ABSTRACT
For many years, the belief has dominated that the association between hemisphere dominance for language and for handedness is not random and that these two dominance factors are two aspects of the same function, with structural asymmetries being sought (and found!) to explain functional asymmetries. For approximately 80 years, from Broca (1865) to Brain (1945), the view that “the cerebral hemisphere in which are situated the neural pathways of speech is the left hemisphere in right-handed persons, and conversely” (Brain, 1945, p. 839) has been well entrenched. However, it rapidly became apparent that the simple rule of right-handedness = left-hemisphere language dominance, left-handedness = right-hemisphere language dominance, did not hold true because many left-handers developed aphasia after left-hemisphere lesions, as did some right-handers after right-hemisphere lesions. When a patient did not conform to the rule, various explanations were offered that did not put the rule itself into question. For right-handers who had become aphasics after a right-hemisphere lesion, it was either supposed that they were natural left-handers who had been obliged to use their right hand or that they came from left-handed stock (see chapter 7, Crossed Aphasia, this volume). For left-handed (LH) aphasics with left-hemisphere damage, left-hemisphere dominance for language was considered due to right-hand training for writing, which conferred dominance for language to the left hemisphere. Incidentally, hand training was also suggested as a rehabilitation technique: If an aphasic acquired skilled movements with the hand ipsilateral to the lesion, this was supposed to help the relocation of language to the opposite side of the brain (Buzzard, 1882, cited in Goodglass & Quadfasel, 1954).
