視覚性ワーキングメモリにおける特徴の統合

Feature Integration in Visual Working Memory

視覚情報を短時間保持し，さまざまな知的活動のために変換や操作を行う機能である視覚性ワーキングメモリにおける情報統合の働きを概説した。特徴の組合せの明示的な報告を要する課題は前頭前皮質の関与を示しているが，特徴を統合した物体情報の保持，変換に関しては議論がある。一方，潜在指標を使った研究は視覚性ワーキングメモリにおける特徴統合の証拠を示し，特徴統合した物体を単位とした保持，変換の存在を支持している。

Abstract

This article reviews studies on feature integration in visual working memory, which is critical for various cognitive activities using visual information. Studies involving change detection and multiple object tracking tasks reported that feature-integrated object representations are successfully maintained, and that the parietal cortex plays a major role. Subsequent studies that involved explicit tasks on feature combination, such as feature swap detection and multiple object permanence tracking, revealed the role of the prefrontal cortex, but it remains equivocal whether visual working memory holds feature-integrated object representations. In addition, recent studies using an implicit-association test measure, the redundant feature reviewing task, combining object reviewing and redundancy gain paradigms, provided evidence on feature-integrated object representations in visual working memory. Electroencephalography data analysis showed prefrontal activities reflecting the integration of the color and shape of an object, which is consistent with the result of studies measuring explicit tasks. Altogether, these findings are consistent with a recently proposed “feature confirmation” model, claiming that object features can be integrated in bottom-up visual processing and the limitation in feature binding occurs in the top-down mechanism which confirms the presence of features and their combination.