-7, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25212683

RESUMO

Peer relationships become a major concern in adolescence, yet event-related potential (ERP) measures of reactivity to social feedback in adolescence are limited. In this pilot study, we tested a novel task to elicit reactivity to social feedback in youth. Participants (10-15 years old; 57.9% male; N=19) played a game that involved exchanging personal information with peers, voting to remove players from the game, and receiving rejection and acceptance feedback from peers. Results indicated that participants modified their voting behavior in response to peer feedback, and rejection feedback was associated with a negativity in the ERP wave compared to acceptance (i.e., the feedback negativity, FN). The FN predicted behavioral patterns, such that participants who showed greater neural reactivity to social feedback were less likely to reject co-players. Preliminary analyses suggest that the task may be a useful measure of individual differences: adolescents higher in social anxiety symptoms were less likely to reject peers and showed an enhanced FN to rejection vs. acceptance feedback, and higher depressive symptoms predicted an increased FN to rejection specifically. Results suggest that the FN elicited by social feedback may be a useful, economical neural measure of social processing across development and in clinical research.


Assuntos
Potenciais Evocados/fisiologia , Retroalimentação Psicológica , Jogos Experimentais , Rejeição em Psicologia , Adolescente , Comportamento do Adolescente , Transtornos de Ansiedade/fisiopatologia , Transtornos de Ansiedade/psicologia , Criança , Comportamento Infantil , Depressão/fisiopatologia , Depressão/psicologia , Feminino , Humanos , Individualidade , Masculino , Grupo Associado , Transtornos Fóbicos/fisiopatologia , Transtornos Fóbicos/psicologia , Projetos Piloto
16.
Dev Neurosci ; 36(3-4): 239-49, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25034314

RESUMO

Adolescence is associated with the onset of puberty, shifts in social and emotional behavior and an increased vulnerability to social anxiety disorder. These transitions coincide with changes in amygdala response to social and affective stimuli. Utilizing an emotional face-matching task, we examined amygdala response to peer-aged neutral and fearful faces in relation to puberty and social anxiety in a sample of 60 adolescent females between the ages of 8 and 15 years. We observed amygdala activation in response to both neutral and fearful faces compared to the control condition but did not observe differential amygdala activation between fearful and neutral faces. Right amygdala activity in response to neutral faces was negatively correlated with puberty and positively correlated with social anxiety, and these effects were statistically independent. Puberty and social anxiety did not relate to amygdala activation in response to fearful faces. These findings suggest that emotional differentiation between fearful and neutral faces may arise during later pubertal development and may result from decreasing sensitivity to neutral faces rather than increasing sensitivity to threatening faces. Furthermore, these findings highlight the importance of considering individual differences in social anxiety when examining the neural response to social stimuli in adolescents.


Assuntos
Tonsila do Cerebelo/fisiopatologia , Ansiedade/psicologia , Face , Puberdade/psicologia , Adolescente , Envelhecimento/psicologia , Ansiedade/fisiopatologia , Criança , Medo/psicologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Estimulação Luminosa , Meio Social
17.
J Abnorm Psychol ; 123(2): 287-297, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24886003

RESUMO

Depression appears to be characterized by reduced neural reactivity to receipt of reward. Despite evidence of shared etiologies and high rates of comorbidity between depression and anxiety, this abnormality may be relatively specific to depression. However, it is unclear whether children at risk for depression also exhibit abnormal reward responding, and if so, whether risk for anxiety moderates this association. The feedback negativity (FN) is an event-related potential component sensitive to receipt of rewards versus losses that is reduced in depression. Using a large community sample (N = 407) of 9-year-old children who had never experienced a depressive episode, we examined whether histories of depression and anxiety in their parents were associated with the FN following monetary rewards and losses. Results indicated that maternal history of depression was associated with a blunted FN in offspring, but only when there was no maternal history of anxiety. In addition, greater severity of maternal depression was associated with greater blunting of the FN in children. No effects of paternal psychopathology were observed. Results suggest that blunted reactivity to rewards versus losses may be a vulnerability marker that is specific to pure depression, but is not evident when there is also familial risk for anxiety. In addition, these findings suggest that abnormal reward responding is evident as early as middle childhood, several years prior to the sharp increase in the prevalence of depression and rapid changes in neural reward circuitry in adolescence.


Assuntos
Transtornos de Ansiedade/fisiopatologia , Filho de Pais com Deficiência/psicologia , Transtorno Depressivo/fisiopatologia , Potenciais Evocados/fisiologia , Mães/psicologia , Recompensa , Transtornos de Ansiedade/genética , Criança , Transtorno Depressivo/genética , Pai/psicologia , Feminino , Humanos , Masculino , Fatores de Risco
18.
J Abnorm Psychol ; 123(3): 557-65, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24933276

RESUMO

Generalized anxiety disorder (GAD) may be characterized by emotion regulation deficits attributable to an imbalance between top-down (i.e., goal-driven) and bottom-up (i.e., stimulus-driven) attention. In prior work, these attentional processes were examined by presenting unpleasant and neutral pictures within a working memory paradigm. The late positive potential (LPP) measured attention toward task-irrelevant pictures. Results from this prior work showed that working memory load reduced the LPP across participants; however, this effect was attenuated for individuals with greater self-reported state anxiety, suggesting reduced top-down control. In the current study, the same paradigm was used with 106 medication-free female participants-71 with GAD and 35 without GAD. Unpleasant pictures elicited larger LPPs, and working memory load reduced the picture-elicited LPP. Compared with healthy controls, participants with GAD showed large LPPs to unpleasant pictures presented under high working memory load. Self-reported symptoms of anhedonic depression were related to a reduced effect of working memory load on the LPP elicited by neutral pictures. These results indicate that individuals with GAD show less flexible modulation of attention when confronted with unpleasant stimuli. Furthermore, among those with GAD, anhedonic depression may broaden attentional deficits to neutral distracters.


Assuntos
Transtornos de Ansiedade/fisiopatologia , Atenção/fisiologia , Encéfalo/fisiopatologia , Emoções/fisiologia , Potenciais Evocados/fisiologia , Memória de Curto Prazo/fisiologia , Adolescente , Adulto , Transtornos de Ansiedade/psicologia , Cognição/fisiologia , Eletroencefalografia , Feminino , Humanos , Pessoa de Meia-Idade , Testes Neuropsicológicos , Tempo de Reação/fisiologia , Adulto Jovem
19.
Brain Cogn ; 87: 134-9, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24735733

RESUMO

The feedback negativity (FN) is an event-related potential component which is typically conceptualized as a negativity in response to losses that is absent in response to gains. However, there is also evidence that variation in the FN reflects the neural response to gains. The present study sought to explore these possibilities by manipulating the context in which loss and gain feedback was presented in a straightforward gambling task. In half the blocks, participants could win or lose money (Value condition), and in half the blocks, participants could not win or lose any money (No Value condition). The degree to which losses and gains were differentiated from one another (i.e., the ΔFN) was greater in the Value condition than in the No Value condition. Furthermore, though the responses to loss feedback and gain feedback were each enhanced in the Value condition relative to the No-Value condition, the effect of the monetary manipulation was substantially larger for the positivity to gains than the negativity to losses. This is consistent with the notion that the FN might reflect two independent processes, but that variation in the FN depends more upon the response to rewards than losses.


Assuntos
Encéfalo/fisiologia , Potenciais Evocados Visuais , Retroalimentação Psicológica/fisiologia , Recompensa , Adolescente , Comportamento de Escolha/fisiologia , Eletroencefalografia , Feminino , Humanos , Masculino , Adulto Jovem
20.
J Vis ; 14(3): 8, 2014 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-24599946

RESUMO

The visual-search literature has assumed that the top-down target representation used to guide search resides in visual working memory (VWM). We directly tested this assumption using contralateral delay activity (CDA) to estimate the VWM load imposed by the target representation. In Experiment 1, observers previewed four photorealistic objects and were cued to remember the two objects appearing to the left or right of central fixation; Experiment 2 was identical except that observers previewed two photorealistic objects and were cued to remember one. CDA was measured during a delay following preview offset but before onset of a four-object search array. One of the targets was always present, and observers were asked to make an eye movement to it and press a button. We found lower magnitude CDA on trials when the initial search saccade was directed to the target (strong guidance) compared to when it was not (weak guidance). This difference also tended to be larger shortly before search-display onset and was largely unaffected by VWM item-capacity limits or number of previews. Moreover, the difference between mean strong- and weak-guidance CDA was proportional to the increase in search time between mean strong-and weak-guidance trials (as measured by time-to-target and reaction-time difference scores). Contrary to most search models, our data suggest that trials resulting in the maintenance of more target features results in poor search guidance to a target. We interpret these counterintuitive findings as evidence for strong search guidance using a small set of highly discriminative target features that remain after pruning from a larger set of features, with the load imposed on VWM varying with this feature-consolidation process.


Assuntos
Sinais (Psicologia) , Memória de Curto Prazo/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Percepção Visual/fisiologia , Adulto , Movimentos Oculares/fisiologia , Humanos , Tempo de Reação , Adulto Jovem
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