The Brain Voltage Change Based On Outside Light Stimulation

The brain is an organ which dominates human consciousness, thinking, emotion, movement, and to accept a variety of senses, and it’s physiological functions is achieved by bioelectrical activity. Brain voltage is an important characterization for the electrical activity of brain cells. EEG(Electroence-phalogram) technology can detect potential changes in the brain caused by different stimuli such as light, sound, electricity and pressure which is applied to specific external stimuli or sensory organs, it is a good reflection of the electrical activity of the brain. Epilepsy is one of the serious threats to human health. One of the main reasons for the onset of the disease is the strong light stimulation. Suddenly flash, blinding glare of light can lead to the onset of the disease, making patients suffer brain disorders and leading brain voltage dramatic changes, thus resulting in sharp spikes. At present, there is no effective epilepsy cure, mainly due to its unclear mechanism. So it is very important to understand and grasp the variation of the voltage of the external light stimulation of human brain and it’s better to study the pathogenesis of epilepsy, predict and improve clinical outcomes which have important guiding significance for people. The main researches of this thesis is how the different frequency, different intensity of external light stimulation affect the scalp voltage of the human brain, in order to grasp the human brain voltage change with light frequency and light intensity characteristics and mechanism of theory. The main researches are as follows:1. Based on electromagnetic fields and neuronal equivalent current dipole theory, theoretical calculation and analysis of the variation between the external current stimulation and the human brain scalp voltage. The results show that: The brain voltage change is inversely proportional to the frequency of the outside current stimulation and is proportional to the outside current stimulation under different extern current stimulation. The results lay the necessary theoretical basis for us to do further mechanism research about light intensity and frequency characteristics of the voltage change when extern light stimulates the human brain.2. Based on EEG technology, the effect about the changes in the cerebral cortex voltage when the human eyes were stimulated by different intensity of light was studied. The results show that:when the human eyes are irradiated with the light of the same frequency but different brightness, the brain scalp voltage variation is not the same:the brightness of the light is stronger, the greater the mean value of the absolute value of the voltage of the brain scalp is, whereas smaller. The result provides experimental evidence for people to do a better study of brain neurons light stimulating effect. 3. Based on EEG technology, the effect about the changes in the cerebral cortex voltage when the human eyes were stimulated by different frequencies (colors) of light was studied. The results show that:the smaller the optical frequency light stimulates the human eyes, the mean of the absolute value of the voltage of the brain scalp gets larger, whereas smaller. The results of the study are good to prevention and clinical treatment of epilepsy and other brain diseases.4. The light, irradiating to the human eyes, is received by photoreceptor cells. The optical signal is converted to an electrical signal in its hyperpolarization process. Based on the effect study of the voltage on the human eyes with brain stimulation current above, the mechanism about how human brain scalp voltage changes with external light stimuli with different intensity was discussed. When external light stimulates on the epilepsy patients’eyes, the current amplitude increases greatly, making the brain scalp voltage sharply increased through the cerebral cortex of brain cell membranes. The stronger the light stimulates, the stronger trans-membrane current is, leading to a greater brain voltage change. When the light intensity caused by the penetrating current exceeds a certain threshold, it will cause a series of physiological or biological side effects induced epilepsy seizures produce. The meaningful theoretical basis is provided for further study of the brain light stimulus effects, prevention and treatment of epilepsy and other brain disorders.5.Based on the brain scalp voltage calculation model derived above and according to the variation of external different frequency light stimulation with the scalp voltage, the change mechanism under light intensity of external stimuli characteristics was discussed:When a lower frequency external light stimulates on the human eyes, the resulting cortical neurons penetrating current frequency is low, thus the cell discharge process is longer, while the number of neurons is more. Therefore, the scalp voltage tested is changed more as well. The meaningful theoretical basis is provided for further study of the optical frequency characteristics of neurons.