From a paper in Animal Cognition, we find out that mules are smarter than horses and donkeys.
This raises interesting questions about hybrid vigor and, especially, in humans, if multiracial individuals or people with more diverse genetic ancestry have a higher IQ on average than people from a more uniform ethnic background.
Thursday, July 31, 2008
From a paper in Animal Cognition, we find out that mules are smarter than horses and donkeys.
Monday, July 28, 2008
LOL at a comment from Dr. Drew:
Is there a culture of restriction at treatment facilities? For example, what is the tolerance for lesser vices like caffeine, or sex?Caffeine is a stimulant. You can find a better post explaining why this is so at Chris's website. Refer to this article too.
Sex is a no; relationships are what take people out. Caffeine is not actually a stimulant. It removes a nervous system depressant so the brain can feel stimulated. Addicts will always put things in their mouth. They always try to alter [their perception] automatically — that's their orientation. Of course we want that behavior to stop. However, there's no evidence that caffeine alters their course [of recovery]. We used to say the same thing about nicotine. Now there is evidence that we should be focusing on stopping nicotine early.
'Stimulant' by definition means at least removing a nervous system depressant; in addition, the effects of caffeine on the body are well-documented. Sphere: Related Content
Thursday, July 24, 2008
Warning: Rant. If you do not want to read this, page down.
Sometimes I come across things which are supremely stupefying in their simplemindedness and their illogic; the long list of things that are wrong with them is so long and interwoven that I don't even know where to begin describing them. I comprehend the problem, but it is difficult to translate it into words and organize the points sometimes.
Mostly, I am not sure how much to explain some things sometimes. I come from an upper-middle-class family, for example, the progeny of two parents who have masters' degrees, and am planning to get a PhD in neuroscience (as you all know, I am currently in college studying neuroscience), which is actually fairly easy for me, compared with how hard it seems to be, from the reactions I've gotten from many whom I've told about my studies, for many others. Sometimes, when for example I have to communicate with someone who has less than a high school education, I wrack my brain trying to tell them about various intricate concepts in simple terms. Even people in other fields, who may be as educated or more educated than me, make me wrack my brain in telling them things in ways they can understand. I really only have a certain amount of ease communicating with people who study what I study; I don't have to do a whole lot of explaining.
(As an aside, though I have a distaste for Mooney, Nisbet, Olson and their ilk, the sentiment that we could do a little better in communicating science to people is true, though I disagree with them on how.)
As for social criticism, I have some of the same problems - I cannot muster the words, no matter how much grandiloquence I can wedge into my posts, to express how utterly disastrous the world is right now. I make no move to hide my misanthropy. I mean, yes, it is informed, to some extent, by a past that I mostly vigorously shove to the back of my mind where I am seldom reminded of it, though it is also informed by what I read in the news and my understanding from my point of view. Sometimes the explanations I muster are long enough that I do not have the patience to say everything I want to say, that the other person probably doesn't have the time to listen to me, and sometimes they're also filled enough with harsh and well-deserved criticism, which is usually fairly angry even if somewhat eloquent, that emotionally it makes me feel like retreating into a room for a while and either beating the shit out of an inanimate object or crying. Anger is tiring. I make no move to hide the fact that I have much of it, and it tires me daily.
Sometimes my blog posts sound a little clipped; honestly, I don't get enough feedback in my comments to know what the apparent several hundred people who've read this blog think of what I write. Those are usually because sometimes, on some topics, it's hard to know where to start - some are so wonderfully or nastily complex that no one angle seems quite adequate to explore what I'm writing about.
I tried to make this post somewhat organized, and I think I didn't organize it much; I was already reluctant to post this anyway, because of what a reader might think, and because I've been shit on enough for just bringing up some of my own problems - I mean, seriously, there's a shortage of people who seem to really care when their friend has problems instead of pushing them away for temporarily being a sad sack, even though everyone has problems at some point (man, if this loses me any friends at Wisconsin - I know some of you read this blog from time to time - I'm not gonna be happy), but I got tired of being quiet about this.
I'm tired, I'm tired, I'm tired.
Wednesday, July 23, 2008
Monday, July 21, 2008
Via Cognitive Daily, older people are worse at some visuospatial tests than younger people.
Mélanie Joanisse, Sylvain Gagnon, Joshua Kreller, Marie-Claude Charbonneau (2008). Age-related differences in viewer-rotation tasks: Is mental manipulation the key factor? Journal of Gerontology: Psychological Sciences, 63B (3), 193-200
This is very interesting - not only for the whole neuroscientific aspect, but because I have also tested as having much higher visuospatial abilities than other people my age. The study looked at three different methods of presenting an object to a viewer - updating, ignoring, and imagining. See the Cognitive Daily post for the study methods.
What is cool about this is the fact that some aspects of mentally rotating objects decline in older people but not other methods, which makes me wonder whether these aspects are controlled by different areas of the brain - different parts of the visual cortex or the intraparietal cortices? Do older people lose particular synapses? Does this vary by original visuospatial ability?
Put an fMRI in there - I want to see the activity of the parietal lobe in this study.
An article in the journal Neurology says that exercise may prevent your brain from shrinking if you have Alzheimer's.
Well, exercise has some neuroprotective effects. It increases the flow of blood to the brain and promotes growth factors and neurochemical protectivity. It's not going to hurt your brain.
There is no idea what causes this, but there was four times less brain shrinkage in Alzheimer patients with moderate physical activity than in Alzheimer patients with slight physical activity.
Sunday, July 20, 2008
Saturday, July 19, 2008
Thursday, July 17, 2008
Most science blogs out there are from graduate students or faculty members. I'm still in college, and I'm looking pretty feverishly for research.
Part of the problem is personal issues; I've got a few pretty difficult ones to deal with, and I'll hopefully deal with them by the beginning of the semester. I'm not going to tell readers what the issues are, but they suck.
I'll admit my grades are not what they should be, either, because of these personal issues. One of the things that has been helping me keep my head up is Brian Switek's series of posts at Laelaps, telling the reader about his own struggles, which are different than mine, but reading the advice there keeps me from crumbling.
My first attempt at finding research was back in 2007, when I emailed a neurogeneticist at my university who was doing work on Drosophila. There was a lot of back-and-forth with emails until he said 'I can't train you' and I just went batshit until his graduate student said 'Hey, I'm looking for someone to help me' and I volunteered and he said 'I can't train you'.
Fall of 2007 was spent grumbling about the missed research and doing my classes. Spring of 2007 was when I started trying to pick up more research, but after contacting at least six or seven different people, there was nothing to do.
This semester will be spent trying to pick my grades up, and after that I'll probably try a few other places and reapply, since my grades will be higher. My advisor, another professor in my department, and a few others are good sources of information.
But I spend most of my precious little free time on campus reading blogs from fellow science people, reading new information, and sucking up every bit of knowledge I can find. I have a passion for what I study - neuroscience is my life. I've gotten encouragement from my fellow students; one who works at the VA hospital that's near the university hospital has given me some useful advice on trying to find a lab.
I'll get my degrees. I have to.
Sunday, July 13, 2008
Lest you think tolerance of stupidity and fanaticism is a good thing, read this blog post and some of the comments beneath it (luckily most of the comments are sensible).
I mean, srsly, death threats? The fuck?
Saturday, July 12, 2008
If you replay the video, and listen under Stephanopoulos' interruption, this is point Koppel was trying to get across:Sphere: Related Content"And I think there is just a small but significant fraction of Americans for whom...the truth in this instance is never going to matter."
Which sounds like a small thing, but for me it was almost a cultural event, because it is almost the only time in my memory when a Big Time Newscritter sat in front of a camera and called bullshit on some specific, identifiable group other than "bureaucratsinwashington" or "liberalelites".
Because in Stephanopoulos' world (as in fairy tales of old) knowing and using the True Name of things comes with the possibility of dire fucking consequences, and so one must never, ever, ever, ever, ever call the 27%-ers out by their True Name lest All Conservative Hell break loose.
And so, in Stephanopoulos' world the 27%-ers are people who have merely been somehow bamboozled by the medium through which the message passes.
They are innocent naifs, bedazzled by Teh Sparkly Internets.
The inhabitants of Stephanopoulos' world will never come within a million miles of even forming their mouths to say the words "Jesse Helms was a despicable, racist motherfucker who stayed in power for as long as he did because his supporters and admirers were and are despicable, racist motherfuckers, one and all."
Instead, the inhabitants of Stephanopoulos' world believe that on the occasion of the death of this evil man we should toddle down to the Piggly Wiggly and buy some brand of Kiwi shoe polish powerful enough, to buff this turd of a human being to a shine high enough, so that he can be buried under a gooey, compromise word like "Controversial" or "Provocative".
But Koppel -- admittedly in the weakest, most tepid way possible -- was trying to at least hint at the terrible truth that dare not be spoken, because its implications are so enormous.
The truth that, fundamentally, it's not that our courts that are broken. Not our roads and bridges. Not our schools.
Not something from which science or engineering or manufacturing will rescue us. Not something we can figure out, prototype and then make a fortune selling a million units for a buck apiece.
Because it is we ourselves that are broken.
When I look at Dubya's poll numbers staying absolutely dead-level week after week after week regardless of what he has fucked up this week, or how badly, I learn nothing new about George W. Bush. But A-B-Cs behind just about everything else I need to know about America stand painfully revealed. Those numbers confirm for me for the unmpteenth time that inside the mushy skulls of the 27%-ers there is nothing but a hatbox of junk machine parts, still twitching and clattering mindlessly along on corrupted software that was already obsolete before men walked on the Moon.
The 27%-ers are slugs madly fighting for the right to jump into the salt bucket and drag us all down with them, and any solution to the problems that vex us must begin with their grotesquely mutant versions of patriotism, economics, virtue and civilization being discredited, sequestered and driven into oblivion.
Our first, great, national problem is that our fellow citizens -- in their millions -- are damaged beyond repair.
Friday, July 11, 2008
Wednesday, July 9, 2008
Doing my part to contribute to basic science blog posts on the Web.
This blog is, as stated, mostly a neuroscience blog. In this post, I'll be teaching those of you who don't know, perhaps, a friggin' thing I'm talking about about the basic component of the nervous system.
The neuron is the basic building block of the nervous system. There are several different shapes of neurons, which I'll describe later, but here's a basic neuron:
(Carlson, Niel. A. (1992). Foundations of Physiological Psychology. Needham Heights, Massachusetts: Simon & Schuster. pp. 36)
There are some parts of the neuron that aren't labeled here, including the nodes of Ranvier, but this is a basic neuron. A basic description of the parts -
Dendrites - These receive synaptic signals and contain receptors on them for neurotransmitters.
Soma - The cell body contains the nucleus and all that other cellular shit.
Axon - The tunnel which electric and chemical signals travel down.
Myelin sheath - The insulating cover for the axon. Gets eaten in people with MS.
Nodes of Ranvier - The axon between the myelin sheaths. Electrical signals travel in saltatory ('jumping') motion between the nodes.
Terminal button - These send synaptic signals.
The most important part of a neuron is its cell membrane. This is what receives electrical and chemical signals. Here is a diagram of a neuron membrane:
There are ion pumps in the cell walls. There are three ions which are important to the neuron: sodium, potassium, and calcium. These make your electrical impulses work. Gradients of charge across a cell produce potentials, which are differences in the voltage across a cell membrane and which drive electrical charges, known as action potentials, which do the work of your nervous system. Here is an action potential:
Action potentials always begin with a stimulus and depolarization - once the voltage across the membrane approaches a threshold (in this case a small negative voltage), the action potential is triggered. Action potentials are an all-or-nothing action, kind of like an orgasm, where the voltage becomes positive then drops down again and undershoots a tad.
There's an equation which relates the charge in a cell given the concentrations of ions, which is called the Nernst equation (which relates to a lot of other cells, but is used in neurons) and something one of my professors called the Extremely Important Equation.
The Nernst equation:
- where E = equilibrium potential, RT/F = 59.1 mV, z = the number of electrons transferred, and the words in brackets should be self-explanatory.
where Em = equilibrium potential of the membrane, E(ion) = equilibrium potential of an ion, P(ion) = the permeability of the ion in arbitrary units, usually siemens for conductance, and Ptot = the total permeability of all permeant ions.
And here's some basic physics equations:
Here's some different types of neurons, categorized by function:
http://en.wikipedia.org/wiki/Neuron#Classes Sphere: Related Content
Discussion at Respectful Insolence.
Jump in the fray, it's fun to make fun of idiotic parents who don't know the first thing about autism and are likely making their offspring and other people's offspring susceptible to other diseases.
I wonder if they've heard of genetics.
Tuesday, July 8, 2008
This morning, I stumbled across this heinous post, in which some asshole decided to use my blog's content in an attempt to justify his racism:
This is the content he used from my blog, which comes from this post:
"NOT SO. I can name a couple of genes and not much more that influence intelligence:
And this is what the asshat wrote in the rest of his article:<
"Some comments on Jim Manzi’s article at above link. This is well written and thought out. However, we can measure IQ racial differences at the top of the column easily. Very few blacks produce great math. One exception is David Blackwell and there are others.
"To tell if two bodies of water are the same height you look at the top. Same with trees, people, etc. You don’t have to know the chemistry of the insides of the lakes, trees, or people to tell that one is higher than the other. Its the same with intelligence. We look at the top of the races and see a huge difference. That is the measurement. We can look at the societies and civilizations and see a large part of the distribution.
"If blacks can’t figure out not to eat lead, that is an indication of intelligence. Whites did figure that one out. Claiming its lead or whatever in the environment doesn’t explain why one group can figure out lead is a problem and avoid it. If lead was the problem, then liberals say its whites fault for not keeping blacks from ingesting lead."
Let the shaming commence! Sphere: Related Content
Monday, July 7, 2008
Hernandez-Gonzalez M, Guevara MA, Agmo A (2008). Motivational influences on the degree and direction of sexual attraction. Ann. N.Y. Acad. Sci. 1129: 61–87
Motivation can be defined as a class of central nervous processes determining the likelihood of display of a behavior and the intensity of the behavior if displayed. All behavior is, according to this definition, caused and controlled by motivation. Although the concept of motivation eventually could be replaced by an entirely mechanistic explanation of the causes of behavior, in terms of neural events, such explanations would be overly complex for everyday use. This is particularly the case with regard to the momentaneous fluctuations in the intensity of a behavior, like those occurring during copulation in rats. Thus, the concept of motivation will remain useful even when mechanistic explanations become available. Even though the propensity to perform sexual responses is determined by sexual motivation, another element is required for the execution of such responses. This other element is an appropriate stimulus, a sexual incentive. For a male rat, an appropriate incentive could be a sexually receptive female. For a human, it could be a mental representation of a sexual partner. The incentive activates approach behaviors, and the intensity of these behaviors will be determined by motivation and by the quality of the incentive stimulus, its attractivity. Much work has been done with the purpose of identifying the nature of the incentive stimulus or stimuli emitted by rats and other mammals. While visual stimuli seem to be of limited importance, auditory and particularly olfactory stimuli have been found to have incentive properties. Soluble chemicals may be important for some aspects of copulation, but copulatory motor patterns are basically under the control of tactile stimuli. The processing of sexual incentives in the rat brain has been studied with electroencephalographic techniques, and data show that the prefrontal cortex (PFC) participates in the identification of sexual incentives. Furthermore, there are important differences between the medial and orbital frontal cortices. The medial PFC, as well as the ventral tegmental area, also seem to participate in the generation of pelvic thrusting.Sphere: Related Content
What you thought about depression is about to be up-ended.
Recent studies from Yale and Princeton and a university in Italy suggest that depression is a mild neurodegenerative disease. Instead of simply disturbing your brain's neurochemistry, depression destroys neurons. (This is bad for the 10% of people in the United States who are depressed.)
Antidepressants work depending on each individual's neurochemistry, but they supposedly perform another function: they prevent neurons from dying. My question is - how do the neurons die? What biochemical trigger makes them die? If we dissected the brains of a happy rat and a depressed rat, what would we find? Loss of neurons has been already found in the hippocampus - so maybe SSRIs help protect the hippocampus.
The gamut of drugs for already-identified neurodegenerative diseases is acetylcholinesterase inhibitors, NMDA receptor inhibitors, L-dopa (dopamine), dopa decarboxylase inhibitors, dopamine agonists, MAO-B inhibitors, MAOIs, and other drugs. MAO inhibitors are a class of antidepressant reserved for those cases that cannot be treated with other antidepressants, and antidepressants and antipsychotics are used to decrease symptoms of depression and psychosis in people with neurodegenerative diseases.
Depression is a disorder which contains some wacky brain chemistry, which would no doubt kill a few neurons. The neurotransmitters affected in depression are serotonin, dopamine, norepinephrine (the catecholamines), and possibly GABA and glutamate. A lot of brains also secrete excess amounts of MAO-As, where the MAOIs come into play.
As we further understand the processes of neuronal death in depression, treatment will advance. Some treatments for more advanced neurodegenerative disease might, in small doses, cure depression.
Friday, July 4, 2008
Via Neurophilosophy, the Kaibo Zonshinzu, a set of medical illustrations from the 1800s.
An exposure of the meninges and their vasculature.
The cerebral cortex.
The cortex opened exposing the corpus callosum and the cranium.
The cerebellum opened and the ventral view of the cranium, showing cranial vasculature and how the brain is oriented in the cranium .
The ventral view of the brain, showing the brainstem, olfactory bulbs, pons, pineal gland, and medulla.
Thursday, July 3, 2008
Comment open season:
I have temporarily enabled anonymous posting so I can get a better idea of who's reading and what posts they've liked and what they haven't liked so far. Please, feel free to include or not include this information in your post:
- A little bit about yourself - where you're from, a broad idea of what you do
- Critique of the blog
Today I'm going to post about death.
This post is dedicated to my canine buddy whom I knew for thirteen years, Hot Shot (don't laugh; I got the dog when I was seven, and I called him that for thirteen years - I'm 20, and I got him when he was a mere sixteen weeks old - he died at the ripe old age of thirteen, which, if you use the 7 years to one human year rule, is equivalent to a 91-year-old human. He was an elderly ), who I euthanized two days ago after finding he suffered from a tumor on his enlarged heart, a tumor on his testicles, chronic kidney failure , and a stroke. He was beginning to convulse as I held his furry little body while the veterinarian sedated him, and the only indication that he'd died was his stopped heart, his lack of breathing, and some spasms. He died peacefully, and I'm glad he has no more agony, even if he is no longer alive. I feel like shit, as you can guess, and even though I look mildly stoic on the outside, I am grieving for my old very small friend who is, at least, going to do his part for nature after he has croaked by feeding organisms. Eat up, bacteria.
When the brain dies, all electrical activity ceases. Simple.
The problem is, how do you determine the brain has died? The American Academy of Neurologists has a set of criteria for determining brain death.
Brain death is defined by the American Academy of Neurologists as 'the irreversible loss of function of the brain, including the brainstem'. The brainstem is an important part of the definition because it controls your basic bodily functions - breathing and heartbeat.
The criteria are listed thus:
- Directly quoted from the list of criteria, clinical or neuroimaging evidence of an acute CNS catastrophe (which is our term for a critical occurrence in the brain or spinal cord) that is compatible with the clinical diagnosis of brain death
- Exclusion of complicating medical conditions that may lead to a different assessment - rule out various disturbances in the body's chemical milieu
- No poisoning
- Core temperature higher than 90 degrees F (32 degrees C)
- Three cardinal findings: coma/unresponsiveness, absence of brainstem reflexes, and apnea
- Eyes: Unresponsive to bright light, normal to dilated, no oculocephalic reflex if there is no apparent fracture or instability of the cervical spine, no deviation of the eyes in response to ear irrigation
- Facial sensation and motor responses: No corneal reflex, no jaw reflex, no grimacing in response to pressure on sensitive parts of the body
- Pharyngeal reflexes: no response to stimulation with tongue depressor, no cough response to bronchial suctioning
- PCO2 pressure higher than 60 mm Hg
Visual observations that can still be seen in brain death include spontaneous movements of limbs other than pathologic flexion or extension response, respiratory-like movements, sweating, blushing, tachycardia, normal blood pressure without pharmacologic support or sudden increases in blood pressure, absence of diabetes insipidus, deep tendon reflexes, superficial abdominal reflexes, triple flexion response, and the Babinski reflex (quoted almost directly from the criteria).
Tests that can be performed to diagnose brain death include conventional angiography, EEG, transcranial Doppler ultrasonography (except in ten percent of patients, who may not have temporal insonation windows, which are structures in the temporal bone of the cranium allowing sound waves to provide a picture of your brain), small systolic peaks in early systole without diastolic flow or reverberating flow, technetium-99m hexamethylpropyleneamineoxime brain scan, and somatosensory evoked potentials.
These criteria are vital in determining when a patient has died so the family may take them off life support, harvest their organs for donation, and a physician may declare them legally dead. There have been people declared legally dead who are still alive. There is a bunch of hemming and hawing about when death occurs, mostly split along religious/ideological lines (as an atheist, I think when their brain goes, they're effectively dead). Even among physicians, there are variations. - according to 'Greer et al. (2008) Variability of brain death determination guidelines in leading US neurologic institutions. Neurology; 70: 284-289', there is significant variability in 'requirements for performance of the evaluation, prerequisites prior to testing, specifics of the brainstem examination and apnea testing, and what types of ancillary tests could be performed, including what pitfalls or limitations might exist'. Does brain death stop, for that matter, when consciousness stops? Consciousness comes from our frontal lobe; we would have to find a way to judge when those neurons fall silent. (But that gets into a big argument about what consciousness is, and philosophy of mind is, as you know, one of the things I love to hate, as a person in neuroscience who is highly positivist, highly materialist, and absolutely hates dualists. Why the hell are they still debating whether the mind is part of the brain when we've already established it and are doing more research? Let us people in neuroscience do research on the brain; you go sit over there with your Kant, especially you bloody dualist bastards, who can keep your Descartes, the worthless frog)
If the diagnosis of brain death is this shaky, a few limitations might exist in determining it: misinterpretation of tests, unreliable test results, complicating comorbid symptoms, unknown factors in the neurological milieu (likely neurochemical processes), and other bits of human imperception.
I expect, as we grow in our knowledge of the healthy living brain, that we can use it to determine when that brain stops being living.