TED TALK: I am my Connectome by Sebastian Seung


TED TALK by Sebastian Seung: I am my connectome

We are in the age of genomics. Your genome is the entire sequence of your DNA. Your genes give you diseases, shape your personality, give you mental disorders. Genes seem to have power over your destiny, yet we are more than our genes.

You are your Connectome.
Only one connectome has been defined.
C. Elegans, 1986, 300 neurons. 7000 connections.

We speculate that memories are stored in the connections between your brains neurons.
Personality could also been encoded in the connections between them.

The connectome is only a hypothesis. More sophisticated technology is needed to test this hypothesis.

In order to find connectomes we have to see all the neurons at the same time.

Male vs Female brain.
Men Are Like Waffles–Women Are Like Spaghetti – Bill Farrel Pam Farrel
Male: brains are like waffles, they keep their lives compartmentalized in boxes
Females: brains are like spaghetti, everything in their life is connected to everything else.

However, everyone’s brains are like spaghetti, all strands like neurons contact other neurons through their entangled branches. One neuron can be connected to so many other neurons because there can be synapses at these points of contact.

When you look at a brain with your naked eye you can’t really envision its complexity. Once you study it through a microscope its hidden complexity is revealed.

17th century mathematician BLAISE PASCALE wrote of his dread of the infinite.
He felt insignificant relative the vast reaches of outer space.
How dare we think that we might ever understand the brain, the inner universe??

One must persist in this quixotic endeavor, as some day a fleet of microscopes will be able to capture every neuron and every synapse in a vast database of images. AI super computers will analyze the images to summarize then into a Connectome.

Finding the entire human connectome is the greatest technological challenges of all time. It will take the work of generations to succeed.
Presently, what scientists are aiming for is much more modest: partial connectomes of tiny chunks of mouse and human brain. This will be enough to test the hypothesis of “i am my connectome”.

Is this hypothesis Plausible? Is it worth taking seriously?
As you grow during childhood and age during adulthood your personal identity changes slitley. Likewise every connectome changes over time.

Changes:
1. Neurons, like trees, can grow new branches and lose old ones.
2. Synapses can be created and eliminated. They can grow larger and smaller.

What causes these changes?
1. They can be programmed be your genes. But this is not the whole story though.
2. Neural Activity, electrical signals that travel across branches of neurons and chemical signals that jump across from branch to branch.
Lots of evidence exists that neural activity is encoding our mental experiences (thoughts, feelings and perceptions).
Also, evidence exists that neural activity can cause your connections to change.
These facts mean that your experiences can change your connectome.
This is why every connectome is unique.

The connectome is where nature meets nurture.
The mere act of thinking can change your connectome.

Metaphore between neural activity and conductivity:
Neural activity is constantly changing, like the water of a stream it never sits still. The connections between neurons determine where neural activity flows. ie. the connectome is like the bed of a stream.
The bed guides the flow of water, but over long time scales, the water also reshapes the bed of the stream.

Neural activity is the physical bases of thoughts, feelings and perceptions.
STREAM OF CONCIOUSNESS: Neural activity is its water and the connectome is its bed.

Testing the hypothesis: “i am my connectome”.

Direct test: attempt to read out memories from connectomes.
Consider the memory of long temporal sequences of movements (pianist playing a Beethoven Sonata). According to a 19th century theory, such memories are stored as chains of synaptic connections inside your brain. Once the first synapse fires the stream flows down the line like a chain of falling dominoes. This sequence of neural activation is hypothesized to be the neural basis of the sequence of movement.
One way of testing the theory is to look at those chains inside connectomes.
The chains are very complex and computers must be used to unscramble the chain. If successful, the sequence of neurons recovered by unscrambling will be a prediction of the pattern of neural activity that is replayed in the brain during memory recall.

THE BRANCHES OF NEURONS ARE THE WIRES OF THE BRAIN.
Length of wires in the brain is millions of miles all packed in your skull.
Thus, there is huge potential for miswiring in the brain.
We are not sure if neurological diseases are brought about such miswirings in the brain. The technologies of seeing connectomes will allow finally read miswiring in the brain, to see mental disorders in connectomes.

Sometimes, to best test a hypothesis is to consider its most extreme implication.
Testing the beliefs of cryonics: studying the connectomes of cryoprotected individuals.
We know that damage to the brain occurs after death and during freezing, the questions is has the damage erased the connectome?
If so, there is no way the these memories can be recovered.
Resurrection might succeed for the body but not for the mind.

What distinguishes us from other animal’s is our larger brain.
The Human Connectome will mark a turning point in human history.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

  • Top Rated

  • العقل السليم في الجسم السليم

  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 27 other followers

  • Meta

  • Blog Stats

    • 124,395 hits
%d bloggers like this: