The evolutionary psychology of war

Nothing too shocking here for students of evolutionary psychology but it’s always interesting to see real world examples of how our shared behavior. There is a new book by Sebastian Junger called War, in which he recounts how men do not fight for larger ideological goals (eg. “a safer Iraq”, “finding Bin Laden”) but instead they can overcome fears because “they’re more concerned about their brothers than what happens to themselves individually”. Here’s Junger on Good Morning America:
http://abcnews.go.com/assets/player/walt2.6/flash/SFP_Walt.swf

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

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When Will We Be Able to Build Brains Like Ours?

When Will We Be Able to Build Brains Like Ours? – by Terry Sejnowski – scientificamerican.com

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

Bayesian truth serum

Neville told me about this neat article from ’04. It presents a way to offer rewards to people taking a poll in such a way so as to motivate them to be honest, with no prior information about what the distribution of correct answers is. Apparently, previous such techniques are based on the idea of rewarding people for agreeing with other people’s answers. This new thing about this technique for calculating the reward is that it provides people with an incentive to tell their true opinion even if they know that they hold a minority viewpoint.

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

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The truth about TTX!

If the Fish Liver Can’t Kill, Is It Really a Delicacy? [NYT, login]

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 Continue reading