Monday, June 27, 2011

The Mind Machine Interface

The human brain is a fascinating topic. Isn't it ironic that the one part of our bodies which seems to be the most closely linked to our first hand experience, the one associated with our very thoughts and awareness, is the same part of our bodies that we understand the least about? It is this striking contrast that makes speculation about the brain the subject of so much interesting science fiction material. Even as the pace of our knowledge about it increases, it seems such material is in no danger of becoming obsolete. The recent film Inception delved into the nature of dream states in a way that was original, even if not connected to any recognizable science. Other subtopics include mind control, psychokinesis (ability to move things by thought), telepathy, remote viewing, states of consciousness (e.g. Altered States), memory (e.g. Dark City), and many others.

One of the most common sci-fi topics in this category is the interface between the brain and machines. Although many writers use it simply as a story telling mechanism embedded into some larger context, there are still many films that employ it as a central theme, especially in recent years. Witness the list below in reverse chronological order:

Source Code (2011)
Tron Legacy (2010)
Surrogates (2009)
Avatar (2009)
Minority Report (2002)
The Matrix Trilogy (1999-2003)
The Thirteenth Floor (1999)
Johnny Mnemonic (1995)
Lawnmower Man (1992)
Total Recall (1990)
Dreamscape (1984)
Brainstorm (1983)
Tron (1982)
Forbidden Planet (1956)

The question I wish to explore here is, given that we understand the technology side of this interface, which is just information processing, does what we know or do not know about the brain today make such future technologies plausible, or are they another impossible ubiquity of the genre? The answer I arrive at for myself is that it really depends on which type of technology it is. I'd like to try to explain some of my reasoning behind this belief and then how it applies to various future technologies. I sincerely hope it is worth the read.

If we liken the functions of the brain to a modern computer, we can identify many things that both computers and brains can do: logical computation (thinking), memory storage (remembering), retrieval (recalling), and erasure (forgetting), interfacing (communicating), and data processing (recognizing). These are important categories because they represent functions that in principal could be duplicated by a computer. Let's list them again:

Computer-Like Brain Functions:
  • thinking (as in deductive reasoning)
  • remembering
  • recalling
  • forgetting
  • communicating
  • recognizing
There are several other functions that seem to be unique to human beings, such as the following:

Human-Like Brain Functions:
  • choosing (as in free will) - Computers make choices based on predetermined conditions, which is the same as computation. For this reason, there are many who believe free choice to be an illusion.
  • feeling
  • imagining - This is a very interesting one. It refers to creating or recreating an experience in the mind.
  • dreaming - Similar to imagining but without the same level of conscious awareness.
  • insight - Understanding that is greater than the sum of the evidence.
In fact, anything we can refer to as subjective experience, in my opinion, is a uniquely human trait. It is wrapped up in what we often refer to as consciousness. I read a fascinating book recently by physicist Roger Penrose called Shadows of the Mind in which he lays out what I think is a water tight proof that consciousness cannot be the product of computation and therefore it will never be attained by computer systems or even any system based on known physical laws. He believes that consciousness arises from yet undiscovered physical laws which the brain is utilizing. Once discovered, he believes a machine could be constructed based on those laws that does attain consciousness. But Penrose also leaves open one other possibility, the one to which I subscribe, which is that consciousness is a metaphysical phenomenon that is outside the realm of scientific explanation. This short summary regarding my views on consciousness is here to help explain where my own conclusions about the futuristic technologies below come from.

Let's now take a look of some technologies or capabilities related to the brain that commonly appear in sci-fi literature:

Mind Reading - Unlikely Yet Possible
    What I refer to here is a transfer of thoughts from one mind to another, or telepathy. It is a capability frequently portrayed by alien characters or even enhanced humans. It includes real time telepathy as exhibited by the Psi Corps of Babylon 5, and memory reading as employed by the Vulcan mind meld. I believe that these capabilities are not a huge stretch given our own experiences today. How many times have you "known" what someone is else thinking? If we can do this via external clues such as expressions and body language, whose to say you couldn't learn to do the same from an EEG or other type of signal? A connection from one mind to another does not require any real understanding of the mechanism underlying that connection, which is why I leave it open to the realm of at least metaphysical possibility.

Mind Viewers - Almost Certainly Impossible
    It's one thing to know what another person is thinking, but the term mind viewer refers to constructing a representation of a person's thought's into actual images that can be viewed. This does not mean seeing what someone else is seeing in real time, which could be accomplished in principal by attaching tiny cameras to their eyeballs. Rather, we are talking about translating what a person is imagining into real images, or even reconstructing things that were seen in the past from stored memories. This seems to me a much more difficult proposition, yet it is amazing how often it is portrayed. How many episodes of Star Trek feature aliens who "reconstruct" artificial Earth environments from the minds of their human subjects? The earliest mind viewer I can recall is in Quatermass and the Pit, where Dr. Roney has invented a device that fits over a person's head and allows others to see their thoughts on a CRT monitor.
    It is easy for us to conceive of such a technology because when we imagine things, it is like we are re-living an actual experience. As mentioned above, I believe that this subjective experience within the brain is inaccessible to any physical process or device in principal. What is accessible is the movement of the electrons within the cells of the brain at the time a person is imagining something. I also do not believe that images are stored in the brain in the low level representation of light pixelation. That would be extremely inefficient. Rather, it is stored as a set of modifications in the neural network at sites associated with the content of the images that are seen. I also believe that each person develops this network in their brain differently, like a fingerprint, making it impossible to find a mapping from the brain structure back to the original image content. Thus, mind viewers in my opinion are completely outrageous, and they always seem to make me wince when I encounter them in stories.

Memory Erasure - General Memory Possible, Specific Memories Not Possible
    Men in Black features a "neuralyzer" device that selectively erases the last X minutes or so of a person's memory. We already know that getting bumped in the head can cause people to forget things. If we know that memories are stored in the brain by altering the neural connections, it is certainly possible that by some form of deliberate brain "damage", one can cause someone to forget things. The question is, how do you know which parts of the brain to fiddle with? Erasing the most recent memories seems plausible since those changes could probably be identified in some way. However, trying to selectively erase a particular memory, or all memories of a particular subject, would be quite impossible for the same reasons given for the viewer technology above, unless you had been there to record the changes at the time the memories were formed.

Mind Control - Possible, To A Degree
    In The Wrath of Khan, the villain uses an alien worm creature to control Chekov. The worm somehow attaches to the subject's brain and makes them succumb to commands. This is not unlike hypnosis, and certain drugs are known to make people more open to suggestion. But hypnotists and even cult leaders know that without the subject's willing cooperation, they could not control anyone's behavior entirely. Recent research, for example, suggests that the parietal cortex is the place where decisions about movement are made, but it is not that simple. Stimulating this region either makes people have the desire to move, or makes them think they moved when they in fact did not. Stimulating the premotor cortex causes them to move involuntarily, but they are aware that they did not intend it. I believe the actual decision to move originates in the will, which is a metaphysical event. Thus, I think certain degrees of mind control may be possible, but the human will can never be completely subdued. Fortunately, most writers seem to agree with this and allow their mind controlled characters to break away from their captors given sufficient willpower.

Virtual Reality Systems - External Easy, Internal Not
    This theme has appeared a lot in modern times, with The Matrix serving as the poster-child example. We know that virtual reality is easy to accomplish if you do it by sending sensory data directly into a person's senses, and this is how it is often portrayed. The interface in Matrix is instead a direct connection to the brain. This means it requires stimulation of the sensory input centers of the brain in such a way as to re-create the desired sensations. However, Matrix has the advantage of creating an interface that each person grows up with from birth, and therefore would have the opportunity to "teach" the brain how to interpret its signals. The big problem there, of course, is that it would render your real senses useless. Once unplugged, it would most likely be impossible for your brain to re-wire itself to experience the real world through eyes, ears, and skin. The system in Surrogates does not have this limitation, but it presents an even more problematic technology based on some type of digital telepathy.

There is so much that could be covered on this topic, but I decided to try to keep it to one long entry rather than a lot of short ones because it is not the main focus of the blog. It is, however, a relevant topic in science fiction literature that won't be going away any time soon. I'm sure there are a lot of other opinions out there if you care to share them.

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