当然是。
但这句话似乎还是有问题的。
国家地理05年3月的封面:
By James Shreeve Photographs by Cary Wolinsky
在一个不知什么时候，人能够把自我意识的活动定位到大脑，应该算是个不大不小的领悟。
但从意识现象出现在这个物质世界里面的意义来看，意识的荣耀不只是属于大脑这个最新创造物。
也许这是一个事情的两个方面。
意识到是大脑在作思维，而不是手指或心脏，这就预示着人终将确定大脑每一个可观察对象的功能：中枢神经系统各个部位->核团，回路...>>>>神经元，受体，递质，基因，...
然后呢？
人有两种问问题的方式：是什么？为什么？
假设大脑的物化过程都是可视的了，那么我们似乎可以说，这个语言可述的意识活动原来是这么一番物化的过程。
然后还是会有人问，为什么？
当然，也会有人斥责诸如为什么之类的问题，不是恰当的问题，是基于一种错误态度的伪问题。
这里可能得需要分辩一下目的论和一个事件的涵义，这两者的不同。
这两者本质上都起源于动物生存的一个需求：选择。
动物被迫要求具有选择的能力，因为从获得运动能力开始，可选择既是机会又是挑战。
可选择是一个如此基本的范畴，小到蚂蚁对路径的选择，大到成年人对恋人的选择，都是动物生活当中的基本元素。
谢谢yolanda提供材料。
Printer-friendly version
Comments
把自我意识的活动定位到大脑
把自我意识的活动定位到大脑凭得是天然的感觉，做梦、发呆、思考，都会感觉到它们在大脑里活动。
当你害怕紧张的时候
会心跳加快；当你饥饿的时候，胃会难受；当爱因斯坦思考的时候，小指头也会觉得累：）
我觉得清晰地把意识活动归结为大脑的功能表现，是基于解剖学和生理学给我们带来的认识。纯粹基于直觉的话，人可以有而且也确实曾经有过一些不同的理路。
未必无意义的是可以把这种现代认识和中医经典对于意识与精神的认识进行比较，这样能够说明我们对于意识的认识的嬗变。
这里是一个我觉得有意思的认知历史问题。
What Is the Biological Basis of Consciousness?
What Is the Biological Basis of Consciousness?
Greg Miller
For centuries, debating the nature of consciousness was the exclusive purview of philosophers. But if the recent torrent of books on the topic is any indication, a shift has taken place: Scientists are getting into the game.
Has the nature of consciousness finally shifted from a philosophical question to a scientific one that can be solved by doing experiments? The answer, as with any related to this topic, depends on whom you ask. But scientific interest in this slippery, age-old question seems to be gathering momentum. So far, however, although theories abound, hard data are sparse.
The discourse on consciousness has been hugely influenced by René Descartes, the French philosopher who in the mid-17th century declared that body and mind are made of different stuff entirely. It must be so, Descartes concluded, because the body exists in both time and space, whereas the mind has no spatial dimension.
Recent scientifically oriented accounts of consciousness generally reject Descartes's solution; most prefer to treat body and mind as different aspects of the same thing. In this view, consciousness emerges from the properties and organization of neurons in the brain. But how? And how can scientists, with their devotion to objective observation and measurement, gain access to the inherently private and subjective realm of consciousness?
Some insights have come from examining neurological patients whose injuries have altered their consciousness. Damage to certain evolutionarily ancient structures in the brainstem robs people of consciousness entirely, leaving them in a coma or a persistent vegetative state. Although these regions may be a master switch for consciousness, they are unlikely to be its sole source. Different aspects of consciousness are probably generated in different brain regions. Damage to visual areas of the cerebral cortex, for example, can produce strange deficits limited to visual awareness. One extensively studied patient, known as D.F., is unable to identify shapes or determine the orientation of a thin slot in a vertical disk. Yet when asked to pick up a card and slide it through the slot, she does so easily. At some level, D.F. must know the orientation of the slot to be able to do this, but she seems not to know she knows.
Cleverly designed experiments can produce similar dissociations of unconscious and conscious knowledge in people without neurological damage. And researchers hope that scanning the brains of subjects engaged in such tasks will reveal clues about the neural activity required for conscious awareness. Work with monkeys also may elucidate some aspects of consciousness, particularly visual awareness. One experimental approach is to present a monkey with an optical illusion that creates a "bistable percept," looking like one thing one moment and another the next. (The orientation-flipping Necker cube is a well-known example.) Monkeys can be trained to indicate which version they perceive. At the same time, researchers hunt for neurons that track the monkey's perception, in hopes that these neurons will lead them to the neural systems involved in conscious visual awareness and ultimately to an explanation of how a particular pattern of photons hitting the retina produces the experience of seeing, say, a rose.
Experiments under way at present generally address only pieces of the consciousness puzzle, and very few directly address the most enigmatic aspect of the conscious human mind: the sense of self. Yet the experimental work has begun, and if the results don't provide a blinding insight into how consciousness arises from tangles of neurons, they should at least refine the next round of questions.
Ultimately, scientists would like to understand not just the biological basis of consciousness but also why it exists. What selection pressure led to its development, and how many of our fellow creatures share it? Some researchers suspect that consciousness is not unique to humans, but of course much depends on how the term is defined. Biological markers for consciousness might help settle the matter and shed light on how consciousness develops early in life. Such markers could also inform medical decisions about loved ones who are in an unresponsive state.
Until fairly recently, tackling the subject of consciousness was a dubious career move for any scientist without tenure (and perhaps a Nobel Prize already in the bag). Fortunately, more young researchers are now joining the fray. The unanswered questions should keep them--and the printing presses--busy for many years to come.
http://www.sciencemag.org/cgi/content/full/309/5731/79
inherent paradox
"how can scientists, with their devotion to objective observation and measurement, gain access to the inherently private and subjective realm of consciousness?"
perception--consciousness--and "higher" levels of consciousness--provide life-long questions, and hopfully, grant funding for some lucky few that managed to join the fray, only to "keep(ing) printing presses busy for many years"! the other more mediocre ones are left to fill up holes of a big picture that has already emerged decades ago...
表面的paradox
我认为objective observation and measurement和主观内省乃至更深刻的观照，是两件不同的事情，不构成真正的paradox。
随着技术的进步，对于大脑功能的客观观测必然会一直获得进展，到某个地步，会出现类似目前对于基因的研究的类似困境：海量数据如何理解。
然后可以依赖的途径就是实时心理过程与客观观测的比对。
然后7788的模型都会出来。
然后对于心理过程会有更切乎实际的范畴判定。
...
总之这个进程不会因为意识所具有的主观属性而受到绝对的阻止。
而主观内省是否也存在深入的空间呢？
这个问题大概得放到人类更为广泛的经验背景下来讨论，而不止是局限于客观观测的知识。
不过我相信，这两件事到一定程度是相得彰益的。
why conscious fades as we sleep--
NEUROSCIENCE:
Neural Communication Breaks Down As Consciousness Fades and Sleep Sets In
Greg Miller
By using magnetic pulses to stimulate the brains of waking and sleeping volunteers, scientists may have gained an important insight into the age-old mystery of why consciousness fades as we nod off to sleep. In a report on page 2228, a research group at the University of Wisconsin (UW), Madison, concludes that as sleep sets in, communication between different parts of the cerebral cortex breaks down. Such communication is a likely prerequisite for consciousness, the team argues.
Some, but not all, neuroscientists find the team's evidence compelling. The research "definitely tells us something about sleep and may have important implications for understanding the neural correlates of consciousness," says Christof Koch, a cognitive neuroscientist at the California Institute of Technology in Pasadena.
Early neuroscientists assumed that consciousness wanes during sleep because the cerebral cortex simply shuts down. "In the last century, we had three Nobel Prize winners who thought that the cerebral cortex is completely inhibited during sleep," says Mircea Steriade, a neuroscientist who studies sleep at Laval University in Quebec, Canada. Electroencephalography (EEG) and other methods have since ruled out that explanation, showing that the electrical chatter and metabolism of neurons in the cortex continues unabated during sleep. That left neuroscientists puzzling over why consciousness fades when the brain is still active.
Giulio Tononi of UW has spent years developing a theory that the essence of consciousness is the integration of information. Communication between different regions of cortex might be one sign of this integration--and of consciousness, Tononi says. To test that idea, he and his team recorded electrical activity in the brains of six sleepy volunteers using high-density EEG. Before the subjects nodded off, the researchers stimulated a small patch of right frontal cortex with transcranial magnetic stimulation (TMS), a noninvasive method that uses magnetic pulses to induce an electrical current inside the head. The EEG record revealed how the neural activity triggered by TMS spread from the site of stimulation to other parts of the brain. The team repeated the experiment once the subjects had entered non-rapid eye movement (non-REM) sleep. Noise-canceling earphones ensured that subjects couldn't detect the sound of the TMS magnet.
Drifting off. Magnetically stimulating the brains of sleeping volunteers may provide clues about the nature of consciousness.
CREDIT: M. MASSIMINI ET AL., SCIENCE
When the subjects were awake, TMS elicited waves of neural activity that spread through neighboring areas of the right frontal and parietal cortex and to corresponding regions on the left side of the brain. During non-REM sleep, the same TMS stimulus only elicited neural activity at the site of stimulation.
Tononi says the findings suggest that different areas of cortex do indeed stop talking to each other during non-REM sleep--a stage of sleep in which people often report little or no conscious experience on waking. An important follow-up, he says, will be to repeat the experiments during late-night REM sleep, when people report consciouslike experiences in the form of dreams. "We would predict a pattern which is much more similar to wakefulness," he says.
Linking cortical connectivity to consciousness makes sense, says Rodolfo Llinas, a neuroscientist at New York University. A key feature of consciousness is the ability to integrate many aspects of an experience into a single perception--combining red petals, rosy scent, and prickly thorns into the perception of a rose, for example. "To make an object in your head, to make one single cognitive event, you have to bind the activity of many cortical areas," Llinas says.
But not everyone accepts Tononi's conclusions. The experiments are "very elegant and pretty," but their relevance to understanding consciousness is questionable, says Robert Stickgold, a neuroscientist who studies sleep at Harvard Medical School in Boston, Massachusetts. "There are many, many differences in brain chemistry and physiology ... between wakefulness, non-REM sleep, and REM sleep," including differences in neurotransmitter and hormone levels and patterns of neural activity, Stickgold says. The change in cortical communication is yet another such difference, he agrees, but there's no convincing evidence that it's the key to fading consciousness.
Science, Vol 309, Issue 5744, 2148-2149 , 30 September 2005
怎么看意识
*非快眼运动睡眠期和清醒期，皮层左右对称部位间的神经元活动关联的有无，以论证：意识的关键是皮层不同部位间信息的集成
*非快眼运动睡眠期和清醒期，还同时存在非常多的差异，这个关联未必构成意识的关键
上面这两个观点的差异，其实源于观念的差异：前者认为意识的关键在于宏观些的构造，后者认为也许意识在递质，激素那样的微观些的活动层面也可能找到要素。
这两者的差异很象是这样的：两个外星观察者问，为什么同一辆汽车会有行驶和停车的差异？一个观察者说行驶的关键是输油管里有油在流动，另一个观察者说行驶的关键在于驾驶室里面那个动物的脑电活动，当然还可以有观察者说关键是50公里外一位女士的脑电活动，因为刚才这位妻子在召唤作为丈夫的驾车者赶紧回家：）
我觉得清醒期所独有的意识部分，肯定在各个尺度下都具有其相应的面目，起始的目的固然是尽量多地要看到这些现象，不管它是发生在哪个尺度下，但我们更应该在追问意识的生物学涵义上，来指导我们对于所有那些现象的理解：
__意识肯定不是对于递质或者激素或者其他什么微观活动具有意义的，意识只是在人的行为上具有其意义.__
那么意识作为一个生理活动，我们会更倾向于往宏观方向上去理解其本质，这也是我不愿把意识作为一种功能，把它局限在大脑的范畴内进行讨论的缘故。
意识，从起源要件上而言，哪怕在局域生态系统的层面上，都肯定有追究其涵义的必要。
我的意识
yijun总是能够说服我，虽然有时候我也摸不着头脑。这个问题对我来说深奥了点。