Nootropic effect enhancer

摘要

The invention is to provide an antidementic and/or antiamnesic potency enhancer that comprises an aminopiperazine or aminopiperidine derivative of a formula: (wherein R¹ is a lower alkyl, etc.; R² is hydrogen, etc.; R³ is an aryl, etc.; A is -CO-, etc.; X is N or CH; Y is -CO-, etc.), for attaining higher antidementic and/or antiamnesic potency.