neuroscience
purepedantry | July 6, 2006What does a scanner see? Into the head? Into the heart? Does it see into me? Clearly? Or darkly?
Think about it this way. Everything that you have ever been or ever will be, everything you have loved, every preference, every joy, every sweet or sordid memory is contained in a squishy mass of about 1.5 kg. That squishy mass is so fragile that whiplash can mortally wound it and so demanding that you must eat constantly to feed it. The slightest change in temperature or decrease in oxygen will leave it useless.
True, it is surrounded by a skull -- which from personal experience in anatomy…
clock | July 6, 2006The second installment of The Synapse, the neuroscience carnival, will be held right here this coming Sunday, on July 9th. Please send your submissions to me by Saturday night at 8pm EDT at: Coturnix1 AT aol DOT com.
cortex | July 5, 2006This charming article, on Shamu, positive reinforcement, and the malleability of men, has been one of the NY Times' most emailed articles for the last 10 days. (Is that some kind of record?) The basic message is very straightforward:
The central lesson I learned from exotic animal trainers is that I should reward behavior I like and ignore behavior I don't. After all, you don't get a sea lion to balance a ball on the end of its nose by nagging. The same goes for the American husband.
The article goes on to detail how the author used "approximations" - rewarding small steps toward a whole…
purepedantry | July 4, 2006When a man wakes up after a 20 year coma, you know that people are going to pay attention. Particularly after the Terry Schiavo business, I think it is important to add some facts to this debate as early as possible before it gets completely out of control.
So let's talk about this guy. In 1984, Terry Wallis has a car accident where he was thrown from his pickup. He goes into a coma. Despite his family's objections, it would appear he was misdiagnosed as being in a persistent vegetative state rather than a minimally conscious state:
But improvements in the care of patients could be made…
cortex | July 3, 2006This week's question is "What are some unsung successes that have occurred as a result of using science to guide policy?"
That's a tough question. I'm going to go with mental health. Until relatively recently (i.e., the 1960's), our mental health institutions were illiberal asylums, mass penatentaries for the psychotic, schizophrenic, depressed, autistic, retarded, etc. They were Foucaultian prisons where we sent anyone who couldn't quite manage the real world.
But thanks to the discoveries of science, we now know that the mad are sick and that mental illness is really an illness. Of course…
cortex | July 3, 2006The NY Times Magazine had an interesting article on deja vu and memory. It's about a group of cognitive psychologists who are using patients afflicted with a continual sense of deja vu (sounds a little hellish to me) in order to understand the neural mechanisms of remembering.
This is a relatively new field. While psychologists and neuroscientists have long wondered how we create new memories, they have shied away from a far more complicated question: how we remember our old memories.
But now that's beginning to change. The Times' article doesn't discuss this research, but I think some of…
purepedantry | July 2, 2006What is wrong with this picture?
It's wrong for one. What this picture represents is what is called the "motor homunculus." The motor homunculus is the idea that on a particular gyrus of the brain -- the precentral gyrus -- all muscle are represented by discrete pools of neurons. Activation of these discrete pools of neurons leads to activation of the muscles.
This model was generated when a neurologist named Wilder Penfield, while performing brain surgery, used an electrode to zap different regions of the brain. When he would zap this gyrus at different points, it would result in…
purepedantry | July 2, 2006Popular Science has a great article on the recent advances in prosthetics. They hit on one of the topics that I think has been really under-researched: neural to machine interfaces. What you would really like to do with a prosthetic is have it communicate directly to and recieve information directly from the central nervous system. To whit:
Once science figures out better ways to attach artificial limbs, prosthetics themselves need to become smarter, able to act on signals sent directly from the brain. Consider the case of Jesse Sullivan, a power lineman from Dayton, Tennessee, who lost…
clock | July 1, 2006Yes, there are two neurocarnivals. They occur on alternate weeks.
So, if you have written something this past week, send your entry to the Encephalon which will be posted on Neurophilosopher's blog on 3rd July, 2006.
Posts you write afterwards, during next week (or, if you really, really, really hate Neurophilosopher and really, really, really, love me), send to me for the inclusion in the next edition of the Synapse, to be held right here on July 9th, 2006.
Both carnivals are listed on Blogcarnival.com so you can use their automated submission forms.
cortex | June 30, 2006So we now have a short list of some great but forgotten psychologists:
Karen Horney: "Neurosis and Human Growth"
Frederic Bartlett: "Remembering"
Kurt Lewin
William James: "Pragmatism"
Alfred Adler
Edward Tolman
John Dewey
George Mead
Keep the suggestions coming!
purepedantry | June 30, 2006This article in The Scientist describes a paper where the authors claim to have found empathy in mice. The problem is that what you define as empathy may be more a matter of semantics than of science:
There is an "increasingly popular" view that this kind of basic, pre-cognitive response to social cues may be present in all mammals, said Frans de Waal at Emory University and the Yerkes National Primate Research Center, who did not participate in the study. "This "highly significant [paper]...confirms that empathy is an ancient capacity," he told The Scientist in an Email.
...
In this study,…
cortex | June 30, 2006Why can't we supress laughter?
I have no idea, but this video is hilarious. It's also a little cruel. I dare you not to laugh.
purepedantry | June 29, 2006How does cooperation evolve? It is in an organism's best interest to screw its competitors in order to best convey its genes to the next generation, yet we see a variety of human and animals examples of cooperation. The answer falls to a division of mathematics and economics called Game Theory. Game Theory examines the behavior of individuals (or software constructs designed to replicate individual behaviors) as they interact. Generally, this interaction occurs in terms of simple games where the effects of different strategies on the outcome -- cooperation or competition -- can be…
cortex | June 29, 2006Did you know that we can thrive with only half a brain? Weird. The New Yorker has a wonderful article documenting the lives of patients who live through these hemispherectomies. The strangest thing is that no one knows how they do it:
When I asked the surgeons how it's possible for people with half a brain to live, let alone have a life, each of them spoke about plasticity, flexibility, redundancy, and potential, and then they smiled and said the same thing: "We don't really know."
cortex | June 29, 2006Over at Small Gray Matters, there is an excellent critique of my last post on fMRI. Here is the nut graf:
While fMRI certainly has important technical limitations people should be aware of (low spatial and temporal resolution, high costs giving rise to underpowered studies, etc.), I think the issue Lehrer chooses to focus on-namely, the relationship between the BOLD signal (the signal measured by fMRI machines) and underlying neuronal activity-is actually one of the few areas that aren't controversial.
Well, yes, that was my point. There have been no shortage of philosophical critiques of…
cortex | June 28, 2006Mixing Memory's post on the undeserved obscurity of Franz Brentano got me thinking. What other great scientists of mind are modern neuroscientists neglecting?
My own vote goes to William James. While his Principles of Psychology are often mandatory reading in Intro to Psych courses - not bad for a 19th century textbook - few neuroscientists grapple with his philosophical writings. That's a shame, because they are often more relevant than his Principles. Take this quote from his late essay "Psychical Research":
"This systematic denial on science's part of personality as a condition of events…
purepedantry | June 28, 2006Are there neurobiological correlates of economic behavior such as utility seeking? The answer is yes, as demonstrated by some very elegant work by Berns et al in Science.
Bern et al. wanted to establish what areas activate during the feeling of dread. Dread is defined as the feeling during the wait for a bad outcome that one knows is going to be inevitable. Why would we have dread? What is the purpose of dread? Well, the decision about whether to delay a bad outcome or get it over with quick is determine, in their view, by a comparison of the utility of the time during the delay to the…
clock | June 27, 2006
The origin and early evolution of circadian clocks are far from clear. It is now widely believed that the clocks in cyanobacteria and the clocks in Eukarya evolved independently from each other. It is also possible that some Archaea possess clock - at least they have clock genes, thought to have arived there by lateral transfer from cyanobacteria.[continued under the fold]
It is not well known, though, if the clocks in major groups of Eukarya - Protista, Plants, Fungi and Animals - originated independently or out of a common ancestral clock. On one hand, the internal logic of the clock…
cortex | June 27, 2006Mixing Memory posted an interesting reply to my "Gladwell is the New Freud" post. He argued that my "Freud bashing was just wrong":
For one, while Jonah attempts to criticize Gladwell for being too Freud-like in his discussion of the "adaptive unconscious" (another term for the "cognitive unconscious"), the very fact that contemporary psychologists have begun to show just how important unconscious processes are is, in a way, a vindication of Freud. As is the fact that we are just now beginning to understsand the interplay of affect, motivation, and cognition -- the very focus of Freudian…
cortex | June 26, 2006It's in every neuroscience textbook: the kitten that never saw with stereoscopic vision, because Hubel and Weisel sutured one of its eyes shut during the "critical period" of brain development. The moral, at least as I was taught it, was that plasticity has limits. After infancy, our brain begins to harden into shape. If you don't see stereoscopically as a baby, then you never will. Binocular cells don't develop in adults.
Oliver Sacks had an insightful article in The New Yorker a few weeks ago about a woman who seems to disprove Hubel and Weisel's cat. And now, Robert Krulwich has a…