유동 지능에 따른 인지 제어 관련 뇌 활동의 차이 분석

초록

The present study examined how individual differences in fluid intelligence modulates the neural mechanism of cognitive control during reasoning. A four term verbal analogical reasoning task was used with a variation in the degree to which cognitive control was needed to overcome interference from semantic relationships between words. During trials entailing strong cognitive interference, there was a stronger need for cognitive control. In Experiment 1, subjects made more errors and took longer to solve analogies when there was a greater need for cognitive control. In Experiment 2, functional magnetic resonance imaging was used to investigate the relationship between individual differences in fluid intelligence and the neural mechanism of cognitive control. Individuals with a higher fluid intelligence engaged bilateral anterior cingulate cortex, visual cortex, medial frontal pole, right lateral prefrontal cortex, basal ganglia and the ventral tegmental area of the midbrain to a greater extent when the need for cognitive control increased. These results indicate that fluid intelligence modulates the activity of the lateral prefrontal cortex, anterior cingulate cortex and the visual cortex which are commonly activated across various studies of cognitive control and reasoning and that individuals with higher fluid intelligence showed elevated activity levels in these regions. On the other hand, the medial prefrontal cortex which is one of the commonly deactivated regions of the brain showed less deactivation in individuals with higher fluid inteligence. This finding supports previous studies proposing that the default mode activity of the brain may be sustained during task performance in individuals with a high capacity for information processing.

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