Research and Innovations

A typical neuron can be divided into three functionally distinct parts, called dendrites, soma, and axon. Roughly speaking, the dendrites play the role of the `input device’ that collects signals from other neurons and transmits them to the soma. The soma is the `central processing unit’ that performs an important non-linear processing step: If the total input exceeds a certain threshold, then an output signal is generated. The output signal is taken over by the `output device’, the axon, which delivers the signal to other neurons.

The junction between two neurons is called a synapse. Let us suppose that a neuron sends a signal across a synapse. It is common to refer to the sending neuron as the presynaptic cell and to the receiving neuron as the postsynaptic cell. A single neuron in vertebrate cortex often connects to more than 10⁴ postsynaptic neurons. Many of its axonal branches end in the direct neighborhood of the neuron, but the axon can also stretch over several centimeters so as to reach to neurons in other areas of the brain.

The neuronal signals consist of short electrical pulses and can be observed by placing a fine electrode close to the soma or axon of a neuron; see Fig. 1.2. The pulses, so-called action potentials or spikes, have an amplitude of about 100 mV and typically a duration of 1-2 ms. The form of the pulse does not change as the action potential propagates along the axon. A chain of action potentials emitted by a single neuron is called a spike train – a sequence of stereotyped events which occur at regular or irregular intervals. Since all spikes of a given neuron look alike, the form of the action potential does not carry any information. Rather, it is the number and the timing of spikes which matter. The action potential is the elementary unit of signal transmission.

Action potentials in a spike train are usually well separated. Even with very strong input, it is impossible to excite a second spike during or immediately after a first one. The minimal distance between two spikes defines the absolute refractory period of the neuron. The absolute refractory period is followed by a phase of relative refractoriness where it is difficult, but not impossible to excite an action potential.

Source: http://icwww.epfl.ch/~gerstner/SPNM/node3.html

An interesting paper, “On-line voluntary control of human temporal lobe neurons” talks about how the brain can, by human thoughts, control the firing of the neurons. An environment is designed where a subject is given a superimposed image on a screen with each visibility set to 50%, he was asked to make the preferred image ‘fade in’ and the other one ‘fade out’. Each ‘fading sequence’ is based entirely on the spiking activity of a handful neurons in the subject’s brain. Twelve patients were implanted with intracranial electrodes to localize the neurons to be detected. The results shows that:

-The average neurons unit fires more than six times as vigorously when the subject is attending to the unit’s preferred image than when he/she is attending to the distractor(the other image)

-Successful fading was not caused by a generalized change in excitation or inhibition but by a targeted increase and decrease in the firing of specific populations of neurons.

-Overall, subjects successfully ‘fade-in’ 69% of all trials. Cognitive processes voluntarily initiated by the subject, such as focusing on the target or suppressing the distractor, affected the firing activity of four units in different MTL(Medial Temporal Lobe) neurons.

This paper presents an interesting fact that our thought will actually affect our brain. By focusing or imagining something it will generate specific neurons’ spiking.

For example, if you are given a task to distinguish two images of an apple and a banana, part of the brain that stores the instruction ‘think of apple’ reaches into the medial temporal lobe and excites the set of neurons responding to apple, simultaneously suppressing the population of neurons representing banana, while leaving the vast majority of cells representing other concepts or familiar fruits untouched.

More than 300 different known martial arts styles are practiced in China. There are two Chinese Martial Art systems, the internal and the external systems. The internal system includes Tai Chi, Sheng-I and Pa-Qua styles. They emphasize stability and have limited jumps and kicks. The external system includes Shao Lin, Long Fist, Southern Fist, and other styles. They emphasize linear movements, breathing combined with sound, strength, speed and hard power impact contact, jumps, and kicks.

There are many different styles or families of Tai Chi Chuan. The five which are practiced most commonly today are the Yang(杨), Chen(陈), Wu(吴) , Sun(孙), and Woo(武) styles. All Tai Chi styles, however, are derived from the original Chen family style.

Some people believe that Tai Chi was developed by a Taoist Priest – Zhang San-feng(张三丰) from a temple in China’s Wu Dang Mountains. It is said that he once observed a white crane preying on a snake, and mimiced their movements to create the unique Tai Chi martial art style.

Initially, Tai Chi was practiced as a fighting form, emphasizing strength, balance, flexibility, and speed. Through time it has evolved into a soft, slow, and gentle form of exercise which can be practiced by people of all ages.

The different styles of Tai chi varies in its form and pace of movement but follows the same basic principle. That is to maintain a state of slowness and softness while executing relaxed and repetitive actions, which ultimately achieve a state of balance.

Source: http://www.chebucto.ns.ca/Philosophy/Taichi/history.html

Tai Chi, or also called ‘Tai Chi Chuan’, originated in China about six hundreds ago as a martial art, has slowly become a widely popular physical exercise reporting to have many interesting health benefits. It is believed that there is Qi generated from this body-mind exercise. However, due to lack of scientific definition about Qi, it is still remains as a myth. Thus we carried out our investigation with focus on the effects of Tai Chi exercise. Some electrical measurements have been conducted before and after Tai Chi, using Ryodoraku equipment. The results showed that Tai Chi has significant effects in decreasing the electrical conductance in our body, in another word, an increase of the electrical flow. We also realized that we are backed up by western medicine about the healing effects of the electrical flow within the body. A new theory might be possible to unlock the myths of Taichi or Qigong

My research have moved from networking to Taichi and Qigong. I am entering an area that are filled with myths and difficult to suport concepts but yet appear to be logical in some sense unsubstantiated by sciencific principles. Many appear to be wisemen yet it is like 盲人摸象 and each being confident and expresses great insight in his own perception. Just like the 盲人, who touched the tail, says that the 象 is like a rope. Is he wrong? Not in his own perspective. So we have so many supposedly wise concepts, each not wrong in individual perspective, but the true picture is much more than individual parts. Let’s begin the journey.