The phrase "chemical responses" refers to the reactions or changes that occur within a chemical system as a result of an external stimulus. Full definition
The same type of chemical response creates all three types of pleasure. (techtimes.com)
What the viewer sees in these sculptures is an ephemeral chemical response. (aaa-a.org)
'' @Red Dwarf «ancestors eating certain mind expanding mushrooms which unlcked certain chemical responses in their brains allowing them to effectively look outside the box that was their survivalist existence and begin contemplating the why along with how of survival.» (religion.blogs.cnn.com)