Brain and Behavior
clock | May 17, 2007Remember last summer when some guy named Paul Manger wrote a paper asserting how dolphins and other Cetaceans are really quite dumb? There was quite an interesting discussion about it on blogs back then, e.g., here, here, here and here.
Now, a formal rebuttal got published in PLoS-Biology:
Cetaceans Have Complex Brains for Complex Cognition:
The brain of a sperm whale is about 60% larger in absolute mass than that of an elephant. Furthermore, the brains of toothed whales and dolphins are significantly larger than those of any nonhuman primates and are second only to human brains when…
goodmath | May 17, 2007 I've been seeing articles popping up all over the place about a recent
PLOS article called Order in Spontaneous Behavior. The majority of
the articles seem to have been following the lead of the Discovery Institute, which claims that the article demonstrates the existence of free will, which they argue is inconsistent with naturalism and darwinism.
The thing is, the paper says nothing of the sort.
The paper did a very interesting study on the behavior of fruit-flies. They basically tethered fruit flies inside of a small cylindrical apparatus, which basically amounts to
a little tiny…
zooillogix | May 16, 2007The results of a diabolical experiment are forcing scientists and philosophers to reevaluate their notions of free will.
Bj/drn Brembs from the Free University in Berlin began his experiment by postulating that if fruit flies are no more than biological robots simply reacting to their environments (i.e. beings without free will), then they should move completely randomly in a featureless room. Then in stroke of pure, evil genius, Brembs and his team glued tiny hooks (attached to strings) to the heads of fruit flies and let them "loose" in completely white surroundings. The fruit flies could…
cortex | May 16, 2007David Leonhardt has an interesting column on the importance of using subtle environmental cues - Leonhardt calls them "nudges" - to encourage good decision-making. He begins with a fascinating anecdote about patients in hospital beds:
For more than a decade, it turns out, medical researchers have known that people on ventilators should generally have their heads elevated. When the patients are lying down, bacteria can easily travel from the stomach, up to the mouth and breathing tube, and ultimately into the lungs, causing pneumonia. When people are propped up, gravity becomes their ally.…
denialism | May 16, 2007Or at least "Darwinism" whatever the hell that means these days. I guess they couldn't keep quiet all day. UD's new argument is an easily dismissed straw man. It goes like this.
Scientists discover fruit flies put in a sensory-deprivation chamber,instead of flying around randomly, or in a rigid pattern, fly in a pattern with both random and non-random properties. (PLoS one article)
Uncommon Descent which should have its RSS feeds revoked, says it's proof of design! Darwinism requires there is no free will! This is apparently based on a stunning misunderstanding of Dawkin's ideas by…
developingintelligence | May 16, 2007The analytic depth of cognitive neuroscience is, in many ways, a curse. Those aspects of high-level cognition most relevant to real-world applications are the least understood at a neurobiological level, and those mechanisms that are well-understood neurobiologically are too simple to inform real-world practices.
The explanatory gaps between these levels of analysis is a result of hyper-reductionism in science, itself rooted in a lasting preference (reverence?) for the simplistic and "parsimonious." But natural phenomena, like the emergence of behavior from the brain, are ultimately more…
developingintelligence | May 15, 2007It could be argued that any single level of scientific analysis is at once too simple (since there are always important emergent phenomena at higher levels) and also too complex (poorly-understood phenomena inevitably lurk at lower levels). If I wanted to kick the sacred cow of science again, as I did yesterday, I'd suggest that parsimony can be a misleading principle here too: whatever data is used to evaluate a theory may not include phenomena occurring at other levels of analysis that may be relevant to the theory. So inevitably, the simplest theory (i.e., the one with the fewest…
pharyngula | May 12, 2007This is a beautifully done movie, although it does get a bit silly in the end.
One point this brought to mind: have you ever looked at sperm? They're amazing. We humans do go through a single-celled haploid stage which is the focus of some very intense selection pressure, and humans in their haploid phase possess some impressive abilities. No brains, but the sperm are motile and exhibit seeking behavior. Eggs are also wonderful — they are precisely balanced on the edge of criticality, ready to erupt into a cascade of changes with a single stimulus. It's easy to dismiss gametes as blobs and…
grrlscientist | May 11, 2007tags: snail, bird, parasite, streaming video
This streaming video describes the life cycle of parasite worms that infect both snails and birds. Basically, these worms control their snail host's brain and thereby alter the snail's behavior such that it enhances the chances that it will spread the worm's eggs into a wild bird, its next host [1:21].
grrlscientist | May 10, 2007tags: bipolar disorder, manic-depressive illness, mental health, molecular biology
Bipolar disorder depends upon small, combined effects from variations in many different brain genes, none of which is powerful enough by itself to cause the disease, according to a new genome-wide study. Despite this revelation, this new study shows that targeting one enzyme produced by one of these altered genes could lead to development of new and more effective medications.
The research, conducted by Amber E. Baum, Francis J. McMahon, and their colleagues, is the first study to genetically scan thousands of…
mikethemadbiologist | May 10, 2007Remember the old joke that a conservative is a liberal who has been mugged? By way of Ed Brayton, I came across this post by Kent Hovind about his time in jail. Both the post and some of the responses are fascinating (in a 'car wreck' sort of way) because they illuminate the authoritarian mind so well. Hovind has reached an epiphany of sorts about the criminal justice system:
At lunch last week, one of the inmates said, "If I could, I would bomb the Christian Coalition. They are the reason we are here." I was shocked by his statement! I love the Christian Coalition, but I understand the…
clock | May 9, 2007Lots of interesting Neuro/Behavioral stuff came out lately, some really cool, some questionable...so you let me know what you think:
Brain's White Matter: More 'Talkative' Than Once Thought:
Johns Hopkins scientists have discovered to their surprise that nerves in the mammalian brain's white matter do more than just ferry information between different brain regions, but in fact process information the way gray matter cells do. The discovery in mouse cells, outlined in the March issue of Nature Neuroscience, shows that brain cells "talk" with each other in more ways than previously thought. "…
purepedantry | May 8, 2007Less than a week after I had to correct myself on autism and face perception, I read another article on the subject that has me skeptical.
Let's see if we can apply what we learned before. The conclusions from my earlier piece were a couple: 1) people with autism do not seem to possess a global deficit in face perception although they may evaluate faces differently and 2) the evidence with respect to fMRI is mixed.
Here is the new work (unfortunately not available as a paper yet):
In a report to be presented May 5 at the International Meeting for Autism Research in Seatlle, researchers…
revere | May 7, 2007We've know for some years now that traumatic brain injury (TBI) is the "signature wound" of the Iraq War (see here, here). We know it's true but we don't know its full extent. Nor has the Department of Defense bothered to find out how bad it is, despite the fact that they designed a screening test for TBI "years ago" according to USA Today:
The Pentagon must use computers to screen troops before and after they go to Iraq or Afghanistan to better determine whether they suffered traumatic brain damage in combat, according to a plan by a congressional brain-injury task force.
The Defense…
jstemwedel | May 5, 2007Depending on your blog reading habits, you may already have heard the news that feels almost like cosmic justice that a law firm has rescinded an offer of employment from a third year law student whose online activities the firm found troubling. The linked posts will give you some flavor for those activities (as will this post), so I'm not going to go into the gory details here. However, I wanted to say a few words about this comment Amanda Marcotte made on Sheezlebub's post on the matter:
While it couldn't have happened to a nicer guy, I simply have to voice my unease with the politics of…
grrlscientist | May 4, 2007tags: mental health, verbal abuse, sexual abuse, children
How many of you are survivors of childhood verbal abuse? I am not talking about an occasional parental outburst, but rather, consistent full-scale verbal assaults by your parents? According to a recent study by Harvard University psychiatrists, these so-called verbal beatings are as hurtful to an individual as sexual abuse and may also have long-lasting effects on the brain and behavior.
"Exposure to verbal aggression has received little attention as a specific form of abuse," notes Martin Teicher, associate professor of psychiatry at…
purepedantry | May 2, 2007The Freakonomics guys have a simply hysterical article in the New York Times magazine about monkey economics. The article discusses how monkeys possess the mental apparatus for economic valuation including the use of money. They train the monkeys to use silver tokens as currency to trade for food, and then they show that the monkeys behave very similarly to humans in a variety of situations. Money quote:
The capuchin is a New World monkey, brown and cute, the size of a scrawny year-old human baby plus a long tail. ''The capuchin has a small brain, and it's pretty much focused on food and…
cortex | May 2, 2007Mind Matters, David Dobbs' research blog over at Scientific American, is indispensable weekly reading. This week is no different. The topic is a paper documenting the importance of maternal presence in rat-pups. Apparently, the absence of a rat mother during a critical period of pup development permanently alters the behavior of the pup*:
In their recent Nature Neuroscience article, researchers Stephanie Moriceau and Regina Sullivan explore learned olfactory preference and aversion as mediated by maternal presence. In this study rat pups were exposed to a peppermint odor that was paired with…
developingintelligence | May 2, 2007What neural mechanisms underlie "fluid intelligence," the ability to reason and solve novel problems? This is the question addressed by Gray et al. in Nature Neuroscience. The authors begin by suggesting that fluid intelligence (aka, gF) is related to both attentional control and active maintenance of information in the face of ongoing processing (i.e., working memory). Each of these concepts, in turn, has been associated with the functioning of the lateral prefrontal cortex - a region that has been massively expanded in humans compared to even our closest evolutionary relatives.
To…
goodmath | May 1, 2007 Before diving off into real content, the name of my little π-calculus monstrosity has been chosen. As several people recommended in the comments, I'm going to go with Pica.
So, today, we're going to take the dive, and start looking at some interesting semantics of the language. The goal of this is still to work on Pica's type system: I want
to work towards a first draft of what a process type will look like. But to figure out what a process type should look like, we need to think about how process abstractions will be
defined and used in Pica, what control structures are going to look like…