neomycin: an antibiotic obtained from an actinomycete and used (as a sulphate under the trade name Neobiotic) as an intestinal antiseptic in surgery
causal agent: any entity that produces an effect or is responsible for events or results
split-brain technique: brain surgery on animals in which the corpus callosum (and sometimes the optic chiasm) is severed so that communication between the cerebral hemispheres is interrupted