When tumors or malformations abut these language areas, the surgeon takes numerous precautions, ordering a host of different scans, a detailed neuropsychological examination. Critically, however, the surgery is performed with the patient awake and talking. Once the brain is exposed, but before the tumor excision, the surgeon uses a hand-held ball-tip electrode to deliver electrical current to stun a small area of the cortex while the patient performs various verbal tasks: naming objects, reciting the alphabet, and so on. When the electrode sends current into a critical piece of cortex, it
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