Thursday, October 30, 2008

Taking Place Science Quickies

Okay, so, getting back to some of the original intent of this blog, I'm going to toss you guys some quick science abstracts below the fold. Give me some feedback here, if you want, on what kind of stuff you want to hear about. If it were up to me, I'd mostly be posting neuroscience or cognitive psychology, as that's my field of interest.

Anyway, see you after the jump (quantum jump, that is...)

First of all, we have an abstract for a study that shows that development puts constraints on variety in evolution. Now, this article is interesting for several reasons. First of all, it is an interesting question: nature certainly seems to have an abundance of strange creatures...but the extent of this strangeness is nowhere near as large as it could be. For example, look through the creature creations of Spore players. Why aren't there things like that walking around? Also keep in mind, Spore creatures are bilateral and have a single spinal cord. So, basically, Spore players are exploring the design space of vertebrate, bilateral creatures...a much smaller subset of the total possible space. Why is it that creatures occupy only a small subset of possible design space?

This article suggests that developmental factors (basically gene regulation, all sorts of fun epigenetic factors, etc) allow for great variance between taxonomic groups, but less variance within a group - groups begin to occupy more diverse body types, but within a group, they tend to cluster. An interesting finding, overall. I'd like to know what level of taxonomic group they're talking about, so I'll probably be getting the actual paper. I suggest you do the same.

A good abstract on why some people are better at learning languages. Basically, it boils down to a correlation of being able to better discriminate sound differences. Impersonators, vocalists, etc, should be better at learning second languages, at least statistically. Of course, this is not a causal argument - some people may simply have an altered brain structure that would make them good at both. I do wonder how plastic that area of the brain is, however, and if you could train it...something to look into.

Next, we have the hypnotic induction of synaesthesia. Now, i know, I know. "Hypnosis" should set off all sorts of skeptical alarms in your head. I'd be interested to read the entire paper, though, and I'd like to see some confirmation from other lines of evidence - basically, that there is wide-range enervation between sensory modalities and that normal people merely have strong inhibition of these connections. That's about the only model I can think of that this would work for. We'll see. It's an interesting first find, and if it's confirmed by converging evidence, all the better. It actually tells us something about how the brain is hooked up.

Here's an interesting study on individual differences in memory damage as result of damage to the hippocampus. Now, in the literature, the hippocampus is thought to be key to memory formation. Damage that, and you get amnesia. For example, H.M., a famous case, had his hippocampus and adjacent parahippocampal gyrus removed to treat epileptic seizures. Well, his seizures stopped, but he also developed severe anterograde amnesia and retrograde amnesia for events about 11 years prior to the surgery. This study shows, however, that damage to the hippocampus does not necessarily lead to memory deficits. The authors admit it may be specific location and pathology - we just don't have technology sensitive enough for this, but it does put up a challenge to current neuroscience models of memory that involve the hippocampus. Look for more research in this area soon.

Finally, my favorite, the selective and safe erasure of memories in mice. Now, I read this article early this year for a class, and the abstract's just popped up on Science Daily. I find this one incredibly impressive. One of the basic take away messages is that recalling something is not like playing back a video tape - a steady-state relic of the event. Instead, recall is actually "reconsolidation" - you reconstruct an event when you remember it. This is one of the basic reasons why eye-witness testimony and memory in general is so dubious.

So, the basic paradigm is, you get a creature to "recall" an event, and then you suppress it's ability to form a memory. In this case, by the over-expression of a particular protein in the NMDA pathway. This thereby erases that memory. Now, hopefully this is memory-specific, and it seems to be, at least as far as we can tell with mice and the experiments that have been run so far.

Some people get a little antsy when you start talking about things like this..."The gub'ment's gonna come in an' take my mem'ries!" and such. Well, no...first of all, these mice were genetically engineered to be able to over-express this protein. We aren't. A drug could be developed that mimics the effects, maybe. But that's a long way down the line. Secondly, while there is certainly a potential danger in this technique, it could also be a powerful therapy tool. In fact, the "reconsolidation" idea can powerfully inform cognitive therapy already. On the other hand, the ability to erase particular memories, say, for war veterans, could be a useful tool if the patient so desires it.

Anyway, that's some of the science news that's caught my eyes in the last week or so. I'm going to try to get back on a more regular posting schedule. We'll see if it lasts.

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