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You can't. You just think you can because you over-estimate your abilities. I encourage you to do an internet search for the relevant research. There was a slashdot story about it ~ 5 years ago.

I did do an Internet search, and in fact found plenty of research that indicates humans and other mammals can in fact localize sound in the vertical plane (i.e. whether it comes from in front of behind of you). Of course, it doesn't work for all sounds, but the capability is there.

http://jn.physiology.org/content/83/6/3548.full

The rebuttal you link to on xiph.org ignores research that illustrates that humans can in fact perceive frequencies far beyond the classical limit of ~20 kHz. Higher frequencies present essential localization cues. Higher sample rates, like 192 kHz., allow for the reproduction of higher frequencies (assuming playback equipment that can actually reproduce the higher frequencies) leading to recordings which are far more realistic than what is possible with the 44.1 kHz sampling rate.

The difference between 24-bit and 16-bit amplitude resolution is like night and day. As someone that has recorded much contemporary and classical concert music, I can certainly attest to the huge difference between the two bit rates. If you listen to music with a wide dynamic range, then the comparison between the two bit rates is highly noticeable. Quiet sounds can be masked by quantization noise. You want the highest bit rate possible.

You may find this paper interesting.

This all is kind of foreign to me (learning about acoustics in physics was cool and all, but not my strength). But here is a study that seems to suggest that the parent is correct: http://jn.physiology.org/content/83/6/3548.full

"Blind tests show that we perceive ultrasound: http://jn.physiology.org/content/83/6/3548.full [physiology.org] "

Since the body of ABX tests that shows people do not hear any difference between present and filtered ultrasound in music is much much larger that the body of theses guys we can safely assume that ultrasound frequencies, albeit maybe perceptable, have no significance whatsoever on listening to music.

And neurophysicists conclude that while the higher frequencies might not be consciously percepable that does not stop them having effects upon the perception of the audible ones.

They went to the level of measuring brain waves.

Even if not consciously audible, the higher frequencies have effects upon the perception of audible ones.

This has been scientifically tested, even going to the level of measuring brain waves.

Even if not consciously audible, the higher frequencies have effects upon the perception of audible ones.

This has been scientifically tested, even going to the level of measuring brain waves.

Even if not consciously audible, the higher frequencies have effects upon the perception of audible ones.

This has been scientifically tested, even going to the level of measuring brain waves.

I've got one better than blind tests, which are still based on introspection: _measure_ the effect precisely. And when you do, it turns out that the brain can perceive even ultrasound: http://jn.physiology.org/content/83/6/3548.full

Blind tests show that we perceive ultrasound: http://jn.physiology.org/content/83/6/3548.full So I suggest you GTFO. Albeit the effect is not conscious, no one has ruled out that it cannot subtly affect the perception of audible sound over long periods of time to the point where a conscious preference may develop in long term listening, without subjects of a study being able to describe the specific difference. In fact, this is more than plausible, given the reference I posted and others like it.

They only determined there's no immediately detectable conscious difference. Now consider this research: http://jn.physiology.org/content/83/6/3548.full So frequencies we don't consciously notice affect brain activity. Thus your reference is not as conclusive as you imply; still need studies to eliminate the possibility that inaudible frequencies do not impact the brain's perception of audible frequencies in a subtle manner over long listening. I've been suggesting we need long-term listening blind tests with psychological assays for about a decade, but haven't found volunteers that want to go through the trouble.

Just because you can't consciously hear it does not mean it doesn't have effects on your perception of the audible portion of the sound.

There's an argument that, on one hand, because he doesn't have to drag along the extra weight of lower legs, feet, and shoes, and his prostheses return energy very efficiently, that he might have an energetic advantage. On the other hand, he's missing a lot of musculature that ordinarily contributes power to forward progression, so he ought to be at an energetic disadvantage.

One of the most complete studies of this question, in this particular athlete, was not published until 2009 http://jap.physiology.org/content/107/3/903.long Unfortunately too late to contribute to the Olympics decision.

A little light reading for you: http://physrev.physiology.org/content/81/2/629.full

http://ajpregu.physiology.org/cgi/content/full/291/3/R768 Here's a study among others that show the ability of the environment to override genetic predispositions. I won't dispute the importance of genetics in governing behaviour, but given the range of cultural norms experienced by humans in time frames far too short to be explained by genetics I think it's clear that the environment is the overriding factor. What I will dispute is your claim of an on-or-off state, where a person either can or cannot be a rocket surgeon regardless of their environment.

There is no significant difference in latency or duration for vertical vs. horizontal saccades (eg: see ), and you're dead wrong about reading speed: In English, the optimal column width for fast reading is somewhere between 50 and 100 characters per line, depending on exact circumstances.

However, there are two other relevant facts: 1) The lower visual hemifield has a larger cortical representation than the upper visual hemifield, and shows modest improvements in visual performance (this is unsurprising, since our hands/tools/ground near us is usually in our lower hemifield) and 2) We can move our head side-to-side more rapidly, and with a larger range of motion than we can up and down, which changes some saccade distributions.

Irregardless of the mechanics of the situation, reading is a highly trained activity, and direction of reading is not universal. Chinese, for instance, can be read top-to-bottom, or with either horizontal possibility as the initial direction, with the reader cued by slightly differing strokes and punctuation . I'm not aware of any bottom-to-top sequential reading in any culture, which is probably due to the above mentioned processing differences. However, there are also mixed reading sequences that use multiple horizontal and vertical elements in a single block, like Mayan hieroglyphs (2x2 blocks LR->TB within block, blocks are read TB->LR ) or the Korean Hangul system (variety of block sizes, read TB->RL). Arguably, the latter systems are most efficient in terms of leveraging the early geometry of the visual system (log-polar, with resolution dropping exponentially with distance from the fovea.

If an electrical connection can control an arm, how much longer until you can control a whole body?

I think we're likely to be able to repair spinal cord damage long before we learn how to patch around it with electronics. We're getting closer every day.

> Ethnic groups are a sociological classification and have little or no bearing on actual genetics.

But there are breeds of humans nonetheless. Though the differences are not as significant as they are for dogs, they are there.

So far there's just one breed of humans that does well in the 100m race. Only two non-west african breeds have done sub 10 seconds, and one of them just barely. Out of more than 1 billion chinese, they still can't field a sub 10 sec 100m sprinter. African pygmies aren't going to be running faster than the west-african breeds either.

The fastest chihuahua isn't going be faster than the fastest greyhound anytime soon. A fat slob couch potato greyhound may be beaten by the fastest chihuahua, but there certainly is a difference in the breeds.

And the East African breeds seem better suited for long distance running than the white caucasian breeds especially in warm humid conditions:

http://jap.physiology.org/cgi/content/full/96/1/124

I'm curious how the white caucasians will do in freezing air temperatures or even subzero. After all it seems insufficient cooling can be the first limiter for physical performance, see:

http://www.wired.com/wired/archive/15.03/bemore_pr.html

Hmm, it seems that this article might be somewhat relevant: Proton semiconductors and energy transduction in biological systems

Unfortunately I don't have access to the journal in question - my university proxy doesn't even work :/

I wonder if this means doping ice with extra protons for conductance or similar? It seems like it'd take a lot of energy to rip a proton off a H2O molecule stuck in the crystal matrix.

"SOME biologists and neuroscientists will always be around who say what you want. If you can show that the mainstream opinion is against me, I'll happily concede the point, and thank you for enlightening me, but I doubt it."

Some studies of insect locomotion (which was where this discussion started) which use experimental data, modelling, or a mixture of the two to show that a great deal of locomotion sensing and control happens either in the limbs themselves before they reach any nerve centres, or in the thoracic ganglia. Nerve stimulation experiments have also shown that the characteristic "dual tripod" gait of hexapods is a mechanical oscillatory cycle that runs automatically when single nerves in the brain or mesothoracic ganglia are stimulated. The same is true for wing beats (which is some types share both muscles and central ganglia with the legs), which will cycle repeatedly when nerves in the thoracic ganglia are stimulated. The notable similarity in the data gathered from not only animals of the same species, but but those of different but closely related ones indicates that these movements are produced by a fixed "hardware" pattern generator, similar in principle to the electro-mechanical sequencers used in dishwashers and washing machines before microprocessor control became common:

(Note I apologise in advance for some of these only abstracts. Full scientific papers and book texts are hard to find on the web):

http://jn.physiology.org/cgi/content/full/82/1/512
http://www3.interscience.wiley.com/journal/45436/abstract

http://pt.wkhealth.com/pt/re/ejnr/abstract.00009274-200419070-00019.htm;jsessionid=KwpKVK0J1jTLRRXsZmb2QJJ53LlxD8s1Tnhv6l5Fqj9qNF2ncS7l!-1104825961!181195629!8091!-1

http://www.nature.com/nature/journal/v283/n5749/abs/283768a0.html

http://www3.interscience.wiley.com/journal/109692463/abstract

http://www.cell.com/biophysj/abstract/S0006-3495(65)86706-6

http://209.85.229.132/search?q=cache:5jTmyj1E8ywJ:biology.queensu.ca/~locust/Publications/locust%2520flight.pdf+insect+proprioceptors+ganglia&cd=75&hl=en&ct=clnk

"Oh really? You read it's mind then?"

There is absolutely no evidence that insects have anything that fits the description of a "mind" to read. Note though that some spiders may well have minds, e.g. Portia labiata, which displays a level of intelligence that makes many small mammals look like warm-blooded morons.

"Humans are predictable too. Doesn't mean they're not intelligent. They're just creatures of habit."

Humans are predictable en-masse, but not individually. Most insects on the other hand are entirely predictable individually, i.e. they always react in precisely the same way to the same sets of stimuli as another insect of the same species.

"Well, Jellyfish ARE pretty dumb, you know. The most complex behaviour I know of is in Box Jellyfish, which use simple visual contrast to avoid obstacles."

All jellyfish are sensitive to a variety of external factors such as light, orientation, water currents, temperature, and a variety of types of touch, so they're by no means as unsophisticated as you're trying to make out. It's notable that you avoid trying to deal with echinoderms, which like most animals with radial rather than bilateral symmetry, also lack cen

Obviously, responding to a flamebait post is probably going to get me in karma trouble, but I can't help it. Now, what you have said may have merit, but it is how you said it that got you modded down. Let me propose to put it another way.

Personally, I believe that, just as there are sounds that drive teens off, there are also sounds that can drive adults off. I think such things can be hard-wired. For example, a cat's visual cortex can be heavily patterned by early stimuli. It is well known that early patterning is usually irreversible and manifests itself throughout development.

One would be remiss to assume the same patterning would not function similarly for the auditory centers. I would postulate that your disdain of rap and hip-hop comes from the type of music you listened to as a young child--which was probably what your mom was listening to (maternal patterning). Perhaps you were a child of the 70's, like me, and sacrificed your sense of rhythm for the melodic sounds of the Bee Gees or Paul McCartney. Perhaps you were young during the 80's and your musical sensibilities were destroyed by the likes of Spandau Ballet, Cindy Lauper, and, god forbid, Duran Duran. Now remember, these groups would be the ones your Mom was listening to--you would probably not listen to such groups by your own choice.

The natural question, of course, becomes: what the hell were the hip-hoppers and rap kids' moms listening to?

Given that we as human beings haven't had any significant predators and really don't forage for food...you'd expect those lesser-used parts of the brain to "grow limp"

It has long been known that much of walking is reflex-driven. A decerebrate cat (i.e. with the brain disconnected) supported on a treadmill will go through normal walking movements (known as "fictive locomotion") and will even correct for "stumbles". It seems likely that the timing required for coordination of walking is simply too tight for the brain, with its longer transmission delays, to manage properly.

Brain is central chemoreceptors. There are also peripheral chemoreceptors which are sensitive to O2.

http://en.wikipedia.org/wiki/Peripheral_chemorecep tor for a very basic stub summary

http://jap.physiology.org/cgi/content/full/96/1/35 9 for a slightly more in depth analysis of O2 as a breathing stimulus.

Now, at 12 000 feet pO2 is only about 60 mm Hg. This is less than half the distance to the top of Mount Everest. The highest human habitation occurs at about 20,000 feet where the pO2 is in the low 50s. I don't expect non-acclimatised people to go for a jog up there but we're not going to need close to that low levels here. References here: http://hypertextbook.com/facts/2005/MoniqueAnthony .shtml.

At sea level, 21% O2 gives pO2 of 21/100 x 760=159 mm Hg
This gives 18% O2 -> 18/100 x 760 = 136 mm Hg; 15% O2 gives 114 mm Hg; 10% O2 gives 76 mm Hg.

Lactic acidosis will occur with inadequate tissue oxygenation, but minute ventilation would be increased by peripheral chemoreceptor stimulation.

A summary of the physiology can be found at http://www.lib.mcg.edu/edu/eshuphysio/program/sect ion4/4ch7/s4ch7_27.htm (you may have to read a few pages).

So, to sum up: the low oxygen levels would be detected and the body would adjust ventilation accordingly. Levels of )2 lower than 10% are certainly compatible with life.

I would have preferred if everyone would have just taken my word for it originally rather than argue, but I suppose this is slashdot...

Wikipedia has lots of links to actual research papers showing the advantages to HIIT when it comes to fat loss. Since you seem to have a hard time using a quick search I'll even post them.

One study concludes:

In conclusion, this study showed that moderate-intensity aerobic training that improves the maximal aerobic power does not change anaerobic capacity and that adequate high-intensity intermittent training may improve both anaerobic and aerobic energy supplying systems significantly, probably through imposing intensive stimuli on both systems.


Another study also concludes:

These findings show that high intensity interval exercise produces improvements in body composition, fitness, and acute RMR compared to low intensity steady state training.


Sadly, I can't find the original study I read which talked about glycogen stores and HIIT. If you like to run marathons, then go for it. If you want to burn fat and achieve an athletic look HIIT is the more effective method.

Another study here. Page with a summary of a lot of studies here.

I think it's pretty clear that people who are still doing steady state for fat loss are missing out.

Perhaps it's the obesity virus that's causing the problem?

Anyone knowledgeable about this?

From the CBC:
It's a contentious idea, but Dr. Leah Whigham is not the first to suggest that a virus could make us fat. In her latest study, the associate scientist from the University of Wisconsin, Madison, has studied the effect of some human adenoviruses on chickens. She found that one such virus, Ad-37, seems to cause obesity in the birds. Her finding builds on other studies that show that two related viruses also cause obesity in animals. Dr. Whigham admits that more research is needed to determine if viruses play a role in obesity, and indeed, developing a vaccine is still a long way off. She plans to study other adenoviruses to see if they, too, have the same fat-making effect in animals.

Related Links:
http://www.the-aps.org/press/journal/06/4.htm
http://archives.cnn.com/2000/HEALTH/07/28/fat.viru s.ap/index.html
http://ajpregu.physiology.org/cgi/content/abstract /290/1/R190?maxtoshow=&HITS=10&hits=10&RESULTFORMA T=&author1=whigham&andorexactfulltext=and&searchid =1138723430984_644&FIRSTINDEX=0&sortspec=relevance &resourcetype=1
http://www.webmd.aol.com/diet/news/20040805/fat-vi rus-could-obesity-be-contagious

The first type of back-propagation is the term as it is used by computer scientists using neural networks. (This is what you're thinking of.) The second type of back-propagation is the term as it is used by neuroscientists. Unfortunately, they are two completely different things. As a computer scientist who does brain modeling, this greatly irritates me.

When you use fuzzy buzz words like 'wholesome' and 'crap' - yah, you can claim anything you want simply by adjusting the definitions.

It's not FUD. It's a good summary of the contrast between typical processed food and typical unprocessed food. Why do you think there's all this banning of trans fat going on? Are you blind to the twin epidemics of diabetes and obesity? Have you not seen the reports that link chronic diseases to the modern, Western diet?

We weren't evolved for a diet based on flour, sugar, and partially hydrogenated oil. Maybe in 200 years people will have adapted to this diet. There's going to be a lot of unnecessary suffering in the meantime. Do some googling. Here's a start: Effects of exercise and diet on chronic disease

Believe it or not, there is a slight degree of backing to this. http://jn.physiology.org/cgi/reprint/83/6/3548.pdf

For example in:

Spatial Structure and Symmetry of Simple-Cell Receptive Fields in Macaque Primary Visual Cortex
http://jn.physiology.org/cgi/content/full/88/1/455 ?ijkey=ddb28389f9eef3e1068e5c9289f57895993b5602#B2 7

The "Methods" section only says the methods are the same as in "Ringach DL, Hawken MJ, and Shapley R. Dynamics of orientation tuning in macaque primary visual cortex.", which I did not find on-line.

I've looked a little bit for the procedure used. TFA says the university won't say. You say the papers are out there that describe what he was doing in the expirements being protested against, so link us up with the information, buddy. I'd be interested to know what is actually done instead of hearing only one side.

Check out this study WARNING PDF! http://ajpregu.physiology.org/cgi/reprint/00205.20 02v1.pdf

It seems to find that core temp increases help brain function.

I couldn't find the study I remember, which was one where test subjects wore special caps that heated just their heads only 1 degree (which is why they didn't just wear hats I guess). I vaguely remember that it increased a math test performance metric by about 5%.

Anyway, the article writer did not even consider, "hey I put my brain in my chest, now how do I eat with my brain in the way? How do I keep it from getting squished by my supersized meal or lungs, etc." Lots of design issues need to be worked out before you he gets this one off the planning board.

Here would be my favorite adaptations.

1) Better back and knees!
2) Maybe some retractable claws with poison.
3) Gills

-A

Why aren't hibernating mammals eaten alive by microorganisms? (yes there was a discussion before) Well, apparantly their immune system is actually disabled. However, they wake up periodically, specifically to fight off any infections.

http://www.sciencedaily.com/releases/2002/04/02040 2074547.htm

Humans can't do this if their cytochrome C is inhibited by hydrogen sulfide, so if you ever do this with humans, you'd have to make sure they wake up periodically to prevent all kinds of nastyness.

Bats seem to have a different strategy. They stay in deep hibernation for prolonged periods up to 90 days, but their biochemistry changes quite drastically in order to do this. It's unlikely that human cells are able to change themselves so drastically.

http://physrev.physiology.org/cgi/content/full/83/ 4/1153

I really wonder what would happen to a mouse if you induce hibernation for more than a month.

Buying hours and preventing damage would be a good purpose for artificial human hibernation, but I think space travel is a little far fetched.

The problem is that there is no such thing as a perfect filter. If you dump the raw signal from a microphone onto CD then any frequencies that were present above 22 khz will alias down into audible range. So you have to set up a filter that blocks any frequencies above 22 kHz--but that filter is going to have a transition band which starts significantly below 22 khz. When you play it back from your CD player the signal gets run through another set of filters in the DAC. You wind up losing fidelity and phase linearity in the audible range.

Additionally, I can point you to several experiments that show that the presence of harmonics above the normal threshold of hearing does affect the perception of sound. Hearing thresholds are determined by listening to pure sine waves, but your ears are not linear devices. The fact that you can't hear a sine wave by itself at 30 kHz does not mean that you can't hear the difference between a 15kHz sine wave and a 15kHz square wave.

Twenty-eight healthy, young (20-44 yr) volunteer subjects (13 male, 15 female) were studied with a paradigm-driven functional magnetic resonance imaging (fMRI) technique during barostat-controlled rectal distension at perception threshold and 10 mmHg below and above perception threshold. Male subjects showed localized clusters of fMRI activity primarily in the sensory and parietooccipital regions, whereas female subjects also showed activity in the anterior cingulate and insular regions.

Heartbreak is like a Woman with an anal probe

the single most frequent thing that I hear when I visit the doctor's office is "drink lots of water".

Do the Physiologists have amazingly deep databases, or is something funny going on here?

Either you're a troll or completely unaware of the publication process.

The biggest service journals offer is the coordination of peer review. So, in any decent journal, you can be sure that every article has been read, understood, and criticized by a few independent scientists in the particular discipline. It takes a lot of time to send copies of every submission to 2-3 reviewers (often identifying the reviewer in the first place), pester the reviewers to respond, meta-review the reviews and decide whether to publish or not. That process provides credibility and is why I pay more attention to, say the AJP than the AJC. They have these costs independent of whether they put out a paper product or not and it is an enormous added value.

Nor are most journals the official organs of academic societies. 50 years ago, maybe, but not now. Take a look at Academic Press, Kluwer, Wilkins... Some of their titles are society journals, but the explosion of academic journals has been mostly the for-profit variety