somatotopic

adjective

so·​ma·​to·​top·​ic -ˈtäp-ik 

: of, relating to, or mediating the orderly and specific relation between particular body regions (as a hand or the tongue) and corresponding motor areas of the brain

the somatotopic arrangement within the thalamus

somatotopically

-i-k(ə-)lē 

adverb