The timing of brain

There are approximately 100 billion neurons within the brain. Most of the time they are firing and communicate information with each other. Just imagine the scene of a crowded restaurant, where people are talking to each other. How noisy would it be? You wouldn’t get any information from these people but noise. However, our mind is very good at separating and groupping information from different sources according to different purposes to generate the lucid mental image.

To achieve this goal, establishing large-scale connection might be a solution. Local communication between neurons may be facilitated by wiring, but there are only a few of connections between brain areas in global scale. The fast flow of information couldn’t be achieved by these connections. Then how could brain regulate the information flow?

The answer is timing. There are several temporal scale in brain, ranging from seconds to tens of milliseconds. The temporal scale is regulated by brain rhythm, such as theta oscillation and gamma oscillation. The neural oscillations are among the earliest discoveries in neuroscience. Until now, their functions start to become known to us, but only a little.

Back to our question, how does brain control information flow?    It turns out that time is the key. When several neurons fire within a specific temporal window, they bind with each other. The information they represent group together. if neuron fires ten milliseconds late and miss that temporal window, then the information of this neuron won't be grouped into the former group. We call firing simultaneously synchrony. Just a few connections   with inhibition output can achieve synchrony. It is very efficient.

Neurons fire synchrony in local scale to process information, and then bind with neurons of distant areas through global synchrony. Information is grouped with high temporal precision.
Patient who have mental disorder usually show abnormal neural oscillations. For example, schizophrenia patients show unusual gamma oscillation. The medicine which alleviates the symptoms decreases abnormal gamma oscillation.

If we view brain as an information-processing  system, then its heart or pacemaker is the neural oscillation. The timing is the key to successful information processing

the physics of mind

The information process of brain is a quasi-deterministic process. To think it as a linear system is due to our preference for simplicity. The linear property is easy to declare verbally and be treated as a rule without the further doubt. However, the truth should not be so convenient for our mind. We can get a lot of results if we follow this type of thinking. The drawback of this thought is that it is still an empirical method, and is far from the scientific theory.
Science is not about the appearance of the world what we see and hear. The well-established theories of science are usually deviated from our sensation. Most of the time we cannot  see or experience the world described by the theory of science, but it has a huge power for prediction when the conditions are detailed.
We use our mind to study the mind. It is not necessary to assume that the mind itself is like our feeling of the mind. We think we know our mind because we are so familiar to it. However, what if our mind is just an interface of the complex system unknown to us?
Introspect won't help. If it does, why need a group of people who call themselves neuroscientist? The great philosopher or the great writer would have cracked the mystery of mind hundreds of year ago. Now what we are doing is probably just to follow their route. With a large amount of data, we introspect, think, and meditate. We are so obsessed with our mind. We like ourselves.
It is time to drop the power of mind. It is time to use the tool of science. The omnipotent maths and physics are the right tools we should take advantage of. We are stupid, but the logic of science is not.
Go, read this paper!

On some unwarranted tacit assumptions in cognitive neuroscience.

Mausfeld R.

Source

Department of Psychology, Christian-Albrechts-Universität zu Kiel, Institut für Psychologie Kiel, Germany.

Abstract

The cognitive neurosciences are based on the idea that the level of neurons or neural networks constitutes a privileged level of analysis for the explanation of mental phenomena. This paper brings to mind several arguments to the effect that this presumption is ill-conceived and unwarranted in light of what is currently understood about the physical principles underlying mental achievements. It then scrutinizes the question why such conceptions are nevertheless currently prevailing in many areas of psychology. The paper argues that corresponding conceptions are rooted in four different aspects of our common-sense conception of mental phenomena and their explanation, which are illegitimately transferred to scientific enquiry. These four aspects pertain to the notion of explanation, to conceptions about which mental phenomena are singled out for enquiry, to an inductivist epistemology, and, in the wake of behavioristic conceptions, to a bias favoring investigations of input-output relations at the expense of enquiries into internal principles. To the extent that the cognitive neurosciences methodologically adhere to these tacit assumptions, they are prone to turn into a largely a-theoretical and data-driven endeavor while at the same time enhancing the prospects for receiving widespread public appreciation of their empirical findings.

学外语头会变大

       成年人学外语是一件十分痛苦的事。无论学了多长时间，口音都不如本地人地道，而且时不时的会说一些无厘头的句子让外国人摸不着头脑。这是为什么呢，有可能是因为你的头还不够大。
       在国际著名期刊Neuroimage上新发表的一项研究表明，成年人努力学外语一段时间后，他们大脑的一些区域会变大，大脑皮层会变厚。越是学得很吃力的同学，在经过学习后脑子就长得越多。产生变化的大脑区域主要集中在负责记忆的海马体（hippocampus）和负责加工声音的颞上回（superior temporal gyrus）。很可能说明，对成年人来说，学习外语主要训练了大脑记忆功能，并学习加工新的外语提高了声音加工能力。
       那么在学习外语时，吃一些健脑长脑的保健品是否会有帮助呢？脑白金？我个人持保留意见，倒不是说这项科学研究可能有问题，而是......你懂的。

Johan Mårtensson, Johan Eriksson, Nils Christian Bodammer, Magnus Lindgren, Mikael Johansson, Lars Nyberg, Martin Lövdén, Growth of language-related brain areas after foreign language learning, NeuroImage, Available online 29 June 2012, ISSN 1053-8119, 10.1016/j.neuroimage.2012.06.043.
(http://www.sciencedirect.com/science/article/pii/S1053811912006581)