Personal identity is a changing pattern in the brain that can be reproduced in a computer, says transhumanist James Hughes; philosopher Nir Eisikovits argues that the copy must also carry on the person's subjective experience of life
Personal identity is a changing pattern in the brain that can be reproduced in a computer, says transhumanist James Hughes; philosopher Nir Eisikovits argues that the copy must also carry on the person's subjective experience of life
Episode 51 of the Prosthetic Gods podcast, released on October 14, explores mind uploading. The hosts are Hughes and Nir Eisikovits, director of the Center for Applied Ethics at the University of Massachusetts Boston.
For many transhumanists, mind uploading offers a way to survive the death of the body. Hughes begins with the technology: Eon Systems released a video showing a model of a fly's brain in a virtual body. The model is based on the connectome, a map of connections between neurons. He then turns to the philosophical question: what must continue for the copy to remain the same person?
Hughes uses an analogy to explain what would need to be copied. A connectome is like a city's street map: it cannot tell you how the city functions. That requires a model of its processes. He suggests that an approximate model might be enough, in which case “mindfiles” could suffice: a digital version of a person assembled from their correspondence, videos and voice. Eisikovits objects that such a version tells us nothing about whether first-person experience continues, meaning the person's experience of life from within.
Philosophers have long debated what makes someone the same person over time. Hume compared the self to a republic that retains its identity as its citizens change. Hughes says most transhumanists probably understand personal identity as a changing pattern that can be reproduced in a computer. A longstanding difficulty for mind uploading is the duplicate problem: a copy existing alongside the living original cannot be that person. According to Hughes, philosopher Susan Schneider sees this problem as fatal to mind uploading. She requires continuity of personal identity and regards waking up in an electronic body as a break in that continuity. Hughes responds that consciousness is interrupted even without uploading, during sleep and deep cooling, yet people still remember who they are afterward.
Eisikovits proposes a thought experiment: thirty years from now, he dies, and a copy activated at the moment of his death continues the podcast. In his view, uploading would succeed only if the copy thought something like, “Wow, that was strange. All right, where were we?” Hughes accepts that such continuity is theoretically possible, but current brain models take little account of hormones and other chemical signals from the body. He says that waking up without a body in an empty void would probably lead to a rapid loss of sanity, so the copy would need bodily sensations, such as hunger and anxiety.
Of the three routes to mind uploading, Hughes considers gradual replacement the most plausible. The other two involve scanning the brain. A destructive scan rules out a duplicate but leaves open whether the person survives the “jump” into a computer. A nondestructive scan could produce a duplicate. In his gradual replacement scenario, brain-computer interfaces take over more and more brain functions while recording memories, dreams and personal identity. Over time, what is stored in the interface would become as important to the sense of self as what remains in the brain, and would survive the brain's decay.
Hughes describes a similar shift in dementia: if AI remembers everything the person has forgotten, continuity of personal identity diminishes in the body and grows in the AI. “I don't dwell too much on whether it's really me, because I'm not the same from one minute to the next myself,” he says.
Eisikovits asks who would be accountable if a copy with network access committed fraud, and what rights it would have if it suffered. Hughes distinguishes two questions: whether the copy's interests should count, which for him depends on its capacity to suffer, and whether it should have the same rights as the original, such as receiving half the original's property.