Limitations and Possibilities
"By the 2030s, the nonbiological portion of our intelligence will predominate"
- Ray Kurzweil
Although technology has come a long way since the idea of mind uploading has come about, we may not actually be much closer to realize it than we were back in the 50s. Currently, there are two main types of barriers to realizing downloaded consciousness:
Those stemming from the limitations of current technology
Those stemming from the need to invent new technologies/theories to realize mind uploading
We will now examine a couple of these examples.
A Limitation: The Bekenstein Bound and Modern Computing Power. This bound is an upper limit on the amount of information or entropy that can be contained within a finite region of space given a finite amount of energy. With regards to mind uploading, some researchers consider the Bekenstein Bound an upper limit on the amount of information needed to perfectly recreate a human brain down to the quantum level. Some have estimated that the Bekenstein Bound would be on the order of 10^41 bytes. Consider that personal computers generally have under 1 TB of hard-drive space, and a few gigabytes of RAM. 1 TB is approximately 10^12 bytes. Note that 41-12 = 29; in other words, the number representing the amount of information stored in the human brain has an additional 29 0's on the end of the number representing the amount of memory in an average computer. Clearly, today's average home and business computers would not be able to handle the intense amount of processing and information storage required to “run” a human brain.
What about supercomputers? If a laptop can be called an average representation of modern computing power, then supercomputers are surely the highest level current technology has to offer. In 2010, China unveiled the world's fastest supercomputer: A machine rated at 2.5 petaflops. A petaflop is approximately a thousand trillion operations per second; thus, the amount of information this supercomputer can process is on the order of 10^18. While this is a good deal more power than a personal computer, it is still many orders of magnitudes smaller than 10^41, the scale of the Bekenstein Bound. It seems evident that we lack the necessary technology to represent such massive amounts of information.
An Actual and Hypothetical Technology: Brain-computer interfaces (BCIs). BCIs are technological interfaces which allow a human brain to directly interface with a computer. Current BCI technology is already fairly advanced. One invasive, or implanted, BCI allows once blind people to regain some of their vision. This BCI worked by using cameras to send signals to the implant. It was invented in 2002, and progress on this technology continues today. However, modern BCIs are only very slightly related to the theoretical BCIs which would allow us to transfer our brain states into a digital medium.
This BCI allows a monkey to control a robotic brain. Cool!
Brain-computer interfaces which allow for mind uploading would need for a technology similar to modern day brain scanning technology. Some researchers theorize that the scanning technology would need to be precise enough to scan human brains at a quantum particle level. Although a super precise scanning technology would be necessary to make downloading consciousness a reality, but it would not be sufficient to achieve downloading consciousness. There would be at least a few other components of this hypothetical brain-computer interface. One of these would be the technology needed to transfer the information to the digital medium. It is unknown how fast the brain scan data might need to be sent to the digital medium, but is is possible that the massive amount of information might require an extremely large rate of transfer. Thunderbolt, Apple's latest high speed transfer I/O, is rated at 10Gbps across two channels. However, if the Bekenstein Bound is any indication at all of the amount of information needed to achieve mind uploading then our current technologies are not sufficient; we will have need of a much greater speed to transfer all that information so quickly. Finally, the actual storage medium itself. Those versed in the matter only theorize as to the form an uploaded brain would take. Would it be a digital circuit, like a clock? A machine like a computer, with parts of the computer? Or something more similar to cloud computing, with distributed storage locations? Perhaps the computer analogy is the best, because the human brain has different regions specialized in different tasks. No one will know for sure if and until brain uploading becomes a reality.
Currently, brain-computer interfaces are considered to be extremely invasive, generally leaving the mind irreparably damaged. Invasive BCIs involve being implanted directly into the grey matter of the human brain. While these types of invasive devices do produce the highest quality signals of BCI devices, they have a tendency to leave scar-tissue build-up. In addition to invasive brain-computer interfaces there are partially-invasive BCIs and non-invasive BCIs. Partially-invasive brain-computer interfaces are when the BCI devices are implanted within the skull but outside of the actual grey brain matter. Current research involving partially-invasive BCIs has shown that less technical difficulties and increased long-term stability in patients indicates the potential for real world applications. We do not yet have a way of knowing how damaging this theoretical mind uploading BCI would be. However, it seems possible that the BCI would not necessarily have to be invasive, but instead operate more like a modern day CAT scan.
Non-invasive brian-computer interface research has involved using neuroimaging technologies as interfaces between the human mind and human technology. Despite the fact that non-invasive brain-computer interfaces are easy to use, they are generally considered to provide low signal strengths due to the cranium acting as a wall that impedes the connection.
These interfaces, which link human minds and computers, are also touched upon in the Philosophical Issues section of the site.
Research is already underway involving new forms of memory storage that are exponentially more efficient than current technologies. Moore's Law, which states that the computing power of technology doubles every 1.5 years (and is in effect exponentially increasing), illustrates the fact that mind uploading is still a possibility.