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