Research On Eeg Synchronization To The External Audio-visual Stimulation

Alpha waves are one basic type of the brainwaves, commonly detected by electroencephalograph (EEG) and dominantly found to originate from the occipital lobe of normal adults when they are awake, relaxed with the eyes closed. The goal of this study is to determine how the Alpha waves change when the healthy volunteers are exposed to external audio-visual stimulation (AVS), which is based on the features that EEGs will show synchronization to exterior driving. The AVS technique has been validated as a useful method in evoked EEG research field and it is easily performed requiring minimal skill between operator and volunteer. Also, some elementary steps were carried out to evaluate the volunteers'mental status after outer stimulation period. The significance of this study lies in augmenting Alpha band power by the utilization of EEG induced device, guiding people to adjust their mental status fast and then focusing more attention to working or studying.The main contents and innovative result of this study are as follows:1. Design and develop a set of Alpha EEG induced device and test its stability by putting it under continuous work condition;2. Make a experiment plan in detail, record and collect EEG data of twenty-one healthy volunteers who are in silence state and are exposed to external Alpha frequency stimulation condition respectively;3. Analyze the data systematically. The analysis of available data selected by the way of pretreatment and signal processing in time domain and time-frequency domain proved that the EEG induced device can enhance the Alpha waves significantly and moreover it has good performance according to the oscilloscope results;4. Preliminary studies were carried out on evoked Alpha waves through the external Alpha-frequency audio-visual stimulation using the EEG induced device. To some extend, the results that the Alpha band power is enhanced under the same frequency audio-visual stimulation deserve the reference value in future studies on what is the influence of external stimulation to evoked EEGs.