Category Archives: neuroscience

Teenagers are crazy because they’re just like lizards

Remember that time you went to the zoo, and there were these huge reptiles, like maybe Komodo Dragons, and they just sat around doing nothing? Except every so often one of them would make some vaguely unpleasant noise, or snap viciously at one of the others? And finally it dawned on you that it was just like watching teenagers, and you could have saved yourself the cost of a ticket by hanging out at the mall food court?

Well, as it turns out, you were on to something. Clinical Psychologist Richard Friedman wrote an interesting piece in Sunday’s New York Times in which he argues that many of the behaviors we associate with adolescence — like risk taking, fear, and anxiety — may be a consequence of asynchronous development of different brain structures:

Different regions and circuits of the brain mature at very different rates. It turns out that the brain circuit for processing fear — the amygdala — is precocious and develops way ahead of the prefrontal cortex, the seat of reasoning and executive control. This means that adolescents have a brain that is wired with an enhanced capacity for fear and anxiety, but is relatively underdeveloped when it comes to calm reasoning.

The amygdala is one of the evolutionarily ancient parts of the brain that is involved in things like the “fight or flight” response. If you enjoy using outdated terms and/or trolling brain researchers (and I do!), you would say that this is a component of the “reptilian” brain. The prefrontal cortex is more like the “thinkin’ and plannin'” region, and part of the “mammalian” brain, in that these structures became larger in the evolutionary lineage leading to mammals (and bigger again in primates, and even more biggerer in humans).

If you’re a Daniel Kahneman fan, the reptilian bit is like the fast-thinking System 1, and the mammalian bit is like the slow-thinking System 2.

These two parts are in a sort of balance in children, but, when you enter adolescence, the System 1 stuff matures more quickly, and it dominates the more reflective System 2. Eventually, System 2 catches up, so that the balance is regained in adults.

We’ve recently learned that adolescents show heightened fear responses and have difficulty learning how not to be afraid. In one study using brain M.R.I., researchers at Weill Cornell Medical College and Stanford University found that when adolescents were shown fearful faces, they had exaggerated responses in the amygdala compared with children and adults.

These developmental patterns may help to explain not only certain stereotypical adolescent behaviors, but also perhaps systematic differences in how adolescents and adults respond to certain medications.

Alright, so what are we going to do with this information?

Parents have to realize that adolescent anxiety is to be expected, and to comfort their teenagers — and themselves — by reminding them that they will grow up and out of it soon enough.

Wait, that’s not a magic bullet solution that will allow me to overcome the challenges of raising a child with little or no effort on my part! Between this and the World Cup, it’s like this isn’t even America anymore!

Three questions about Jonah Lehrer

So, the saga of Jonah Lehrer has kept trundling on, now with the publication in Slate of this article, where NYU Journalism professor Charles Seife describes what he discovered when he was asked by the editors of Wired to look into Jonah Lehrer’s past blog posts for evidence of “journalistic malfeasance,” including plagiarism, recycling (self plagiarism), “press-release plagiarism,” misrepresentation of quotes, and misrepresentation of facts.

The article is a must read if you have any interest at all in journalism, science, and/or schadenfreude.

For the past few years, Lehrer was the wunderkind of popular science writing. He was Malcolm Gladwell with a better haircut. Then, about a month ago, Michael C. Moynihan published this piece (also a must read, for all the same reasons), where he described his discovery that many of the quotes attributed to Bob Dylan in Lehrer’s most recent book, Imagine, were actually fabricated. More disturbingly, Moynihan described how Lehrer “stonewalled, misled, and, eventually, outright lied” to him when confronted with the fabrications.

The Moynihan piece followed on from some grumblings about Lehrer’s journalism, when it was pointed out that an that he wrote for the New Yorker was largely recycled from something he had previously written for the Wall Street Journal.

As I understand things, recycling is a fairly minor journalistic crime. It is not really misrepresentation, since you are still presenting your own material as your own. It is a bit of a violation of trust of the readers of the New Yorker, but if they had not read the Wall Street Journal piece, maybe there was little harm. And, I suspect that the overlap between New Yorker readers and WSJ readers is fairly small. The two entities that Lehrer actually screwed over were the New Yorker, who presumably thought that they were paying him for new material, and the Wall Street Journal, who presumably had some expectation that they were paying him for exclusive rights to the article.

The recycling prompted people to start looking more closely at Lehrer’s record, though, where they found a much more diverse and serious set of “journalistic malfeasances.” It seems that Lehrer is an egregious cherry picker, sifting through papers to find studies that support his thesis, irrespective of the quality of those studies or the existence of other studies that contradict it. He also apparently has a serious quotation problem, splicing together frankenquotes from different sources, presenting quotes gathered by other people as if he had gathered them himself, and when a convenient quote did not exist (or would require actual effort to discover), simply making quotes up. Furthermore, when specific errors were pointed out to him, he would nevertheless republish those same “errors” again and again. (Again, for the details, read Seife and Moynihan.)

I use quotation marks here because, while an original error might have been an actual error, in the sense of being an honest mistake, once you know it’s wrong, and you keep putting it out there, it becomes something different. A candidate word would be “lie.”

To me, the whole Lehrer fiasco raises three questions:

1. WTF?

I mean, look, this is a whole lot of crazy behavior. It reminds me of those movies, like Big or 13 Going on 30, where a kid suddenly wakes up in the body of an adult and finds themselves in way over their head. Except instead of teaching all of the other adults around them to reconnect with their inner child, they spin totally out of control and devolve into a murderous, narcissistic pathological liar.

Maybe sort of like what you would get if you cast Linday Lohan in a mashup of Freaky Friday and Carrie.

2. Who is to blame?

Sure, the obvious answer here is Jonah Lehrer. Curiously, Charles Seife’s article ends with this conclusion:

Lehrer’s transgressions are inexcusable—but I can’t help but think that the industry he (and I) work for share a some of the blame for his failure. I’m 10 years older than Lehrer, and unlike him, my contemporaries and I had all of our work scrutinized by layers upon layers of editors, top editors, copy editors, fact checkers and even (heaven help us!) subeditors before a single word got published. When we screwed up, there was likely someone to catch it and save us (public) embarrassment. And if someone violated journalistic ethics, it was more likely to be caught early in his career—allowing him the chance either to reform and recover or to slink off to another career without being humiliated on the national stage. No such luck for Lehrer; he rose to the very top in a flash, and despite having his work published by major media companies, he was operating, most of the time, without a safety net. Nobody noticed that something was amiss until it was too late to save him.

My twitter feed was full of responses along these lines of “You don’t need formal training to know that lying is wrong.” Agreed. If the only thing keeping most journalists from acting like Lehrer is the threat of a grumpy, old, cigar-chomping editor telling them to shape up (and then offering them a swig of whiskey from the flask they keep in the bottom drawer of their desk), we’re all in a lot of trouble.

(If you want to see a real psychopathic maestro at work, read this classic piece on Stephen Glass, who fabricated whole stories, and concocted elaborate schemes to fool his editors.)

On the other hand, there is something real here. The current trend in journalism is to cut down on editors and fact-checkers, increasingly relying on the competence and honesty of individual reporters. This might have important implications for how we evaluate journalism in the future. In the past, publications had reputations, but maybe in the future, journalistic reputations will be more personal. I’d love to hear your thoughts in the comments.

3: How is it that Jonah Lehrer has not yet been hired as a speechwriter for the Romney campaign?

Seriously, this guy has it all. Cherry-picking facts, making up other facts, bald-faced lying when confronted about it. In fact, I’m a little bit surprised he’s not on the ticket. Sure, Paul Ryan may have those dreamy blue eyes, but Jonah Lehrer’s glasses are so cool, he doesn’t even need eyes!

It’s Toxoplasmosis week at Darwin Eats Cake

So, tomorrow (March 13) marks the one-year anniversary of the launch of my webcomic Darwin Eats Cake on its very own website (here). Normally, Darwin Eats Cake updates approximately twice a week (hemicircaseptanally), on approximately Monday and Thursday (circa-Mondarily and circa-Thursdarily, I assume). However, to mark this special anniversary occasion, we are rolling out a daily series of strips on Toxoplasma gondii, the parasite responsible for Toxoplasmosis. This bug was recently in the news thanks to a profile of Jaroslav Flegr published recently in the Atlantic (here).

Here are the first two of this week’s six strips:

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And remember: Sharing is Caring!

Study sheds light on coming robot apocalypse

So, in many of the standard narratives, the robot apocalypse is triggered when the machines figure out that humans are fundamentally flawed, or because their self awareness produces an instinct for self defense.

Well, a new paper just out in Biological Psychiatry describes an experiment in which researchers successfully teach a computer to reproduce aspects of schizophrenia. This raises the possibility of an alternative scenario: the machines just go crazy and start killing people, Loughner-style.

After suffering from paranoid delusions, Skynet sends Vernon Presley back in time to kill his own grandfather, or something.

Actually, the paper reports a study in which a computational (neural network) model is used to examine eight different putative mechanistic causes of a particular set of symptoms often seen in schizophrenia: narrative breakdown, including the confusion of autobiographical and non-autobiographical stories. This models one putative source of self-referential delusions.

The basic setup is that the researchers use an established system of neural networks called DISCERN. The system is trained on a set of 28 stories. Once the system is trained, you can feed it the first part of any one of the stories, and it will regurgitate the rest of the appropriate story.

Half of the stories are autobiographical, everyday stuff like going to the store. The other half are crime stories, featuring police, mafia, etc.

The experiment is to mess with the DISCERN network in one of eight different ways. Each of the eight types of perturbation is meant to instantiate a neural mechanism that has been proposed to cause delusions in schizophrenia. Then, the researchers feed the computer the first line of a story and look at the magnitude and nature of the errors in the output.

Models were evaluated by their ability to reproduce errors seen in an experimental group of subjects diagnosed with schizophrenia. Basically, they are interested in finding perturbations that mix up different stories, so that the “I” of the autobiographical stories becomes associated with the gangsters and police in the non-autobiographical crime stories.

Two of the eight perturbations performed significantly better than the others:

  1. Working memory disconnection: Connections within the neural network that fell below a certain threshold strength were discarded.
  2. Hyperlearning: During the backpropagation part of the neural network training, the learning algorithm overreacts to prediction errors. After DISCERN was trained, hyper-trained for an additional 500 cycles.
These two were then further extended, with the addition of a parameter to each, at which point the modified hyperlearning model outperformed the disconnection model. 
So, what to make of it?  It seems like an interesting piece of work. It is hard to know how much light this sheds on schizophrenia, since the brain is a heck of a lot bigger and more complicated than this model. And, well, sometimes things scale up in the straightforward way, and sometimes they don’t. 
What one hopes will be the outcome of this sort of work is that is will prompt additional research. While we can’t guarantee that results extrapolated from computational systems such as this one will have any predictive value for the brain. But, it should be possible at least to construct predictions. A collaboration involving neuroscientists of various stripes could then potentially come up with some clever experiments, which would be interesting, if for no other reason than that they had a direct connection back to this sort of computational model.
Spot-on commentary. Via, as usual, xkcd.
The other thing we can take away is this. We now know how to train up a schizophrenic neural network. Combine it with this punching robot:
Asimov’s-law-violating robot. Via Geekologie.

Teach it to snort coke, and we’ve got all the makings of a Charlie Sheen bot.

Hoffman RE, Grasemann U, Gueorguieva R, Quinlan D, Lane D, & Miikkulainen R (2011). Using computational patients to evaluate illness mechanisms in schizophrenia. Biological psychiatry, 69 (10), 997-1005 PMID: 21397213

For more on this article, check out 80beats, over at Discover Blogs.