THE APHASIC SYMPTOM-COMPLEX: A Psychological Study on an Anatomical Basis*

TLDR: That destruction of Broca's area causes aphasia appears to be established beyond doubt through such cases as the striking one of Simon, which actually resembled an experiment, but other conscientious and experienced observers are also correct in insisting that Broca’s area is not the only speech center, and that circumscribed lesions in the region of the Sylvian fissure can produce aphasIA.

Abstract: .... That destruction of Broca's area causes aphasia appears to be established beyond doubt through such cases as the striking one of Simon, which actually resembled an experiment. However, other conscientious and experienced observers are also correct in insisting that Broca's area is not the only speech center, and that circumscribed lesions in the region of the Sylvian fissure can produce aphasia. We may now ask what lies near the Sylvian fissure, and we note a gyrus on the convex surface of the cerebrum, running in a curve directed posteriorly and superiorly, almost enclosing the Sylvian fissure. From the central sulcus it runs anteriorly in a distinct longitudinal tract, the ... first frontal gyrus. Its posterior peduncle is in the first temporal gyrus, just clearly discernible as the longitudinal tract. That the whole is to be considered as one gyrus is clear from comparison with the brains of animals, such as dogs.