Split-brain patients: A clinical vs experimental perspective.

For more than 80 years, the clinical perspective on the behavioral outcome of split-brain surgery suggested that it "may be carried out without any untoward effect on the patient," despite some initial and transient disconnection effects. The last 60 years of experimental studies, however, have shown quite the opposite. Using lateralized testing procedures, split-brain patients have demonstrated profound disconnection effects that can last a lifetime. This experimental work has transformed our understanding of hemispheric specializations and cerebral asymmetries. It paints a picture of patients with two distinct neural systems processing and operating independently with, nevertheless, a seemingly unified conscious experience. This chapter tracks how these two divergent perspectives have coexisted for so long and offers some explanations for why these patients appear normal from a clinical and social perspective.