Neurobiological Reflections on "The Matrix"

"Have you ever had a dream, Neo, that you were so sure was real? If you were unable to awake from that dream, how would you know the difference between that dream world and the real world?" -Morpheus 0:31:45



    "The Matrix," the 1999 movie by the Wachowski brothers, tells the story of a futuristic world in which machines enslave the minds of humans for energy harvesting. Humans carry out their lives in a highly developed simulation known as the Matrix, completely unaware of the true purpose of their existence. This paper intends to analyze the neurobiological aspects of the movie, investigating the feasibility of such a dystopia. Many of the themes presented by The Matrix bear direct relationship to what we have been discussing throughout the semester. Using the movie as a starting point, I shall explain the notions of Descartes' Evil Genius, the Brain in a Vat thought experiment, and Plato's Allegory of the Cave. Finally, I will discuss whether we use our iFunction and sensory inputs to define what is real.

The Evil Genius
    Most analyses of "The Matrix" quickly point out the strong nod to Descartes' notion of an "Evil Genius." Descartes suggests a thought experiment wherein we live in a world run by a powerful figure who architects a brilliant deception. Specifically, the Evil Genius fools us all into believing that we are living the lives we are living. In reality, we may have no idea what is actually going on "behind the scenes" of this illusion. Through masterful control of our senses, we are fooled into believing a false world. As Descartes explains,

"God could have given me a nature such that I was deceived even in matters which seemed most evident." (Descartes, Meditation 3, AT 7:36)

    In other words, we could be fooled through the manipulation of our sensory inputs. As we endear our senses with unquestioning trust, such a manipulation would likely be highly successful. Obviously this is very similar to the world presented in The Matrix, wherein the machines enslave humans through the use of a computer-generated illusory world. Descartes' thought experiment suggests an interesting question: why is it that we trust our senses so much? We might question our state of mind, but do not generally question the validity of our sensory input. One might say to themselves, "I should not make this important decision right now because I am too tired," or "I am getting frustrated and need to calm down, maybe it's because I haven't eaten." Such statements question the efficacy of our reasoning abilities. But rarely does one think, "I wonder if that desk in front of me is actually brown." We may temper our emotions and at times even doubt the logical capabilities of our iFunction, yet we rarely scrutinize the input feed we use to make these decisions. In moving forward with our discussion of the neurobiological themes presented in The Matrix, we shall call heavily upon the possibility that we are being deceived in such a manner as presented by the Evil Genius Hypothesis.

Brain in a Vat
    In addition to Descartes' Evil Genius, the world presented in The Matrix is frequently analogized to the "Brain in a Vat" thought experiment. In the "brain in a vat" model, a brain exists in a controlled laboratory and is suspended in a life-sustaining medium. A scientist hooks up electrodes and connects a computer that serves as the sensory input for the brain. The brain "thinks" that it is a fully independent human being, complete with sensory input and free will. In fact, it is nothing more than a brain being fed an array of computer-generated sensory inputs. Specifically, this model bears close resemblance to the energy mining fields run by the machines. In both cases, the creatures are not aware of their "true state," but rather live in a computer-generated world.
    We can use the "brain in a vat" model as a useful starting point to analyze the feasibility of such a world. Is it possible that we live in such a world? We can call the possibility that we are living in such a world "The Matrix Hypothesis." (1) As suggested by David Chalmers (U. Arizona), we shall define the Matrix Hypothesis as the positive assertion "yes, we exist in a matrix or illusory world."1 Now we shall attempt to determine if such a system is indeed feasible. In order to do so, we must take on three assumptions.

Assumption 1: A Feasible Computer Program
    The first assumption of the Matrix Hypothesis is that there must be a computer or system of computation that is capable of simulating an interactive world. While computers may not presently be able to do such a task, it would be foolish to eliminate this possibility at some future time. Such a computer would have to anticipate likely sensory input and then deliver it. Using our own nervous system as a starting point, theoretically this is not a huge impossibility. Each of us is able to establish expectations for sensory input through the use of corollary discharge signals. Our bodies are constantly calculating and readjusting sensory expectation. Hence, such a computer would be tasked with determining these signals for a population en masse. While perhaps not presently feasible, the notion of such a computer program does not lie outside the realm of possibility. [It is interesting to think what would happen if such a computer encountered an operational error and miscalculated. In this situation, the subject (or subjects) would experience a misalignment of expectation and sensory input. Perhaps all subjects would be suddenly stricken with a feeling of nausea!]

Assumption 2: The Simulation Can Convey Input
    The second assumption is more interesting from a neurobiological perspective. It must be possible for the simulation output to be given as input for someone's brain. In other words, the simulation must be able to not only accurately calculate the sensory information, but it must also be able to convey it completely. If the simulation wants to project the sight or smell or touch of a chair, the brain must be able to receive this signal.
    Again, such an assumption seems plausible. Consider the example of Deep Brain Stimulation, wherein surgically implanted electrodes emit electrical signals that can control sensation and activity, reducing negative disease factors like pain or tremors (4). As presented by Deep Brain Stimulation, it is feasible that direct innervation of the brain could be used to convey sensory input. As an electrode can stimulate or alter perception, it is possible that a computer could convey input to a connected user. Furthermore, users could be connected back to the computer so as to convey output signals. Once again, we see this is already possible. Computer cursors and other external devices can already be controlled using the mind (8). Considering that the technology already exists [at least on a very elementary level], I suggest that this assumption is also feasible.

Assumption 3: It Must Be Convincing
    The third assumption concerns the quality of such a system. The system must be sufficiently good that the simulation is convincing; the brain cannot be able to identify it as an externally generated illusion. I use the word "illusion" with great caution, because it is difficult to define what is "real," but we will address that later.
One should first ask, "Is it possible that we may be deceived into perceiving something that does not actually exist?" Yes, I believe it is. Consider the example of the blind spot test. Our retinas do not actually see any continuous line, yet we still perceive the broken line as continuous. Our own nervous system is tricking our conscious self into perceiving something that does not actually exist. This occurs because our nervous system fills in sensory gaps with what is expected. Therein, if a matrix could somehow match the expectations of our nervous system, theoretically it could similarly deceive us. To be efficacious, such a model would have to offer a reality that is significantly aligned with our expectations. In other words, you can't be walking down the street and see someone dodging bullets in slow-motion without raising suspicion regarding the validity of your reality. Provided the simulation could meet our expectations, it may be sufficiently convincing such that we could not identify it as an illusion.

    As outlined by these three assumptions, there are several key criteria necessary for the Matrix Hypothesis to be considered valid. However, I suggest that all three assumptions are feasible. Hence, I believe it is possible from a neurobiological approach to suggest that the Matrix Hypothesis is viable. The intricacies of this debate rapidly deteriorate into a moral and philosophical nightmare, hence for our sake we will stick primarily to the neurobiological aspects that suggest the feasibility of such a construct.
   
Allegory of the Cave
    The Matrix also borrows strongly from Plato's Allegory of the Cave, which we also discussed earlier in the semester. The Allegory of the Cave tells the story of prisoners who grow up chained facing a blank wall in a cave. Shadows cast on the cave wall project what the prisoners believe to be true forms, but in reality these visions are just illusions cast by puppeteers. When a prisoner is able to break free, they wander outside and are blinded by light. This bears strong resemblance to the dialogue between Morpheus and Neo when Neo first emerges from the Matrix:

Neo: "Why do my eyes hurt?"
Morpheus: "You've never used them before."  (0:36:05)

    By subsequently mastering the interchange between the Matrix and the real world, Neo is able to switch between being chained in the cave and walking free. He is able to internalize and understand the false sensory perception of the prisoners. Just like the newly freed prisoner, Neo is overwhelmed by the first use of actual sensory input.
This bears strong resemblance to Plato's Theory of Forms, wherein non-material Forms exist as the most true and valid form of being. The lesser Forms we perceive through sensation are similar to the actual true forms, but are not true in nature. As Morpheus explains to Neo, "Your appearance now is what we call residual self image...it is the mental projection of your digital self" (0:40:11). Neo's self-perception is actually a distorted version of his true self. Once again, we must consider the feasibility of such a hypothesis. As we have discussed, we endear our senses with such a great degree of trust that we would likely be deceived by non-material Forms, or by illusions such as those presented by the shadows. But if we cannot determine non-material Forms from truth, how do we know what is actually real?

Defining the "Real" World
    As mentioned earlier, The Matrix begs the philosophical question "what is real?" As Morpheus explains to Neo:

    "What is real? How do you define real? If you're talking about what you can feel, what you can smell, what you can taste and see, then real is simply electrical signals interpreted by your brain."  -Morpheus, 0:40:25

    How can one say that a certain world is more real than the other? Is it possible to define reality using the neurobiological construct we have established? To say that the Matrix is "false" is to say that the presence of our brain alone is insufficient for the definition of reality. That is, the mere presence of the iFunction in one world is insufficient criteria for categorizing it as a valid reality. There must be something else additionally present in order to define a reality as valid.
Consider the alternate hypothesis, "in order to be real we must be using our senses." This also is a tricky line of reasoning. How do you account for quadriplegics, blind, or deaf people? Certainly those with suppressed sensory function are not living in a less-real world. Similarly, what if we use our senses but not our iFunction? Consider the example of someone who is sleeping. If you poke them, they may withdraw (indicating there was some sensory stimulus), but their iFunction may have nothing to do with it. Most of the time the iFunction is inactive when we are sleeping. When you are not dreaming, you are not there. Yet, you are still moving around and responding to inputs. Specifically, you are not falling out of the bed because the nervous system is still receiving and processing inputs. Consider the case of Hannah Upp (http://www.philadelphiaweekly.com/news-and-opinion/39878827.html). Hannah was able to accomplish numerous tasks and live in the absence of an iFunction. Because she did not consciously internalize what happened, does that make the series of events any less real? It appears that neither the presence of the iFunction or of sensory inputs is sufficient to define reality.
    As an example, consider the "real" world presented in The Matrix, the world of the human energy harvesting fields. For those humans in the pods, neither sensory input nor the iFunction is present; both exist elsewhere. It is not entirely clear which reality they live in. Their iFunctions (and their corresponding storytellers) appear to live in the Matrix, but where are their sensory inputs? The sensory inputs are turned off in the "real" world, but they are under external control in the Matrix. In other words, they do not have any autonomous sensory inputs. Rather, their sensory input is in a "null" state, a falsified version of a constructed reality. We cannot say that these humans are "unreal," because certainly their realities must exist somewhere. It is not entirely clear where or what constitutes reality for them.
In evaluating these examples, how could we determine what is reality? It seems that both sensory input and the iFunction ought to play some role in determining reality, but the exact specifications are unclear. Consider general anesthesia, yet another instance of questionable reality. Patients under general anesthesia generally do not report dreams, yet we also know that their sensory inputs are inactivated. Just as the case presented in the Matrix, it is not entirely clear which reality the patient exists in, or where that reality is.
    This discussion of the criteria for defining a reality leaves us in a difficult spot. It appears that the iFunction and sensory input may play a role in defining a reality, yet neither is exclusively sufficient or necessary. Perhaps this question is impossible to answer. Do we really need reality? Trees do not have any well-defined reality. Furthermore, even amongst those who appear to have a reality (such as humans), no two realities are the same. In fact, they are necessarily all different. If each reality is determined by the aggregation of numerous facets, (including sensory input, corollary discharge signals, and past experiences), then we know that we must each live in a different reality. By definition, no two realities can be the same. Perhaps most importantly, we can conclude that defining a reality could only be viable for the definer; it is impossible to understand any other reality than our own. As Morpheus suggests, perhaps the notion of "reality" is something of a construct. Although some things may feel intuitively "real," we have no evidence to suggest that anything we can see, feel, or think of has any indication of a real state of being.

    The Matrix puts forth a variety of philosophical and neurobiological questions that challenge the validity of our sensory inputs. Many of the concepts we have discussed this semester can be seen as underlying themes of the movie. In The Matrix, the iFunctions of humans are held captive in a computer-generated dream world, and sensory input is managed by a computer simulation. Is it possible that we also are held captive in such an illusion? As shown by the Brain in a Vat thought experiment, there is no definitive way to eliminate such a hypothesis. The three assumptions that I have suggested for the Matrix Hypothesis appear to all be plausible. Similarly, what are the criteria to define a reality? It appears that the presence of an iFunction and of sensory input are insufficient. Perhaps more importantly, is it actually possible to define a reality? As we have continually emphasized this semester, each person's experience is unique as determined by a variety of factors. Hence, it is likely impossible to define any viable universal reality. For now, we will have to search for more clues to further answer these difficult questions.





Side Note: Be sure to check out "How to Live in a Simulation," by Robin Hanson (source 5 below). This incredible piece discusses the optimal solution for surviving if indeed we do live in a constructed reality!


Sources

(1) "The Matrix," Andy & Lana Wachowski, 1999

(2) "The Matrix as Metaphysics" David Chalmers, University of Arizona, http://consc.net/papers/matrix.html

(3) http://plato.stanford.edu/entries/descartes-epistemology/

(4) http://www.ninds.nih.gov/disorders/deep_brain_stimulation/deep_brain_stimulation.htm

(5) http://www.jetpress.org/volume7/simulation.htm

(6) http://www.nytimes.com/2007/08/14/science/14tier.html?pagewanted=2&_r=1

(7) http://www.redorbit.com/news/science/37019/the_science_behind_the_matrix/index.html

(8) http://www.livescience.com/health/050317_brain_interface.html

Class notes, Neurobiology (Prof Grobstein), Spring 2010





Direct References from "The Matrix"

"a prison that you cannot smell or taste or touch...a prison for your mind"
Morpheus 0:28:30

"the pill you took is part of a trace program... it's designed to disrupt your input/output carrier signals so we can pinpoint your location"
Morpheus 0:30:30

"Have you ever had a dream, Neo, that you were so sure was real? If you were unable to awake from that dream, how would you know the difference between that dream world and the real world?"
Morpheus 0:31:45

"Your appearance now is what we call residual self image...it is the mental projection of your digital self"
Morpheus 0:40:11

"What is real? How do you define real? If you're talking about what you can feel, what you can smell, what you can taste and see, then real is simply electrical signals interpreted by your brain."
Morpheus 0:40:30

"It exists now only as part of a neural-interactive simulation we call the matrix."
Morpheus 0:40:43
1 The Matrix Hypothesis does not refer necessarily to the Matrix, (capital "M"), the specific world presented in the movie, but rather to the presence of any computer-generated matrix or artificial environment.