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Abstract:
It was reported that an event-related potential (ERP)
component N270 can be elicited in a stimulus pair when the second
stimulus differed from the first one in its any attribute, and it
reflects the activation of conflict processing system in human
brain. To investigate the attention effect on conflict processing
system, fifteen subjects made shape and color matching task. ERP
was recorded on the scalp while subjects received stimulus
sequences. Colored shapes of stimulus pair, with an onset interval
of 500 ms, were sequentially presented on a screen. The two stimuli
in a pair may be identical or different. The inter-trial interval
was 5 seconds. ERP components of P100, N130, P180, N200 and late
positive component (LPC) were recorded in each condition, while
N270 was elicited only when the second stimulus conflicted with the
first one in its color, in shape or in both of them. The N270
amplitude elicited by attention relevant conflict was significantly
enhanced than irrelevant conflict. Another conflict related
component N450 was elicited in double conflicts when subjects
attended to the two attributes at the same time. Conflict
processing system can detect conflict automatically and it
processes multi-conflicts in serial. The activation of the system
can be modulated by attention.
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