In a remark­able sur­gi­cal pro­ce­dure led by Dr. Eddie Chang, a neu­ro­sur­geon in San Fran­cis­co, a pro­found chal­lenge unfold­ed when he oper­at­ed on a mid­dle-aged man with a brain tumor locat­ed near essen­tial lan­guage regions. This del­i­cate maneu­ver involved an awake cran­ioto­my, where the patient was secured in a vice-like appa­ra­tus to ensure immo­bil­i­ty. After an ini­tial cut to remove a sec­tion of the skull, the patient was awak­ened from anes­the­sia, tasked with count­ing or read­ing from a screen while elec­trodes stim­u­lat­ed var­i­ous sec­tions of his brain. Cru­cial­ly, this patient was pro­found­ly deaf, rely­ing on sign lan­guage instead of vocal­iza­tion, a sce­nario Dr. Chang had nev­er encoun­tered before.

His­tor­i­cal­ly, the explo­ration of lan­guage in the brain began with Pierre Paul Bro­ca, who, in 1861, uncov­ered insights into lan­guage pro­cess­ing through the autop­sy of a patient, nick­named “Tan,” who could only utter that sin­gle word despite being able to com­pre­hend every­thing com­mu­ni­cat­ed to him. Bro­ca’s exam­i­na­tion revealed exten­sive dam­age to a spe­cif­ic area in the left frontal lobe, now known as Bro­ca’s area, essen­tial for speech pro­duc­tion. Although Wer­nicke lat­er iden­ti­fied anoth­er cru­cial area for lan­guage com­pre­hen­sion, Bro­ca’s find­ings laid the ground­work for neu­ro­sur­gi­cal prac­tices con­cern­ing stroke and brain injury patients.

Dur­ing the oper­a­tion, Dr. Chang dis­cov­ered that stim­u­lat­ing Bro­ca’s area caused the patient to cease sign­ing, indi­cat­ing a com­plex inter­con­nec­tion between sign lan­guage pro­cess­ing and tra­di­tion­al speech cen­ters. This rev­e­la­tion con­sid­er­ably expand­ed the under­stand­ing of lan­guage with­in the brain, illus­trat­ing that com­mu­ni­ca­tion path­ways encom­pass both spo­ken and ges­tur­al lan­guages. Five years post-surgery, Dr. Chang encoun­tered sim­i­lar results when oper­at­ing on a musi­cian, fur­ther cement­ing the the­o­ry of a gen­er­al­ized com­mu­ni­ca­tion cen­ter with­in the brain.

The chap­ter also reflects on the his­tor­i­cal mis­con­cep­tions about sign lan­guage, once brand­ed as prim­i­tive, tied to ear­li­er sci­en­tif­ic nar­ra­tives equat­ing sign lan­guage with low­er evo­lu­tion­ary sta­tus. How­ev­er, in the 1960s, schol­ars like William Stokoe cham­pi­oned the lin­guis­tic com­plex­i­ty of sign lan­guages, paving the way for mod­ern recog­ni­tion of Amer­i­can Sign Lan­guage as equiv­a­lent to spo­ken lan­guages. Oth­er stud­ies sub­se­quent­ly val­i­dat­ed that the acqui­si­tion of language—be it through sound or sign—engaged sim­i­lar neur­al path­ways, chal­leng­ing pre­con­ceived dichotomies of com­mu­ni­ca­tion and fun­da­men­tal­ly reshap­ing the under­stand­ing of human lan­guage. Today, Amer­i­can Sign Lan­guage is right­ly acknowl­edged as a com­plex and essen­tial aspect of deaf iden­ti­ty and human com­mu­ni­ca­tion.