A nice summary of “humaniquness,” or the cognitive talents that make homo sapiens such an unprecedented species:
[Marc] Hauser describes animals as having “laser-beam” intelligence, in which each cognitive capacity is locked into a specific function. Humans, by contrast, have “floodlight” intelligence, he says: they can use a single system of thought in multiple ways and can translate information from one context to another. “Animals,” he elaborates, “live in a world in which the systems don’t talk to each other.”
This sort of abstract cognition is generally thought to reside in the prefrontal cortex (PFC), the fold of brain stuffed behind the forehead. (The same nub of tissue also plays a crucial role in self-control, which is why stuff like this can happen.) While the PFC is now celebrated as the Promethean part of the cortex, responsible for rationality, logic and all those executive functions, it wasn’t always held in such high regard. In 1935, the Portuguese neurologist Antonio Egas Moniz performed the first prefrontal leucotomy, a delicate surgery in which small holes were cut into the frontal lobes. (The surgery was inspired by reports of chimpanzees becoming less aggressive after undergoing similar procedures.) Moniz restricted the surgery to patients with severe psychiatric problems, such as schizophrenia, who would otherwise be confined to dismal mental institutions. The leucotomy certainly wasn’t a cure-all, but many of Moniz’s patients did experience a dramatic reduction in symptoms. In 1949, he was awarded the Nobel Prize in Medicine for pioneering the procedure.
The success of the leucotomy led doctors to experiment with other kinds of frontal lobe operations. In the United States, Walter Freeman and James Watts developed a procedure known as the transorbital lobotomy, which was designed to completely ablate the tracts of white matter connecting the prefrontal cortex and the thalamus. The surgery was brutally simple: a thin blade was inserted just under the eyelid, hammered through a thin a layer of bone, and shimmied from side to side. The treatment quickly became exceedingly popular. Between 1939 and 1951, the “cutting cure” was performed on more than 18,000 patients in American asylums and prisons.
Unfortunately, the surgery came with a wide range of tragic side-effects. Between 2 and 6 percent of all patients died on the operating table. Those who survived were never the same. Some patients sank into a stupor, utterly uninterested in everything around them. Others lost the ability to use language. (This is what happened to Rosemary Kennedy, the sister of President John F. Kennedy. Her lobotomy was given as treatment for “agitated depression.”) The vast majority of lobotomized patients suffered from short-term memory problems and the inability to control their impulses.