Showing posts with label Brains. Show all posts
Showing posts with label Brains. Show all posts

Monday, 1 October 2007

Genius and Madness

From Science Daily:
Psychologists from the University of Toronto and Harvard University have identified one of the biological bases of creativity.

The study in the September issue of the Journal of Personality and Social Psychology says the brains of creative people appear to be more open to incoming stimuli from the surrounding environment. Other people's brains might shut out this same information through a process called "latent inhibition" - defined as an animal's unconscious capacity to ignore stimuli that experience has shown are irrelevant to its needs. Through psychological testing, the researchers showed that creative individuals are much more likely to have low levels of latent inhibition.

"This means that creative individuals remain in contact with the extra information constantly streaming in from the environment," says co-author and U of T psychology professor Jordan Peterson. "The normal person classifies an object, and then forgets about it, even though that object is much more complex and interesting than he or she thinks. The creative person, by contrast, is always open to new possibilities."

Previously, scientists have associated failure to screen out stimuli with psychosis.
...
The authors hypothesize that latent inhibition may be positive when combined with high intelligence and good working memory - the capacity to think about many things at once - but negative otherwise.
...
"Scientists have wondered for a long time why madness and creativity seem linked," says Carson. "It appears likely that low levels of latent inhibition and exceptional flexibility in thought might predispose to mental illness under some conditions and to creative accomplishment under others."

That might explain why those that survive being TS tend to be both hyper-intelligent and also hyper-creative. Being TS, having a brain neither entirely M nor F - likely leads to creativity, being open to stimuli others filter out. But unless the person is also unusually bright, it may lead to insanity too. Only the bright don't kill themselves, and the stratospherically high TS suicide rate would certainly fit in with that. So the mystery of the evidenced 2 standard deviation increase in IQ isn't caused by some weird neurology, as the creativity seems to be. It's possibly a result of Natural Selection, not Natural Talent.

Call it Evolution in Action.

Tuesday, 18 September 2007

Constructing the Human Brain

There's more to the specification than is in the DNA.

From Lloyd of It Looks Different From Here :
When the Human Genome Project was completed everyone was surprised at how few gene there were. Only about 20-25,000 protein coding genes. It was not that much larger than that for much simpler organisms. So where was the greater complexity of humans and other mammals coming from? Where was the coding for the difference between human brains and those of other mammals?
...
The talk I went to today was on estimating how many micro-RNAs there were in a given species. It turned out to be a lot. An awful lot. In a mouse they estimated that there were over a million micro-RNAs. Less complicated organisms had an order of magnitude or more less micro-RNAs. And what was really interesting was that humans had over three million different micro-RNAs. Nothing else came close.

Guess what they think most of the extra micro-RNAs in humans are doing? That's right. They are probably a major part of the plan of the brain.
And in the comments:
It seems to be the construction plans. Of course the brain modifies itself, there is no sharp distinction between hardware and software. And these micro RNAs will be involved in the modifications.
Debugging self-modifying systems is notoriously difficult.

Sunday, 2 September 2007

Count the Catches

From the Visual Cognition Lab of the University of Illinois, an experiment to see how much we notice.

Carefully count the number of times a ball is caught, or bounced.

Notice anything unusual?

Tuesday, 28 August 2007

I'd Forgotten to Post about this one

A Brain Post. Summary: Long-term memory is DRAM, and the refresh mechanism allows errors.

From ScienceMag.Org:
Rapid Erasure of Long-Term Memory Associations in the Cortex by an Inhibitor of PKM
Little is known about the neuronal mechanisms that subserve long-term memory persistence in the brain. The components of the remodeled synaptic machinery, and how they sustain the new synaptic or cellwide configuration over time, are yet to be elucidated. In the rat cortex, long-term associative memories vanished rapidly after local application of an inhibitor of the protein kinase C isoform, protein kinase M zeta (PKM{zeta}). The effect was observed for at least several weeks after encoding and may be irreversible. In the neocortex, which is assumed to be the repository of multiple types of long-term memory, persistence of memory is thus dependent on ongoing activity of a protein kinase long after that memory is considered to have consolidated into a long-term stable form.
Not only is Long-term memory DRAM, but the refresh mechanism can be chemically interrupted, causing what appears to be permanent degradation of long-term memory.

DRAM - dynamic random-access memory - is the "memory" on your PC or laptop. It's cheaper to make than SRAM, Static RAM, which maintains its contents even when switched off as long as there's power applied. The memory in your mobile phone is SRAM Flash RAM, the addresses are still there even when you change the battery. The Hard Disk on your PC is also SRAM Flash Ram, essentially. When your system "boots up", the saved contents in it are loaded into the blank DRAM of the computer's memory. It's blank, because if DRAM isn't refreshed every 64 milliseconds, it loses its contents.

This work implies that the long-term memory in rats - and thus presumably all mammals, and probably all vertebrates - is DRAM. It has to get refreshed every few days (at most) by some form of inate mechanism. Interrupt the mechanism, and memory will fail.

(My thanks to Hildy for the correction. Even Jove nods)

Friday, 20 April 2007

Left or Right?

Not Politics : Brains
You Are 30% Left Brained, 70% Right Brained

The left side of your brain controls verbal ability, attention to detail, and reasoning.
Left brained people are good at communication and persuading others.
If you're left brained, you are likely good at math and logic.
Your left brain prefers dogs, reading, and quiet.

The right side of your brain is all about creativity and flexibility.
Daring and intuitive, right brained people see the world in their unique way.
If you're right brained, you likely have a talent for creative writing and art.
Your right brain prefers day dreaming, philosophy, and sports.

Except that I'm a Dog person, am not into sports at all, and combine meticulous attention to detail (I write safety-critical software!) with a hefty dollop of feminine intuition.
So this is one survey I have my doubts about.

Parenthetically, I've also gone from being outstandingly good at intuitive thinking in my field to being just another female engineer. What was rare and prized is now expected as a matter of cpurse.

With the hormonal re-wiring, I genuinely have lost some degree of typically male cognitive ability, despite efforts to retain it. I can't even fool myself that I haven't. Overall though, my thinking efficiency is improved. I miss not having an instinctive awareness of direction, but I use landmarks more to make up for it. Most of all, I relate far better to people, and they to me. I like that.

Wednesday, 18 April 2007

Pre-Natal Hormones and Post-Natal Cognition

From PhysOrg.com :

In one of the first research studies to assess sex differences in cognitive performance in nonhuman primates, researchers at the Yerkes National Primate Research Center have found the tendency to use landmarks for navigation is typical only of females.

This finding, which corroborates findings in rodents and humans and is available in the online edition of Hormones and Behavior, suggests there is not just a difference in how well females and males solve spatial problems, but also in which types of cues they use to solve such problems. Researchers are applying this knowledge to gain a better understanding of how the brain develops and functions.

Lead researcher Rebecca Herman, PhD, says the very fact females and males use different strategies suggests there are subtle sex differences in the way the brain develops. As an example of these strategies, Herman said men, when finding a location, generally use north and south as well as distance estimates whereas women prefer physical cues such as street names, signs and buildings.
...
All animals were studied once they reached adulthood. Researchers observed as the monkeys navigated an open area to locate highly valued food items in goal boxes. The researchers varied the consistency of the food locations (spatial information) and the presence of colored markers (landmarks) on baited goal boxes so they could assess the monkeys’ memory and use of spatial arrangement and markers.

"When both spatial and marker cues were available, performance did not differ by sex or prenatal treatment," said Herman. "When salient landmarks directly indicate correct locations but spatial information is unreliable, females perform better than males," she continued. “Male subjects whose testosterone exposure had been blocked early in gestation were more able to use the landmarks to navigate than were control males. They performed more like females. This suggests that prenatal testosterone likely plays a role in establishing the sex difference in using landmarks for navigation," said Herman. The researchers’ next steps are to study if males’ performance differs as their circulating testosterone levels change normally.
I think it will, based on my own experience. Even before we knew what was happening, I recorded differences like this. I find it remarkable though that this is not a characteristic of H.Sap, but in Primates in general. The way our brain-structure is sexually dimorphic - gendered - appears to be embedded deep in our evolutionary tree. It could be that instead of the social ordering of females as gatherers and males as hunters leading to the evolution of congnitive specialisation, but that the social ordering was already hard-wired in us from ancestors far more distant than the proto-chimpanzee that human, bonibo and forest chimps are all descended from.

Tuesday, 10 April 2007

An Interview for Cosmos

A Freelance reporter for Cosmos Magazine interviewed me a little while ago. His article is on Intersex, and I'm sorta kinda the Australian National University's Ally Programme "Expert" on the issue. Scare quotes intended. I did tell him that "in the country of the blind, the one-eyed man is king", but he went ahead anyway.

I'm bound to cop some flak for my views in Transsexuality being just a subset of Intersex: some Intersexed people argue passionately that it isn't. They argue, and with justification, that the evidence for this theory is by no means conclusive. Yet the trouble is, if it isn't biological, how can we explain, well, ME??? That's the trouble. Yes, I'm a "lusus naturae", a Freak if you like, but it's not as if I could do anything about that apart from play the best hand I could with the cards dealt to me. No Black Queens marked "Myeloma" or "Sarcoma". Ok, well, yes, I did have a few bad cards that landed me in Ward C3 West of Royal Prince Alfred (Thoracic Surgery and Oncology), but I survived. Many didn't, and getting to know people who didn't make it has given me a sense of perspective that has helped me throughout my life. It's difficult thinking "poor little me" because of some bureaucratic persecution when you've seen people whose kids are dying.

But I digress.

The point is, that unusual as I am, I'm a "boundary case" if you like that I think has lessons for us regarding Intersex and Transsex conditions. I'd like to think that I'm exaggerating the natural changes, that my intense desire to have a body that fitted my mind has caused me to ms-interpret (sic) the evidence, and I have yet to have any professional medic commit themselves in writing to anything other than a safe, standard diagnosis of Transsexuality.

Verbally is a different matter. And in some e-mails too, I've been described as "endocrinally weird" and more. This is by people used to dealing with "standard transsexuals" - standard Intersex cases too.

I wish someone would study my case more - even if it's to examine the hypothesis that I'm exaggerating things. (But what about the photos? The blood tests? The Eye Witnesses for Goodness' Sake? Hush, Zoe). There are lessons to be learnt, I just don't know for sure what they are, being too close to the situation to be objective.

Anyway, the article may end up in the cutting-room floor, and never see the light of day. The Editor may take to it with an Axe, removing my "words of wisdom" in whole or in part. But then again, they may not.

Tuesday, 13 March 2007

Arms Manufacturers


We've had the mechanics for good prostheses worked out for some time. The motors, the materials., the control circuitry. What we haven't had is the link from the upstream nerves: we haven't decoded the complex multichannel AM/FM and chemical broadcast that conveys the information down the limb to, say, wiggle the toes. Or just the big toe. (Try wiggling just a middle toe - odds are you can't).

It's still in the labs - but as I blogged in January, less than a decade away.

Anyway, as the above film demonstrates, Drexel University's Engineer of the year Dean Kamen and his team have done it.

The next step is to perfect the feedback - so there is more than just crude feeling too. That's coming.

Tuesday, 20 February 2007

Silicon Brains

From MIT's Technology Review :
An ambitious project to model the cerebral cortex in silicon is under way at Stanford. The man-made brain could help scientists understand how the most recently evolved part of our brain performs its complex computational feats, allowing us to understand language, recognize faces, and schedule the day. It could also lead to new neural prosthetics.

"Brains do things in technically and conceptually novel ways--they can solve rather effortlessly issues which we cannot yet resolve with the largest and most modern digital machines," says Rodney Douglas, a professor at the Institute of Neuroinformatics, in Zurich. "One of the ways to explore this is to develop hardware that goes in the same direction."

Neurons communicate with a series of electrical pulses; chemical signals transiently change the electrical properties of individual cells, which in turn trigger an electrical change in the next neuron in the circuit. In the 1980s, Carver Mead, a pioneer in microelectronics at the California Institute of Technology, realized that the same transistors used to build computer chips could be used to build circuits that mimicked the electrical properties of neurons. Since then, scientists and engineers have been using these transistor-based neurons to build more-complicated neural circuits, modeling the retina, the cochlea (the part of the inner ear that translates sound waves into neural signals), and the hippocampus (a part of the brain crucial for memory). They call the process neuromorphing.

Now Kwabena Boahen, a neuroengineer at Stanford University, is planning the most ambitious neuromorphic project to date: creating a silicon model of the cortex. The first-generation design will be composed of a circuit board with 16 chips, each containing a 256-by-256 array of silicon neurons. Groups of neurons can be set to have different electrical properties, mimicking different types of cells in the cortex. Engineers can also program specific connections between the cells to model the architecture in different parts of the cortex.
So we're ready to start making silicon brains, right?
Not exactly.
We have now invented bricks. We have yet to invent architecture.
"We want to be able to explore different ideas, different connectivity patterns, different operations in these areas," says Boahen. "It's not really possible to explore that right now." Boahen ultimately plans to build chips that other scientists can buy and use to test their own theories of how the cortex operates. That new knowledge can then be built into the next generation of chips.
Regular readers of this blog will realise just exactly how much we don't know about how the brain works. The idea of this piece of equipment is that scientists can try out various hypotheses about how bits of the brain function, and see how close to reality their models are. Then refine, and try again. Continue as needed.
Unfortunately it's not clear from the article whether any of the really complex stuff is being modelled. You see, the architecture merely describes electrical and data connectivity. As one commenter put it :
When a transistor models a neuron, it models parts of its electrical properties and perhaps also wiring pattern. But seldomly, it takes into account all of its intricate chemical and physical functionality. The temporal aspects stemming from deprivation of neurotransmitter, enhancement of synapses, gene expression leading to additional receptors and the like, are most often not inherent in the silicon models presently suggested and I would question whether they are part of Boahen's but will appreciate it if it is the case.
Exactly. We know enough about the electrical signals to know that they are both amplitude- and frequency-modulated, at least simple(!) pain signals are.

I can see this technology being useful for testing various hypotheses, and even modelling simple neurological structures in isolation, such as retinas. But unless there is significant computational capability built into the connections, not just the neurons, it will not be a particularly good model of what happens in any biological brain. "Not particularly good" may just be enough to be useful though. We shall see.

Monday, 29 January 2007

Purely in the Interests of Science, Of Course

From Dr. Kunio Kitamura, head of the Japan Family Planning Association, and as published in MSN-Maidichi :
I couldn't drag the fight on any longer and looked at the issue from the point of view of a columnist. I'm sure you've heard of the phrase "sex is all in the mind." It's true, because sex is not just something that happens between the legs, but instead involves all the senses -- sight, sound, smell, touch and taste -- stimulating the brain (and specifically, the frontal lobe). Just as heroes are said to love sex, the more developed a person's frontal lobe is, the more active their sex life is going to be.

When it comes to the difference between male and female sexuality, it's impossible to rule out some sort of connection between the sex nerves in the hypothalamus, where sexual dimorphism (or distinction between the sexes) makes men twice as large as women. It is perhaps this difference in the brains that sees men seek direct stimulation while women need more touching. Even though men can reach climax with incredible speed, they also cool down rapidly, occasionally making it very irritating for them to be touched after ejaculation. This is a major difference from women, who take a long time to get back to normal following orgasm.

So, how do I answer my old classmate's question about why good sex for women feels so much better than good sex does for men? There's a hint hidden in the brainwaves. And I'll turn to another friend, in this case Ryuichi Kaneko, who joined me as one of the co-authors of "Sex no Subete ga Wakaru Hon (Everything You Need to Know About Sex)."

When an orgasm has been achieved through sex, you can measure theta waves. These are also said to cause the "running high" feeling of euphoria experienced sometimes by marathon runners. If theta waves are taken as a criterion, the entire brain emits theta waves when women reach an orgasm that are close on 10 times stronger than when men climax. So, if theta waves are an indication of an orgasm's strength, then women experience an orgasm that is physically impossible for men to go through. Putting it a little crudely, if the intensity of a woman's orgasm was played through a man's brain, there's a danger that the shock to his system would kill him. That risk makes it impossible to experiment on a man at the moment. And men can never become women. But my co-author, Kaneko, used the experience of people who have undergone a sex change (either a woman born with a man's brain or vice versa) to explain the pleasure women feel.

There is a very strong correlation between nerve transmitters called dopamine and pleasure. Arousal causes the pulse to rise, turns the face red and makes the eyes misty because of the effects of dopamine. There also appears to be a link between this and a woman's tendency to become prettier when she falls in love. If it becomes possible to measure dopamine, it may also become possible to measure a woman's pleasure.

I must try some experimentation one day. Purely in the Interests of Science, Of Course.

Sunday, 28 January 2007

Aye, Robots

An interesting conjunction. From Space Daily :
U.S. scientists say they plan to create a new class of technology designed to produce completely soft-bodied robots. Tufts University researchers say such robots -- based on biological materials and the adaptive mechanisms found in living cells and organisms -- could repair space stations, conduct safer surgical procedures and work in hazardous environments such as landmine fields.
Clearing Landmines? Perhaps not. From the BBC :
Robots could one day demand the same citizen's rights as humans, according to a study by the British government.

If granted, countries would be obliged to provide social benefits including housing and even "robo-healthcare", the report says.

The predictions are contained in nearly 250 papers that look ahead at developments over the next 50 years.
...
The paper which addresses Robo-rights, titled Utopian dream or rise of the machines? examines the developments in artificial intelligence and how this may impact on law and politics.

The paper says a "monumental shift" could occur if robots develop to the point where they can reproduce, improve themselves or develop artificial intelligence.

The research suggests that at some point in the next 20 to 50 years robots could be granted rights.

If this happened, the report says, the robots would have certain responsibilities such as voting, the obligation to pay taxes, and perhaps serving compulsory military service.

Conversely, society would also have a duty of care to their new digital citizens, the report says.

It also warns that the rise of robots could put a strain on resources and the environment.
20 years? Even 50? Barring some totally inherently unpredictable breakthrough (like discovering FTL and contacting aliens who are thousands of years agead of us) No Way.

I've blogged about brains, cyborgs and hybrots since the first day this blog was published, back in July 2003. We've made enormous strides in understanding how individual neurons work, and even small subassemblies of the brain. Dynamic MRI promises to increase our understanding of how the human brain works enormously.
But as for the nature of consciousness? How do you train an Artificial Intelligence to become a person, what mixture of hardwired instinct and learned behaviour do you need... that's another matter. There are human bodies with brains that are almost normal, yet they are not people, they're vegetative, with no higher cognitive functions, they don't even think as much as an earthworm does. Until we can understand what happens in these cases, and how to fix it, we can't train an AI into personhood. For an AI is not made, it's grown.

Wednesday, 24 January 2007

Cyborgs Within A Decade

From the January issue of Neurosurgery, via Space Daily :
"We're at a junction now of developing a new approach for a brain-machine interface," says senior author Douglas H. Smith, MD, Professor of Neurosurgery and Director of the Center for Brain Injury and Repair at Penn. "The nervous system will certainly rebel if you place hard or sharp electrodes into it to record signals. However, the nervous system can be tricked to accept an interface letting it do what it likes - assimilating new nerve cells into its own network."

To develop the next generation of prosthetics the idea is to use regions of undamaged nervous tissue to provide command signals to drive a device, such as an artificial limb. The challenge is for a prosthesis to perform naturally, relaying two-way communication with the patient's brain. For example, the patient's thoughts could convert nerve signals into movements of a prosthetic, while sensory stimuli, such as temperature or pressure provides feedback to adapt the movements.

The central feature of the proposed interface is the ability to create transplantable living nervous tissue already coupled to electrodes. Like an extension cord, of sorts, the non-electrode end of the lab-grown nervous tissue could integrate with a patient's nerve, relaying the signals to and from the electrode side, in turn connected to an electronic device.

The difficult thing is going to be decoding the sensory data from parts of the body below the break. But simple control of a prosthetic, that is at worst only a decade away.