I've Got Half a Mind...

If you think you’ve had a bad day at work spare a thought for 14 year old Ahad Israfil. In 1987 his boss knocked a gun to the ground, shooting Ahad in the head and blowing his brains out. A bad day at work certainly, but remarkably, not a terminal day at work. Though he lost the entire right hemisphere of his brain, Ahad survived and recovered well enough to earn an honours degree at his local college not to mention appearing in several TV documentaries.

Photo: Meo / Pexels

Ahad was the unwitting recipient of an instant hemispherectomy. A surgical procedure where one hemisphere of the brain is surgically removed and the resulting space filled with silicone. This is not to be confused with a callosotomy. That slightly less drastic procedure just cuts the corpus callossum – the bundle of nerve fibers that connect the two hemispheres of the brain. This results in both halves of the brain perceiving, thinking and sometimes acting independently as they respond differently to information received by one, but not the other hemisphere.

A full hemispherectomy – the total removal of one hemisphere – is an extreme surgical solution for individuals suffering treatment-resistant, uncontrollable seizures. The procedure is usually performed on very young children since their brain plasticity allows for a fuller recovery but has been successfully applied to adult patients with side effects not too much more severe. In either case, recovering patients experience a loss of motor control in the arm opposite the removed hemisphere as well as a loss of vision in the opposite eye. Those side effects are not enough to prevent recovered patients – who literally have only half a brain – scoring normal or above on IQ tests, having fully developed personalities or becoming chess champions. Often, observers who are unaware of the surgery will not notice anything out of the ordinary.

It would seem that half a brain (either half) is sufficient to make a whole person. If so, a couple of thought experiments suggest themselves…

Imagine in the near future that it is possible to perfectly preserve the half of the brain that is removed (some form of cryogenic suspension perhaps). A surgeon removes half a patient’s brain in order to save their life from recurring seizures. The patient recovers well and gets on with their life. Some time later they experience seizures again and it is discovered that through a terrible oversight, the wrong half of the brain was removed. Fortunately, the hospital preserved the half that was originally removed and a skilled surgeon can replace the original hemisphere and remove the one having the seizures. If this was you, would you consent to a second surgery? If you did, would the ‘you’ who woke up from it – who obviously does not have memories from the intervening period – be the same ‘you’ who was anaesthetised? Would you consider the surgery as a memory loss of the intervening time or the death of the ‘current’ you?

I know many readers enjoy a good whodunnit so let’s stretch the scenario a little. Suppose a patient has consented to just such a second surgery. Unsurprisingly, she insists on a different surgeon to perform the second procedure. The night before the surgery, she waits until late evening then sneaks out of her room and down a dark hospital corridor to wait outside the original surgeon’s office. Seeing the surgeon nod off at his desk, she silently lets herself in and slashed the surgeon’s neck with a stolen scalpel, murdering him in a fit of revenge. The murder isn’t discovered until the day after the surgery. CSI identify the patient as the murderer (fingerprints, hair samples, security footage, “I done it” scrawled in blood and signed by the patient etc) but should the police arrest the patient when she recovers? The patient was fully compos mentis both during the murder and now but – with a different hemisphere running the show – she can claim she literally wasn’t in her right mind committing the crime and obviously has no knowledge of it. So who, exactly, did do it?

If you’re feeling a little macabre we can take our potential crime drama further. Imagine a near future Hannibal Lecter. A brilliant surgeon, he doesn’t kill but instead kidnaps and then removes one brain hemisphere from his victims which he keeps alive in a life support apparatus (basically a brain, or half a brain in this instance, in a jar). Using an advanced MRI device and a camera input for the jar hemisphere, the future Hannibal makes the victim lead two separate lives by exposing them to different environments. The two hemispheres are allowed to occasionally communicate. Crudely at first as the brain’s natural plasticity takes over the missing functions of the other’s hemisphere, both halves – jar and embodied hemisphere – swap notes on their incarceration and bizarre circumstance. Starting from the same brain state, both halves diverge enough to become individuals.

After a year of this fiendish captivity, future Hannibal swaps the hemispheres – jar hemisphere goes back in skull, skull hemisphere comes out (I mentioned he was a brilliant surgeon, right?). Jar hemisphere is now back in his body after a year. As he recovers from the surgery, he sees future Hannibal holding out the hemisphere he removed and instead of putting it back in the life-support jar, he chucks it in the incinerator, destroying it utterly.

Just at that moment, future Clarice Starling bursts in, arrests future Hannibal and rescues the victim. In the subsequent trial there are some interesting questions. Was the half a hemisphere that controlled the body for a year a separate individual to the re-embodied hemisphere? Can destroying one hemisphere really be called murder when the named victim is clearly present in court? Can the victim be called as a witness to their own murder?

Dragging us back to the here and now for a moment; brains are bodily organs just like hears and kidneys. Few would have qualms about replacing a defective heart or kidney but the brain is what makes us us. Replace a person’s kidney – or any other organ – and the person is still the same. Leave everything else in situ and remove the brain though and the person is dead, diddly-ed dead. With existing medical technology the excised half of the brain in a hemispherectomy dies but if either half of the brain has an equal claim to be the whole person, does each hemisphere not have an equal right to life regardless of how ill it is? Is killing one hemisphere to save the other functionally equivalent to murder?

And what of Ahad Israfil? If the accidental shot that destroyed his right hemisphere had been at a slightly different angle he might have lost his left hemisphere instead and survived to live just as full a life with the right hemisphere. Should his boss have been charged with manslaughter for ending that potential life?

Just something to think about. Or half think about at any rate.

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