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1.
J Cogn Neurosci ; 24(7): 1571-83, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22452558

RESUMO

Despite the intuition that strongly held beliefs are particularly difficult to change, the data on error correction indicate that general information errors that people commit with a high degree of belief are especially easy to correct. This finding is called the hypercorrection effect. The hypothesis was tested that the reason for hypercorrection stems from enhanced attention and encoding that results from a metacognitive mismatch between the person's confidence in their responses and the true answer. This experiment, which is the first to use imaging to investigate the hypercorrection effect, provided support for this hypothesis, showing that both metacognitive mismatch conditions-that in which high confidence accompanies a wrong answer and that in which low confidence accompanies a correct answer-revealed anterior cingulate and medial frontal gyrus activations. Only in the high confidence error condition, however, was an error that conflicted with the true answer mentally present. And only the high confidence error condition yielded activations in the right TPJ and the right dorsolateral pFC. These activations suggested that, during the correction process after error commission, people (1) were entertaining both the false belief as well as the true belief (as in theory of mind tasks, which also manifest the right TPJ activation) and (2) may have been suppressing the unwanted, incorrect information that they had, themselves, produced (as in think/no-think tasks, which also manifest dorsolateral pFC activation). These error-specific processes as well as enhanced attention because of metacognitive mismatch appear to be implicated.


Assuntos
Biorretroalimentação Psicológica/fisiologia , Encéfalo/fisiologia , Cultura , Processos Mentais/fisiologia , Desempenho Psicomotor/fisiologia , Biorretroalimentação Psicológica/métodos , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia , Adulto Jovem
2.
Brain Cogn ; 78(3): 248-56, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22305924

RESUMO

Effects of dual-responding on tracking performance after 49-h of sleep deprivation (SD) were evaluated behaviorally and with functional magnetic resonance imaging (fMRI). Continuous visuomotor tracking was performed simultaneously with an intermittent color-matching visual detection task in which a pair of color-matched stimuli constituted a target and non-matches were non-targets. Tracking error means were binned time-locked to stimulus onset of the detection task in order to observe changes associated with dual-responding by comparing the error during targets and non-targets. Similar comparison was made with fMRI data. Our result showed that despite a significant increase in the overall tracking error post SD, from 20 pixels pre SD to 45 pixels post SD, error decreased to a minimum of about 25 pixels 0-6s after dual-response. Despite an overall reduced activation post SD, greater activation difference between targets and non-targets was found post SD in task-related regions, such as the left cerebellum, the left somatosensory cortex, the left extrastriate cortex, bilateral precuneus, the left middle frontal gyrus, and the left motor cortex. Our results suggest that dual-response helps to alleviate performance impairment usually associated with SD. The duration of the alleviation effect was on the order of seconds after dual-responding.


Assuntos
Encéfalo/fisiopatologia , Desempenho Psicomotor/fisiologia , Privação do Sono/fisiopatologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Estimulação Magnética Transcraniana
3.
Behav Brain Res ; 210(2): 229-39, 2010 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-20188768

RESUMO

Subjects performed a continuous tracking concurrently with an intermittent visual detection task to investigate the existence of competition for a capacity-limited stage (a bottleneck stage). Both perceptual and response-related processes between the two tasks were examined behaviorally and the changes in brain activity during dual-tasking relative to single-task were also assessed. Tracking error and joystick speed were analyzed for changes that were time-locked to visual detection stimuli. The associated brain activations were examined with functional magnetic resonance imaging (fMRI). These were analyzed using mixed block and event-related models to tease apart sustained neural activity and activations associated with individual events. Increased tracking error and decreased joystick speed were observed relative to the target stimuli in the dual-task condition only, which supports the existence of a bottleneck stage in response-related processes. Neuroimaging data show decreased activation to target relative to non-target stimuli in the dual-task condition in the left primary motor and somatosensory cortices controlling right-hand tracking, consistent with the tracking interference observed in behavioral data. Furthermore, the ventral attention system, rather than the dorsal attention system, was found to mediate task coordination between tracking and visual detection.


Assuntos
Atenção/fisiologia , Mapeamento Encefálico , Córtex Cerebral/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Adolescente , Adulto , Análise de Variância , Córtex Cerebral/irrigação sanguínea , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Masculino , Vias Neurais/irrigação sanguínea , Vias Neurais/fisiologia , Testes Neuropsicológicos , Oxigênio/sangue , Estimulação Luminosa/métodos , Fatores de Tempo , Adulto Jovem
4.
Cortex ; 43(7): 1004-19, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17941356

RESUMO

For reasons that remain unknown, there is marked inter-person variability in awareness of episodic memory loss in patients with Alzheimer's disease (AD). Existing research designs, primarily subjective in nature, have been at a relative disadvantage for evaluating disordered metamemory and its relation to the clinical and neuropathological heterogeneity of AD, as well as its prognosis for various disease outcomes. The current study sought to establish an objective means of evaluating metamemory in AD by modifying traditional metacognitive paradigms in which participants are asked to make predictions regarding their own memory performance. Variables derived from this measure were analyzed in relation to clinically rated awareness for memory loss. As predicted, a range of awareness levels existed across patients with mild to moderate AD (n=24) and clinical ratings of awareness (CRA) were significantly associated with verbal episodic memory monitoring (r = .46, p = .03). Further, patients who were rated as aware of their memory loss remained well calibrated over the course of the task whereas those rated as relatively unaware grew over-confident in their predictions [F (1, 33) = 4.19, p = .02]. Findings suggest that over-confidence may be related to impaired online error recognition and compromised use of metamemory strategies such as the Memory for Past Test (MPT) heuristic. Importantly, clinically rated awareness did not vary as a function of demographic variables, global cognition, or verbal memory. However, participants characterized as relatively unaware were impaired on a nonverbal memory task as compared to aware participants [F (1, 20) = 6.98, p = .02]. The current study provides preliminary support for the use of a recognition-based verbal episodic memory monitoring task as a quantitative measure of awareness for memory loss in AD, and offers insight into the manner in which metamemory breaks down. Discrepancies in nonverbal memory across the two awareness groups provide preliminary support for the idea that metamemory variability in AD may be related to the neuroanatomic presentation of the disease, with disordered awareness potentially reflective of a critical level of right hemisphere involvement.


Assuntos
Agnosia/diagnóstico , Doença de Alzheimer/complicações , Conscientização , Transtornos da Memória/diagnóstico , Testes Neuropsicológicos , Autoavaliação (Psicologia) , Idoso , Idoso de 80 Anos ou mais , Agnosia/complicações , Agnosia/psicologia , Doença de Alzheimer/psicologia , Estudos de Casos e Controles , Humanos , Transtornos da Memória/complicações , Transtornos da Memória/psicologia , Valores de Referência
5.
Soc Cogn Affect Neurosci ; 1(2): 75-86, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17392928

RESUMO

Students' beliefs and goals can powerfully influence their learning success. Those who believe intelligence is a fixed entity (entity theorists) tend to emphasize 'performance goals,' leaving them vulnerable to negative feedback and likely to disengage from challenging learning opportunities. In contrast, students who believe intelligence is malleable (incremental theorists) tend to emphasize 'learning goals' and rebound better from occasional failures. Guided by cognitive neuroscience models of top-down, goal-directed behavior, we use event-related potentials (ERPs) to understand how these beliefs influence attention to information associated with successful error correction. Focusing on waveforms associated with conflict detection and error correction in a test of general knowledge, we found evidence indicating that entity theorists oriented differently toward negative performance feedback, as indicated by an enhanced anterior frontal P3 that was also positively correlated with concerns about proving ability relative to others. Yet, following negative feedback, entity theorists demonstrated less sustained memory-related activity (left temporal negativity) to corrective information, suggesting reduced effortful conceptual encoding of this material-a strategic approach that may have contributed to their reduced error correction on a subsequent surprise retest. These results suggest that beliefs can influence learning success through top-down biasing of attention and conceptual processing toward goal-congruent information.


Assuntos
Cognição , Cultura , Inteligência , Aprendizagem , Neurociências/métodos , Percepção Social , Logro , Eletroencefalografia , Potenciais Evocados/fisiologia , Feminino , Lobo Frontal/fisiologia , Humanos , Masculino , Motivação , Adulto Jovem
6.
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
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