We found that APP/PS1 mice at the early stage (4 months of age) before cognitive impairment had increases in heart rate and a reduction of overall autonomic function and parasympathetic function during sleep but not during wakefulness; the same autonomic dysfunction existed not only during sleep but also during wakefulness in APP/PS1 mice with cognitive impairment at the advanced stage (8 months of age). The gene discussed is APP; the disease is Cognitive impairment.