1. A method for improving cognitive ability, comprising administering to a patient (R) -7-chloro-N- (quinuclidin-3-yl) benzo [b] thiophene-2-carboxamide or a pharmaceutically acceptable salt thereof and an acetylcholinesterase inhibitor. 2. The method according to claim 1, characterized in that the patient was diagnosed with Alzheimer's disease or preclinical Alzheimer's disease. The method according to claim 1, characterized in that the patient was diagnosed with mild to moderate Alzheimer's disease. The method according to claim 1, characterized in that the patient was diagnosed with moderate to severe Alzheimer's disease, 5. A method according to any one of the above paragraphs, wherein the acetylcholinesterase inhibitor is selected from tacrine, donepezil, rivastigmine and galantamine. The method according to claim 5, characterized in that the acetylcholinesterase inhibitor is selected from donepezil, rivastigmine and galantamine. The method according to claim 5, characterized in that the acetylcholinesterase inhibitor is selected from donepezil and rivastigmine. The method according to claim 1, characterized in that the patient is administered an acetylcholinesterase inhibitor in the period prior to the introduction of (R) -7-chloro-N- (quinuclidin-3-yl) benzo [b] thiophen-2-carboxamide or a pharmaceutically acceptable thereof salt. 9. The method of claim 8, wherein the previous administration is carried out in at least one month. The method according to claim 9, characterized in that the previous administration is carried out for at least three months. The method according to claim 10, characterized in that the previous administration is carried out for at least six months. The method according to claim 1, characterized in that it improves one or more indicators: learning, deferred memory, attention, working memory, visually1. Способ улучшения когнитивной способности, включающий введение пациенту (R)-7-хлор-N-(хинуклидин-3-ил)бензо[b]тиофен-2-карбоксамида или
