neuroscience
cortex | March 22, 2007On Monday, I posted about some recent imaging work documenting the way the brain distinguishes between "personal" and "impersonal" moral dilemmas. Now comes a new Nature paper from a medley of researchers documenting how damage to a single brain region - the ventromedial prefrontal cortex (VMPO) - erases this fundamental distinction.
Damage to an area of the brain behind the forehead, inches behind the eyes, transforms the way people make moral judgments in life-or-death situations, scientists reported yesterday. In a new study, people with this rare injury expressed increased willingness to…
cortex | March 21, 2007Here are your disturbing prison facts for the day:
Percentage of American adults held in either prison or mental institutions in 1953 and today, respectively: 0.67, 0.68
Percentage of these adults in 1953 who were in mental institutions: 75
Percentage today who are in prisons: 97
That's from the latest Harper's magazine. My first reaction to this bit of data was dismay: we've turned prisons into insane asylums, and are locking up people who should be treated for mental illness. These statistics make it clear that the boom in the prison industry is fed, in part, by the closing of our mental…
omnibrain | March 20, 2007It was one year ago today that I made the first post to Omni Brain. I never imagined we would do this well.
In the last year Omni Brain has undergone many many changes, the biggest of which have been Sandra of Neurofuture fame joining the blog, and moving to ScienceBlogs.
We started with not-even 3000 page views in our first full month and now receive tens of thousands of page views and visitors - which is pretty great for a smart ass little science blog! Our Technorati ranking has also grown by leaps and bounds; near 14,000 today.
Thanks everyone, for reading and for all your lively…
clock | March 20, 2007I have written about the relationship between circadian clocks and food numerous times (e.g., here, here and here). Feeding times affect the clock. Clock is related to hunger and obesity. Many intestinal peptides affect the clock as well.
There is a lot of research on food-entrainable oscillators, but almost nothing on the possibility that there is a separate circadian pacemaker in the intestine. It is usually treated as a peripheral clock, entirely under the influence of the SCN pacemaker in the brain, even when it shows oscillations in clock-gene expression for several days in a dish.…
cortex | March 20, 2007It's hard to believe that just over fifty years ago psychology was in the firm grip of behaviorism, which denied any semblance of intelligence or emotion in animals. (They were just biological machines.) Talk of anything but stimulus and reward was just sentimental pseudoscience. Then came Chomsky and Goodall and de Waal and a legion of other brave scientists who dared to document the actual behavior of animals. And now we have discoveries like this, in which birds display behavior that seems quintessentially human (at least if you frequent bars and nightclubs):
Emily DuVal, a biologist at…
clock | March 19, 2007It has been known for quite a while now that bipolar disorder is essentially a circadian clock disorder. However, there was a problem in that there was no known animal model for the bipolar disorder.
Apparently that has changed, if this report is to be believed:
"There's evidence suggesting that circadian genes may be involved in bipolar disorder," said Dr. Colleen McClung, assistant professor of psychiatry and the study's senior author. "What we've done is taken earlier findings a step further by engineering a mutant mouse model displaying an overall profile that is strikingly similar to…
cortex | March 19, 2007Descartes is turning over in his grave: the mind and body grow more intertwined by the day. It's becoming clear that maintaining a healthy mind into old age isn't simply a matter of keeping the brain active with card games and crossword puzzles. Perhaps equally important is an active body. Physical exercise is a crucial part of mental health:
Researchers are realizing that the mental effects of exercise are far more profound and complex than they once thought. The process starts in the muscles. Every time a bicep or quad contracts and releases, it sends out chemicals, including a protein…
clock | March 19, 2007Every time someone proposes a radical rewriting of science textbooks, one needs to proceed with caution. There is so much evidence for electrical potentials in nerve cells, this sounds really fishy:
Action Of Nerves Is Based On Sound Pulses, Anesthetics Research Shows:
Nerves are 'wrapped' in a membrane composed of lipids and proteins. According to the traditional explanation of molecular biology, a pulse is sent from one end of the nerve to the other with the help of electrically charged salts that pass through ion channels in the membrane. It has taken many years to understand this…
cortex | March 16, 2007The 20th century was the American century, but we got progressively less happy as the years rolled along:
The authors also find that over the last century, Americans, both men and women, have gotten steadily--and hugely--less happy. The difference in happiness of men between men of my generation, born in the 1960s, and my father's generation, born in the 1920s, is the same as the effect of a tenfold difference in income. In other words, if my father had little money compared to his contemporaries and I have lots of money compared to mine, I can still expect to be less happy. Here, curiously,…
omnibrain | March 15, 2007Ahh... about 20 years after beginning the project our paper was finally accepted at the Journal of Neurophysiology. If you'd like a copy go to my reprint website which will let you request a reprint and will email you a copy. A great sneaky way of dealing with copyright/distribution laws ;)
Here's the abstract:
Humans and animals use information obtained from the local visual scene to orient themselves in the wider world. although neural systems involved in scene perception have been identified, the extent to which processing in these systems is affected by previous experience is unclear.…
cortex | March 15, 2007Do any neuroscientists actually take Roger Penrose's theory of quantum microtubules seriously? When I hear phrases like "quantum Platonic non-computational influences" being applied to the brain, I tend to get very sleepy. But Andrew Sullivan, in a post titled "The Big Wow," recently featured a long letter laying out Penrose's latest musings on the quantum nature of consciousness, life after death, etc. I haven't looked at The Emperor's New Mind for several years, but Penrose's new version of the theory sounds even more improbable than I remember.
I have a feeling that the attractiveness of…
cortex | March 13, 2007Since the science of humor is in the news today, I thought I'd point out an interesting tidbit from a recent Cerebral Cortex paper:
The speculation that humor may be a uniquely human cognitive trait (Bergson 1924; Caron 2002) prompted our third hypothesis: humor will activate both anterior cingulate cortex (ACC) and frontoinsula cortex (FI), the 2 regions in which an evolutionarily recent neuron type, the Von Economo cells (previously termed ''spindle neurons''), are present. A review of the functional imaging literature reveals that the Von Economo cell regions, particularly FI, are active…
j7uy5 | March 13, 2007I
really liked Jonah's post at The Frontal Cortex,
about
href="http://scienceblogs.com/cortex/2007/03/dreaming_smelling_and_memory.php">Dreaming,
Smelling and Memory. But I have to take issue with
his treatment of the use of dream interpretation in Freudian
psychotherapy.
I know this is a nit-picky point, and is completely tangential to the
point of his post. But this close to Piday, we need to be
thinking about things like tangents.
It is true that psychoanalysts refer to dreams as "the royal road to
the unconscious." It is true that the interpretation of
dreams can be an…
omnibrain | March 12, 2007Grunt pant exhale grunt uugh grunt exhale. Pump that iron!
That's all you really need to know.
So get with it! Get to the gym and start exercising!
Actually, it seems that aerobic exercise was the beneficial form of physical activity. The researchers next step is to determine what forms of activity are the best for avoiding memory loss.
Here's some details from the CNN article:
Exercise boosts brainpower by building new brain cells in a brain region linked with memory and memory loss, U.S. researchers reported Monday.
Tests on mice showed they grew new brain cells in a brain region called…
purepedantry | March 12, 2007Jeffrey Rosen has an excellent piece in the NYTimes magazine about the increasing use of neurological arguments in the courts:
One important question raised by the Roper case was the question of where to draw the line in considering neuroscience evidence as a legal mitigation or excuse. Should courts be in the business of deciding when to mitigate someone's criminal responsibility because his brain functions improperly, whether because of age, in-born defects or trauma? As we learn more about criminals' brains, will we have to redefine our most basic ideas of justice?
Two of the most ardent…
omnibrain | March 12, 2007It looks like under very controlled circumstances, with rats, you can pick and choose which memory stays and which memory goes with a new drug. Don't worry though - the CIA won't be implanting and removing memories of last Tuesday any time soon. I'm not saying they can't wipe out most of last January, but they've always been able to do that with a whole lot of electric shocks and crazy drugs ;) Now, aliens on the other hand, they have a decent success rate with people. At last it seems that way since some people don't recover the memories of their anal probes until years later.
In any case…
cortex | March 9, 2007After Freud lost his scientific credibility, psychology became very dismissive of dreams. The leading scientific theory held that dreams consisted of mental detritus, the scraps and fragments of memories that your brain didn't want to remember. While Freud mined our nighttime thoughts for hidden meanings - they were symbol laden narratives of wish-fulfillment - this modern theory held that our dreams were entirely meaningless, a montage of hallucinations. They were the result of our hippocampus taking out the trash.
But dreams have been slowly making a comeback. There's now a large body of…
neurontic | March 8, 2007Hello fellow brain geeks,
The Neurophilosopher has done us all a huge favor and compiled an exhaustive list of all of the neuroscience-related blogs out there. I've spent the morning adding new (and long-delayed) sites to the blogroll and thought you might want to take a look as well: Neurophilosopher's Neuroscience Blog List.
cortex | March 8, 2007A friend of mine recently asked me a simple question that I couldn't answer:
i want to know if there is a physiological explanation for why we have an easier time remembering things that we perceive to be true.
bad example: suppose that you believed that the earth was flat. then i took you out into space and showed you that it was round. you would not forget that. i'm having a hard time expressing this very simple thought: we are constantly replacing old beliefs with new ones that are in some sense "more true". you can intuitively distinguish between those thoughts that you have that…
j7uy5 | March 8, 2007The
href="http://en.wikipedia.org/wiki/Diagnostic_and_Statistical_Manual_of_Mental_Disorders">DSM
refers to anhedonia as one of the two core symptoms
of depression; the other core symptom is depressed mood itself.
What is anhedonia, and why is it so important?
First, let's consider what it is not. Those of you who tend
to
derive the meaning of a word from the Greek roots will recognize the
similarity to the word, hedonism (
href="http://www.answers.com/hedonism&r=67">1
href="http://plato.stanford.edu/entries/hedonism/">2),
which is commonly understood to be a focus,…