A catalog of identified neurons, the circuits they form, and inter-species homologies.

After the jump some more from Junger and a nice talk from Robert Sapolsky about similar behaviors in chimps.

Another example from soldiers in Afghanistan is the “blood-in, blood-out” ritual for increasing group cohesiveness and testing individual sacrifice for the group, as Junger describes near the end of this Daily Show clip:

All of these explanations and rituals reminded me of Robert Sapolsky’s and Frans de Waal’s observations of similar behavior that is reported in baboon/chimp groups.

In the clip below (from Stanford’s Class Day 2009 speech), Sapolsky describes several “uniquely human” behaviors (or at least ones that had been thought to be “uniquely human”) which really are shared by these close relatives. Starting around 12:20 (the clip below will auto-start there), he talks about aggression and the organized group killing done by “border patrols”. The entire talk by Sapolsky (~35 mins) is worth watching too!

Terry Sejnowski discusses the recent ‘catfight’ that erupted between Dharmenda Modha of IBM and Henry Markram of the EPFL over claims from Modha that his group had successfully modeled the brain of a cat.

Dr. Sejnowski provides a summary of the quest to describe the nervous system using computational models and introduces a central question: What level of abstraction is appropriate?

“Looking at the same neuron, physicists and engineers tend to see the simplicity whereas biologists tend to see the complexity. The problem with simplified models is that they may be throwing away the baby with the bathwater. The problem with biophysical models is that the number of details is nearly infinite and much of it is unknown. How much brain function is lost by using simplified neurons and circuits?”

Despite the differing approaches, both Modha and Markram say we’ll have a model human brain by 2019. Sejnowski claims that these will be impoverished brain models, “at best these simulations will resemble a baby brain, or perhaps a psychotic one”, but he does remain hopeful in his closing remarks:

“And gradually, as it increasingly mimics the workings of our brains, the world around us will become smarter and more efficient. As this cognitive infrastructure evolves, it may someday even reach a point where it will rival our brains in power and sophistication. Intelligence will inherit the earth.”

Submitted By: Dan Knudsen

http://fold.it/

According to the website, currently they are collecting data from the game to see if humans can actually contribute anything beyond what the computers can already do.

Drazen Prelec. A Bayesian Truth Serum for Subjective Data. Science 15 October 2004: Vol. 306. no. 5695, pp. 462 – 466. DOI: 10.1126/science.1102081

Here’s an example that demonstrates the crux of the method. The question is, “Is Picasso your favorite visual artist?” — assume that Picasso lovers are a minority. We want to develop an incentive system that gives Picasso lovers an incentive to answer truthfully that Picasso is their favorite, even though they are in the minority:

People who, for example, rate Picasso as their favorite should — and
usually do … — give higher estimates of the percentage of the population who shares
that opinion, because their own feelings are an informative `sample of one’ …. It
follows, then, that Picasso lovers — who have reason to believe that their best estimate of
Picasso popularity is high compared to others’ estimates — should conclude that the true
popularity of Picasso is underestimated by the population. Hence, one’s true opinion is
also the opinion that has the best chance of being surprisingly common.

Based off this idea, the method rewards people for giving “surprisingly common” answers. Each person is asked not only for their own answer, but also to predict the frequency of each answer in the population. The following equation is used to calculate the reward to give each person (equation 2, “score for respondent r” in the paper, page 5 of the PDF linked above):

log ((the actual frequency of this guy’s answer in the poll)/(the geometric mean of the predicted frequency of this guy’s answer in the poll))
+
alpha * sum over all answers (the actual frequency of this answer in the poll * log((this guy’s prediction of the frequency of this answer in the poll)/(the actual frequency of this answer in the poll)))

where alpha is a parameter between 0 and 1.

The first term in the reward rewards people for giving “surprisingly common” answers. The second term rewards people for giving accurate predictions of the frequency of answers.

The paper goes on to show that, given this reward function, truth-telling is a Nash equilibrium, and furthermore that for sufficiently small alpha, this equilibrium Pareto-dominates expected scores in other equilibria. It also discusses things that can go wrong, and what to do about them.

http://blogs.spectrum.ieee.org/tech_talk/2009/01/ibm_pulls_out_of_blue_brain_co.html

Does anyone know anything more about this?

Amazing. It looks like TTX (tetrodotoxin, a potent voltage-gated sodium channel blocker well-known to electrophysiologists) is not made by the pufferfish (which I had always assumed), rather it is from the bacteria/food consumed by the fish.

Decades earlier, another Japanese scientist had identified fugu’s poison as tetrodotoxin, a neurotoxin that leaves victims mentally aware while they suffer paralysis and, in the worst cases, die of heart failure or suffocation. There is no known antidote.

Researchers surmised that fugu probably got the toxin by eating other animals that carried tetrodotoxin-laden bacteria, developing immunity over time — though scientists then did not rule out the possibility that fugu produced the toxin on its own.

By this year, Mr. Noguchi had tested more than 7,000 fugu in seven prefectures in Japan that had been given only feed free of the tetrodotoxin-laden bacteria. Not one was poisonous.

“When it wasn’t known where fugu’s poison came from, the mystery made for better conversation,” Mr. Noguchi said. “So, in effect, we took the romance out of fugu.”

Aside from the interesting science, it appears there is also a small Japanese “industry” (de-ttx? detox?) seriously affected by TTX-free fugu. More after the jump

But what could be seen as potential good news for gourmands has instead been grounds for controversy: powerful interests in the fugu industry, playing on lingering safety fears, are fighting to keep the ban on fugu livers even from poison-free fish.

“We won’t approve it,” Hisashi Matsumura, the president of the Shimonoseki Fugu Association and vice president of the National Fugu Association, said of the legalization of fugu liver. He added, “We’re not engaging in this irrelevant discussion.”

Acting as a giant clearinghouse, this port city in southwestern Japan buys fugu from all over Japan and China, guts it and expertly removes its poison before shipping it throughout Japan and as far as New York. Though Shimonoseki’s share has fallen in recent years, it still controls about half of Japan’s fugu market.