Science Picks on Twitter

Science Picks has had a Twitter account since its inception in order to tweet its posts, but recently I’ve started using Twitter more frequently. There are lots of articles and videos out there that I don’t feel I have much to add to in a post, or that may not be quite on-topic, so I retweet them without commentary instead, since I think they’ll appeal to followers of this blog.

In order for the non-Twitter users among us to not miss out too much, I added a widget to show my latest tweets on the sidebar on the right. It’s a bit clunky for my tastes, so I thought I’d make it clear why I decided to put it there. It’s for you! Everything I do is for you!! As always, let me know if you have any thoughts.

Babies With a Sense of Justice

I always find articles about cognitive development in babies to be fascinating, because they show the threshold of what we consider to be quintessential human traits. Now a study out of the University of British Columbia shows that somewhere between 5 and 8 months old, babies go from always preferring helpful individuals to preferring individuals who are helpful or not according to the behaviour of the recipient.

The research is pretty well described by LiveScience:

So the researchers set up a series of experiments using puppets to act out scenarios of helping and harming while each of 32 5-month-olds and 32 8-month-olds watched separately. After each experiment, the infants indicated their preference for the puppets’ behaviors by picking their favorite puppet to hold.

The puppets — a series of cheerful characters, including moose, elephants and a yellow duck — were first shown interacting in either nice or mean ways. One puppet would struggle to open a box containing a toy, while another either jumped in to help or cruelly slammed the lid shut.

Next, the infants watched as the puppet that had helped or hindered played with a ball and dropped it. A third puppet then came into the scene, either to take the puppet’s ball away or to hand it back…

The researchers wanted to know if the babies would prefer the ball-giving puppet or the one that took the ball away. They found that 5-month-olds always preferred the ball-giver, no matter whether the puppet that had dropped the ball had been mean or helpful in the previous scene. At this young age, the babies simply liked puppets to be nice in the moment.

But 8-month-olds were more discerning. They liked it when the third puppet gave the ball back to a previously helpful puppet. But they didn’t like it when the third puppet helped out a previously unhelpful puppet. In scenarios involving the mean, toy box-slamming puppet, 8-month-olds favored a third puppet taking its ball away by 13 to three.

The researchers then repeated the experiments with 32 toddlers ages 19 months to 23 months, this time adding a twist. The toddlers got to watch puppets being nice or mean to each other and then got to play the role of rewarder or punisher. Some toddlers were shown one nice puppet and one mean puppet and asked which they’d like to share a treat with. Others were shown a nice puppet and a mean puppet, both with treats, and were asked to take a treat away from one.

In all cases, the toddlers meted out justice according to the puppets’ earlier actions. Thirteen of 16 gave a treat to a nice puppet, while 14 of 16 took treats away from a mean puppet.

LiveScience also has a video of the puppet show and the babies choosing a puppet – it’s kind of adorable.

This finding is pretty cool. I wonder what the physical switch is that enables babies to be more discerning, if there is one distinct switch? For some small context, here’s a graph of a person’s change in brain weight over time, where blue is male and red is female:

Data from Dekaban, A.S. and Sadowsky, D., Changes in brain weights during the span of human life: relation of brain weights to body heights and body weights, Ann. Neurology, 4:345-356, 1978, via University of Washington

Notice that babies at the ages used in this experiment (5 or 8 months) have brains less than half the size of an adult, and maybe half that of a 3-year-old. They have a long way to go before everything clicks.

This study, to me, raises the question of which behaviours are learned, and which are ingrained. It seems clear here that a sense of justice, in the sense shown, is probably inherent, or at least the capability to learn it is. I’m also kind of surprised that the babies could distinguish between different puppets who were only distinguished by the colour of their clothes. It’s never caught my interest as a field of study, but I’m starting to understand why people might like developmental biology… 

Implanted Neurons Integrate Into Brain Circuitry

Here is some awesome news via PhysOrg: neurons made from human embryonic stem cells in a lab were transplanted into mice and formed functional connections. They adopted the activity patterns of their area and could apparently modify their neighbouring cells through their behaviour too. 

Neurons are specialized, impulse conducting cells that are the most elementary functional unit of the central nervous system. The 100 billion or so neurons in the human brain are constantly sending and receiving the signals that govern everything from walking and talking to thinking. The work represents a crucial step toward deploying customized cells to repair damaged or diseased brains, the most complex human organ…

The Wisconsin team tested the ability of their lab grown neurons to integrate into the brain’s circuitry by transplanting the cells into the adult mouse hippocampus, a well-studied region of the brain that plays a key role in processing memory and spatial navigation. The capacity of the cells to integrate was observed in live tissue taken from the animals that received the cell transplants.

Weick and colleagues also reported that the human neurons adopted the rhythmic firing behavior of many brain cells talking to one another in unison. And, perhaps more importantly, that the human cells could modify the way the neural network behaved.

If human neurons could integrate in and work with mouse neurons, one would hope they can do the same in humans. There are plenty of diseases that involve the loss of neurons (neurodegenerative diseases), so this could possibly be a step towards better treatment for the many millions of people affected. 

They also describe how they modulated the implanted neurons’ behaviour using light, the basic mechanism of which I explained in the context of heart muscle cells earlier.

A critical tool that allowed the UW group to answer this question was a new technology known as optogenetics, where light, instead of electric current, is used to stimulate the activity of the neurons.

“Previously, we’ve been limited in how efficiently we could stimulate transplanted cells. Now we have a tool that allows us to specifically stimulate only the transplanted human cells, and lots of them at once in a non-invasive way,” says Weick.

Weick explains that the capacity to modulate the implanted cells was a necessary step in determining the function of implanted cells because previous technologies were too imprecise and unreliable to accurately determine what transplanted neurons were doing…

The new study opens the door to the potential for clinicians to deploy light-based stimulation technology to manipulate transplanted tissue and cells. “The marriage between stem cells and optogenetics has the potential to assist in the treatment of a number of debilitating neurodegenerative disorders,” notes Su-Chun Zhang, a UW-Madison professor of neuroscience and an author of the new PNAS report. “You can imagine that if the transplanted cells don’t behave as they should, you could use this system to modulate them using light.”

The idea of having brain cells implanted into me that can be externally manipulated by light is a bit eerie, but I guess flying through the air at super speeds in a big metal vehicle used to be weird too. 

Weekending

Dear reader, it looks like I might be unavailable for the next couple of days, so Science Picks might be quiet until Sunday or Monday. If you want to scratch your science itch for the time being, you can check out any of the science news sites and blogs in my Sources page (uh, I’ll clean that page up in the future). Some of my favourite blogs there are 80 beats, Cosmic Variance, and Starts With a Bang, while ScienceDaily and PhysOrg have the most news but LiveScience and New Scientist have lots of news as well as more pop-sci articles.

See you soon!

Lethal Underwater Briny Icicle

BBC has some phenomenal footage of an icicle forming from salty water in the Antarctic. It crawls down into the water (because the density of the saltwater makes it sink) and freezes everything around it, including the poor animals underneath.

That video was not posted by the BBC so hopefully it doesn’t get taken down too soon. Here’s the camera set-up they used:

I don't think my camera can do that

You should check out their article for the description of the brinicle. Very cool stuff. It feels like nature is just always up to random amazing things without us ever realizing it. 

Why Empty Space Isn’t Empty

New Scientist has a nice little video explaining that vacuums, empty space, aren’t really empty. You, my dear reader, already know that from reading about the big laser that will tear apart virtual particles, and the recent experiment that materialized virtual photons, but you should check this short video out if you’re interested (can’t embed the video here, sadly). 

They also link to a full-length article discussing how the theory of the vacuum has evolved over time, which it looks like you’ll have to register (for free) to read. I won’t go into all of it, but in essence it portrays a somewhat philosophical struggle over the millennia about how emptiness could be empty, which led to and away from the idea of a luminiferous aether filling everything, and finally to quantum mechanics.

Now we know that because of the quantum uncertainty involved at the smallest scales, there are always fluctuations of fields and particles in a vacuum, meaning that any vacuum does indeed have energy in it. There’s never nothing. Is that reassuring? I think a constantly fluctuating space is much more interesting than a giant, vast emptiness. 

What Casual Climate Science Deniers Don’t Understand About Science

I’m really averse to writing about the political controversy around climate science because it’s beaten to death in every kind of media already, and there are plenty of blogs revolving around it. Without it, though, I might not have started this blog in the first place, since that and the political controversy over evolution are the biggest symptoms of a society that doesn’t know enough about science.

You may have heard about what the media gleefully called “Climategate 2.0”, a release of more stolen emails from climate scientists. Here’s Scientific American and LiveScience discussing the leak, and Life’s Little Mysteries addressing the scientific complaints against anthropogenic climate change. 

In my opinion, the controversies over evolution and climate science stem largely from a sheer lack of understanding of how science works. As I see it there are a few main misunderstandings:

1) Nothing is 100% certain. Deniers demand 100% certainty in scientists’ claims, which is literally impossible. There is always room for error and misinterpretation, in every kind of science. Scientists know this and so they tend to talk about their findings cautiously. This doesn’t translate well in the public sphere; we’re used to people in everyday life making certain claims, especially when those claims are relevant to politics. What kind of politician would say “My plan is to do this, because such-and-such is probably the problem with our economy, and such-and-such will probably help”? That would be honest, but it wouldn’t sell, and that politician’s dishonest opponent would come off much more convincingly.

This creates a conflict when science is dragged kicking and screaming into politics. There’s pressure to put things into certain terms – it’s technically bad science, but good politics. From what little I’ve seen excerpted from the hacked emails, it looks like this is what these scientists are discussing – how to remain scientifically accurate while trying to get across an important public message. Does glossing over the science in this way make them liars or frauds? No, it makes them roughly as inaccurate as everyone else in the public sphere. It’s regrettable that science has to be dumbed down for public presentation, but the dumbing down is obviously not a conspiracy. 

2) There will always be internal disagreement between scientists on smaller issues. Deniers will point out any and every sign of disagreement between scientists when it comes to climate science or evolution, and use this to claim that the science isn’t settled. There will probably always be differing hypotheses when it comes to the details of the matter, but that has no bearing on whether the field as a whole is valid. There’s tons of uncertainty in climate science, and personally I don’t like it at all when bold predictions about 100 years into the future are made, because it seems obvious that those predictions are so error-prone as to be meaningless. However, there’s negligible uncertainty when it comes to the facts of the Earth gradually warming over the last century, and the human release of greenhouse gasses as a significant contributing factor.

Do we know how all of this will pan out? No, not at all. I summarized a New Scientist article earlier showing just how little we know about the magnitude of the problem. This kind of subtlety can be confusing to the public – if we don’t know, then why should we take such dramatic and costly steps to respond? Science doesn’t work strictly by knowing though, as should be clear by the fact that nothing is 100% certain. Everything is a matter of probability. If curbing greenhouse gas release is very likely to be beneficial, then it makes sense to do it, whether or not we can know for sure – which we really can’t, ever. Doing nothing is making an active choice to act on the much less probable future scenario, which doesn’t make any sense. 

3) Science is not an opaque, elite clubhouse. The fact that e-mails from a small group of scientists are being used to smear an entire field betrays a profound misunderstanding of, everything. Science is a global pursuit. Even if these fantasies about these emails being incriminating were true, it would have virtually no implications for climate science, since different groups of scientists have independently come to the same conclusions anyway. Individual scientists can’t just make things up or conspire with impunity. They’re accountable to everyone – anyone can debunk their claims, and if they’re caught forging data or being incredibly dishonest in any way, it’ll probably mean the end of their careers. Science is not like politics – you can’t just lie and move on. If you’re a bad scientist, you’re done, for the rest of your life. There’s no way one particular group of scientists would just decide to make enormous lies about something that’s being investigated all over the world. 

I think the faster-than-light neutrino story is a great example for understanding science better in this context. Were the CERN scientists shunned for going against the overwhelmingly dominant consensus theory? No, quite the opposite. Is there a possibility that the theory of relativity is incomplete? Yes, anyone will admit to that. Does that mean we should ignore all of the findings brought to us by assuming that relativity was completely correct for the last hundred years? No, that would be ridiculous. 

In sum: even the best of theories can be challenged, even the best of theories can be incomplete, but it makes sense to act on what information we have even if it’s not perfect (which, again, it never will be). This alone should be enough to finally move past this political misunderstanding.

All of that being said, another reason why I’m averse to writing about topics like this is because I get the impression that facts and reason are not what’s driving the discussion. I have no idea what will convince most deniers to jump on the modernity bandwagon and trust the global institution of science, but it’s probably not posts like this. 

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