1. A therapeutic agent or prophylactic against cognitive impairment, containing as an active ingredient an antibody that is involved in the interaction of an antigen-antibody with a tau protein that is phosphorylated at least one amino acid residue present at positions 410-421 tau the protein represented by SEQ ID NO: 1.2. The therapeutic agent or prophylactic against cognitive impairment according to claim 1, wherein the antibody is an antibody that is involved in the interaction of an antigen-antibody with a phosphorylated tau protein characteristic of cognitive impairment. 3. The therapeutic agent or prophylactic against cognitive impairment according to claim 1, wherein the antibody is involved in the interaction of an antigen-antibody with a tau protein that is phosphorylated at one or more sites selected from Ser412, Ser413, Thr414 and Ser416.4. The therapeutic or prophylactic against cognitive impairment of claim 1, wherein the antibody is an antibody that competes with an antibody containing VH consisting of the amino acid sequence designated as SEQ ID NO: 20 and VL consisting of the amino acid sequence indicated as SEQ ID NO: 26 for binding to a tau protein. 5. The therapeutic or prophylactic agent against cognitive impairment according to claim 1, wherein the antibody is an antibody comprising VH consisting of the amino acid sequence designated as SEQ ID NO: 20 and VL consisting of the amino acid sequence indicated as SEQ ID NO: 26.6. A therapeutic agent or prophylactic against cognitive impairment according to any one of paragraphs. 1-4, while anti1. Терапевтическое средство или профилактическое средство против когнитивных расстройств, содержащее в качестве активного ингредиента антитело, которое участвуют во взаимодействии антиген-антитело с тау-белком, который фосфорилирован в, по меньшей мере, одном аминокислотном остатке, присутствующем в позициях 410-421 тау-белка, представленного SEQ ID NO: 1.2. Терапевтическое средство или профилактическое средство
