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SURVEY OFILE
TECHNOLOGIESV1.0
• functionalism of consciousness
• qualia has no direct physical correlate
• a computer simulating the brain will be conscious
PHILOSOPHY
• a computer simulation executing just 1 instruction per 1000000 years will experience the same qualitative consciousness as the brain
qualia does not depend on space- or time- scale
SPACE-TIME
• Jonah is fullyconscious insidethe whale
• his consciousnessdoes not contribute tothe whale’s consciousness
qualia does not depend on substrate
SUBSTRATE
there is no clear-cut distinction betweenlife and death
in post-upload world substrate-hopping will bethe norm
LIFE ISINFORMATION
PATTERN
MOORE’S LAW
• in ~10-80 years computer = human brain in power
• explosive increase in computational intelligence will bring disruptive change
• identity crisis for human race
“PROPHECY”
• sexual reproduction is not necessarily the most competitive / desirable
• technological progress will continue, driven by human desires
• balance between desirability and competitiveness
SEXUAL REPRODUCTION
NEED OF INTERFACING
artificial intelligence &intelligence augmentation
AI / IA
uploads
seamless
integration
meat brains
AI / IA
cryonics
1. uploading / neuroprosthesis2. anti-ageing
2 APPROACHES TO
IMMORTALISM
UPLOADING
• transfer memories and personality to computer
• brain will be destroyed during scanning
• philosophically sound but somewhat unnatural
OBSTICLES1. insufficient computational power
( computational power of brain = ? )
2. incomplete understanding of neurobiology
3. uploads will not be accepted without high confidence of isomorphism with biology
4. funding is a problem (uploading cannot be done partially; lack of an incremental strategy)
BRAIN EMULATIONrequires:
1. electrophysiology (spiking models)
2. neural plasticity (modeling @ molecular level)
3. brain connectivity map (scanning)
4. whole-brain neurochemical database (automated bioassay)
1. ELECTROPHYSIOLOGY• electrophysiology is relatively well-
understood• realistic models tend to have too
many parameters• dimensionality reduction: apply
statistical analysis to highly realistic computer models to automatically reduce # of parameters
2. NEUROBIOLOGY
• simplify molecular models
• memory encoded @ molecular level?
• proteomics required
• neural plasticity (especially synaptic) is not fully understood
• complete elucidation of 1 pathway to give estimate of total complexity
3. SCANNING
4. NEUROCHEMICALDATABASE
PRESERVING MEMORY
• scanning, vitrification, and reconstruction may introduce artifacts
• still, scanning is the best for preserving information vs other methods
• forgetting can be adaptive –selective forgetting is preferred
“SOFT” UPLOADING
gradual replacement of the brain with bionic components
CONFIGURATION
ALGORITHM• Perceptron learning:progressively adjustsline to divide planeaccording to sign of error
• extends to hyperplane and hypercube in higher dimensions (n = # synapses)
• generalizes to gradient descent on high-dimensional landscape (cost function) for non-linear models
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ANTI-AGING• body is relatively unimportant
• within ~10-50 yrs all parts of the body can be replaced by synthetic / biological technologies
• heart, liver, blood, immune system, etc… except the brain
BRAIN AGING
• myriad cellular processes
• pathways mostly unknown
• replacement is more feasible than repairing
• progressive deviation from optimality
BRAIN REJUVENATION
requirements:1. integration with host2. suppression of rejection3. innervation of targets –
requires re-expression of developmental cues
4. proper neurochemical function
AVAILABLE TECHNIQUES
1. xenotransplantation2. neural stem cells3. regeneration4. neurogenesis5. genetic approaches6. nanomedicine
1. XENOTRANSPLANTATION
recent progress: immunosuppression of host immunomodification of graft integration with host synapse formation
2. NEURAL STEM CELLS
recent progress: long-range innervation from
implant to host cryopreservation
• developmental niche is lost in adult brain
3. REGENERATION
1. facilitate axonal regeneration using Schwann cells and olfactory enshealthing cells
2. applicable to spinal cord injuries and peripherals
sub-ventricular zone (SVZ)
in hippocampus, and
migrate to cortex
• up-regulate to replenish neurons in the brain
4. ADULT NEUROGENESIS
4. GENETIC APPROACHES
• use of retroviral vectors to modify genetic code
• modification of the cells’ neurochemical properties such as axonal guidance
5. NANOMEDICINE
• requires sophisticated nanotechnology which is uncertain
• may become unnecessary because of uploading
CONCLUSION
high-complexity road blocks in both approaches:
• uploading: neural plasticity & information-encoding at molecular level is murky
• brain rejuvenation: re-creation of developmental “niche”
linear approach is bound to fail
success
must concentrate resources to systematically solve problem
complexity barrier
funding
© Dec/2003