PROBLEM TO BE SOLVED: To provide a cognitive function improving agent that effectively improves cognitive functions such as memory and learning, and a method for evaluating or selecting said cognitive function improving agent.SOLUTION: A cognitive function improving agent comprises a GIP function inhibitor as an active component.SELECTED DRAWING: None【課題】記憶、学習能力等の認知機能の改善に有効な認知機能改善剤、当該認知機能改善剤の評価又は選択方法の提供。【解決手段】GIP機能阻害剤を有効成分とする認知機能改善剤。【選択図】なし