Alcohol and other psychoactive drugs affect which parts of the brain? #1. primitive brain #2. reasoning center of the new brain #3. neocortex #4. old brain

The part of the brain which is affected is reasoning center of the new brain. Drinking alcohol also decreases motor function and slow reaction time, this is why when a person is drunk, he/she may not be able to stand or walk a straight line. Psychoactive drug or psychotropic substance is a chemical substance that acts primarily upon the central nervous system where it alters brain function resulting in temporary changes in perception, mood, consciousness and behavior.