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Abstract:
Abstract: Cognitive interference occurs when the processing
of stimulus features impedes the simultaneous processing of a
second stimulus attribute. The Stroop Task requires a person to
respond to specific elements of a stimulus (color) while
suppressing a competing response (meaning). Previous PET and fMRI
studies using the Stroop paradigm have shown increased activity in
the cognitive division of the anterior cingulate cortex. In our
fMRI study with 9 subjects, we used both the Counting Stroop and a
single-trial Color-Word Stroop Task. The Color-Word Stroop Task,
when compared to the Counting Stroop Task, showed a more pronounced
interference effect on the basis of reaction times and imaging
results. A similar fronto-parietal network, including structures
along the border of the posterior inferior frontal sulcus, and the
intraparietal sulcus, was activated for both tasks. The Color-Word
version produced stronger hemodynamic responses then the Counting
Stroop when contrasting the neutral versus the interference
condition. Interestingly, neither of the two tasks showed any
substantial activation in the anterior cingulate cortex, neither in
the left nor in the right hemisphere. We argue that the anterior
cingulate cortex is not specifically involved in interference
processes. We further argue that the ventrolateral frontal cortex
around the posterior inferior frontal sulcus is used to solve
interference problems, a concept that can also be seen as a task
management problem.
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