PERSON
Roger Sperry
The neuroscientist who divided the self in two with a surgeon’s knife—proving that consciousness can be split by severing the brain’s connecting cable—and then spent his later career insisting, against the reductionist temper of his age, that mind is real, causal, and not reducible to the neurons that generate it.
Roger Sperry won the 1981 Nobel Prize in Physiology or Medicine for showing, through exquisitely designed experiments on patients whose epilepsy had been treated by severing the corpus callosum, that a single mind can be divided into two largely separate spheres of
consciousness—each perceiving and willing without the other’s knowledge. The left hemisphere controlled speech and serial reasoning; the right, mute but clearly awake, controlled spatial perception, face recognition, and emotional response. The mute hemisphere could know things the speaking hemisphere could not reach, and the speaking hemisphere, when asked to explain its own behavior, would confabulate confident reasons for actions it had not initiated—inventing explanations with sincerity and without any access to the real cause. This discovery simultaneously dissolved the intuition of indivisible selfhood and required a radical upward revision of what the right hemisphere was doing. And then Sperry did something that astonished