PROBLEM TO BE SOLVED: To improve a cognitive function.SOLUTION: A composition for improving a cognitive function comprises a mixture of glycogen and a monosaccharide/oligosaccharide component with 20 or less glucose residues (G) (G1-20; where Gn indicates a sugar with n glucose residues joined together by a glycosidic bond), the mixture comprising ESG of 50-98.5 wt.% and the monosaccharide/oligosaccharide component of 1.5-50 wt.%.