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[The following is tentative material for my presentation at the Society for Philosophy & Technology Conference this summer.]
[Other entries in this series.]
Do Posthumanists Dream of Pixilated Sheep?
Bostrom and Sandberg's Brain Emulation,
Examined and Critiqued
Section 3:
Awake! Arise! or be Forever Disorganized
Bostrom’s & Sandberg’s Roadmap presupposes a physicalist standpoint. So everything has a physical basis. Minds emerge from the brain’s pattern of physical dynamics. If you replicate this pattern-dynamic in some other physical medium, the same phenomena should likewise emerge. They write that “sufficient apparent success with [Whole Brain Emulation] would provide persuasive evidence for [this theory that consciousness may be realized in multiple distinct physical forms, or what’s called] multiple realizability.” (Bostrom & Sandberg 14)
Our mind’s emergence requires a dynamic process. Paul Humphreys calls it diachronic pattern emergence. (Humphreys 438)
According to emergentist theories, all reality is made-up of a single kind of stuff. But its parts aggregate and assemble into dynamic organizational patterns. The higher levels exhibit properties not found in the lower ones. Yet, the higher level would not exist were it not for its constituent lower level. (Clayton, 2-3)
Todd Feinberg suggests water, for example. The H2O molecule does not itself bear the properties of liquidity, wetness, and transparency. However, an aggregate does. (Feinberg, 125) Emergent features go beyond what we may expect from the lower level. Hence the higher levels are greater than the sum of their parts.
In our brains, no one single neuron is conscious. Yet our minds emerge from the complex dynamic pattern of all our neurons communicating and computing in parallel. Roger Sperry offers compelling evidence. There are "split brain" patients whose right and left brain hemispheres are disconnected from one another. Nonetheless, they maintained unified consciousness. But there is no good account for this on the basis of neurological activity. (Clayton 20)
William Hasker follows Sperry. He says that mental properties “manifest themselves when the appropriate material constituents are placed in special, highly complex relationships.” (Hasker, 189-190) He offers the analogy of magnetic fields, which he says are distinct from the magnets producing them. For, they occupy a much broader space. The magnetic field is generated because its “material constituents are arranged in a certain way – namely, when a sufficient number of the iron molecules are aligned so that their ‘micro-fields’ reinforce each other and produce a detectable overall field.” Once generated, the field exerts its own causality, which affects not only the objects around it, but even the very magnet itself. Hence Hasker’s analogy: just as the alignment of iron molecules produces a field, so too the particular organization of the brain’s neurons generates its field of ‘consciousness.’ (190) This emergent consciousness-field permeates and haloes our brain-matter, occupying its space and traveling along with it. (192)
Suppose whole brain emulation continually falls short. This could support Todd Feinberg’s argument that the mind does not emerge from the brain. He agrees with Searle that
the naïve idea here is that consciousness gets squirted out by the behavior of the neurons in the brain, but once it has been squirted out, then it has a life of its own (Searle, 1992) (qt. in Feinberg 126)
Feinberg does in fact think consciousness results from the interaction of many complex layers of neural organization. However, no level emerges, because none are more independent than any other. Our vision illustrates. We see a wide variety of stuff. But we can recognize singularities like our grandmother. Much visual information must be processed through many layers of neuron-circuits until finally arriving at the “grandmother cell.” Yet all layers must work together at once to achieve this recognition. The brain is a vast network of circuits far too interconnected to discern higher and lower levels of organization. (Feinberg 130-131)
But perhaps Feinberg, so to speak, looks too much among the iron atoms and so he never notices the surrounding magnetic field. Nonetheless, his objection may still be problematic for whole brain emulation. Bostrom & Sandberg write:
An important hypothesis for WBE is that in order to emulate the brain we do not need to understand the whole system, but rather we just need a database containing all necessary low-level information about the brain and knowledge of the local update rules that change brain states from moment to moment. (Bostrom & Sandberg 8)
But if Feinberg’s holistic theory is correct, we cannot only emulate the lower levels and expect the rest to spontaneously emerge. For, we need already to understand the higher-levels in order to program the lower ones. Thompson et al. write:
The brain is thus a highly cooperative system: the dense interconnections among its components entail that eventually everything going on will be a function of what all the components are doing. (Thompson, Varela, & Rosch 94a-b)
Thus the behavior of the whole system resembles a cocktail party conversation much more than a chain of command. (96a)
Consciousness results from neural activity. But it might do so in a way that is not perfectly suited to emergentist theories. Hence whole brain emulation might provide evidence indicating whether and how our minds relate to our brains.
Clayton, Philip. "Conceptual Foundations of Emergence Theory." in The Re-Emergence of Emergence: The Emergentist Hypothesis from Science to Religion. Ed. Philip Clayton and Paul Davies.
Feinberg, Todd E. "Why the Mind is Not a Radically Emergent Feature of the Brain." in The Emergence of Consciousness. Ed. Anthony Freeman,
Hasker, William. The Emergent Self.
Humphreys, Paul. "Synchronic and Diachronic Emergence." Minds and Machines. Vol.18, Number 4, December, 2008, pp.431-442. More information and online text available at: http://www.springerlink.com/content/d442431150343t17/?p=f1cef51a00d346b582d2c3ad1386c814π=1
Sandberg, A. & Bostrom, N. (2008): Whole Brain Emulation: A Roadmap, Technical Report #2008‐3, Future of Humanity Institute,
Searle, J. R. The Rediscovery of the Mind.
Varela, Francisco J, Evan Thompson, & Eleanor Rosch. The Embodied Mind: Cognitive Science and Human Experience.
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