discriminant stimulus

dis·crim·i·nant stim·u·lus

a stimulus that can be differentiated from all other stimuli in the environment because it has been, and continues to serve as, an indicator of a potential reinforcer.

dis·crim·i·nant stim·u·lus

(dis-krim'i-nănt stim'yū-lŭs)
A stimulus that can be differentiated from all other stimuli in the environment because it has been, and continues to serve as, an indicator of a potential reinforcer.