The Itch

Sci­en­tists once saw itch­ing as a form of pain. They now believe it to be a dif­fer­ent order of sen­sa­tion, one which sug­gests that per­cep­tion is more than mere recep­tion. Per­cep­tion is infer­ence. Atul Gawande explains the “brain’s best guess” the­ory of per­cep­tion:

Per­cep­tion is the brain’s best guess about what is hap­pen­ing in the out­side world. The mind inte­grates scat­tered, weak, rudi­men­tary sig­nals from a vari­ety of sen­sory chan­nels, infor­ma­tion from past expe­ri­ences, and hard-wired processes, and pro­duces a sen­sory expe­ri­ence full of brain-provided color, sound, tex­ture, and meaning.