Between-hemisphere Separation of Target and Distractor Reduces Response Interference

표적과 방해자극의 반구간 분리가 반응 간섭에 미치는 영향

There has been a claim that Interaction between the cerebral hemispheres could reduce the effect interfering information (Weissman & Banich, 1999). We ran three experiments to show that between-hemisphere separation of target and distractor could be more effective for reducing interference than Interaction between the hemispheres. In experiment 1, a colored box and a rotor name were presented to a single or to separate hemispheres. In experiment 2 and 3, a colored circle (distractor) was presented along with a colored box and a color name which was always printed in black. In experiment 3, a peripheral cue was presented either to the target location(66.7%) or to the distractor location(33.3%) Immediately before the presentation of stimuli. In all experiments, the participants were asked to deride whether the moaning of the color matched the rotor of the box, Ignoring the printed rotor of the word(Exp. 1), or the color of the circle(Exp. 2 & 3). There were three renditions of distractor (congruent, incongruent, and neutral) and two conditions of matching (between- and within-hemisphere matching). If interhemispheric interaction were effective for interference reduction, there should be a decrease in the interference in the between-hemisphere compared to the within-hemisphere matching condition. The results showed that there was no difference in the interference between the two matching conditions in Exp 1. In Exp 2 and in the target-cue renditions of Exp. 3, the amount of interference in the between-hemisphere condition was greater than that in the within-hemisphere condition. These findings are consistent with what we have previously reported (Sohn et al., 1996, Sohn & Lee, 2003). However, when the distractor was precued in Exp. 3, the amount of interference did not differ between the two marching conditions. These results suggest that between-hemisphere separation of target and distractor can be more effective for reducing response interference than interhemispheric communication. It implies a possible role of an interhemispheric shielding mechanism (Merola & Liederman, 1985) to prevent the transfer of task-irrelevant, harmful information across the hemispheres.

이 연구는 Weissman과 Banich(1999)가 제안했던 반구 간의 상호작용보다도 표적자극과 방해자극의 반구 간 분리처리가 간섭을 감소시키는 데 더 효과적이라는 것을 밝히기 위해 수행되었다. 이를 위해 사각형의 색과 단어가 의미하는 색을 비교하는 세 개의 실험이 수행되었다. 실험 1에서는 표적자극 중의 하나인 단어의 색 차원이, 실험 2와 3에서는 단어의 글자 색이 검정색으로 고정된 상태에서 제 3의 자극인 원의 색이 방해자극으로 사용되었다. 실험 결과 두 표적자극의 비교를 위해 반구간 상호작용이 요구되는 반구간 비교조건에서, 반구간 상호작용은 요구하지 않지만 방해자극이 표적자극과 다른 반구로 투사된 반구내 비교 조건보다 더 큰 간섭효과가 관찰되었다. 이 결과는 반구간 상호작용보다도 표적과 방해자극의 반구간 분리가 간섭 감소에 더 효과적임을 시사한다. 실험 3에서는 원이 단어나 사각형과 분리되어 다른 반구에 제시될 때 주변단서를 이용하여 원의 위치로 주의를 유도하면 방해자극의 반구간 분리 효과가 사라지면서 반구간 비교와 반구내 비교 조건의 간섭효과가 유사해지는 것을 보여 주었다.