I came across a great video called The Great Mystery of the Brain which brings together experts from different fields in a round-table format. Part 1 of the video is available at:
http://www.charlierose.com/view/interview/10694
Very Rough Notes – May be Useful – No Guarantee Provided 🙂
There are more neurons in the brain than stars in the galaxy.
We have learned more in last few years than entire previous.
Scientists have unprecedented access to brain activity using modern technology.
Some Questions for the Program (and science)
How does brain lead to mind?
How do the circuits allow us to feel, cognition, and function?
Can we get insight into how to cure alzheimers, depression etc.
Where does intelligence come from?
How can education move in a new direction?
Mind is a series of functions carried out by the brain. Every aspect of our behavior is carried out by the brain – from simple reflexes to running a TV program.
People have been thinking about the mind since the Ancient Greeks, but in the first 19 centuries, they had only philosophy. Then psychology and now much more.
Psychology, brain sciences, molecular biology are coming together.
The mind will be the main focus of biological science this century. Understanding the human mind is the most complex challenge of science.
“What is consciousness?” This is interesting because I cannot experience what is going on in your head and I have no immediate access to that. This is the most complex question in all of brain science.
Neuroscientists and Humanists can come together. Psychology departments and neuroscience departments are already almost indistinguishable.
The brain is always changing. After this program, you will be a different person. Drinking a glass of water changes the brain. This explains how we grow intellectually and how we can recover from accidents to the brain.
Brain is at the center of our individuality and our existence.
Eric Kandel
John Searle – philosopher
Gerald Fischbach – neuroscientist
Cornelia Bargmann – studies brains of microscopic brains
Tony Movschon – studies visual system of primates
Movschon
Cereberal cortex is most highly evolved area of brain.
Customarily divided into four lobes.
Occiptital Lobe: Visual Function
Temporal Lobe: Higher processing of visual; laying down of memory; processing of sound; conversion of sound into language
Parietal Lobe: Spatial processing; formats motor commands for muscles
Frontal Lobe: Most highly evolved; makes us human; responsible for executive functions such as decisions, actions,
Cerebral cortex looks like a cauliflower, but is actually elaborate sheet of cells which has been folded like a piece of paper.
Cool video of “inflating” brain. The video shows it being flattened into a single flat sheet of cells. Localized areas of the brain can be visualized as appearing on this flat sheet.
Bargmann
Studies at much finer level of detail.
We have now decoded the human genome.
Humans can generate language because we have genes.
The map of the human genome is like an encyclopedia with 25,000 entries.
Question: How much of behavior is determined by genes and experience?
e.g. Colours is determined by expression of three genes. If you’re missing one, you will be colour blind.
e.g. Language is completely determined by environment and experience
Searle
More interested in how Consciousness is produced than the fine details of neurobiology
Easy problem: What are the neurobiological correlates of conscious processing?
Hard problem: How does the brain get over the hump from neuron firings to human feelings?
Each of these feelings is
a) a special qualitative feel
2) subjective
3) unified (part of a bigger field in the brain)
Fischbach
Insights into neuroscience are now poised to make major contributions to understanding disease.
Discusses localization
Long-term memory is a change in the expression of the genes – leads to growth of new synaptic changes. Watching this program causes a change in the connections in the brain.
Nerve cells are the building blocks of the brain.
Just like any other cell.
Then he says they are very different! Much more vulnerable.
Axon continues to grow and grow.
Dendrite is like a forest.
Axons are really really long! The cells have to work really really hard to generate the protein to supply the protoplasmic structure.
Nerve cells send signals, at about 100 miles per hour.
You can actually hear the bursts of activity with a precise microphone.
If blood flow is gone for a matter of seconds, these cells will die. Muscles elsewhere in the body can survive for minutes.
There are 100 billion nerve cells. For every nerve cell, there may be 1,000 synapses.
The brain is made of meat, not silicon or computer. The connections are chemical. The computer is a useful analogy, but the brain works the way it does because it isn’t made of silicon. The anatomy of the brain matters a lot! You can’t replicate its function with just any structure.
Bargmann
We have genes. We have to make billions of different brain cells (we don’t know how many kinds.
Somehow the genes divide out the functions. Then they have to connect these cells together through trillions of synapses. These are not random, but rather reliable between individuals and orderly. The highways in each person’s brains are the same. The smaller roads are partly genetic and partly experience. A thought can be turned into a biological reality in your brain.
When we sequenced the human genome, we found that very few of them are brand new. They are similar to those shared with animals. We tweaked them, used them in new ways, and used them for longer times.
We work with worms because they are simpler to understand.
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Every cell in the body has the same genes. The difference is which ones are turned on and in what order. The cells turn them on.
Movschon
Studies primates.
The principles of circuit construction mean that circuit design seems to be the same in low-level animals and humans. The advantage of studying primates is that we can ask similar questions that we ask of humans – issues of cognition.
A monkey’s brain is 1/5 the size of a human brain and shares the same architecture.
e.g. The visual area seems to be very similar.
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Searle
Biggest question: What is consciousness?
1. Find correlates (NCC =neuronal correlates of consciousness)
2. Find out if these are causal. Can we turn on/off the consciousness.
3. Then develop a theory. How do the correlates cause consciousness
Bargmann: How does one brain generate infinite combinations?
Fischbach:
All current therapies are symptomatic.
How can we cure by stopping the pathology?
Movschon:
Which level of analysis of the brain is suitable?
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Lack of progress in psychiatry. No better drugs since the 1950s for schizophrenia. No new drug for depression in 20 years.
Kandel
Interested in how memory is perpetuated.
New synapses that grow have to be maintained.
Interested in how things get maintained for very long time.
What is it that allows a human brain to be switched in one way or another?
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