I Am Researching The Side Effects Of Nasal Sprays Containing

I am researching the side effects of nasal sprays containing olopatadine hydrochloride, such as Patanase. It says that concurrent use of olopatadine hydrochloride nasal solution (nasal spray) witih alcohol or other central nervous system depressants should be avoided because additional reductions in alertness and "additional impairment of central nervous system performance may occur." What are some examples of impairments of the central nervous system performance?