Stimulus context determines whether non-target stimuli are processed as task-relevant or distractor information.
Clin Neurophysiol
; 117(11): 2532-9, 2006 Nov.
Article
em En
| MEDLINE
| ID: mdl-17005448
OBJECTIVE: The P300 event-related brain potential (ERP) was elicited using a visual three-stimulus oddball paradigm (standard 0.70, target 0.15, non-target 0.15) to examine how target/standard stimulus context affects non-target processing. METHODS: Target/standard discrimination difficulty (easy or difficult) and non-target /target similarity (similar or dissimilar) were manipulated orthogonally. Participants (N=13) were instructed to respond to each infrequent target stimulus by pressing a button. RESULTS: Target stimuli in all task conditions elicited P3b, which was affected only by the difficulty of target/standard discrimination. When target/standard discrimination was easy, the amplitude of non-target P3 was larger for similar than for dissimilar non-target. In contrast, when target/standard discrimination was difficult, non-target stimuli elicited P3a, the amplitude of which was larger for dissimilar than for similar non-target. Thus, the P300 component for non-target stimuli and the pattern of the effect of target similarity on each P300 component varied as a function of the target/standard stimulus context. CONCLUSIONS: The target/standard stimulus context influences the attentional set for stimulus processing such that it determines whether non-target stimuli are processed as task-relevant or distractor information. SIGNIFICANCE: The present results are important for understanding the mechanism of cognitive modification in non-target processing.
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Base de dados:
MEDLINE
Assunto principal:
Potenciais Evocados P300
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Clin Neurophysiol
Assunto da revista:
NEUROLOGIA
/
PSICOFISIOLOGIA
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Japão