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1.
J Cogn Neurosci ; 22(3): 457-73, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19301990

RESUMO

In social interactions, it is often necessary to rapidly encode the association between visually presented faces and auditorily presented names. The present study used event-related potentials to examine the neural correlates of associative encoding for multimodal face-name pairs. We assessed study-phase processes leading to high-confidence recognition of correct pairs (and consistent rejection of recombined foils) as compared to lower-confidence recognition of correct pairs (with inconsistent rejection of recombined foils) and recognition failures (misses). Both high- and low-confidence retrieval of face-name pairs were associated with study-phase activity suggestive of item-specific processing of the face (posterior inferior temporal negativity) and name (fronto-central negativity). However, only those pairs later retrieved with high confidence recruited a sustained centro-parietal positivity that an ancillary localizer task suggested may index an association-unique process. Additionally, we examined how these processes were influenced by massed repetition, a mnemonic strategy commonly employed in everyday situations to improve face-name memory. Differences in subsequent memory effects across repetitions suggested that associative encoding was strongest at the initial presentation, and thus, that the initial presentation has the greatest impact on memory formation. Yet, exploratory analyses suggested that the third presentation may have benefited later memory by providing an opportunity for extended processing of the name. Thus, although encoding of the initial presentation was critical for establishing a strong association, the extent to which processing was sustained across subsequent immediate (massed) presentations may provide additional encoding support that serves to differentiate face-name pairs from similar (recombined) pairs by providing additional encoding opportunities for the less dominant stimulus dimension (i.e., name).


Assuntos
Aprendizagem por Associação/fisiologia , Córtex Cerebral/fisiologia , Potenciais Evocados/fisiologia , Adolescente , Adulto , Percepção Auditiva/fisiologia , Mapeamento Encefálico , Face , Feminino , Humanos , Masculino , Nomes , Reconhecimento Visual de Modelos/fisiologia , Reconhecimento Psicológico/fisiologia , Reforço Psicológico , Adulto Jovem
2.
Front Psychol ; 11: 2094, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32982858

RESUMO

Rumination is a recurrent and repetitive manner of thinking that can be triggered by blockage of personally relevant goals, creating a temporary state of abstract and evaluative self-focus. Particularly when focused on passive "brooding" over one's problems and feelings, however, rumination can increase negative affect, interfere with problem-solving, and, through a negative feedback cycle, become a chronic trait-like style of responding to personal challenges, particularly in women. Given the pervasiveness of rumination and its potential impact on cognitive processes and emotional states, the present study asks how it impacts attention to feedback that either reminds individuals of goal-state discrepancies (reminders of errors) or could help to remediate them (corrective information). Using eye-tracking, we examined both state and trait rumination effects on overt measures of attention [first fixation duration (FFD) and total fixation duration (TFD)] during simultaneous presentation of these two types of feedback following failed attempts to answer challenging verbal general knowledge questions (average accuracy ∼30%). After a pre-induction baseline, we induced either a state of rumination using a series of writing exercises centered on the description of an unresolved academic concern or a state of distraction by centering writing on the description of a neutral school day. Within our women-only sample, the Rumination condition, which writing analysis showed was dominated by moody brooding, resulted in some evidence for increased initial dwell time (FFD) on reminders of incorrect answers, while the Distraction condition, which did not elicit any rumination during writing, resulted in increased FFD on the correct answer. Trait brooding augmented the expression of the more negative, moody brooding content in the writing samples of both Induction conditions, but only influenced TFD measures of gaze duration and only during the pre-induction baseline, suggesting that once the inductions activated rumination or distraction states, these suppressed the trait effects in this sample. These results provide some support for attentional-bias models of rumination (attentional scope model, impaired disengagement hypothesis) and have implications for how even temporary states of rumination or distraction might impact processing of academic feedback under conditions of challenge and failure.

3.
Front Psychol ; 10: 1179, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31293466

RESUMO

Previous research has shown that the prospect of attaining a reward can promote task-engagement, up-regulate attention toward reward-relevant information, and facilitate enhanced encoding of new information into declarative memory. However, past research on reward-based enhancement of declarative memory has focused primarily on paradigms in which rewards are contingent upon accurate responses. Yet, findings from test-enhanced learning show that making errors can also be useful for learning if those errors represent effortful retrieval attempts and are followed by corrective feedback. Here, we used a challenging general knowledge task to examine the effects of explicitly rewarding retrieval effort, defined as a semantically plausible answer to a question (referenced to a semantic knowledge database www.mangelslab.org/bknorms), regardless of response accuracy. In particular, we asked whether intermittent rewards following effortful incorrect responses facilitated learning from corrective feedback as measured by incidental learning outcomes on a 24-48 h delayed retest. Given that effort-contingent extrinsic rewards represent the intersection between an internal locus of control and competency, we compared participants in this "Effort" group to three other groups in a between-subjects design: a Luck group that framed rewards as related to participant-chosen lottery numbers (reward with internal control, not competence-based), a random Award group that framed rewards as computer generated (no control, not competence-based), and a Control group with no reward, but matched on all other task features. Both men and women in the Effort group showed increased self-reports of concentration and positive feelings following the receipt of rewards, as well as subjective effort on the retest, compared to the Control group. However, only women additionally exhibited performance benefits of effort framing on error correction. These benefits were found for both rewarded and non-rewarded trials, but only for correction of low confidence errors, suggesting that effort-contingent rewards produced task-level changes in motivation to learn less familiar information in women, rather than trial-level influences in encoding or consolidation. The Luck and Award groups did not demonstrate significant motivational or behavioral benefits for either gender. These results suggest that both reward context and gender are important factors contributing to the effectiveness of rewards as tools to enhance learning from errors.

4.
Memory ; 16(8): 873-95, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18821167

RESUMO

According to the distractor-selection hypothesis (Mulligan, 2003), dividing attention during encoding reduces perceptual priming when responses to non-critical (i.e., distractor) stimuli are selected frequently and simultaneously with critical stimulus encoding. Because direct support for this hypothesis comes exclusively from studies using familiar word stimuli, the present study tested whether the predictions of the distractor-selection hypothesis extend to perceptual priming of unfamiliar visual objects using the possible/impossible object decision test. Consistent with the distractor-selection hypothesis, Experiments 1 and 2 found no reduction in priming when the non-critical stimuli were presented infrequently and non-synchronously with the critical target stimuli, even though explicit recognition memory was reduced. In Experiment 3, non-critical stimuli were presented frequently and simultaneously during encoding of critical stimuli; however, no decrement in priming was detected, even when encoding time was reduced. These results suggest that priming in the possible/impossible object decision test is relatively immune to reductions in central attention and that not all aspects of the distractor-selection hypothesis generalise to priming of unfamiliar visual objects. Implications for theoretical models of object decision priming are discussed.


Assuntos
Atenção , Sinais (Psicologia) , Memória/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Análise de Variância , Cognição/fisiologia , Tomada de Decisões/fisiologia , Feminino , Percepção de Forma/fisiologia , Humanos , Masculino , Testes Psicológicos , Desempenho Psicomotor , Adulto Jovem
5.
Soc Neurosci ; 13(4): 451-470, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-28724323

RESUMO

For individuals high in Rejection Sensitivity (RS), a learned orientation to anxiously expect rejection from valued others, negative feedback from social sources may disrupt engagement with learning opportunities, impeding recovery from mistakes. One context in which this disruption may be particularly pronounced is among women high in RS following evaluation by a male in authority. To investigate this prediction, 40 college students (50% female) answered general knowledge questions followed by immediate performance feedback and the correct answer while we recorded event-related potentials. Error correction was measured with a subsequent surprise retest. Performance feedback was either nonsocial (asterisk/tone) or social (male professor's face/voice). Attention and learning were indexed respectively by the anterior frontal P3a (attentional orienting) and a set of negative-going waveforms over left inferior-posterior regions associated with successful encoding. For women, but not men, higher RS scores predicted poorer error correction in the social condition. A path analysis suggested that, for women, high RS disrupted attentional orienting to the social-evaluative performance feedback, which affected subsequent memory for the correct answer by reducing engagement with learning opportunities. These results suggest a mechanism for how social feedback may impede learning among women who are high in RS.


Assuntos
Encéfalo/fisiologia , Retroalimentação Psicológica/fisiologia , Aprendizagem/fisiologia , Personalidade/fisiologia , Percepção Social , Afeto/fisiologia , Ansiedade/fisiopatologia , Atenção/fisiologia , Eletroencefalografia , Potenciais Evocados , Feminino , Humanos , Masculino , Caracteres Sexuais , Adulto Jovem
6.
Neuropsychologia ; 45(9): 2038-50, 2007 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-17382975

RESUMO

Valid cueing has been shown to accelerate target identification and improve decision accuracy. However, the precise nature and extent to which biasing influences the successive stages of target processing remain unclear. The present event-related potential (ERP) study used a "hybrid" task that combined features of standard cued-attention and task-switching paradigms in order to explore the effects of expectation on both identification and categorization of centrally presented stimuli. Subjects made semantic judgments (living/nonliving) on word targets ("bunny"), and perceptual judgments (right/left) on arrow targets ("<<<<<"). Target expectancy was manipulated using cues that were valid (60 percent of trials), invalid (10 percent), or neutral (30 percent). Invalidly cued targets required task-set switching before categorization could commence, and resulted in RT costs relative to validly or neutrally cued targets. Additional benefits from valid-cueing were only observed for word targets. Invalid cueing of both arrow and word targets modulated early posterior visual potentials (P1/N1) and elicited a subsequent anterior P3a (270 ms). The temporal relationship of these effects suggests that the P3a indexed domain-general task-set switching processes recruited in response to the detection of unexpected perceptual information. Subsequent to the P3a and immediately preceding the behavioral response, validly cued targets elicited enhanced stimulus-specific waveforms (arrows: parietal positivity [P290], words: inferior temporal negativity [late ITN: 400-600 ms]). The degree of neural enhancement relative to the invalid and neutral conditions mirrored the magnitude of corresponding RT benefits, suggesting that these waveforms indexed categorization, decision processes or both. Together, these results suggest that valid cueing increases the neural efficiency of initial stimulus identification, facilitating transmission of information to subsequent categorization stages, where increased neural activity leads to behavioral benefits.


Assuntos
Sinais (Psicologia) , Discriminação Psicológica/fisiologia , Potenciais Evocados Visuais/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Semântica , Adulto , Atenção , Mapeamento Encefálico , Eletroencefalografia , Feminino , Humanos , Julgamento/fisiologia , Masculino , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia
7.
Neuropsychologia ; 44(10): 1962-77, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16580700

RESUMO

Patients with Parkinson's disease (PD), a degenerative disorder primarily affecting the nigrostriatal dopamine system, exhibit deficits in selecting task-relevant stimuli in the presence of irrelevant stimuli, such as in visual search tasks. However, results from previous studies suggest that these deficits may vary as a function of whether selection must rely primarily on the "bottom-up" salience of the target relative to background stimuli, or whether "top-down" information about the identity of the target is available to bias selection. In the present study, moderate-to-severe medicated PD patients and age-matched controls were tested on six visual search tasks that systematically varied the relationship between bottom-up target salience (feature search, noisy feature search, conjunction search) and top-down target knowledge (Target Known versus Target Unknown). Comparison of slope and intercepts of the RT x set size function provided information about the efficiency of search and non-search (e.g., decision, response) components, respectively. Patients exhibited higher intercepts than controls as bottom-up target salience decreased, however these deficits were disproportionately larger under Target Unknown compared to Target Known conditions. Slope differences between PD and controls were limited to the Target Unknown Conjunction condition, where patients exhibited a shallower slope in the target absent condition, indicating that they terminated search earlier. These results suggest that under conditions of high background noise, medicated PD patients were primarily impaired in decision and/or response processes downstream from the target search itself, and that the deficit was attenuated when top-down information was available to guide selection of the target signal.


Assuntos
Doença de Parkinson/fisiopatologia , Reconhecimento Visual de Modelos/fisiologia , Detecção de Sinal Psicológico/fisiologia , Percepção Visual/fisiologia , Idoso , Estudos de Casos e Controles , Discriminação Psicológica/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tempo de Reação/fisiologia
8.
J Exp Psychol Learn Mem Cogn ; 32(2): 230-48, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16569143

RESUMO

This study was designed to differentiate between structural description and bias accounts of performance in the possible/impossible object-decision test. Two event-related potential (ERP) studies examined how the visual system processes structurally possible and impossible objects. Specifically, the authors investigated the effects of object repetition on a series of early posterior components during structural (Experiment 1) and functional (Experiment 2) encoding and the relationship of these effects to behavioral measures of priming. In both experiments, the authors found repetition enhancement of the posterior N1 and N2 for possible objects only. In addition, the magnitude of the N1 repetition effect for possible objects was correlated with priming for possible objects. Although the behavioral results were more ambiguous, these ERP results fail to support bias models that hold that both possible and impossible objects are processed similarly in the visual system. Instead, they support the view that priming is supported by a structural description system that encodes the global 3-dimensional structure of an object.


Assuntos
Tomada de Decisões/fisiologia , Aprendizagem por Discriminação/fisiologia , Potenciais Evocados/fisiologia , Modelos Psicológicos , Reconhecimento Visual de Modelos/fisiologia , Adolescente , Adulto , Análise de Variância , Mapeamento Encefálico , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Memória/fisiologia , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia
9.
J Gen Psychol ; 133(1): 37-65, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16475668

RESUMO

Enactment may improve memory for verb phrases by facilitating episodic integration of object-action components into a unitized whole. It is unclear, however, whether the influence of enactment on episodic integration is related to or independent of the strength of the preexisting semantic relationship between components. To address this issue, the authors examined the influence of enactment on memory for lists of semantically related object-action phrases ("Put money in the wallet") and semantically unrelated phrases created by repairing these objects and actions to make phrases that were unusual but still were possible to perform ("String a thread through the wallet," "Put money in the napkin"). As such, phrases in the related and unrelated lists were matched for familiarity of the individual components and differed only in the associative strength of the object-action relationship. Although verbatim recall of unrelated lists was poorer under standard verbal encoding conditions, enactment succeeded in bringing performance to the level of related lists, indicating that enactment's influence on episodic integration was independent of the semantic relatedness of the object and action components. Analysis of partial recall errors (accurate recall of only one component) suggested that enactment benefited recall in the unrelated lists by improving memory for the action and reducing fragmentation of the association, providing further support for the unitization view. This pattern of results was replicated in normal older adults, a population that exhibits particular difficulty with episodic memory for unrelated associations. The cognitive mechanisms by which enactment may improve episodic integration in both younger and older adults are discussed.


Assuntos
Envelhecimento/psicologia , Aprendizagem por Associação , Idioma , Rememoração Mental , Reconhecimento Psicológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cognição , Feminino , Humanos , Masculino , Semântica
10.
Brain Sci ; 6(1)2016 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-26901231

RESUMO

Rumination is a trait response to blocked goals that can have positive or negative outcomes for goal resolution depending on where attention is focused. Whereas "moody brooding" on affective states may be maladaptive, especially for females, "reflective pondering" on concrete strategies for problem solving may be more adaptive. In the context of a challenging general knowledge test, we examined how Brooding and Reflection rumination styles predicted students' subjective and event-related responses (ERPs) to negative feedback, as well as use of this feedback to rebound from failure on a later surprise retest. For females only, Brooding predicted unpleasant feelings after failure as the task progressed. It also predicted enhanced attention to errors through both bottom-up and top-down processes, as indexed by increased early (400-600 ms) and later (600-1000 ms) late positive potentials (LPP), respectively. Reflection, despite increasing females' initial attention to negative feedback (i.e., early LPP), as well as both genders' recurring negative thoughts, did not result in sustained top-down attention (i.e., late LPP) or enhanced negative feelings toward errors. Reflection also facilitated rebound from failure in both genders, although Brooding did not hinder it. Implications of these gender and time-related rumination effects for learning in challenging academic situations are discussed.

11.
Neuroreport ; 16(2): 117-22, 2005 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-15671858

RESUMO

Neuroimaging studies have suggested that the frontal and parietal lobes may be important for the process by which we remember information. However, little is known about how these regions exchange information during memory retrieval. We measured EEG synchronisation in the gamma-band (25-55 Hz), a putative measure of functional coupling between brain regions, while human subjects performed a recognition memory task. Fronto-parietal synchrony was increased for true old memories relative to false memories and new items. Our results suggest that synchronization of neuronal responses in the gamma-band may be an important mechanism by which frontal and parietal regions exchange information during the recognition of past events.


Assuntos
Lobo Frontal/fisiologia , Lobo Parietal/fisiologia , Reconhecimento Psicológico/fisiologia , Adulto , Mapeamento Encefálico/métodos , Eletroencefalografia/métodos , Feminino , Humanos , Desempenho Psicomotor/fisiologia
12.
Neuropsychology ; 19(1): 54-65, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15656763

RESUMO

The authors explored the effect of Parkinson's disease (PD) on the generation and maintenance of response readiness in a simple reaction time task. They compared performance of idiopathic PD patients without dementia, age-matched controls, and younger controls over short (1-, 3-, and 6-s) and long (12- and 18-s) foreperiod intervals. After each trial, the authors probed memory for visual information that also had to be maintained during the trial interval. Patients and controls did not differ overall in their ability to maintain readiness over long delays. However, within the PD group only, errors in maintaining visual information were correlated with difficulty in maintaining readiness, suggesting that systems impaired in PD may facilitate the maintenance of processing in both motor and cognitive domains.


Assuntos
Envelhecimento/fisiologia , Memória/fisiologia , Doença de Parkinson/fisiopatologia , Tempo de Reação/fisiologia , Leitura , Adulto , Fatores Etários , Idoso , Análise de Variância , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Análise de Regressão , Fatores de Tempo , Percepção Visual/fisiologia
13.
Neuropsychologia ; 40(13): 2369-85, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12417466

RESUMO

Eleven patients with mild traumatic brain injury (MTBI) and 13 patients with moderate-to-severe TBI (STBI) were compared to 10 matched controls on episodic memory for pictorial scene-object associations (e.g. kitchen-bread) and a range of standardized neuropsychological tests of memory and frontal-lobe functions. We tested the hypothesis that deficits in episodic memory result from impaired attentional resources and/or strategic control by manipulating attentional load at encoding (focused versus divided attention) and environmental support at retrieval (free recall and recalled cued by scene versus recognition of object and scene). Patients with TBI were disproportionately affected by the divided attention manipulation, but this effect was modulated by injury severity and encoding strategy. Overall, MTBI patients were impaired only when items were encoded under divided attention, indicating memory deficits that were secondary to deficits in the executive control. STBI patients could be differentiated into two distinct functional subgroups based on whether they favored a strategy of attending to the encoding or digit-monitoring task. The subgroup favoring the digit-monitoring task demonstrated deficits in the focused attention condition, and disproportionate memory deficits in the divided attention condition. In contrast, the subgroup favoring the encoding task demonstrated intact performance across all memory measures, regardless of attentional load, and despite remarkable similarity to the other STBI subgroup on demographic, neuropsychological, and acute injury severity measures. We discuss these outcome differences in terms of the relationship between strategy and executive control and highlight the need for more sensitive anatomical and behavioral measurement at both acute and chronic stages of injury.


Assuntos
Atenção , Lesões Encefálicas/complicações , Transtornos da Memória/diagnóstico , Transtornos da Memória/etiologia , Adulto , Encéfalo/fisiopatologia , Lesões Encefálicas/diagnóstico por imagem , Lesões Encefálicas/fisiopatologia , Sinais (Psicologia) , Feminino , Humanos , Escala de Gravidade do Ferimento , Masculino , Transtornos da Memória/fisiopatologia , Rememoração Mental , Testes Neuropsicológicos , Reconhecimento Psicológico , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X
14.
Brain Res Cogn Brain Res ; 17(3): 793-817, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14561464

RESUMO

Event-related potentials (ERPs) were used to investigate the cognitive and neural substrates of immediate and 1-week delayed error correction in a semantic retrieval task. In particular, we pursued the basis for the 'hypercorrection' effect, the finding that erroneous responses endorsed as correct with high confidence are more likely than low-confidence errors to be corrected at retest. Presentation of negative, but not positive feedback about the accuracy of one's response elicited a fronto-central negativity, similar to the ERN, which was somewhat sensitive to the degree to which negative feedback violated expectation. A fronto-central positivity, similar to the novelty-P3/P3a, more generally indexed detection of a metamemory error, given that it was larger in conditions of high metamemory mismatch than in conditions of low metamemory mismatch, irrespective of absolute task accuracy. For errors, amplitude of the fronto-central positivity, but not the preceding negativity, was correlated with correction on an immediate retest. Thus, to the extent that the fronto-central positivity indexes an orienting response, this response appears to facilitate initial encoding processes, but does not play a key role in memory consolidation. In contrast, a broad, inferior-temporal negativity occurring 300-600 ms after presentation of the correct answer was sensitive to subsequent memory performance at both immediate and delayed retests, but only for answers containing familiar semantic information. This negativity may reflect processes involved in the formation of an association between the question and pre-existing semantic information.


Assuntos
Rememoração Mental/fisiologia , Neurônios/fisiologia , Desempenho Psicomotor/fisiologia , Semântica , Adulto , Atitude , Eletroencefalografia , Potenciais Evocados/fisiologia , Retroalimentação Psicológica/fisiologia , Feminino , Humanos , Masculino
15.
Soc Cogn Affect Neurosci ; 7(2): 230-41, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21252312

RESUMO

Gender-based stereotypes undermine females' performance on challenging math tests, but how do they influence their ability to learn from the errors they make? Females under stereotype threat or non-threat were presented with accuracy feedback after each problem on a GRE-like math test, followed by an optional interactive tutorial that provided step-wise problem-solving instruction. Event-related potentials tracked the initial detection of the negative feedback following errors [feedback related negativity (FRN), P3a], as well as any subsequent sustained attention/arousal to that information [late positive potential (LPP)]. Learning was defined as success in applying tutorial information to correction of initial test errors on a surprise retest 24-h later. Under non-threat conditions, emotional responses to negative feedback did not curtail exploration of the tutor, and the amount of tutor exploration predicted learning success. In the stereotype threat condition, however, greater initial salience of the failure (FRN) predicted less exploration of the tutor, and sustained attention to the negative feedback (LPP) predicted poor learning from what was explored. Thus, under stereotype threat, emotional responses to negative feedback predicted both disengagement from learning and interference with learning attempts. We discuss the importance of emotion regulation in successful rebound from failure for stigmatized groups in stereotype-salient environments.


Assuntos
Emoções/fisiologia , Potenciais Evocados/fisiologia , Aprendizagem/fisiologia , Estereotipagem , Mulheres/psicologia , Logro , Nível de Alerta/fisiologia , Atenção/fisiologia , Retroalimentação , Feminino , Identidade de Gênero , Humanos , Individualidade , Matemática/métodos , Resolução de Problemas/fisiologia , Adulto Jovem
16.
Neuroreport ; 19(17): 1695-8, 2008 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-18981819

RESUMO

Event-related potentials associated with disqualifying false memories were recorded in a novel false memory paradigm in which participants were given feedback during an initial recognition test, followed by a surprise retest where true recollection of feedback could be used to disqualify previous errors. Two spatiotemporally distinct components emerged: a parietal left-lateralized positivity indexing the recollection of feedback (500-900 ms), which was subsequently joined by a bilateral frontocentral positivity (700-900 ms) associated with rejection of the erroneous response and/or switching to the correct response. This latter effect seems to be distinct from the more anterior and later right frontal positivity typically associated with postretrieval monitoring.


Assuntos
Córtex Cerebral/fisiologia , Potenciais Evocados Visuais/fisiologia , Retroalimentação Psicológica/fisiologia , Rememoração Mental/fisiologia , Mapeamento Encefálico/métodos , Pré-Escolar , Eletroencefalografia/métodos , Feminino , Lobo Frontal/fisiologia , Lateralidade Funcional/fisiologia , Humanos , Aprendizagem/fisiologia , Masculino , Testes Neuropsicológicos/estatística & dados numéricos , Lobo Parietal/fisiologia , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Reconhecimento Psicológico/fisiologia , Percepção Espacial/fisiologia , Percepção do Tempo/fisiologia , Comportamento Verbal/fisiologia , Adulto Jovem
17.
Brain Res ; 1176: 92-102, 2007 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-17889835

RESUMO

Advance preparation has been shown to improve the efficiency of conflict resolution. Yet, with little empirical work directly linking preparatory neural activity to the performance benefits of advance cueing, it is not clear whether this relationship results from preparatory activation of task-specific networks, or from activity associated with general alerting processes. Here, fMRI data were acquired during a spatial Stroop task in which advance cues either informed subjects of the upcoming relevant feature of conflict stimuli (spatial or semantic) or were neutral. Informative cues decreased reaction time (RT) relative to neutral cues, and cues indicating that spatial information would be task-relevant elicited greater activity than neutral cues in multiple areas, including right anterior prefrontal and bilateral parietal cortex. Additionally, preparatory activation in bilateral parietal cortex and right dorsolateral prefrontal cortex predicted faster RT when subjects responded to spatial location. No regions were found to be specific to semantic cues at conventional thresholds, and lowering the threshold further revealed little overlap between activity associated with spatial and semantic cueing effects, thereby demonstrating a single dissociation between activations related to preparing a spatial versus semantic task-set. This relationship between preparatory activation of spatial processing networks and efficient conflict resolution suggests that advance information can benefit performance by leading to domain-specific biasing of task-relevant information.


Assuntos
Atenção/fisiologia , Córtex Cerebral/fisiologia , Cognição/fisiologia , Tomada de Decisões/fisiologia , Potenciais Evocados/fisiologia , Processos Mentais/fisiologia , Adolescente , Adulto , Viés , Mapeamento Encefálico , Córtex Cerebral/anatomia & histologia , Sinais (Psicologia) , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/anatomia & histologia , Rede Nervosa/fisiologia , Testes Neuropsicológicos , Desempenho Psicomotor/fisiologia , Semântica , Percepção Espacial/fisiologia , Adulto Jovem
18.
J Cogn Neurosci ; 18(7): 1120-32, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16839286

RESUMO

Attention is a necessary condition for the formation of new episodic memories, yet little is known about how dissociable attentional mechanisms for "top-down" and "bottom-up" orienting contribute to encoding. Here, subjects performed an intentional encoding task in which to-be-learned items were interspersed with irrelevant stimuli such that subjects could anticipate the appearance of some study items but not others. Subjects were more likely to later remember stimuli whose appearance was predictable at encoding. Electroencephalographic data were acquired during the study phase of the experiment to assess how synchronous neural activity related to later memory for predictable stimuli (to which attention could be oriented in a top-down fashion) and unpredictable stimuli (which rely to a greater extent on bottom-up attentional orienting). Over left frontal regions, gamma-band activity (25-55 Hz) early (approximately 150 msec) in the epoch was a robust predictor of later memory for predictable items, consistent with an emerging view that links high-frequency neural synchrony to top-down attention. By contrast, later (approximately 400 msec) theta-band activity (4-8 Hz) over the left and midline frontal cortex predicted subsequent memory for unpredictable items, suggesting a role in bottom-up attentional orienting. These results reveal for the first time the contribution of dissociable attentional mechanisms to successful encoding and contribute to a growing literature dedicated to understanding the role of neural synchrony in cognition.


Assuntos
Atenção/fisiologia , Eletroencefalografia/métodos , Rede Nervosa/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Valor Preditivo dos Testes
19.
J Cogn Neurosci ; 18(6): 1004-17, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16839306

RESUMO

Top-down attentional control is required when subjects must attend to one of multiple conflicting stimulus features, such as in the Stroop task. Performance may be improved when such control is implemented in advance of stimulus presentation, yet few studies have examined this issue. Our investigation employed a spatial Stroop task with a manual response, allowing us to focus on the effects of preparatory attention on verbal processing when it is the less automatic attribute. A letter cue (P or W) presented for 2200 msec instructed subjects to respond on the basis of the position or meaning of a word (up, down, left, right) placed in an incongruent position relative to center. Event-related potentials recorded during pre- and poststimulus periods were analyzed as a function of reaction time to the target stimulus (fast vs. slow) in order to differentiate neural activity associated with more or less successful implementation of control. During the prestimulus period, fast responses to subsequent targets were associated with enhanced slow-wave activity over right frontal and bilateral central-parietal regions. During the poststimulus period, fast word trials were uniquely associated with an enhanced inferior temporal negativity (ITN) from 200 to 600 msec. More importantly, a correlation between frontal prestimulus activity and the poststimulus ITN suggested that frontal preparatory activity played a role in facilitating conceptual processing of the verbal stimulus when it arrived, providing an important link between preparatory attention and mechanisms that improve performance in the face of conflict.


Assuntos
Atenção/fisiologia , Mapeamento Encefálico , Potenciais Evocados/fisiologia , Percepção Espacial/fisiologia , Adolescente , Adulto , Córtex Cerebral/fisiologia , Sinais (Psicologia) , Eletrodos , Eletroencefalografia/métodos , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Memória de Curto Prazo/fisiologia , Testes Neuropsicológicos/estatística & dados numéricos , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Comportamento Verbal/fisiologia
20.
J Int Neuropsychol Soc ; 12(4): 493-501, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16981601

RESUMO

Subject-performed tasks (SPTs) may facilitate the deficit in associative learning among individuals with amnestic mild cognitive impairment (aMCI) by inducing episodic integration of object-action associations. To test this hypothesis, we examined free recall and recognition memory following enactment and verbal encoding in healthy elderly controls and individuals with aMCI. Study lists contained either semantically integrated ("Bounce the ball") or crossed object-action commands, in which episodic and semantic associations were placed in opposition ("Pet the compass"). Associative learning was indeed better after SPT than verbal encoding and with integrated relative to crossed lists for the aMCI group, as it was for controls. Moreover, the degree to which SPTs reduced the semantic interference inherent in the crossed conditions was equivalent for the two groups. The results showed that enactment facilitates formation of episodic associations, even when not supported by preexisting semantic knowledge, and even among individuals who have particular difficulty forming new associations.


Assuntos
Amnésia/diagnóstico , Aprendizagem por Associação , Transtornos Cognitivos/diagnóstico , Adulto , Amnésia/epidemiologia , Transtornos Cognitivos/epidemiologia , Discriminação Psicológica , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Reconhecimento Psicológico , Semântica , Índice de Gravidade de Doença
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